12.4: Geometric Sequences and Series
By the end of this section, you will be able to:
- Determine if a sequence is geometric
- Find the general term (\(n\)th term) of a geometric sequence
- Find the sum of the first \(n\) terms of a geometric sequence
- Find the sum of an infinite geometric series
- Apply geometric sequences and series in the real world
Before you get started, take this readiness quiz.
-
Simplify: \(\frac{24}{32}\).
If you missed this problem, review Example 1.24. -
Evaluate: a. \(3^{4}\) b. \(\left(\frac{1}{2}\right)^{4}\).
If you missed this problem, review Example 1.19. -
If \(f(x)=4 \cdot 3^{x}\), find a. \(f(1)\) b. \(f(2)\) c. \(f(3)\).
If you missed this problem, review Example 3.49.
Determine if a Sequence is Geometric
We are now ready to look at the second special type of sequence, the geometric sequence.
A sequence is called a geometric sequence if the ratio between consecutive terms is always the same. The ratio between consecutive terms in a geometric sequence is \(r\), the common ratio , where \(n\) is greater than or equal to two.
A geometric sequence is a sequence where the ratio between consecutive terms is always the same.
The ratio between consecutive terms, \(\frac{a_{n}}{a_{n-1}}\), is \(r\), the common ratio . \(n\) is greater than or equal to two.
Consider these sequences.
Determine if each sequence is geometric. If so, indicate the common ratio.
- \(4,8,16,32,64,128, \dots\)
- \(-2,6,-12,36,-72,216, \dots\)
- \(27,9,3,1, \frac{1}{3}, \frac{1}{9}, \ldots\)
Solution :
To determine if the sequence is geometric, we find the ratio of the consecutive terms shown.
a. Find the ratio of the consecutive terms
\(\begin{aligned} 4, \quad& \:8, \quad 16, \quad 32, \quad 64, \quad 128, \dots \\ &\frac{8}{4} \quad\frac{16}{8}\quad\frac{32}{16}\quad\frac{64}{32}\quad\frac{128}{64} \\ &\:2 \quad\:\:\: 2 \quad\quad2\quad\quad2\quad\quad2 \end{aligned}\)
The sequence is geometric. The common ration is \(r=2\).
b. Find the ratio of the consecutive terms
\(\begin{aligned}-\:2,\quad &\:\:\:6,\quad -12,\quad 36,\quad \:-72\quad \:\:216,\dots \\ & \frac{6}{-2}\quad\frac{-12}{6}\quad\frac{36}{-12}\quad\frac{-72}{36}\quad\frac{216}{-72} \\ & -3\quad -2\quad\:\: -3\quad \:\:\:-2\quad \:\:-3 \end{aligned}\)
The sequence is not geometric. There is no common ratio.
c. Find the ratio of the consecutive terms
\(\begin{aligned}27,\quad &\:\:9,\quad 3,\quad 1,\quad \frac{1}{3},\quad \frac{1}{9}, \ldots\\ & \frac{9}{27}\quad\frac{3}{9}\quad\frac{1}{3}\quad\frac{\frac{1}{3}}{1}\quad\frac{\frac{1}{9}}{\frac{1}{3}}\\ &\frac{1}{3}\quad\;\:\frac{1}{3}\quad\frac{1}{3}\quad\:\frac{1}{3}\quad\:\frac{1}{3}\end{aligned}\)
The sequence is geometric. The common ratio is \(r=\frac{1}{3}\).
Determine if each sequence is geometric. If so indicate the common ratio.
- \(7,21,63,189,567,1,701, \dots\)
- \(64,16,4,1, \frac{1}{4}, \frac{1}{16}, \dots\)
- \(2,4,12,48,240,1,440, \dots\)
- Answer
-
- The sequence is geometric with common ratio \(r=3\).
- The sequence is geometric with common ratio \(d=\frac{1}{4}\).
- The sequence is not geometric. There is no common ratio.
Determine if each sequence is geometric. If so indicate the common ratio.
- \(-150,-30,-15,-5,-\frac{5}{2}, 0, \dots\)
- \(5,10,20,40,80,160, \dots\)
- \(8,4,2,1, \frac{1}{2}, \frac{1}{4}, \ldots\)
- Answer
-
- The sequence is not geometric. There is no common ratio.
- The sequence is geometric with common ratio \(r=2\).
- The sequence is geometric with common ratio \(r=\frac{1}{2}\).
If we know the first term, \(a_{1}\), and the common ratio, \(r\), we can list a finite number of terms of the sequence.
Write the first five terms of the sequence where the first term is \(3\) and the common ratio is \(r=−2\).
Solution :
We start with the first term and multiply it by the common ratio. Then we multiply that result by the common ratio to get the next term, and so on.
\(\begin{array}{cccc}{a_{1}} & {a_{2}} & {a_{3}} & {a_{4}} & {a_{5}} \\ {3} & {3 \cdot(-2)} & {-6 \cdot(-2)} & {12 \cdot(-2)} & {-24 \cdot(-2)} \\& {-6} & {12} & {-24} & {48}\end{array}\)
Answer :
The sequence is \(3,-6,12,-24,48, \dots\)
Write the first five terms of the sequence where the first term is \(7\) and the common ratio is \(r=−3\).
- Answer
-
\(7,-21,63,-189,567\)
Write the first five terms of the sequence where the first term is \(6\) and the common ratio is \(r=−4\).
- Answer
-
\(6,-24,96,-384,1536\)
Find the General Term (\(n\)th Term) of a Geometric Sequence
Just as we found a formula for the general term of a sequence and an arithmetic sequence, we can also find a formula for the general term of a geometric sequence.
Let’s write the first few terms of the sequence where the first term is \(a_{1}\) and the common ratio is \(r\). We will then look for a pattern.
As we look for a pattern in the five terms above, we see that each of the terms starts with \(a_{1}\).
The first term, \(a_{1}\), is not multiplied by any \(r\). In the second term, the \(a_{1}\) is multiplied by \(r\). In the third term, the \(a_{1}\) is multiplied by \(r\) two times (\(r⋅r\) or \(r^{2}\)). In the fourth term, the \(a_{1}\) is multiplied by \(r\) three times (\(r⋅r⋅r\) or \(r^{3}\)) and in the fifth term, the \(a_{1}\) is multiplied by \(r\) four times. In each term, the number of times \(a_{1}\) is multiplied by \(r\) is one less than the number of the term. This leads us to the following
\(a_{n}=a_{1} r^{n-1}\)
The general term of a geometric sequence with first term \(a_{1}\) and the common ratio \(r\) is
\(a_{n}=a_{1} r^{n-1}\)
We will use this formula in the next example to find the fourteenth term of a sequence.
Find the fourteenth term of a sequence where the first term is \(64\) and the common ratio is \(r=\frac{1}{2}\).
Solution :
\(a_{n}=a_{1} r^{n-1}\)
To find the fourteenth term, \(a_{14}\),use the formula with \(a_{1}=64\) and \(r=\frac{1}{2}\).
\(a_{14}=64\left(\frac{1}{2}\right)^{14-1}\)
Substitute in the values.
\(a_{14}=64\left(\frac{1}{2}\right)^{13}\)
Simplify.
\(a_{14}=\frac{1}{128}\)
Find the thirteenth term of a sequence where the first term is \(81\) and the common ratio is \(r=\frac{1}{3}\).
- Answer
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\(\frac{1}{6,561}\)
Find the twelfth term of a sequence where the first term is \(256\) and the common ratio is \(r=\frac{1}{4}\).
- Answer
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\(\frac{1}{16,384}\)
Sometimes we do not know the common ratio and we must use the given information to find it before we find the requested term.
Find the twelfth term of the sequence \(3, 6, 12, 24, 48, 96, …\) Find the general term for the sequence.
Solution :
To find the twelfth term, we use the formula, \(a_{n}=a_{1} r^{n-1}\), and so we need to first determine \(a_{1}\) and the common ratio \(r\).
The first term is three.
\(3,6,12,24,48,96, \dots\)
\(a_{1}=3\)
Find the common ratio.
\(\begin{array}{l}{\frac{6}{3} \quad \frac{12}{6} \quad \frac{24}{12} \quad \frac{48}{24} \quad \frac{96}{48}} \\ {2 \:\:\:\quad 2 \quad \:\:2 \quad\:\:\: 2 \:\:\quad \:2} \\ {\text { The common ratio is } r=2}\end{array}\)
To find the twelfth term, \(a_{12}\),use the formula with \(a_{1}=3\) and \(r=2\).
\(a_{n}=a_{1} r^{n-1}\)
Substitute in the values.
\(a_{12}=3 \cdot 2^{12-1}\)
Simplify.
\(a_{12}=3 \cdot 2^{11}\)
\(a_{12}=6,144\)
Find the general term. We use the formula with \(a_{1}=3\) and \(r=2\).
\(a_{n}=a_{1} r^{n-1}\)
\(a_{n}=3(2)^{n-1}\)
Find the ninth term of the sequence \(6, 18, 54, 162, 486, 1,458, … \) Then find the general term for the sequence.
- Answer
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\(a_{9}=39,366 .\) The general term is \(a_{n}=6(3)^{n-1}\).
Find the eleventh term of the sequence \(7, 14, 28, 56, 112, 224, …\) Then find the general term for the sequence.
- Answer
-
\(a_{11}=7,168 .\) The general term is \(a_{n}=7(2)^{n-1}\).
Find the Sum of the First \(n\) Terms of a Geometric Sequence
We found the sum of both general sequences and arithmetic sequence. We will now do the same for geometric sequences. The sum, \(S_{n}\), of the first \(n\) terms of a geometric sequence is written as \(S_{n}=a_{1}+a_{2}+a_{3}+\ldots+a_{n}\). We can write this sum by starting with the first term, \(a_{1}\), and keep multiplying by \(r\) to get the next term as:
\(S_{n}=a_{1}+a_{1} r+a_{1} r^{2}+\ldots+a_{1} r^{n-1}\)
Let’s also multiply both sides of the equation by \(r\).
\(r S_{n}=a_{1} r+a_{1} r^{2}+a_{1} r^{3}+\ldots+a_{1} r^{n}\)
Next, we subtract these equations. We will see that when we subtract, all but the first term of the top equation and the last term of the bottom equation subtract to zero.
\(\begin{aligned} S_{n}&= a_{1}+a_{1} r+a_{1} r^{2}+a_{1} r^{3}+\ldots+a_{1} r^{n-1} \\ r S_{n} &= a_{1} r+a_{1} r^{2}+a_{1} r^{3}+\ldots+a_{1} r^{n-1}+a_{1} r^{n}\\\hline S_{n}-r S_{n} &= a_{1} -a_{1}r^{n} \end{aligned}\)
We factor both sides.
\(S_{n}(1-r)=a_{1}\left(1-r^{n}\right)\)
To obtain the formula for \(S_{n}\), divide both sides by \((1-r)\).
