breast cancer is the most common cancer affecting women and has an enormous impact on their health .
the incidence of breast cancer varies between countries with the highest incidence in the united states and northern europe . in the united states breast cancer makes up 30% of all cancers in women , while in the netherlands the lifetime risk for a woman for developing breast cancer is about 11% .
the aetiology of breast cancer is varied : inherited genetic susceptibility , acquired genetic changes , and effects of endogenous and exogenous environment factors .
there is limited and indirect evidence that self - examination and physical examination can help in decreasing mortality because tumours smaller than 10 mm will not be detected in the majority of the cases .
most breast cancers are detected with mammography in either a screening situation or by the discovery of a palpable breast mass .
randomised trials have shown that screening with mammography in the age category of 5070 years can reduce mortality by about 25% . however , there is no consensus at the moment about the value of screening younger women with mammography .
one of the reasons is the lower sensitivity of mammography in women below the age of 50 years .
this is because young , pre - menopausal , women have denser breasts compared to post - menopausal women , resulting in an increased chanced that a malignancy will be missed on mammography . in a diagnostic setting ,
magnetic resonance imaging ( mri ) is a very sensitive tool for the detection of breast cancer . especially for invasive breast cancer , the sensitivity of this imaging technique
this sensitivity is not influenced in any way by the amount of glandular tissue present in the breast .
the role of mri as a screening modality has not yet been outlined . in the literature ,
mri has only been evaluated as a screening tool for women with an increased risk for developing breast cancer [ 68 ] . in this paper
the role of mri in the screening of women with an increased risk for developing breast cancer is discussed .
there are two categories of women who have an increased risk for developing breast cancer .
approximately 20%30% of women with breast cancer have a positive family history and about 20% of these individuals have a first degree relative with breast cancer . only about 5%10% of all cases of breast cancer are caused by inherited factors .
the most common gene mutations are the brca 1 and brca 2 . in 1990 ,
hall and co - workers identified chromosome 17 q 21 as the location of a susceptibility gene for early onset breast cancer , now known as the brca 1 gene mutation . shortly after that narod   described a linkage between the genetic marker d17 s 74 on 17 q 21 and ovarian cancer . in two different studies
the suggestion has been made that about 3% of all breast cancers are caused by the brca 1 gene [ 12 , 13 ] and about 45% of all hereditary cases of breast cancer are caused by the brca 1 mutation .
mutations in the brca 1 are most commonly seen in russia , followed by israel and italy .
women who are carriers of the brca 1 gene mutation have a lifetime risk ( ltr ) for developing breast cancer of approximately 80% .
other malignancies suggested to have an increased prevalence in these families are ovarian cancer , prostate and colonic cancer .
brca 1 associated breast malignancies tend to have a high malignancy grade and are often oestrogen and progesterone receptor negative .
median age of onset of breast cancer in this group is younger than 45 years .
approximately 35% of all inherited breast cancers are caused by the brca 2 mutation , first identified by wooster et al . .
the estimated ltr for developing breast cancer in this group is somewhat lower than in the brca 1 group .
it has been suggested by ursin   that in this group the use of oral contraceptives also increases the risk for developing breast cancer .
non - hodgkin s lymphoma has been reported and also prostate cancer and bladder cancer [ 19 , 20 ] .
the brca 2 mutation is associated with a 6% ltr of male breast cancer , which means a 100-fold increase over the general male population . at the moment
little is known about the malignancy grade and receptor status in the brca 2 group .
for both the brca 1 and brca 2 mutation carriers , the ltr for a contralateral breast cancer is about 65% .
there are other more sporadic hereditary diseases with an increased risk for developing breast cancer .
it is an autosomal dominant disease causing an increased risk for developing among others breast cancer , different types of sarcoma and leukaemia . in this group 30% of all malignancies
cowden s disease or multiple hamartoma syndrome showed an increased risk for both benign breast disorders like fibroadenomas and nipple malformations and breast malignancies [ 23 , 24 ] .
other hereditary diseases such as ataxia telangiectasia and the peutz  jeghers syndrome ( hamartomous polyps in the small bowel ) and the muir 
torre syndrome ( a variant of hereditary non - polyposis colon cancer ) also give an increased risk for breast cancer .
