MRI in familial breast cancer

Abstract

Five to ten per cent of all breast cancers are associated with a proven genetic predisposition for the disease or a strong family history of breast cancer in which yet unknown genetic predisposition is suspected. Carriers of germline mutations in genes breast cancer 1 or 2 (BRCA1/2) have up to 85% chance of developing breast cancer during their lifetime. The majority of these women develop the disease before the age of 50 years. Consequently, breast-cancer screening programmes aimed at reducing mortality in this population may only be effective if they start at much younger age than the general breast-cancer screening programmes. Unfortunately, the efficacy of conventional X-ray mammography in premenopausal women is often limited by dense fibroglandular tissue that obscures suspicious lesions. As a result, more advanced breast-imaging techniques have been considered, such as contrast-enhanced (CE) magnetic resonance imaging (MRI). In symptomatic patients, the sensitivity of CE MRI to detect invasive breast cancer is known to be high, regardless of the density of the fibroglandular tissue. Conversely, the specificity of CE MRI to discriminate between benign and malignant lesions is variable, and depends on the indication of the examination. Low specificity could result in many recalls on benign lesions, thus negatively affecting the cost–benefit ratio of CE MRI as a screening technique. Several single- and multi-institutional studies have been performed to investigate the efficacy of CE MRI as a screening tool exclusively for asymptomatic women at increased lifetime risk of breast cancer. Mounting evidence suggests that the addition of CE MRI results in cost-effective detection of tumours at earlier stage in BRCA1/2 mutation carriers. The value of CE MRI in other populations at risk is currently uncertain, and it is unlikely that CE MRI will be cost efficient in the general screening population of women who are not at increased lifetime risk.