\(S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}\)
The sum, \(S_{n}\), of the first \(n\) terms of a geometric sequence is
\(S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}\)
where \(a_{1}\) is the first term and \(r\) is the common ratio, and \(r\) is not equal to one.
We apply this formula in the next example where the first few terms of the sequence are given. Notice the sum of a geometric sequence typically gets very large when the common ratio is greater than one.
Find the sum of the first \(20\) terms of the geometric sequence \(7, 14, 28, 56, 112, 224, …\)
Solution :
To find the sum, we will use the formula \(S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}\). We know \(a_{1}=7\), \(r=2\), and \(n=20\),
Knowing \(a_{1}=7, r=2\), and \(n=20\), use the sum formula.
\(S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}\)
Substitute in the values.
\(S_{20}=\frac{7\left(1-2^{20}\right)}{1-2}\)
Simplify.
\(S_{20}=7,340,025\)
Find the sum of the first \(20\) terms of the geometric sequence \(3, 6, 12, 24, 48, 96, …\)
- Answer
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\(3,145,725\)
Find the sum of the first \(20\) terms of the geometric sequence \(6, 18, 54, 162, 486, 1,458, …\)
- Answer
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\(10,460,353,200\)
In the next example, we are given the sum in summation notation. While adding all the terms might be possible, most often it is easiest to use the formula to find the sum of the first \(n\) terms.
To use the formula, we need \(r\). We can find it by writing out the first few terms of the sequence and find their ratio. Another option is to realize that in summation notation, a sequence is written in the form \(\sum_{i=1}^{k} a(r)^{i}\), where \(r\) is the common ratio.
Find the sum: \(\sum_{i=1}^{15} 2(3)^{i}\).
Solution :
To find the sum, we will use the formula \(S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}\), which requires \(a_{1}\) and \(r\). We will write out a few of the terms, so we can get the needed information.
| Write out the first few terms. | |
| Identify \(a_{1}\). | |
| Find the common ratio. | |
| Knowing \(a_{1}=6\), \(r=3\), and \(n=15\), use the sum formula. | |
| Substitute in the values. | |
| Simplify. |
Find the sum: \(\sum_{i=1}^{15} 6(2)^{i}\).
- Answer
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\(393,204\)
Find the sum: \(\sum_{i=1}^{10} 5(2)^{i}\).
- Answer
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\(10,230\)
Find the Sum of an Infinite Geometric Series
If we take a geometric sequence and add the terms, we have a sum that is called a geometric series. An infinite geometric series is an infinite sum whose first term is \(a_{1}\) and common ratio is \(r\) and is written
\(a_{1}+a_{1} r+a_{1} r^{2}+\ldots+a_{1} r^{n-1}+\ldots\)
An infinite geometric series is an infinite sum whose first term is \(a_{1}\) and common ratio is \(r\) and is written
\(a_{1}+a_{1} r+a_{1} r^{2}+\ldots+a_{1} r^{n-1}+\dots\)
We know how to find the sum of the first \(n\) terms of a geometric series using the formula, \(S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}\). But how do we find the sum of an infinite sum?
Let’s look at the infinite geometric series \(3+6+12+24+48+96+….\). Each term gets larger and larger so it makes sense that the sum of the infinite number of terms gets larger. Let’s look at a few partial sums for this series. We see \(a_{1}=3\) and \(r=2\)
\(\begin{array}{lll}{S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}} & {S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}} & {S_{n}=\frac{a_{1}(1-r^{n})}{1-r}}\\ {S_{10}=\frac{3\left(1-2^{10}\right)}{1-2}} & {S_{30}=\frac{3\left(1-2^{30}\right)}{1-2}} & {S_{50}=\frac{3\left(1-2^{50}\right)}{1-2}} \\ {S_{10}=3,069} & {S_{30}=3,221,225,469} & {S_{50}\approx 3.38 \times 10^{15}}\end{array}\)
As \(n\) gets larger and larger, the sum gets larger and larger. This is true when \(|r|≥1\) and we call the series divergent. We cannot find a sum of an infinite geometric series when \(|r|≥1\).
Let’s look at an infinite geometric series whose common ratio is a fraction less than one,
\(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\ldots\). Here the terms get smaller and smaller as \(n\) gets larger. Let’s look at a few finite sums for this series. We see \(a_{1}=\frac{1}{2}\) and \(r=\frac{1}{2}\).
\(\begin{array}{lll}{S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}} & {S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}} & {S_{n}=\frac{a_{1}(1-r^{n})}{1-r}}\\ {S_{10}=\frac{\frac{1}{2}\left(1-\frac{1}{2}^{10}\right)}{1-\frac{1}{2}}} & {S_{20}=\frac{\frac{1}{2}\left(1-\frac{1}{2}^{20}\right)}{1-\frac{1}{2}}} & {S_{30}=\frac{\frac{1}{2}\left(1-\frac{1}{2}^{30}\right)}{1-\frac{1}{2}}} \\ {S_{10}\approx 0.9990234375} & {S_{20}\approx 0.9999990463} & {S_{30}\approx 0.9999999991}\end{array}\)
Notice the sum gets larger and larger but also gets closer and closer to one. When \(|r|<1\), the expression \(r^{n}\) gets smaller and smaller. In this case, we call the series convergent. As \(n\) approaches infinity, (gets infinitely large), \(r^{n}\) gets closer and closer to zero. In our sum formula, we can replace the \(r^{n}\) with zero and then we get a formula for the sum, \(S\), for an infinite geometric series when \(|r|<1\).
\(\begin{aligned} S_{n} &=\frac{a_{1}\left(1-r^{n}\right)}{1-r} \\ S &=\frac{a_{1}(1-0)}{1-r} \\ S &=\frac{a_{1}}{1-r} \end{aligned}\)
This formula gives us the sum of the infinite geometric sequence. Notice the \(S\) does not have the subscript \(n\) as in \(S_{n}\) as we are not adding a finite number of terms.
For an infinite geometric series whose first term is \(a_{1}\) and common ratio \(r\),
If \(|r|<1\),the sum is
\(S=\frac{a_{1}}{1-r}\)
If \(|r|≥1\),the infinite geometric series does not have a sum. We say the series diverges.
Find the sum of the infinite geometric series \(54+18+6+2+\frac{2}{3}+\frac{2}{9}+\ldots\)
Solution :
To find the sum, we first have to verify that the common ratio \(|r|<1\) and then we can use the sum formula \(S=\frac{a_{1}}{1-r}\).
Find the common ratio.
\(\begin{array}{ll}{r=\frac{18}{54}} & {r=\frac{6}{18} \dots} \\ {r=\frac{1}{3}} & {r=\frac{1}{3} \quad|r|<1}\end{array}\)
Identify \(a_{1}\).
\(a_{1}=54\)
Knowing \(a_{1}=54, r=\frac{1}{3}\), use the sum formula.
\(S=\frac{a_{1}}{1-r}\)
Substitute in the values.
\(S=\frac{54}{1-\frac{1}{3}}\)
Simplify.
\(S=81\)
Answer :
\(S=80\)
Find the sum of the infinite geometric series \(48+24+12+6+3+\frac{3}{2}+\dots\)
- Answer
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\(96\)
Find the sum of the infinite geometric series \(64+16+4+1+\frac{1}{4}+\frac{1}{16}+\dots\)
- Answer
-
\(\frac{256}{3}\)
An interesting use of infinite geometric series is to write a repeating decimal as a fraction.
Write the repeating decimal \(0.5\) as a fraction.
Solution :
Rewrite the \(0.5\) showing the repeating five. Use place value to rewrite this as a sum. This is an infinite geometric series.
0.5555555555555\(\ldots\)
\(0.5+0.05+0.005+0.0005+\dots\)
Find the common ratio.
\(\begin{array}{ll}{r=\frac{0.05}{0.5}} & {r=\frac{0.005}{0.05} \dots} \\ {r=0.1} & {r=0.1 \quad|r|<1}\end{array}\)
Identify \(a_{1}\)
\(a_{1}=0.5\)
Knowing \(a_{1}=0.5 ,r=0.1\), use the sum formula.
\(S=\frac{a_{1}}{1-r}\)
Substitute in the values.
\(S=\frac{0.5}{1-0.1}\)
Simplify.
\(S=\frac{0.5}{0.9}\)
Multiply the numerator and denominator by \(10\).
\(S=\frac{5}{9}\)
We are asked to find the fraction form.
\(0.5 = \frac{5}{9}\)
Write the repeating decimal \(0.4\) as a fraction.
- Answer
-
\(\frac{4}{9}\)
Write the repeating decimal \(0.8\) as a fraction.
- Answer
-
\(\frac{8}{9}\)
Apply Geometric Sequences and Series in the Real World
One application of geometric sequences has to do with consumer spending. If a tax rebate is given to each household, the effect on the economy is many times the amount of the individual rebate.
The government has decided to give a $\(1,000\) tax rebate to each household in order to stimulate the economy. The government statistics say that each household will spend \(80\)% of the rebate in goods and services. The businesses and individuals who benefited from that \(80\)% will then spend \(80\)% of what they received and so on. The result is called the multiplier effect. What is the total effect of the rebate on the economy?
Solution :
Every time money goes into the economy, \(80\)% of it is spent and is then in the economy to be spent. Again, \(80\)% of this money is spent in the economy again. This situation continues and so leads us to an infinite geometric series.
\(1000+1000(0.8)+1000(0.8)^{2}+\ldots\)
Here the first term is \(1,000, a_{1}=1000\). The common ratio is \(0.8, r=0.8\). We can evaluate this sum since \(0.8<1\). We use the formula for the sum on an infinite geometric series.
\(S=\frac{a_{1}}{1-r}\)
Substitute in the values, \(a_{1}=1,000\) and \(r=0.8\).
\(S=\frac{1,000}{1-0.8}\)
Evaluate.
\(S=5,000\)
Answer :
The total effect of the $\(1,000\) received by each household will be a $\(5,000\) growth in the economy.
What is the total effect on the economy of a government tax rebate of $\(1,000\) to each household in order to stimulate the economy if each household will spend \(90\)% of the rebate in goods and services?
- Answer
-
$\(10,000\)
What is the total effect on the economy of a government tax rebate of $\(500\) to each household in order to stimulate the economy if each household will spend \(85\)% of the rebate in goods and services?
- Answer
-
$\(3,333.33\)
We have looked at a compound interest formula where a principal, \(P\), is invested at an interest rate, \(r\), for \(t\) years. The new balance, \(A\), is \(A=P\left(1+\frac{r}{n}\right)^{n t}\) when interest is compounded \(n\) times a year. This formula applies when a lump sum was invested upfront and tells us the value after a certain time period.
