Complications of Advanced (Metastatic) Breast Cancer

Potential Problems With Stage 4 Breast Cancer

If you're living with advanced breast cancer (metastatic or stage 4) you probably aren't excited to hear about possible complications you might face. After all, aren't the symptoms or your cancer and the side effects of treatment enough? Fortunately, unlike common side effects, these potential complications are much less common, and you may not experience many, or even any of these problems.

Let's take a look at some complications related to the site of metastases, followed by some of the problems you may experience with metastatic breast cancer (stage 4 breast cancer) in general.

Side Effects vs. Complications

It's important to make a distinction before starting. You're probably familiar with many of the side effects of breast cancer treatments, such as the hair loss with chemotherapy, or the fatigue with radiation. For the purpose of our discussion we will look at side effects as common occurrences that are often expected.

In contrast, complications are problems that may take you by surprise, and that you may not have heard of prior to living with cancer yourself. Again we have to emphasize that most people do not have all (or even any) of these complications, and we hope not to discourage anyone by listing potential problems. That said, many of these issues are treatable, and treatments are most effective when they are started sooner rather than later. In some cases, recognizing a complication ahead of time can prevent serious problems, even paralysis or death.

General Complications

There are some general complications associated with metastatic breast cancer that carry a risk no matter where your cancer has spread, or the type of treatments you received in the past or are receiving now. These include:

  • Blood Clots: Risk factors for blood clots include having metastatic cancer, some of the treatments (such as chemotherapy) for the disease, bedrest, and more. We are learning that blood clots with cancer are extremely common, and cause considerable illness and sometimes even death. These blood clots often begin in the legs or pelvis (deep vein thrombosis) and can break off and travel to the lungs (pulmonary embolism). Symptoms to be aware of include any redness, swelling, or tenderness of your legs, sudden shortness of breath, sudden severe chest pain, lightheadedness, or even unconsciousness. When caught on time, blood thinners can be used to resolve the clots.
  • Pain: Pain with metastatic cancer can be variable and often depends on the location of metastatic disease (see bone metastases below). We know, however, that pain can interfere with your quality of life, and quality of life is a primary goal in treating stage 4 cancer. Talk to your doctor about pain control for people with cancer. There are many different options available, and most people, even with severe end-stage disease, can be comfortable.
  • Cachexia: Cancer cachexia is a challenging issue with advanced cancer. It is a syndrome of involuntary weight loss, muscle wasting, and reduced appetite. It reduces quality of life and is felt to be the direct cause of death for 20 percent of people with cancer. The syndrome of cachexia, though recognized by weight loss, appears to begin even before weight loss starts. There is significant research in process looking for ways to both prevent and treat cachexia. If you are struggling with loss of appetite, or have lost weight, bring this up with your doctor. Counterintuitively, exercise is helpful. Cachexia is one symptom of cancer that appears to be helped significantly by medical marijuana if this is legal in your state.

Complications Related to Bone Metastases

The bones are the most common site to which breast cancer spreads. Progress is being made not only in treating these metastases but looking at ways to prevent bone metastases in the first place. For those who have breast cancer with bone metastases, the newer bone-modifying drugs such as bisphosphonates and denosumab may reduce the risk of complications such as fractures. Possible issues with bone metastases include:

  • Pain: The pain due to bone metastases can be excruciating, and we know that pain vastly decreases a person's quality of life. At the same time, many of the medications we have for severe pain cause fatigue and drowsiness. In addition to using pain medications, radiation therapy is very effective at reducing the pain due to these metastases. Bone-modifying drugs do not reduce pain to the same degree, but in combination with the above are helpful (and for other reasons as well).
  • Pathological fractures: A pathological fracture occurs when a bone fractures (breaks) through a weakened area. Depending on the location, a fracture of this sort can greatly decrease mobility.
  • Spinal cord compression: Spinal cord compression due to cancer is a medical emergency. When bone metastases occur in the lower spine, they can cause the spine to compress and press on nerves which are important in helping us walk, urinate, and pass our bowels. A very serious form of "microfractures" in the spine can lead to the vertebrae in the back collapsing down on themselves, a compression fracture. When cancer cells in this region result in nerve compression, a medical emergency known as cauda equina syndrome may occur. Without prompt treatment to stabilize the spinal cord, a person may end up paralyzed in the lower extremities in addition to not being able to hold her bladder or bowels.
  • Hypercalcemia. When tumor breaks down bone, it results in the release of calcium into the bloodstream, a condition called hypercalcemia of malignancy. (There are other mechanisms in cancer which can increase calcium in the blood as well) . At first, this may cause nausea and vomiting, increased thirst, weakness, and muscle aches, but can progress to confusion, abnormal heart rhythms, coma, and death.

