‘ECCO – the European CanCer Organisation represents and serves the interests of over 50,000 professionals in oncology through...
Breast cancer is an important public health problem, as it is the leading cause of death from cancer in women and the leading cause of death in 35–55-year-old women in the EU. Well-known risk factors are a previous breast carcinoma, atypical ductal hyperplasia, atypical columnar hyperplasia, lobular lesion in situ, papillomatosis or atypical papillary lesion, mediastinal radiotherapy and family history of breast cancer, especially the positive genes BRCA 1 and 2.1 Invasive breast carcinoma includes a wide range of tumours. The most frequent is invasive ductal carcinoma not otherwise specified ([NOS] 60–80%), followed by invasive lobular carcinoma (about 15%), which is often multicentric or bilateral. The remaining most frequent subtypes are medullary, mucinous, papillary and tubular carcinomas, each of which occurs with a frequency of approximately 2–4%.1 It is important to establish the classification of breast cancer according to its local extent. Multifocal carcinoma refers to two or more tumour areas in a unique quadrant or a distance of <4–5cm (although in breasts of small volume it can involve several quadrants, see Figure 1). Multicentric carcinoma refers to two or more tumour areas in different quadrants of the same breast/to a distance >4–5cm (see Figures 2–3). Contralateral cancer can be synchronous, when the detection of a contralateral tumour occurs in the first six months following diagnosis of the primary tumour, or metachronous, when the recurrence is later.1 Multifocal or multicentric carcinomas are more frequent in young patients or peri-menopausal women with large tumours (>5cm) and high-density fibroglandular parenchyma, women with a family history of breast cancer and in cases of invasive lobular carcinoma.1
Imaging Techniques in Breast Cancer
Breast cancer detection requires a multimodality approach and several imaging modalities must be adequately employed by the radiologist. For this reason we will include a short review of mammography and breast ultrasounds findings and indications before explaining the role of breast magnetic resonance imaging (MRI).
Mammography is the primary diagnostic imaging modality in the evaluation of any mammary pathology because it is accessible, rapid, reproducible, relatively cheap and useful. The sensitivity and specificity for screening of breast cancer depend on the quality of the images, the experience of the radiologist and the reason for the imaging: screening versus diagnostic mammogram in symptomatic patients. It has been demonstrated that the likelihood of death from breast cancer is 50% lower in women who regularly participate in screening mammography programmes than in women who do not, with a similar death rate in the latter group to those obtained prior to the introduction of screening mammograms.2 The sensitivity of mammography is higher in fatty breasts and decreases in dense breasts, especially in young women. Sensitivity for the detection of multifocal–multicentric carcinoma is 66%.3 The classic signs of malignancy in mammography are spiculated nodule, irregular shape, microlobulated or blurred margins and a group of amorphous, heterogeneous or pleomorphic microcalcifications.4