An annuity is an investment that is a sequence of equal periodic deposits. We will be looking at annuities that pay the interest at the time of the deposits. As we develop the formula for the value of an annuity, we are going to let \(n=1\). That means there is one deposit per year.
\(\begin{aligned} &A =P\left(1+\frac{r}{n}\right)^{n t} \\ \text { Let } n=1 .\quad & A=P\left(1+\frac{r}{1}\right)^{1 t} \\ \text { Simplify. }\quad & A=P(1+r)^{t} \end{aligned}\)
Suppose \(P\) dollars is invested at the end of each year. One year later that deposit is worth \(P(1+r)^{1}\) dollars, and another year later it is worth \(P(1+r)^{2}\) dollars. After \(t\) years, it will be worth \(P(1+r)^{t}\) dollars.
| End of year \(1\) | End of year \(2\) | End of year \(3\) | |
|---|---|---|---|
| First Deposit \(P\) @ end of year \(1\) | \(P\) | Amount \(1\) year later \(P(1+r)^{1}\) | Amount \(2\) years later \(P(1+r)^{2}\) |
| \(2\)nd Deposit \(P\) @ end of year \(2\) | \(P\) | Amount \(1\) year later \(P(1+r)^{1}\) | |
| \(3\)rd Deposit \(P\) @ end of year \(3\) | \(P\) |
After three years, the value of the annuity is
This a sum of the terms of a geometric sequence where the first term is \(P\) and the common ratio is \(1+r\). We substitute these values into the sum formula. Be careful, we have two different uses of \(r\). The \(r\) in the sum formula is the common ratio of the sequence. In this case, that is \(1+r\) where \(r\) is the interest rate.
\(\begin{aligned} &S_{t} =\frac{a_{1}\left(1-r^{t}\right)}{1-r} \\ \text { Substitute in the values. }\quad & S_{t}=\frac{P\left(1-(1+r)^{t}\right)}{1-(1+r)} \\ \text { Simplify. }\quad & S_{t} =\frac{P\left(1-(1+r)^{t}\right)}{-r} \\ &S_{t} =\frac{P\left((1+r)^{t}-1\right)}{r} \end{aligned}\)
Remember our premise was that one deposit was made at the end of each year.
We can adapt this formula for \(n\) deposits made per year and the interest is compounded \(n\) times a year.
For a principal, \(P\), invested at the end of a compounding period, with an interest rate, \(r\), which is compounded \(n\) times a year, the new balance, \(A\) , after \(t\) years, is
\(A_{t}=\frac{P\left(\left(1+\frac{r}{n}\right)^{n t}-1\right)}{\frac{r}{n}}\)
New parents decide to invest $\(100\) per month in an annuity for their baby daughter. The account will pay \(5\)% interest per year which is compounded monthly. How much will be in the child’s account at her eighteenth birthday?
Solution :
To find the Annuity formula, \(A_{t}=\frac{P\left(\left(1+\frac{r}{n}\right)^{n t}-1\right)}{\frac{r}{n}}\), we need to identify \(P, r, n\), and \(t\).
Identify \(P\), the amount invested each month.
\(P=100\)
Identify \(r\), the annual interest rate, in decimal form.
\(r=0.05\)
Identify \(n\), the number of times the deposit will be made and the interest compounded each year.
\(n=12\)
Identify \(t\), the number of years.
\(t=18\)
Knowing \(P=100, r=0.05, n=12\) and \(t=18\), use the sum formula.
\(A_{t}=\frac{P\left(\left(1+\frac{r}{n}\right)^{n t}-1\right)}{\frac{r}{n}}\)
Substitute in the values.
\(A_{t}=\frac{100\left(\left(1+\frac{0.05}{12}\right)^{12.18}-1\right)}{\frac{0.05}{12}}\)
Use the calculator to evaluate. Be sure to use parentheses as needed.
\(A_{t}=34.920 .20\)
Answer :
The child will have $\(34,920.20\)
New grandparents decide to invest $\(200\) per month in an annuity for their grandson. The account will pay \(5\)% interest per year which is compounded monthly. How much will be in the child’s account at his twenty-first birthday?
- Answer
-
$\(88,868.36\)
Arturo just got his first full-time job after graduating from college at age \(27\). He decided to invest $\(200\) per month in an IRA (an annuity). The interest on the annuity is \(8\)%, which is compounded monthly. How much will be in the Arturo’s account when he retires at his sixty-seventh birthday?
- Answer
-
$\(698,201.57\)
Access these online resources for additional instruction and practice with sequences.
Key Concepts
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General Term (\(n\)th term) of a Geometric Sequence:
The general term of a geometric sequence with first term \(a_{1}\) and the common ratio \(r\) is
\(a_{n}=a_{1} r^{n-1}\)
-
Sum of the First \(n\) Terms of a Geometric Series:
The sum, \(S_{n}\), of the \(n\) terms of a geometric sequence is
\(S_{n}=\frac{a_{1}\left(1-r^{n}\right)}{1-r}\)
where \(a_{1}\) is the first term and \(r\) is the common ratio. Infinite Geometric Series: An infinite geometric series is an infinite sum whose first term is \(a_{1}\) and common ratio is \(r\) and is written\(a_{1}+a_{1} r+a_{1} r^{2}+\ldots+a_{1} r^{n-1}+\ldots\)
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Sum of an Infinite Geometric Series:
For an infinite geometric series whose first term is \(a_{1}\) and common ratio \(r\),
If \(|r|<1\),the sum is
\(S=\frac{a_{1}}{1-r}\)
We say the series converges.
If \(|r|≥1\), the infinite geometric series does not have a sum. We say the series diverges.
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Value of an Annuity with Interest Compounded
\(n\)
Times a Year:
For a principal, \(P\), invested at the end of a compounding period, with an interest rate, \(r\), which is compounded \(n\) times a year, the new balance, \(A\), after \(t\) years, is
\(A_{t}=\frac{P\left(\left(1+\frac{r}{n}\right)^{n t}-1\right)}{\frac{r}{n}}\)
Glossary
- annuity
- An annuity is an investment that is a sequence of equal periodic deposits.
- common ratio
- The ratio between consecutive terms in a geometric sequence, \(\frac{a_{n}}{a_{n-1}}\), is \(r\), the common ratio, where \(r\) greater than or equal to two.
- geometric sequence
- A geometric sequence is a sequence where the ratio between consecutive terms is always the same
- infinite geometric series
- An infinite geometric series is an infinite sum infinite geometric sequence.


21.1: Cellular Defenses - Overview
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- Ying Liu
- City College of San Francisco
Learning Objectives
- Identify and describe the components of blood
- Explain the process by which the formed elements of blood are formed (hematopoiesis)
- Describe the characteristics of formed elements found in peripheral blood, as well as their respective functions within the innate immune system
In the previous section, we discussed some of the chemical mediators found in plasma, the fluid portion of blood. The nonfluid portion of blood consists of various types of formed elements , so called because they are all formed from the same stem cells found in bone marrow. The three major categories of formed elements are: red blood cells (RBCs), also called erythrocytes; platelets, also called thrombocytes; and white blood cells (WBCs), also called leukocytes.
Red blood cells are primarily responsible for carrying oxygen to tissues. Platelets are cellular fragments that participate in blood clot formation and tissue repair. Several different types of WBCs participate in various nonspecific mechanisms of innate and adaptive immunity. In this section, we will focus primarily on the innate mechanisms of various types of WBCs.
Query \(\PageIndex{1}\)
Hematopoiesis
All of the formed elements of blood are derived from hematopoietic stem cells (HSCs) in the bone marrow. As the HSCs make copies of themselves in the bone marrow, individual cells receive different cues from the body that control how they develop and mature. As a result, the HSCs differentiate into different types of blood cells that, once mature, circulate in peripheral blood. This process of differentiation, called hematopoiesis, is shown in more detail in Figure \(\PageIndex{1}\).
In terms of sheer numbers, the vast majority of HSCs become erythrocytes. Much smaller numbers become leukocytes and platelets. Leukocytes can be further subdivided into granulocytes, which are characterized by numerous granules visible in the cytoplasm, and agranulocytes, which lack granules. Figure \(\PageIndex{2}\) provides an overview of the various types of formed elements, including their relative numbers, primary function, and lifespans.
Key Concepts and Summary
- The formed elements of the blood include red blood cells ( erythrocytes ), white blood cells ( leukocytes ), and platelets (thrombocytes ). Of these, leukocytes are primarily involved in the immune response.
- All formed elements originate in the bone marrow as stem cells (HSCs) that differentiate through hematopoiesis .


8.3: Cancer of the Breast
By the end of this section, you will be able to:
- Educate people on risk factors and breast cancer screening
- Support those diagnosed with breast cancer
- Describe the various treatment modalities for breast cancer
- Provide care post mastectomy
- Refer those with breast cancer and their support people to community agencies
According to the Centers for Disease Control and Prevention (CDC) (2023), more than 239,000 women were diagnosed with breast cancer in 2020, and nearly 43,000 women died from the disease. Breast cancer is the most common type of cancer diagnosed in persons assigned female at birth (AFAB) and the second most common cause of cancer death, second only to lung cancer (Centers for Disease Control and Prevention, 2023). While the lifetime risk for a woman to develop breast cancer is around 13 percent, many factors can influence the risk of developing breast cancer, including race and ethnicity (Susan G. Komen, 2023c). See Table 8.2 for a breakdown of risk by race and ethnicity.
| Race and Ethnicity | Risk of Breast Cancer |
|---|---|
| Non-Hispanic American Indian and Alaska Native | 9.9% |
| Hispanic | 10.8% |
| Non-Hispanic Asian and Pacific Islander | 11.7% |
| Non-Hispanic Black | 12% |
| Non-Hispanic White | 13.8% |
The incidence of breast cancer has declined since the year 2000 (Breastcancer.org, 2023) and is thought to be the result of aggressive screening and better targeted treatment options. These factors are also believed to be responsible for the 43 percent decline in mortality rates from 1989 through 2020 (American Cancer Society, 2023b). Regardless, a new diagnosis of breast cancer is devastating. It affects not only the person diagnosed but also their family, career, and overall well-being.
Breast cancer can affect transgender persons as well. Transgender men (persons AFAB and identify as male) may still have breast tissue and must be aware of their risk for breast cancer. Transgender women (persons AMAB but identify as female) also have breast tissue and can be at risk for breast cancer. Transgender persons with a family history of breast cancer should be offered genetic testing to evaluate their risks.
This module will delve into the comprehensive and holistic care of the person diagnosed with breast cancer, including screening options, diagnostic testing, medical management, and nursing supportive care. Woven throughout are ways that the nurse can provide support not only to the patient but to their family and loved ones, as well.
Breast Cancer Screening
Regular screening is an important step in the early diagnosis and treatment of breast cancer. How often and when that screening should occur is patient specific, but evidence-based guidelines have been developed by several organizations, including the American Cancer Society and the U. S. Preventive Services Task Force, to help providers make those clinical decisions. These guidelines continue to evolve as the evidence changes, and decisions are based on a person’s individual risk and health.