another group of women with an increased risk for breast cancer consists of women who have an individual risk factor .
patients with a history of lobular carcinoma in situ ( lcis ) have a somewhat increased incidence of developing an invasive cancer .
the national surgical adjuvant breast and bowel project ( nsabbp ) suggested an incidence of 13 invasive malignancies in 1000 women with an lcis . in this group
ductal carcinoma in situ ( dcis ) also gives an increased risk for an invasive breast malignancy .
about 30% of women not treated postoperatively with irradiation developed an invasive malignancy after a mean interval of 6 years [ 27 , 28 ] .
invasive lobular carcinoma is characterized by multifocality in the ipsilateral breast and appears to be more often bilateral   than other types of invasive malignancies . in the updated results of the nurses health study ,
post- or per - menopausal use of hormones showed an excess risk for developing breast cancer in the group of women with current or recently used hormones .
women treated with irradiation of the chest for , for instance , ( non-)hodgkin s lymphoma , also have an increased risk for developing breast cancer .
the excess risk in this category of patients is dependent on dose and age at irradiation .
the younger the age at time of exposure to irradiation , the younger the onset of breast cancer .
currently there are four possible breast screening modalities : clinical examination , mammography , ultrasound and mri .
the primary goal of breast examinations during screening is the detection of breast cancer at an as early stage as possible in order to reduce mortality .
clinical examinations of the breasts and self - examination as a screening procedure have been poorly evaluated .
there is only limited and indirect evidence that these methods could help in decreasing mortality due to breast cancer .
as mentioned , small malignant lesions ( < 10 mm ) will not be detected by palpation in the majority of cases .
kriege and co - workers showed a sensitivity of only 17.8% of clinical breast examination in a screening setting .
the younger the woman , the more glandular tissue there is , the denser the breasts are , and the lower the sensitivity of mammography .
for women in the age group 4050 sensitivity ranges from about 50% to 80% , while in the age group over 50 the sensitivity ranges from 70% to about 90% .
the sensitivity of mammography in the case of invasive lobular carcinoma ( ilc ) is lower than in women with invasive ductal carcinoma ( idc ) . in 1973 ,
the breast cancer detection demonstration project ( bcddp ) was started . in the subsequent 7 years
more than 280000 women were screened . the screening depicted about half of all breast cancers detected in the screened area .
in addition , the distribution of stage was more favourable in the screened population than in a control group in that area , so overall long - term survival was also better . in 1998 in the netherlands a mortality reduction of 13% was reached in the age category 5574 since the beginning of screening in 1990 with conventional mammography .
other screening trials like the health insurance plan of new york ( hip - study ) showed a mortality reduction of 30% in the screened group compared to the control group .
analysis of age specific mortality reduction indicates that screening for breast cancer has a special benefit in older women above the age of 50 and less in the younger age group .
in addition , tabar et al . showed that the likelihood of dedifferentiation of a tumour is much higher in women younger than 40 years .
survival is also influenced by both tumour grade and the size of the tumour [ 36 , 37 ] .
there is currently no evidence that ultrasound ( us ) has a role as a screening modality for breast cancer .
the two most important roles of us are differentiation between cystic and solid lesions in the breast and us guided biopsy of solid breast lesions .
the most currently used investigation technique is the flash 3d technique which includes one series of images pre - contrast and five series of images after intravenous administration of contrast medium containing gadolinium .
smoothly outlined round or oval lesions tend more to be benign , while speculated lesions are more suspicious of a malignancy .
if a lesion shows a wash out on kinetic behaviour , this is highly suspicious for a malignancy .
if there is progress in signal intensity over time this is more characteristic for a benign lesion .
although the sensitivity of mri for detecting invasive breast cancer is more than 95% , the value in detecting dcis , especially dcis grade i , is lower .
the sensitivity for dcis is described by orel et al .   to be in the range of 75% .
this is in comparison to the results of boetes et al . , who also described a sensitivity of about 75% in this group .
