Breast cancer surveillance for BRCA1/2 mutation carriers – is “early detection” early enough?

Background: Annual MRI screening is associated with a significant reduction in advanced-stage breast cancer diagnosis in BRCA1/2 mutation carriers. The impact that early detection has on subsequent oncological treatment is less frequently reported. In this study we compared disease stage and therapeutic approaches in BRCA1/2 mutation carriers who developed breast cancer while adhering to the recommended surveillance scheme (“known carriers”), with women who became aware of their BRCA mutation status after breast cancer diagnosis (“latent carriers"). Methods: Data on tumor characteristics, disease stage, and therapeutic decisions were collected on BRCA1/2 mutation carriers treated for breast cancer at the Chaim Sheba Medical Center. Results: Data were available for 298 BRCA1/2 carriers. Median follow-up was 77.4 months (range, 3.5–520). Age at diagnosis was not statistically different between known carriers (n = 96; median age at diagnosis 44.7 years) and latent carriers (n = 202; 43.7 years); p = 0.8284. Of known carriers, 19.8% were diagnosed with carcinoma in situ vs. 5% of latent carriers (p = 0.0012). Stage T1N0 disease was diagnosed in 54/96 (56.3%) of known carriers vs. 59/202 (29.2%) of latent carriers (p < 0.00001). Neoadjuvant or adjuvant chemotherapy was administered to 46/96 (47.9%) of known carriers compared with 162/202 (80.2%) of latent carriers (p < 0.00001). Conclusions: While early stage breast cancer was diagnosed frequently among known BRCA1/2 carriers under tight surveillance, almost half of these women were treated with chemotherapy. Healthy BRCA1/2 mutation carriers should be informed about these rates while discussing risk-reducing surgical options.