Risk Factors
The primary risk factors for breast cancer are having been assigned female at birth and increasing age; however, several other factors are also associated with an increased risk of breast cancer. Risk factors are modifiable (meaning they can be changed by behavior) or nonmodifiable (they cannot be changed). Table 8.3 presents both types of risk factors specific to breast cancer.
| Type of Risk Factor | Risk Factors |
|---|---|
| Modifiable |
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| Nonmodifiable |
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The nurse plays an important role in educating patients about these risk factors and how they interact, as well as whether increased surveillance is necessary.
The National Cancer Institute provides access to an online calculator that allows health-care professionals or women to calculate their approximate risk of developing invasive cancer in the next 5 years and through their lifespan.
Breast Self-Exam
Once the mainstay of breast cancer screening , monthly breast self-exam s are no longer recommended by most medical organizations. This recommendation was removed from the U.S. Preventive Services Task Force in their 2009 breast cancer screening guidelines due to the risk of false positives and the potential harm that could result (American College of Obstetricians and Gynecologists [ACOG], 2017). Instead, providers now suggest that patients become familiar with their breasts, how they look and feel, and the signs and symptoms of breast cancer. Patients should be encouraged to contact their health-care provider about any changes to their breasts or concerning symptoms.
Clinical Breast Exam
The American Cancer Society (2022) no longer recommends regular clinical breast exams by a health-care professional as a valuable part of screening for breast cancer, citing concerns about the lack of effectiveness in finding breast cancer, particularly when a person is getting regular mammogram s. However, the National Comprehensive Cancer Network ( NCCN ) does recommend regular clinical breast exams every 1 to 3 years beginning at age 25 and increasing to once a year by age 40 (Susan G. Komen, 2022a). For persons at high risk, the NCCN may recommend more frequent clinical breast exams, depending on the person’s age and specific risk factors (Susan G. Komen, 2022b). It is important for the provider and patient to discuss these recommendations in the context of the person’s health and individual risk profile before deciding on a screening plan.
Screening Tests
The development of screening tests like the mammogram have been very successful in detecting breast cancers early in their development and reducing mortality. Like the self-exam and clinical breast exams, the decision about when to start regular screening and how often should be made based on a discussion between the person and health-care provider. The results of both mammography and ultrasound are reported using standardized language, known as the Breast Imaging Reporting and Data System (BI-RADS) (American Cancer Society, 2022a). BI-RADS scores range from zero to 6, with 6 being proven malignancy. The mammogram report should also note whether the patient has dense breasts, which can interfere with the ability of the radiologist to see small masses.
Mammography
The x-ray visualization of the breast tissue, obtained by compressing the breast between two plates, is called mammography (Figure 8.7). Images are typically obtained from multiple views, ensuring that all areas of the breast tissue are evaluated.

- Higher-density tissue, like connective tissue, glandular tissue, and tumors, appears white.
Newer mammography procedures use digital technology, allowing the images to be sent directly to a computer. While the different types of tissue appear the same as with film mammography, using digital images does have several advantages:
- ability to manipulate the image to get a better view
- decreased need to retake images
- easy transmission of files to another provider for a second opinion
- production of better images for people with dense breasts
- the ability to use computer programs that help with the detection of tissue abnormalities (National Institute of Biomedical Imaging and Bioengineering, n.d.).
Mammograms can be performed for screening or for diagnostic purposes, such as when a person or health-care provider feels a lump or mass that requires additional testing. Mammograms can also be used to identify a calcium deposit in the breast tissue, or a calcification (Figure 8.8). Calcifications are usually a benign finding, certain patterns of calcification can be an early sign of breast cancer.
- Macrocalcifications: Found in about half of women over the age of 50, macrocalcifications appear as large white dashes or dots on the mammogram; these are completely benign and do not require any additional testing.
- Microcalcifications: These appear as small flecks or grains of salt on the mammogram. Calcifications that are tightly clustered together or have irregular edges may be an early sign of breast cancer and should trigger additional testing.
Different recommendations for screening mammography are outlined in Table 8.4.
| Group | Recommendations |
|---|---|
| American Cancer Society 1 |
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| U.S. Preventive Services Task Force 2 |
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| National Comprehensive Cancer Network 3 |
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1 Data from American Cancer Society, 2022. |
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2 Data from Breast Cancer Screening, 2016. |
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3 Data from Breast Cancer Screening: Average Risk, n.d. |
Ultrasound
Ultrasound of the breast is not a procedure used for routine cancer screening. It can be used, however, as an adjunct to mammography. The uses for breast ultrasound include the following:
- to better visualize dense breast tissue
- to get a better look at lesions not well visualized on mammography
- to distinguish between fluid-filled and solid cysts
- to guide the needle during a biopsy
The test is painless and noninvasive and uses high-frequency sound waves to generate images of the breast tissue. The patient is not exposed to any radiation during this test.
Genetic Testing
Several genetic mutations have been identified with an increased risk of breast cancer. The most well-known genetic mutations associated with an increased risk of breast cancer occur in the BRCA1 and BRCA2 genes, though other mutations in the PALB2 , CHEK2 , ATM , CDH1 , PTEN , and TP53 genes are also associated with an increased risk of breast cancer (American Cancer Society, 2021d). People with a family history of breast cancer can be offered genetic testing to identify if they carry these gene mutations. Genetic testing can be performed using blood drawn in the health-care provider’s office. Nurses can explain that if the genetic testing is positive, the provider will discuss preventive techniques to decrease the patient’s risks. Both men and women can have the BRCA gene mutation. When present, this mutation causes a condition known as hereditary breast and ovarian cancer syndrome. Persons AFAB with this mutation may have an increased risk of breast cancer, pancreatic cancer, and ovarian cancer. Persons assigned male at birth (AMAB) with this mutation are at an increased risk of breast cancer, prostate cancer, and pancreatic cancer.
Only about 5 percent to 10 percent of breast cancers are linked to a genetic mutation (Susan G. Komen, 2023b). Having a family or personal history of breast or other cancers may prompt a person to be tested for the BRCA mutations to determine their risk or to potentially guide treatment decisions. If it is determined that they carry the mutation, more aggressive screening or monitoring protocols can be implemented to detect a growing cancer early in its development.
Breastcancer.org offers a great deal of content about breast cancer diagnosis and treatment that includes a list of breast cancer facts and myths.
Breast Cancer Diagnosis
When a person presents to the health-care provider with a lump or other symptoms or when a suspicious lesion is found on a screening mammography, additional testing is required before a diagnosis can be reached.
Imaging Procedures
Along with screening, both mammograms and ultrasound testing can be used diagnostically. If a suspicious lesion is found on mammogram, an ultrasound scan may be indicated to get a better view. In some cases, magnetic resonance imaging (MRI) may be necessary, though this is usually performed only when a patient has signs or symptoms of cancer or has had an inconclusive mammogram or ultrasound. MRI can also be used after breast cancer has been diagnosed to determine the exact location and size of a tumor or to look for other tumors.
Breast MRIs typically use contrast and are performed while the patient is face down, with the breasts placed in a special opening in the table to avoid compression of the tissue during the scan. In addition to ensuring that the consent form is signed and preparing the patient and room for the test, the nurse should ask about allergies, especially to contrast dye, and ensure that the patient does not have any metal on or inside them, including pacemakers, piercings, aneurysm clips, or cochlear implants. The test typically takes about 30 to 45 minutes.
Biopsy
In many cases, biopsy of the suspicious lesion or mass is the next step in diagnosis. During this procedure, a small sample is removed and sent to the pathologist for analysis. Several different biopsy procedures can be performed, depending on the size and location of the lesion, the patient’s health and preferences, and whether multiple lesions are present.
- During fine needle aspiration (FNA) , a small needle (21 g to 25 g) is placed into the lesion to obtain a tissue or fluid sample. This procedure can be done with ultrasound guidance or without if the lesion is palpable below the skin surface. The procedure should be performed using sterile technique. A local anesthetic can be injected if the lesion is deep, the patient is anxious about the procedure, or the provider anticipates making multiple passes with the needle.
- A core needle biopsy (CNB) is similar to an FNA but removes a larger amount of tissue because it uses a hollow needle with a larger gauge than the one used for the FNA (Figure 8.9). CNB is typically the biopsy of choice when breast cancer is suspected because more tissue can be removed and analyzed. Like the FNA, it can be performed with or without ultrasound guidance, depending on the lesion’s size and location. Local anesthetic is injected before this type of biopsy because a larger amount of breast tissue, called a core, is removed by the needle. A tissue marker, or clip, may be placed in the location where the biopsy was taken to guide in identifying the area for monitoring or further follow-up. This clip can be visualized in imaging procedures so that the provider can quickly find the area in question.
- Surgical biopsy: In rare cases, surgical biopsy may be indicated. This is usually performed when an FNA or a CNB is inconclusive. An incisional biopsy removes only part of the lesion; an excisional biopsy removes the entire lesion and sometimes a small margin around it to ensure that all the suspicious tissue is removed. This procedure is usually performed in a hospital or outpatient surgery center with the patient under intravenous (IV) sedation or general anesthesia.
- Lymph node: If breast cancer is identified, the next step may be to biopsy the nearby lymph nodes to determine whether the cancer has spread to other parts of the body. If the axillary lymph nodes are enlarged, small samples may be removed using FNA or CNB. If they are not enlarged, they will still need to be biopsied, usually during the surgical procedure to remove the breast cancer.
During a sentinel lymph node biopsy (SLNB), only a few lymph nodes, the ones most likely to have cancer spread to them, are removed. A special dye or radioactive substance is injected into the tumor or the area around it. The lymph will carry the dye through the lymph vessels to the nearby nodes, allowing the provider to identify the sentinel nodes and remove them for biopsy.
An axillary lymph node dissection is the other option for lymph node biopsy and involves the removal of around 10 to 20 lymph nodes from the axilla to be checked for cancer. This can be performed during the cancer-removing surgery or later if an SLNB is positive for three or more lymph nodes or if FNA/CNB showed cancer in the nodes.
Tumor Characteristics
Once breast cancer is diagnosed, it is important to evaluate the tumor characteristics to identify how best to treat it. During biopsy or surgery, any cells identified as cancerous may be checked to determine whether the cells have receptors for estrogen or progesterone on the surface. The presence of these receptors means that the cells are responsive to estrogen and progesterone and can be treated using hormone therapy.
- If a tumor has receptors for estrogen and progesterone, it is known as hormone receptor positive (ER positive for estrogen and PR positive for progesterone).
- If a tumor does not have receptors for estrogen and progesterone, it is known as hormone receptor negative (ER negative for estrogen and PR negative for progesterone).