Complications Related to Lung Metastases

The lungs are the second most common site to which breast cancer spreads, and lung metastases occur at some time in roughly a third of people with metastatic breast cancer. The symptoms can vary from none (when lung metastases are found on a scan alone), to significant shortness of breath. In addition to regular treatments for metastatic lung cancer, local treatments are now being used for some people who only have a few lung metastases, and this appears to improve life expectancy. Potential complications of lung metastases include:

  • Shortness of breath: Shortness of breath can often be controlled with medications such as morphine. If an obstruction is leading to shortness of breath, a stent may be placed. Surprisingly, oxygen doesn't seem to be very helpful in reducing the sensation of shortness of breath.
  • Pneumonia: The presence of metastases in the lungs, especially near the airways, can result in the accumulation of fluid and bacteria deep in the lungs. With the narrowing of the airways, people may develop recurrent pneumonia. This can be more serious if your white blood cell count is reduced due to chemotherapy, and often requires hospitalization and intravenous antibiotics.
  • Coughing up blood: Coughing up blood may occur, especially when metastases are near the large airways. Coughing up even a small amount of blood—a teaspoon—is considered a medical emergency. Coughing up a third of a cup of blood has a mortality rate of around 30 percent. In other words, don't ignore any blood you cough up, even if it is only a small amount. When diagnosed promptly, a procedure can often stop the bleeding, even if it is severe.
  • Malignant pleural effusion: A malignant pleural effusion is a condition in which fluid and cancer cells build up between the membranes (the pleura) which line the lung. The severity varies depending on the amount of fluid present as well as how rapidly it occurs. A small pleural effusion may not need any treatment. A large pleural effusion, however, can compress the lungs, leading to severe pain and shortness of breath. The first step is usually a thoracentesis, in which a needle is inserted through the chest wall into the pleural space to drain the fluid. Unfortunately, the fluid often recurs. Options then include recurrent draining, inserting a stint so that people can drain their effusions themselves at home, or performing a procedure called a pleurodesis. In a pleurodesis, a chemical is inserted into the pleural space causing inflammation, which in results in "gluing" of the membranes together so that fluid may not re-accumulate.
  • Pulmonary hemorrhage: Pulmonary hemorrhage, or bleeding into the lungs, isn't common, but may occur.
  • Obstruction of the airways: When metastases grow near or into the airways, they may cause an obstruction. This can lead to both shortness of breath, and infections such as pneumonia. If an obstruction is severe, doctors can place a stent in the airway to hold it open.

Complications Related to Liver Metastases

Liver metastases may not cause any symptoms unless the metastases are near the major vessels and ducts of the liver. If you have symptoms, you may notice a yellowish discoloration of your skin and the whites of your eyes (jaundice), abdominal pain, shoulder pain, and hiccups. Often times, a large part of the liver needs to be replaced by the tumor to cause significant symptoms. A few potential complications include:

  • Ascites: With liver dysfunction, fluid can build up in the peritoneal cavity (ascites). If your abdomen becomes very distended, it can be painful and cause shortness of breath (especially if you also have lung metastases). Doctors may do a procedure called a paracentesis is which a needle is inserted through the skin and into the abdominal cavity to drain off the fluid.
  • Confusion: With extensive metastases, confusion and lethargy may result, due to the build-up of toxins in the body.
  • Bleeding: The liver is responsible for making clotting factors. If the liver is largely non-functioning, an insufficient amount of these factors may be produced leading to bleeding and anemia.
  • Itching: You may not think of itching as a serious complication, but the itching that can accompany liver metastases can be severe. The itching occurs due to the build-up of bile acids in the blood and skin. In addition to asking your loved ones to give you back scratches, there are medications that can reduce this symptom.

