ESR Essentials: screening for breast cancer - general recommendations by EUSOBI

Abstract

Breast cancer is the most frequently diagnosed cancer in women accounting for about 30% of all new cancer cases and the incidence is constantly increasing. Implementation of mammographic screening has contributed to a reduction in breast cancer mortality of at least 20% over the last 30 years. Screening programs usually include all women irrespective of their risk of developing breast cancer and with age being the only determining factor. This approach has some recognized limitations, including underdiagnosis, false positive cases, and overdiagnosis. Indeed, breast cancer remains a major cause of cancer-related deaths in women undergoing cancer screening. Supplemental imaging modalities, including digital breast tomosynthesis, ultrasound, breast MRI, and, more recently, contrast-enhanced mammography, are available and have already shown potential to further increase the diagnostic performances. Use of breast MRI is recommended in high-risk women and women with extremely dense breasts. Artificial intelligence has also shown promising results to support risk categorization and interval cancer reduction. The implementation of a risk-stratified approach instead of a "one-size-fits-all" approach may help to improve the benefit-to-harm ratio as well as the cost-effectiveness of breast cancer screening. KEY POINTS: Regular mammography should still be considered the mainstay of the breast cancer screening. High-risk women and women with extremely dense breast tissue should use MRI for supplemental screening or US if MRI is not available. Women need to participate actively in the decision to undergo personalized screening. KEY RECOMMENDATIONS: Mammography is an effective imaging tool to diagnose breast cancer in an early stage and to reduce breast cancer mortality (evidence level I). Until more evidence is available to move to a personalized approach, regular mammography should be considered the mainstay of the breast cancer screening. High-risk women should start screening earlier; first with yearly breast MRI which can be supplemented by yearly or biennial mammography starting at 35-40 years old (evidence level I). Breast MRI screening should be also offered to women with extremely dense breasts (evidence level I). If MRI is not available, ultrasound can be performed as an alternative, although the added value of supplemental ultrasound regarding cancer detection remains limited. Individual screening recommendations should be made through a shared decision-making process between women and physicians.

Keywords: Breast neoplasms; Early detection of cancer; Magnetic resonance imaging; Mammography; Ultrasonography (mammary).

Fig. 1

Breast density categories according to the Breast Imaging Reporting and Data System (BI-RADS) from the American College of Radiology [57]. Depending on the breast composition, four different categories are identified: a entirely fatty; b scattered areas of fibroglandular density; c heterogeneously dense, which may obscure masses; and (d) extremely dense

Fig. 2

45-year-old woman without significant family/personal risk factors for breast cancer undergoing first breast cancer screening examination. In the left mammogram (a cranio-caudal and mediolateral oblique projections), extremely dense breast tissue can be observed, and no suspicious findings could be identified, only a typical benign calcification can be recognized in the retromamillary region. At supplemental ultrasound (b) performed on the same day, a suspicious mass up to 3.3 cm could be identified at 6 o’clock in the left breast. Ultrasound-guided biopsy was performed, and the lesion histologically corresponded to a NST moderately differentiated invasive ductal carcinoma

Fig. 3

55-year-old woman without significant family/personal risk factors for breast cancer undergoing routine breast cancer screening examination. In the right mammogram (a cranio-caudal and mediolateral oblique projections) scattered areas of fibroglandular density can be observed. A suspicious irregular shaped and spiculated mass can be seen at 12 o’clock. At ultrasound a corresponding irregular shaped, spiculated and hypoechoic mass up to 0.8 cm can be seen (b). Ultrasound-guided biopsy was performed and the mass histologically corresponded to a NST moderately differentiated invasive ductal carcinoma

Fig. 4

46-year-old patient with a prior history of chest irradiation for Ewing sarcoma. Screening examinations. MLO views (a) from mammography examination that was deeemed normal. Contrast-enhanced breast MRI (b) reveals bilateral breast abnormalities. In the right breast, an irregular spiculated mass is visible, corresponding to a 13 mm NST carcinoma. In the left breast, segmental heterogeneous nonmass enhancement is seen, corresponding to extensive DCIS with microinvasion

Fig. 5

Flowchart summarizing the clinical pathways for breast cancer screening in different women subgroups