Most of the time, cancers that are ER positive tend to also be PR positive, and cancers that are ER negative tend to also be PR negative. Most cancers, around 70 percent to 80 percent, are hormone receptor positive (Susan G. Komen, 2023d).
Another biomarker often used in the diagnosis and staging of breast cancer is a protein known as HER2 (human epidermal growth factor receptor 2) . This protein is important in cell growth: When it is found in high levels in breast cancer cells, the cancer tends to grow more quickly and spread more aggressively. However, it is also more likely to respond to certain types of medications that specifically target that protein.
- If cancer cells have high levels of HER2, they are known as HER2 positive.
- If cancer cells have low levels of HER2, they are known as HER2 negative.
- Cancer that is positive for HER2 protein and estrogen/progesterone receptors is triple positive cancer .
- Cancer that is negative for HER2 protein and estrogen/progesterone receptors is triple negative cancer .
Triple negative breast cancers are more difficult to treat because hormone targeted therapies and HER2 targeted therapies will not be effective in treating the cancer. These types of tumors also tend to grow and spread more aggressively than other types of cancers. Triple negative breast cancers are more common in women younger than 40, women who are Black, and women with the BRCA1 gene mutation (American Cancer Society, 2021a).
Some providers may also measure the cell proliferation rate, or how quickly the breast cancer cells are dividing and growing. In general, cancers with a high proliferation rate (percentage of cells actively dividing) tend to be more aggressive and have a worse prognosis (Susan G. Komen, 2023d).
Clinical Manifestations
The clinical manifestations associated with breast cancer depend on the type of cancer (Table 8.5).
| Type of Cancer | Description | Clinical Manifestations |
|---|---|---|
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Stages of Breast Cancer
Staging a breast cancer helps the provider to understand the patient’s prognosis and how the cancer should be treated. Several criteria are considered when staging breast cancer, including the hormone and HER2 receptor status and other characteristics of the tumor. The tumor is staged pathologically using the TNM system:
- T: Tumor size
- N: Nodes (degree of lymph node spread)
- M: Metastasis
The patient is assigned a clinical stage, which informs prognosis and treatment decisions. The clinical stage is between 0 and IV, whereby a patient with stage 0 cancer has a localized tumor with a good prognosis for full recovery, and a patient with stage IV cancer has an aggressive tumor that has spread to distant organs and has a poor prognosis for survival.
Nursing Support of Patients Who Have Just Been Diagnosed with Breast Cancer
The nurse has a complex role in caring for a person who is undergoing testing for breast cancer or whose cancer is newly diagnosed. In addition to clinical nursing interventions involved in patient care, such as preparing for surgery and prepping for and assisting during diagnostic testing, the nurse must provide patient education and emotional support. This time in a person’s life is difficult; they face their own mortality, the loss of health and well-being, changes in body image and sexual function, financial and career concerns, and loss of role or function within the family and community. This can trigger feelings of shame, helplessness, hopelessness, anxiety, and fear. The nurse acts as a key member of the health-care team by teaching the patient about the various types of diagnostic testing, helping the patient navigate the complex world of breast cancer diagnosis, and answering questions and listening to concerns.
If cancer is the diagnosis, the patient and family may go in and out of periods of anger, shock, denial, and disbelief. Initiating education at this time will not be effective because it is unlikely that the patient will be able to retain any of the teaching. It is important to provide all information in terms families can understand and to be prepared to repeat or reinforce it as needed. As time goes on and the person begins to adjust to the diagnosis, the nurse can initiate more education and involve the patient with care planning. This is also a great time to refer the patient and family to counseling that will support them through the different stages, leading to acceptance through the diagnosis and treatment phases.
If the patient tests negative for cancer, the nurse still has an important role in supporting this patient in their next steps, whether that consists of planned follow-up or routine screening. The nurse can also help the patient work through their feelings of relief that they are cancer free and possible anxiety about the future.
Medical Management of Breast Cancer
The medical management of breast cancer depends on the specific diagnosis and stage of the cancer. The many options for treatment include surgery, chemotherapy , radiation, hormonal therapy, and other types of medications.
Surgery
Surgical removal of the tumor is often recommended for patients newly diagnosed with breast cancer. Options include breast-conserving surgery (BCS), mastectomy, and, eventually, reconstruction. The nurse can provide anticipatory guidance on preparation and recovery related to these procedures.
Breast-Conserving Surgery
Breast-conserving surgery, or BCS, is an option for patients with small tumors or early-stage cancer, such as when there is only one tumor and that tumor is smaller than 50 percent of the breast tissue. One such procedure is the lumpectomy , which removes the tumor, a small ring of healthy tissue around the tumor (to ensure that all cancer cells are removed), and possibly some axillary lymph nodes. Another type of BCS is the segmental mastectomy or partial mastectomy. As with the lumpectomy, the tumor and a ring of healthy tissue around it are removed, though the amount of tissue is greater than that removed during lumpectomy. Both procedures allow the retention of much of the breast tissue, minimizing scarring and other tissue loss. Some patients require radiation therapy to the breast after BCS to ensure that all the unhealthy tissue was removed and to reduce the risk of recurrence.
Mastectomy
Removal of the entire breast, including the nipple and areola, is called mastectomy . Patients who are better candidates for mastectomy rather than BCS are those with larger or multiple tumors that occupy a large area of the breast, those with invasive cancer, or those who have had radiation to the breast. In addition to treating an existing breast cancer, mastectomy can be performed as a preventive measure, usually in patients at high risk or who carry the BRCA1 or BRCA2 gene.
There are several different ways that mastectomy (Figure 8.10) can be performed:
- Total simple mastectomy: Removes the entire breast, nipple, areola, and sentinel lymph nodes.
- Modified radical mastectomy: Removes the entire breast, nipple, areola, and axillary lymph nodes but leaves the chest wall intact.
- Skin-sparing mastectomy: Removes the breast tissue, nipple, and areola but leaves the skin of the breast intact, similar to an empty balloon. This allows the placement of an implant for immediate reconstruction during the procedure or a tissue expander for reconstruction later.
- Nipple-sparing mastectomy: Removes the breast tissue, but leaves the skin, areola, and nipple intact. This allows for reconstruction during surgery or later, using an implant or fat tissue from elsewhere on the body. A tissue expander can be placed in the pocket if the patient is having reconstruction later. For this type of procedure, the tumor must be at least 2 cm away from the nipple and areola.
Like BCS, mastectomy is often combined with chemotherapy or radiation once the patient has recovered from surgery. There is a lot of debate about whether mastectomy or BCS gives a better chance at survival. A study published in the Journal of the American Medical Association followed close to 50,000 people in Sweden for 6 years after they had been diagnosed with breast cancer (de Boniface et al., 2021). The researchers found a higher survival rate among people treated with BCS and radiation therapy than among people with a mastectomy (when accounting for key confounders; de Boniface et al., 2021). A study published by Mburu et al. in 2022 supported these results, finding that BCS with radiation was more effective at treating people with triple negative breast cancer than BCS alone, mastectomy alone, or mastectomy with radiation. While further research is needed, patients should discuss with their providers whether BCS may improve their prognosis.
Evaluating Outcomes
The nurse teaches the patient about the process of mastectomy and recovery from the surgery. The following are ways to determine if the patient understands the teaching in order to evaluate the outcomes of the teaching.
- Teach-back: Ask the patient to explain the process of the mastectomy in their own words.
- Ask open-ended questions, such as what to expect before, during, and after surgery.
- Summary: Ask the patient to summarize the information provided by the nurse.
Breast Reconstruction
Surgical breast reconstruction can occur during the mastectomy or later. It is important for the patient to consult with their providers to discuss the different options and which would be most appropriate for the specific clinical scenario. Several factors can influence which option is best:
- overall health status
- size/location of tumor
- breast size and shape
- type of breast cancer surgery
- amount of tissue available for reconstruction
- insurance coverage and costs
- Personal preferences (desire to closely match the other breast, preference for surgery on one or both breasts, willingness to have more than one surgery) (American Cancer Society, 2021c)
There are two main types of breast reconstruction:
- Implants : Implants made of saline or silicone are placed under the skin and muscle. These can be inserted at the time of mastectomy or later.
- Flap procedures : Flap procedures are highly technical procedures performed by plastic microsurgery specialists. Fat and tissue from elsewhere on the body (abdomen, hips, back, buttocks, etc.) are taken and used to recreate the appearance of a breast (Figure 8.11). Many centers still use the abdominal, latissimus dorsi, or gluteal muscle to create the flap, which can cause the patient to have weakness at the donation site and lifting restrictions for the rest of their life.
A patient who has had these procedures may require nipple reconstruction later, depending on what type of mastectomy was initially performed. Some people may also choose to have a tattoo to create the image of areolar tissue. Other options may include the use of a prosthesis or an aesthetic flat closure of the mastectomy scar.
It is important for the nurse to recognize that breast reconstruction is a very personal decision. What’s right for one patient may not be right for the next. Some people may choose to have immediate reconstruction (if a candidate), while others may elect to avoid reconstruction altogether. The nurse should support the patient’s decision, whatever that may be. The nurse should also prepare the patient for the outcomes of those decisions. For example, a flap procedure will cause scarring, not only of the reconstructed breast, but also at the site of the donated tissue.
Chemotherapy
Chemotherapy is the administration of cytotoxic medication that kills cancer cells. These drugs are most commonly given before or after surgery and in combination regimens to improve survival outcomes. Chemotherapy given before surgery, known as neoadjuvant chemotherapy , is used to reduce the size of the tumor so that the surgery is less extensive. It is also used to determine the best therapeutic regimen before removing the tumor or to delay surgery, giving people time to complete genetic testing or discuss reconstructive surgery. Chemotherapy given after surgery is known as adjuvant chemotherapy. This type of chemo is used to destroy any cancer cells that were left behind after surgery or that have metastasized but have not yet been seen on imaging tests. Both neoadjuvant and adjuvant chemotherapies reduce the risk of cancer coming back or metastasizing to other organs.
Chemotherapy is most often administered as a combination of drugs to be most effective in treating both early and advanced breast cancer. Chemotherapy is usually administered intravenously, in a hospital setting or infusion center. It can occasionally be administered subcutaneously or orally. How frequently the medication is administered and for how long depends on the specific dose and regimen. When given IV, it is most commonly given through a large central line due to the risks of tissue damage if extravasation occurs. Long-term administration will require the placement of a peripherally inserted central catheter (PICC) line or a port placed on the side opposite from the breast cancer. The nurse must monitor this access point for patency and signs of infection and teach the patient how to care for it at home. Informed consent for both the access procedure and administration of chemotherapy will also need to be signed. While the nurse is not responsible for obtaining informed consent, they are required to ensure that the form has been signed and that the patient understands the procedure they are undergoing and medication they are taking.