in a series of 17 patients , they missed four cases of dics , 3 grade i and 1 grade iii .
the problem with screening with mri is the relatively low specificity , which means a relatively high number of false - positive findings .
almost all women with a genetic predisposition for developing breast cancer are younger than the age of 50 .
so the value of screening with conventional mammography is doubtful in this group of women .   especially in young women in a screening situation
kuhl was the first to describe the results of mri in a screening situation for women with an increased risk for developing breast cancer .
a group of 192 asymptomatic and six symptomatic women were evaluated . in the symptomatic group
in the same year tilanus - linthorst described an asymptomatic group of 109 women with a 25% or more lifetime risk , in which 12 gene carriers also were included . in this group mri detected three malignancies occult on mammography .
thirteen malignancies in this group showed a cancer on mri while mammography detected five . in 2003 , morris and co - workers described a group of 367 women , retrospectively .
mri detected 14 more malignancies than mammography . in 2004 , the results of screening a group of 1909 women with both mri and mammography were described by kriege et al . .
in the ltr group of 15%30% , the detection rate for cancer was 7.8 per 1000 women , in the ltr of 30%50% the detection rate was 5.4 per 1000 .
however , in the group of carriers of brca 1/2 the incidence of malignancy was 26.5 per 1000 women .
the overall sensitivity for the detection of breast cancer was 40% for mammography and 71.5% for mri ( fig .
if only the invasive cancers were taken into account the sensitivity of mammography dropped to 33% and of mri increased to 79% .
in the mrisk study group 43% of all invasive malignancies were smaller that 10 mm , but in two selected control groups only , 14 and 12.5% , the tumour was smaller than 10 mm .
the negative node status was also better in the mrisk group than in both control groups with 21.4% compared to 52.4 and 56.4% , respectively .  
they evaluated 649 women with a total of 1881 screens both with mammography and mri .
the combination of both imaging techniques showed a sensitivity of 94% . the difference in sensitivity
was especially seen in the gene carrier group . however , as stated by liberman , any method of screening for breast cancer has the potential for both benefit and harm .
the benefit of screening is especially the detection of a malignancy as early as possible .
although prognosis of small breast cancers is better , the detection of a small cancer does not guarantee an improved survival rate .
the real value of screening can only be proved by randomized controlled trials with death as an end point .
the data published to date show that screening with mri has benefit for the group of women at high risk for developing breast cancer .
however , if a centre proceeds to screen with mri it should follow technical and interpretative guidelines and there should be the possibility of performing mr guided biopsies [ 46 , 47 ] .
in the screening of women with an increased risk for developing breast cancer detection needs to be done at a young age .
therefore mammography is of limited value . because the sensitivity of mri is high for detecting breast cancer and
because this sensitivity is not influenced by the amount of glandular tissue present , as with mammography , mri is the best modality available at this time for the screening of women with an increased risk for developing breast cancer .
( a ) , ( b ) the mammography of a 39-year - old woman obtained during annual screening because of a familial history of breast cancer .
( a ) , ( b ) the mammography of a 32-year - old woman obtained during annual screening because of a proven brca 2 gene carrier .
( c ) the mri from the same day . in the medial part of the right breast an irregular strong enhancing area was seen .
 breast cancer is the most common cancer affecting women . in the screening of women for breast cancer 
 , mammography is the most used imaging modality . 
 women with an increased risk for getting breast cancer can develop a malignancy at a relatively young age compared to other women . 
 the increased risk for developing breast cancer can usually be found in a positive familial history . 
 this positive familial history is based on a gene mutation in 510% of cases . 
 the most common gene mutations are brca1 and brca2 
 . this risk makes it necessary to start screening these women at a young age . 
 mammography , however , has proven to be less reliable in younger women because its sensitivity is lowered due to the dense breast tissue often present in this group . 
 mri has a higher sensitivity for detecting breast cancer compared to mammography . 
 mri is not influenced by the density of the breast tissue . 
 this makes breast mri the best modality available for the screening of women with an increased risk for developing breast cancer . 
Introduction
Increased risk for breast cancer
Screening of the breast
Conclusion
Figures and Tables