    Complications Related to Brain Metastases

    The brain is also a common area for breast cancer to spread, and brain metastases may result in any number of symptoms; some which can be life-threatening. You may not be aware that your breast cancer has spread to your brain, or instead, you may experience one of the complications of brain metastases. Some of these include:

    • Seizures: You may be familiar with grand mal, or tonic-clonic seizures, the kind where a person becomes unconscious and her extremities shake violently. Sometimes seizures are localized to one area of the body. Other seizures may result in symptoms such as a person staring into space appearing not to see anything.
    • Falls: Brain metastases can lead to weakness, numbness, and loss of balance. If brain metastases are present, it's important to be extra careful about fall prevention.
    • Visual problems: Visual problems such as double vision, or even loss of vision may occur. People are cautioned against driving or using objects that could be dangerous.
    • A sudden change in mental status: Changes in mental status, personality changes, or a loss of consciousness may occur.

    The treatment of the different complications of brain metastases is often radiation. If a single, or only a few metastases are present, a specialized form of radiation therapy called stereotactic body radiotherapy (SBRT) may be used in an attempt to eradicate the metastasis.

    Complications Due to Other Metastases

    Breast cancer can spread to nearly any region of the body, and if you are having symptoms, even if seemingly unrelated to your cancer, make sure to talk to your oncologist. Some complications related to other regions of spread include:

    • Kidney failure: Kidney failure may occur not only due to metastases to the kidneys (not an uncommon site) but due to medications you are taking, dehydration, and more.
    • Pericardial effusion: Just as breast cancer can spread to the lining of the lungs, it can spread to the lining of the heart. When fluid builds up between the membranes lining the heart (pericardial effusion) it makes it more difficult for the heart to beat (heart rate usually speeds up to make up for the smaller volume pumped to the rest of the body). If the fluid builds up fast or is extensive, it can lead to a condition known as pericardial tamponade (basically restricting the heart so much that it is unable to beat). When this condition occurs due to cancer metastases, a third of people die before it can be diagnosed and treated. This is not common, but a reason to talk to your doctor if you note any increased shortness of breath or a rapid heart rate.
    • Brachial plexus injury: When cancer spreads into the tissues under the arm, it may damage a group of nerve fibers known as the brachial plexus. This can cause weakness or paralysis on the same side arm. Brachial plexopathy due to breast cancer affects only 1 in 200 women but is often a very frustrating complication.

      Complications Due to Breast Cancer Treatments Old and New

      Other complications which may occur are similar to those that sometimes happen to people with early stage breast cancer. A few of the more serious include:

      • Heart disease: Both chemotherapy and radiation therapy for breast cancer can damage the heart. Heart disease may appear many years after the initial treatment and can range from coronary artery disease, to heart failure, to valve problems. Most common is heart failure, which often declares itself with symptoms of shortness of breath, swelling of the extremities, and coughing up pink, frothy sputum.
      • Infections: If you are on chemotherapy, your doctor has likely warned you about developing a fever (fever of neutropenia). A fever that would ordinarily not be alarming, could be life-threatening. When your immune system is suppressed, you are not only more susceptible to infections, but your ability to fight off an infection you contract is compromised. Even mild infections may require hospitalization and intravenous antibiotics. If you believe you may have an infection, don't wait. Call your oncologist.

      Allergic Reactions

      When you're living with stage 4 breast cancer, you will often be using several medications. These may be part of your treatment, and also medications to control your symptoms. What some people don't realize is that even if you've taken a medication 100 times, the next dose you take could result in a severe allergic reaction.

      Ideally, everyone should be aware of the symptoms of anaphylaxis, a severe allergic reaction, as this can be life-threatening. If you notice any swelling of your neck, tongue, or face, the development of hives, or lightheadedness, seek medical attention.

      Psychological Complications

      People often think of cancer survivors as fighting so hard, but there are also times when survivors become very discouraged. Depression can set in. And with depression, some people even become suicidal. The risk of suicide with cancer is lower in breast cancer than with some other cancers, but the risk is still there. As with some of the "milder" symptoms above, you may not think of depression as a complication of metastatic cancer, but it is very important. The goal of treatment is to extend life while giving you the best quality of life possible. If anything is interfering with your ability to enjoy your family and friends, it should be addressed, either by your oncologist, other physicians such as a palliative care specialist, or a cancer therapist.

      A Word From Verywell

      We presented some of the potential complications that may accompany a diagnosis of metastatic breast cancer, though there are other, less common issues you may face. The important point is to be aware of your body and talk to your oncologist with any concerns. Living with stage 4 cancer is not the time to be a hero. Frequently, serious complication can be treated if they are found in a timely manner.

      Keep in mind that many people do not experience these complications. There are many people living with stage 4 breast cancer who are living full and rewarding lives, even if there is uncertainty about the future.

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