QSEN Competency: Safety during Chemotherapy
Oncology nurses are trained in the safe handling of hazardous drugs. Government agencies have created guidelines to protect persons working with hazardous drugs. Some of these recommendations follow.
Personal protective equipment should be used during the following:
- discontinuing an IV and disposing of medications
- deconstituting, mixing, or manipulating chemotherapy medications
- cleaning a spill
- measuring urine output
Specific personal protective equipment is as follows:
- chemotherapy-tested gloves
- chemotherapy-tested gowns
- shoe covers
- eye protection such as goggles or full face shield
- respiratory protection
- Transporting medications in a closed-system transfer device
Persons pregnant or trying to conceive must notify their supervisors. Supervisors are required to offer alternative duties.
(Oncology Nursing Society, 2018)
Chemotherapy can have several side effects, depending on the drug, dose, and length of treatment. Because these medications work on rapidly dividing cells, their side effects include
- hair loss,
- nausea/vomiting,
- fatigue,
- diarrhea,
- hot flashes,
- loss of appetite or weight loss, and
- mouth sores.
The nurse should assess for these side effects during and after each treatment and intervene as necessary. For example, if the patient becomes nauseated after therapy, the nurse can collaborate with the provider to order an antiemetic and provide education about strategies to minimize nausea/vomiting with future treatments. Ongoing evaluation is necessary to ensure that these interventions are successful or to adjust the care plan to try other interventions as needed. Most side effects resolve after chemotherapy has been completed.
Because chemotherapy cannot specifically target cancer cells, the medications can affect normal tissue as well. This is particularly true in the cells of the immune and hematologic systems, leading to increased risk of infection, bleeding, and anemia. Regular monitoring of blood counts will be needed to monitor these parameters. As a result, the patient will need to be extra cautious about exposure to illness by wearing a mask in public or avoiding crowded spaces. Other potential complications could include:
- cardiomyopathy
- neuropathy
- myelodysplastic syndromes
- infertility
While infertility is a common consequence of chemotherapy, the nurse must inform the patient of the significant risk of birth defects if conception does occur. While receiving chemotherapy treatment, the patient and partner must use birth control if there is any chance that sex will result in pregnancy.
Biologic Response Modifiers
A medication that uses the patient’s own immune system to recognize and get rid of cancer cells is called a biologic response modifier . This therapy is often combined with chemotherapy to treat triple negative breast cancer. The main class of drugs used to treat breast cancer comprises checkpoint inhibitors. Checkpoints are found in the immune system and help the immune system to distinguish “self” from “foreign.” These checkpoints can be turned on or off to initiate the immune response against foreign or tumor cells. However, some breast cancers have developed the ability to bind with these checkpoints and turn them off so that the immune system does not attack them. Checkpoint inhibitors turn on the immune response against the breast cancer tumor cells.
Biologic response modifiers are used along with chemotherapy to treat triple negative breast cancer. These drugs can cause an infusion reaction, which can include fever, chills, flushing, wheezing, shortness of breath, rash/itching, and dizziness (American Cancer Society, 2021e). It is important for the nurse to monitor the patient for these symptoms frequently during and after the infusion. The patient should also be educated about this reaction and instructed to notify the provider immediately if they start feeling unwell. If symptoms occur during treatment, the nurse should stop the infusion immediately and notify the provider. The nurse can also discuss premedication for the patient’s symptoms.
Hormonal Therapy
Cancers that are hormone receptor positive for estrogen and progesterone can often be treated with hormone therapy. These medications block the hormone receptors, which prevents the cancer cells from growing. The medications are often started after surgery to remove the tumor and are taken for about 5 years, and sometimes longer if it is determined that a patient has a high chance of the cancer returning. Cancers that are hormone receptor negative will not respond to these types of medications. These drugs can be used in many ways, and the exact protocol or regimen will depend on the provider, the patient, the cancer, and a number of other factors.
Selective Estrogen Receptor Modulators (SERMs)
Selective estrogen receptor modulators (SERMs) block estrogen from attaching to cancer cells, preventing them from growing and dividing. These medications have an antiestrogen effect on the breast tissue. Drugs in this class of medications include tamoxifen (Soltamox), raloxifene (Evista), and toremifene (Fareston). Tamoxifen is an oral medication that is used to treat pre- or postmenopausal women with breast cancer. It can be used to treat hormone receptor–positive DCIS or other invasive cancers by reducing the risk that the cancer will return, decreasing the chance that the cancer will develop in the other breast or metastasize through the body, and slowing or stopping the growth of cancer that has already metastasized elsewhere (American Cancer Society, 2023a). Raloxifene is a SERM often used to treat osteoporosis, but it is also used to reduce the risk of invasive breast cancer in postmenopausal women with or without osteoporosis. Toremifene works similarly to tamoxifen but is approved to treat only postmenopausal women with metastatic breast cancer.
Selective estrogen receptor modulators can cause early menopause, with side effects such as hot flashes and other vasomotor symptoms, weight gain, mood swings, vaginal dryness, and irregular menstrual cycles. There is also a risk of serious complications, including deep vein thrombosis, stroke, endometrial cancer, and pulmonary embolism. Nursing interventions focus on educating patients about these drugs and how to take them, assessing for interaction or side effects, and counseling patients about maintaining preventive care, such as having a regular Papanicolaou (Pap) smear, annual eye exam, liver function testing, and bone density testing.
Tamoxifen
Tamoxifen is a very common hormonal medication used in the treatment of hormone receptor–positive breast cancer. Because of the length of time the patient will be taking it as well as the potential side effects of complications, it is crucial for the nurse to provide teaching about what to expect and how to use the medication safely.
- Generic Name: tamoxifen citrate
- Trade Name: Nolvadex, Soltamox
- Class/Action: selective estrogen receptor modulator (SERM)
- Route/Dosage: Tamoxifen is available as 10 or 20 mg tablets or an oral solution (10 mg/5 mL). For cancer prevention after chemotherapy, patients will take 20 mg daily for 5 to 10 years. For metastatic breast cancer, the dose may increase to 20 mg to 40 mg daily. The dose is 20 mg daily for prophylaxis in patients who are at higher risk.
- High Alert/Black Box Warning: Tamoxifen comes with a higher risk of fatal uterine cancer, stroke, and pulmonary embolism in patients at high risk for cancer or those with ductal carcinoma in situ (DCIS). Patients should discuss the risks and benefits with their provider.
- Indications: Tamoxifen is used in the treatment of hormone receptor–positive metastatic breast cancer and node-positive breast cancer after mastectomy. In patients with DCIS, tamoxifen can be used to reduce the risk of breast cancer in the opposite breast and invasive breast cancer. In some patients at high risk, tamoxifen can be used to reduce their risk of breast cancer.
- Mechanism of Action: Tamoxifen selectively binds to estrogen receptors and has both estrogenic and antiestrogenic effects in different parts of the body. In the breast tissue, it competes with estrogen at the receptor sites, leading to decreased estrogenic activity in tumor cells and a slowing of tumor growth.
- Contraindications: Tamoxifen is contraindicated in patients with known hypersensitivity to the drug, patients who are taking certain anticoagulant therapies, or patients with a history of deep vein thrombosis or pulmonary embolus.
- Adverse Effects/Side Effects: hot flashes, irregular periods, vaginal discharge, hypertension, weakness, nausea/vomiting, mood changes, peripheral edema, arthralgia, lymphedema, and skin changes/rashes
- Nursing Implications: Counsel patients about the more serious side effects of tamoxifen and how to report concerns to the care team. Assess patients for side effects and report them as needed to the provider.
- Patient/Family Education: Patients should be advised to not become pregnant and may need to discontinue breast-feeding. Barrier contraceptives should be used to prevent pregnancy.
( Nursing Drug Handbook , 2023)
Selective Estrogen Receptor Degraders (SERDs)
Selective estrogen receptor degraders (SERDs) have an antiestrogen effect throughout the body. They work by attaching to estrogen receptor cells and causing them to break down. These drugs are most commonly used in postmenopausal women. When used in premenopausal women, they need to be combined with ovarian suppression drugs. The two drugs in this class that are most commonly used are fulvestrant (Faslodex) and elacestrant (Orserdu). Side effects of these drugs include hot flashes, night sweats, nausea, fatigue, loss of appetite, muscle/joint pain, and headache. Nursing interventions for these drugs are similar to those for SERMs.
  These drugs can be combined with ovarian suppression drugs when used in premenopausal women. AIs are oral medications that are taken daily for 5 to 10 years, depending on the cancer and risk of recurrence. The most common side effect of AIs is joint and muscle pain similar to arthritis. This can usually be managed with the use of nonsteroidal anti-inflammatory drugs ( NSAID s), gentle exercise, or switching to a different AI. Other side effects include hot flashes and vaginal dryness. These drugs also increase the risk of osteoporosis and fractures. The patient should be advised to have bone density screenings every 2 years; some women should also take bisphosphonates to increase bone density (Bischof et al., 2022). The most common drugs in this class of medication are letrozole (Femara), anastrozole (Arimidex), and exemestane (Aromasin).
Ovarian Suppression
In premenopausal women, the ovaries are the primary source of estrogen production. Suppressing the ovaries essentially makes them act as if they are postmenopausal by reducing estrogen production. This allows the health-care provider to use treatments and medications that have been approved for use in postmenopausal women, such as aromatase inhibitors and SERDs, in women who are premenopausal. This strategy can also be used in women with a high risk of cancer recurrence. Ovarian suppression can be done with the surgical removal of the ovaries, through the administration of chemotherapeutic gonadotoxic drugs, or through luteinizing hormone–releasing hormone agonists, which temporarily suppress luteinizing hormone–releasing hormone and induce a temporary menopause.
 You are seeing a new 45-year-old patient who was recently diagnosed with stage 3 breast cancer. The provider has recommended neoadjuvant chemotherapy followed by mastectomy followed by radiation therapy and additional chemotherapy.
You sit down with the patient and support person to discuss the upcoming procedures, and the patient is sitting quietly. As you discuss what to expect from chemotherapy, the patient states that they are okay with the surgery if the reconstruction can occur at the same time but that they will not have chemotherapy. When you ask about concerns with chemotherapy, the person replies they do not want to lose their hair and throw up all the time, “especially if the surgery will just remove the cancer anyway.” You start your education by describing the side effects that can be expected from the specific chemotherapy drugs, including hair loss and nausea and vomiting, and you include information about how to manage and minimize those side effects. You go on to explain that the neoadjuvant chemotherapy will help to reduce the size of the tumor and make the surgery easier. Finally, you also explain that stage 3 cancer indicates that the cancer cells have spread to other parts of the body—surgery alone cannot adequately treat it.
After extensive counseling and education, the patient still refuses the chemotherapy and says that decision is final. You know that not having chemotherapy as recommended by the provider will significantly decrease the patient’s likelihood of having a positive outcome, even though the person is young and otherwise healthy. You struggle with this patient’s decision, as you know that they have a good prognosis for recovery with the recommended treatment plan. What is your next step?
Ultimately, the person is a competent adult and can make their own medical decisions. As the nurse, you must inform the provider, support the person’s autonomy to make decisions, and document all your teaching. Ethical issues arise regularly in the oncology specialty, and there may be times that you disagree with a patient’s decision. However, it is important to remember that the role of the nurse includes being a patient advocate, which means supporting their decisions and not what we would choose to do for ourselves.
Radiation
Radiation therapy is used frequently after lumpectomy or breast-conserving surgery (BCS) to remove any remaining cancer cells. Some patients with large tumors may have radiation before surgery to reduce the size of the tumor and make the surgery easier. There are two main types of radiation therapy for breast cancer: external beam radiation therapy and brachytherapy.
External Beam Radiation Therapy
External beam radiation therapy (EBRT) directs radiation at the breast or other structures (Figure 8.12). Which areas of the body receive radiation depend on what type of surgery was done and what type of cancer is present. Someone who had a mastectomy and no cancerous lymph nodes will likely have radiation to the mastectomy scar, the chest wall, and the locations of drains after surgery. If cancer is found in the lymph nodes, radiation may be directed to the areas containing the axillary, supraclavicular, infraclavicular, or internal mammary lymph nodes as well. Someone who had BCS or lumpectomy will likely have whole-breast radiation therapy.
Radiation is typically started after the mastectomy site has healed or, if chemotherapy is prescribed, after the chemotherapy. Radiation is given 5 days a week for 6 or 7 weeks, depending on the provider’s prescribed regimen. Some providers also use accelerated partial breast irradiation (APBI), which consists of higher doses of radiation that are limited to the wound bed to reduce the risk of cancer coming back at the site of the original tumor.
The nurse must advise the patient of potential side effects, which can include:
- swelling in the breast
- fatigue
- skin change s similar to a sunburn
- heaviness in the breast
- lymphedema if radiation is used in the axillary lymph nodes
Some side effects do not appear until later; the breast may become smaller and firmer over time. Radiation can affect the ability to breast-feed or the ability to have reconstruction later due to changes in the skin and breast tissue. Brachial plexopathy (nerve damage causing numbness and pain in the upper limb), lymphedema, and weakening of the ribs leading to fracture can result from radiation (Demarco, 2023).
The primary nursing intervention when caring for a patient undergoing radiation is education and support. It is important to teach the patient and support persons what to expect during radiation therapy, what side effects are common, how they can be alleviated or managed, and what symptoms need to be reported to the provider. The nurse may also implement and teach the patient and the family about comfort measures for the skin after radiation treatment. These can include:
- keeping the skin well moisturized and hydrated
- using hydrogel pads to reduce heat and irritation
- avoiding underwire, nylon, or lace bras
- avoiding shaving the armpits to reduce irritation to the skin
The nurse must continue to monitor and assess the patient regularly for pain, fatigue, and other side effects. Nurses should wear monitor badges measuring their exposure to radiation.
Brachytherapy
Brachytherapy is internal radiation, where radioactive seeds or pellets are placed in a small device inside the tumor bed. The use of brachytherapy is limited by the size of the tumor and its location. There are two types of brachytherapy:
- Intracavitary brachytherapy: The radioactive pellets are placed in a special balloon that is inserted in the empty space after BCS. They will remain there until after treatment is completed. The end of the catheter remains outside the breast so that additional pellets can be placed into the device at prescribed intervals (usually twice a day for 5 days on an outpatient basis) (American Cancer Society, 2021f).
- Interstitial brachytherapy: Small catheters are placed into the breast tissue and left in place. Radioactive pellets are placed directly into these catheters for a short time each day before being removed (American Cancer Society, 2021f).
Nursing care during radiation therapy focuses on assessing for side effects, measuring and monitoring radiation safety, and providing patient education and support. The nurse must also be careful to implement safety measures to protect the patient, the health-care team, and the patient’s family or visitors. Additional training is required for the nurse to safely handle radioactive material, dispose of it properly, calculate the total dose of radiation, and ensure that all appropriate protective personal equipment is used correctly.
In addition, the use of brachytherapy requires that the nurse provide ongoing wound care due to the placement of catheters and other devices into the skin. The nurse will need to monitor for infection, change dressings according to policy or provider orders, and use sterile technique when handling all devices. The nurse should also teach the patient how to care for those devices in the outpatient setting and at home.
Finally, the nurse must assist the patient with managing side effects from the radiation, including assessing for side effects, administering PRN medications as ordered, collaborating with the health-care provider to ensure that the patient’s needs are being met, and teaching the patient about what to expect and how to manage anticipated side effects.
Nursing Care of Patients Undergoing Mastectomy
The pre- and postoperative care of the patient undergoing a mastectomy will depend on the surgical procedure being performed, whether reconstruction will also occur, and the health and medical needs of the patient.
Preoperative Nursing Care
Preoperative care of the patient before a mastectomy is the same as before any other surgical procedure. The nurse will do the following:
- Ensure that the consent form has been signed and witnessed and that the patient has had all of their questions answered.
- Schedule any required preoperative testing, such as chest x-ray, additional imaging, blood testing (complete blood count [CBC], blood chemistry, and blood typing).
- Assist with scheduling the surgery with the surgery center or hospital.
- Provide preoperative teaching, including what to expect during recovery, pain management, equipment that will be in place during the recovery and postoperative period, signs or symptoms that require follow-up care, and any restrictions that may be in place after surgery.
- Provide preoperative instructions, such as staying NPO after midnight, what time to arrive at the surgery center, if there are oral medications that can be taken or should be skipped on the morning of surgery, and wearing comfortable clothing that morning.
- Ensure that the patient has all the equipment and medication they will need in the postoperative period.
- Teach the patient how to deep-breathe and cough and why these actions are important.
On the morning of the surgery, in the immediate preoperative period, the nurse will do the following:
- Perform the initial nursing assessment, including vital signs, medical history, and physical exam.
- Ensure that the patient fully understands the procedure and has no remaining questions and that the consent form has been signed.
- Ask about advance directives. If the patient has them in place, ensure that the medical provider and surgeon are aware of them and that they are in the chart.
- Assess for allergies.
- Ensure that the patient has been NPO and has taken any and all preoperative medications as instructed.
- Administer preoperative medications as ordered.
- Help the patient cope with any preoperative fear or anxiety.
- Ensure that someone is available to take the patient home if they will be discharged the same day.
Specific tasks may vary depending on facility, so the nurse must be aware of the policies and procedures at their specific institution.
Postoperative Nursing Care
In the immediate postoperative period, priority nursing interventions center on the safe recovery from anesthesia and surgery. Vital signs must be checked according to policy, usually every 5 to 15 minutes in the first hour after surgery and then decreasing in frequency with time. The patient must be assessed frequently, with a focus on the management of pain, nausea, and vomiting, particularly in the immediate postoperative period. Breath sounds should also be auscultated, drains examined, and assessment for signs of shock, hemorrhage, or infection completed. Abnormal assessment findings should be reported to the provider promptly. Other nursing care activities may include encouraging the patient to turn, cough, and deep-breathe, assisting with active range of motion exercises, reinforcing and assessing surgical dressings as needed, assisting with ambulation and personal care needs, and providing parenteral fluids as ordered. The nurse should anticipate and plan for discharge early in the recovery process. For expected times of discharge, see (Table 8.6).
| Procedure | Discharge Interval |
|---|---|
| Lumpectomy | The same day |
| Mastectomy without reconstruction | Less than 24 hours |
| Mastectomy with tissue expander placement | About 24 hours |
| Mastectomy with flap reconstruction | 3 to 5 days |
Before discharge, extensive patient teaching should occur for both patient and support person. Ideally, this should reinforce any preoperative teaching that was done, including:
- how to manage and care for dressings and any drains that are in place
- how to take all prescribed medication, including PRN medications for pain or nausea
- when to return to the hospital for emergency care or follow-up
- how to perform arm exercises that should be done at least 4 times a day after axillary lymph node dissection; physical therapy may be ordered for some patients
- When to return for routine follow-up care with the oncologist, breast surgeon, and, if applicable, the plastic surgeon (usually within 1 week after surgery)
It is also incredibly important to teach the patient about what to expect when they remove the bandages, particularly if this has not happened in the hospital. Losing a breast can affect a person’s self-image, and seeing the surgical site can be an emotional time. If the patient sees the wound for the first time in the hospital, the nurse should ask who they would like to be present. The nurse can provide emotional support as needed. If this will happen at home, the nurse should prepare the patient and support person for what they will see so that it will not be as shocking. The patient should be reassured that the wound and scar will improve and that ongoing reconstruction procedures will also continue to improve body image and breast appearance over time. The nurse can suggest using an external prosthesis as a temporary measure (or a permanent one if the patient has declined reconstruction), advising the patient to seek the assistance of a company that specializes in this service and can provide additional support for the patient.
Posttreatment Care of Breast Cancer Survivors and Their Support Persons
New and better technology and medications, along with improved treatment protocols, have led to an increase in the number of people surviving breast cancer. Ongoing surveillance, support, and education are the focus of this period in a patient’s recovery.
Supportive Posttreatment Care
The patient’s need for support does not end with discharge from treatment. Considerable time must be spent on education and preparation for the transition to posttreatment life. Discharge planning should start early and be a comprehensive overview of what the patient will need for this next stage in their life.
Syria and Mastectomies
Cultures can react differently to the loss of the breast. In Syria, breasts represent femininity, beauty, and motherhood, and losing a breast can be a loss of identity (Hasan et al., 2023). Patients having a mastectomy can experience distorted body image, loss of self-esteem, loss of confidence, and changes in relationships. In the Arabic culture, cancer is considered a death sentence, which additionally stigmatizes the patient. Some Syrian people have described difficulty in looking in the mirror because they feel “ugly.” Reconstruction is rare in Syria due to financial difficulties. Some patients have made their own prosthetic breast from different materials available to them. In a male-dominated culture, psychologic care of patients who have undergone a mastectomy is not a priority. These patients must find support from family and friends to help heal the psychologic and physical pain of losing a breast.
Posttreatment Surveillance Protocols
Posttreatment surveillance protocols will depend on the specific type of cancer and stage at diagnosis, treatment, and prognosis.
- It will include a history and physical exam every few months initially, and eventually lengthen to once a year.
- Persons who have had BCS will need regular mammography to detect any new breast cancers. After having a unilateral mastectomy, the person will need a mammogram only on the unaffected breast.
- Regular pelvic exams and bone density screenings may be needed after certain types of treatment (e.g., hormone therapies or aromatase inhibitors) due to an increased risk for endometrial cancer and osteoporosis.
- Persons taking anthracycline-based regimens (doxorubicin [Adriamycin], epirubicin [Ellence]) or taxanes (Taxol, Taxotere) may be at greater risk for cardiotoxicity, requiring regular cardiac care.
Post–Cancer Treatment Side Effects
Many breast cancer survivors deal with ongoing side effects after completing treatment, particularly after chemotherapy . These patients should be monitored for depression and mental health issues. Other ongoing concerns include the following:
- Vasomotor symptoms, like hot flashes, are more common with hormonal treatments that reduce estrogen levels. Patients should be advised to avoid consuming spicy food, keep room temperatures cool, dress in layers, and use fans or air conditioners whenever possible.
- Weight gain often results from reduced activity due to fatigue and lean muscle loss. Participating in regular exercise can help to combat weight gain and improve energy levels.
- Cancer-related fatigue and brain fog are especially common after treatment and may be particularly hard to deal with. Associated with both radiation and chemotherapy, these symptoms can also lead to cognitive issues, such as poor concentration and memory. These symptoms may last well into the survivorship period.
- Sexual dysfunction, such as poor libido, decreased arousal or lubrication, and painful intercourse, can occur due to hormonal changes associated with treatment and sometimes due to body image issues after cancer.
The nurse can help the person understand what to expect and how to deal with the side effects. Being prepared for some of these issues can help patients cope.
Fertility and Pregnancy
Fertility and pregnancy after breast cancer are complicated issues. Many types of chemotherapy can impact a person’s fertility by causing premature ovarian failure. Ovulation and conception would be very difficult, if not impossible, in this situation. Some patients can freeze their eggs after diagnosis and before chemotherapy is started. It is important for the nurse and provider to advise patients of this risk and to offer a consultation with an infertility specialist before initiating any fertility-toxic therapies. Patients with frozen eggs are advised, in general, to wait at least 2 years after completion of treatment before trying to conceive. This time frame may allow providers to detect an early return of the cancer before pregnancy. There is also some concern that the high levels of estrogen produced during pregnancy may cause a cancer to come back, though studies have yet to demonstrate this (American Cancer Society, 2022c).
Hormone therapies are often continued for 5 to 10 years after diagnosis, which can make conception difficult, especially in an older person who may not be fertile by the time therapy is complete. Some people may be able to stop treatment after at least 2 years to pursue pregnancy and then wait a few months before attempting conception (American Cancer Society, 2022c). Hormone therapy would then resume after the birth. However, this decision needs to be made after a conversation with the health-care provider. In some people, cancer can return after the 2-year mark, putting the patient and potential pregnancy at risk (American Cancer Society, 2022c).
Patient Education: Community Agencies and Other Resources
In addition to providing direct patient support, the nurse can and should provide a list of community resources that the patient and support person can also access. Table 8.7 lists and describes several community and Internet resources that the nurse can suggest to patients who are in treatment for cancer.
| Resources | Description |
|---|---|
| American Cancer Society |
|
| Susan G. Komen |
|
| Breastcancer.org |
|
| National Breast Cancer Foundation |
|
| Living Beyond Breast Cancer |
|
| Cancer Care |
|
Many of these organizations also offer support and resources for caregivers, as well as patients. It can be difficult to manage the care of someone who is sick or undergoing chemotherapy. In addition to the exhausting physical challenges of providing care, such as tending to medical needs and helping with activities of daily living, the caregiver is also dealing with stress and fear of the unknown. As a result, it is important for the nurse to assess not only the patient at each visit but also the caregiver. How are they doing? What do they need on this journey? Do they have any questions or needs that can be met by the medical or social work team? It is important for the caregiver to find ways to cope and manage their stress, as well as find a supportive community to help them through their challenges.
Nurse:
Nicole, MSN, RN Senior Managing Editor: Digital Nursing Education
Years in practice:
8
Clinical setting:
large infertility center
Geographic location:
California
It can be difficult to contradict the medical provider that you are working with, but it is very important to do so (respectfully!) when it involves advocating for your patients. Several years ago, I was working at a large, well-known infertility center. I had been working there only a few weeks when a patient called the nursing hotline to inquire about fertility preservation care before she began treatment for breast cancer. I overheard the IVF coordinator informing the patient that she was sorry but there was nothing that we could possibly do in such a short time frame because the patient had just had her period and was not in a hormonally appropriate time to start an egg freezing protocol. I quickly interrupted the IVF coordinator and told her to get the patient’s contact information.
After she hung up, I asked some pointed questions about the patient’s clinical scenario and knew that we could help, based on my own years of experience in caring for patients undergoing fertility preservation. I also went online to look up fertility-preservation protocols from resources well known within the infertility field. I compiled all this information and brought it into a meeting with the provider. When the doctor repeated what the IVF coordinator had told the patient—that there was nothing that could be done to help the patient—I was able to provide evidence-based research with strategies that would help the patient undergo treatment very quickly, regardless of where she was in her menstrual cycle.
The provider was impressed with my research and asked me to call the patient back so that they could come in for an immediate consultation to plan for treatment. As nurses, we build our own breadth of wisdom and knowledge, and it is important to have confidence in that and in ourselves. We must always remember that we are collaborative partners in a health-care team and that we owe it to our patients to contribute to the experience guiding their care.
Nurses working in cancer care must be aware of other local resources for patient and caregiver support. It may be helpful to curate a list of local programs available at community centers, churches, and even the medical or cancer center. The nurse can also consider volunteering for these organizations to increase their community involvement and be more aware of what is actually available for patients. This may lead to finding opportunities for the nurse to initiate such programs in the community or at the medical center.
Health Disparities and Breast Cancer
Distrust of the health-care system, especially in the breast cancer continuum of care, is a known phenomenon. A large literature review of studies from 1990 through 2018 was published in 2020 and found that “Health-care system distrust is prevalent across many different racial and ethnic groups and operates across the entire breast cancer continuum of care” (Mouslim et al., 2020, p. 33). Other studies have demonstrated the disparity in breast cancer care that has existed between White people and Black people for many years. Black people have a significantly higher mortality rate and are more likely to be diagnosed at a younger age, at a more advanced stage, and with aggressive types of breast cancer (Stringer-Reasor et al., 2021).  While the exact cause for this health disparity is unknown, many health-care professionals and researchers attribute it to a combination of factors, including social determinants of health, such as socioeconomic status, racial bias, and access to care. According to several sources, Black people experience higher rates of death from breast cancer because of a combination of factors, including barriers to early diagnosis and high-quality treatment, the aggressive nature of certain breast cancer diagnoses occurring more often in Black people, lack of high-quality care, genetics, discrimination, and systemic racism (Susan G. Komen, 2023c).
Black people under 40 have the highest rate of breast cancer in their age group (McDowell, 2022). In addition, many studies have found high levels of health-care mistrust among Black people, which may result in an unwillingness to have regular breast cancer screening s, which can ultimately impact both care and outcomes (Mouslim et al., 2020).


8.19: Key Takeaways and References
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Key Takeaways
- The overarching goal in designing an artifact rejection strategy is to maximize the likelihood that you will obtain an accurate answer to the scientific question your study is designed to answer. You can ignore any of my specific suggestions for implementing artifact rejection if you have a better way of reaching that goal.
- Artifacts are typically problematic for one of three reasons: 1) they are a large source of noise and therefore reduce your statistical power; 2) they differ systematically across groups or conditions, creating a confound; 3) they indicate a problem with the sensory input (e.g., closed eyes during the presentation of a visual stimulus). In most cases, you are rejecting trials with artifacts to address one or more of these issues.
- Decreasing the threshold for rejection typically reduces the confounding effects of artifacts and the problems with the sensory input, and it may also reduce the noise caused by the artifacts. However, when the threshold gets too low, the number of trials remaining in the averaged ERP waveforms gets small enough that the data quality suffers. You can use the aSME values to help find the optimal threshold for rejection.
- You will typically want to implement several different artifact detection procedures for each participant so that you can intelligently detect the different types of artifacts. This is often achieved with one procedure for detecting blinks, another for detecting eye movements, and a third for detecting C.R.A.P.
- Dealing with small but consistent eye movements is tricky, because small eye rotations are difficult to detect but can be a significant confound in experiments with lateralized stimuli or lateralized responses. The two-stage procedure deals with this by using the greater precision of averaged HEOG waveforms to determine whether the small eye movements that escape rejection are large enough to have a substantial impact.
References
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Eimer, M. (1994). “Sensory gating” as a mechanism for visuospatial orienting: Electrophysiological evidence from trial-by-trial cuing experiments. Perception & Psychophysics , 55 , 667–675.
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Kappenman, E. S., Farrens, J. L., Zhang, W., Stewart, A. X., & Luck, S. J. (2021). ERP CORE: An open resource for human event-related potential research. NeuroImage , 225 , 117465. https://doi.org/10.1016/j.neuroimage.2020.117465
Lins, O. G., Picton, T. W., Berg, P., & Scherg, M. (1993). Ocular artifacts in EEG and event-related potentials I: Scalp topography. Brain Topography , 6 , 51–63.
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Luck, S. J. (2014). An Introduction to the Event-Related Potential Technique, Second Edition . MIT Press.
Luck, S. J., Hillyard, S. A., Mouloua, M., Woldorff, M. G., Clark, V. P., & Hawkins, H. L. (1994). Effects of spatial cuing on luminance detectability: Psychophysical and electrophysiological evidence for early selection. Journal of Experimental Psychology: Human Perception and Performance , 20 , 887–904.
Luck, S. J., Stewart, A. X., Simmons, A. M., & Rhemtulla, M. (2021). Standardized measurement error: A universal metric of data quality for averaged event-related potentials. Psychophysiology , 58 , e13793. https://doi.org/10.1111/psyp.13793
Mangun, G. R., & Hillyard, S. A. (1991). Modulations of sensory-evoked brain potentials indicate changes in perceptual processing during visual-spatial priming. Journal of Experimental Psychology: Human Perception and Performance , 17 , 1057–1074.
Nolan, H., Whelan, R., & Reilly, R. B. (2010). FASTER: Fully Automated Statistical Thresholding for EEG artifact Rejection. Journal of Neuroscience Methods , 192 (1), 152–162. https://doi.org/10.1016/j.jneumeth.2010.07.015
Talsma, D. (2008). Auto-adaptive averaging: Detecting artifacts in event-related potential data using a fully automated procedure. Psychophysiology , 45 (2), 216–228. https://doi.org/10.1111/j.1469-8986.2007.00612.x
Woodman, G. F., & Luck, S. J. (2003). Serial deployment of attention during visual search. Journal of Experimental Psychology: Human Perception and Performance , 29 , 121–138.
Yuval-Greenberg, S., Tomer, O., Keren, A. S., Nelken, I., & Deouell, L. Y. (2008). Transient induced gamma-band response in EEG as a manifestation of miniature saccades. Neuron , 58 (3), 429–441. https://doi.org/10.1016/j.neuron.2008.03.027