Phase II national clinical trial of prophylactic irradiation to the contralateral breast for BRCA mutation carriers treated for early breast cancer (EBC).

514Background: Women who carry germ line mutations in BRCA1/2 face a very high risk of breast and ovarian cancer. Recommendations for BRCA mutation carriers advocate intensified screening and BSO. Risk-reducing bilateral mastectomy is considered by healthy BRCA mutation carriers and by carrier patients who already developed breast cancer. Yet, the procedure is disfiguring. Women fear its effects on body image, sexuality and sensation and seek alternative preventive measures. Most studies found that breast conserving therapy was associated with similar risk of ipsilateral cancer recurrence in BRCA carriers compared to non-carriers. However, the risk of subsequent contralateral (CLT) breast cancer in carriers was markedly increased. In Israel, BRCA associated breast cancer is relatively common. Accordingly, a national protocol was devised for this enriched population. Methods: In this IRB-approved trial, the choice of prophylactic irradiation to the CLT breast, in addition to radiation of the involved side,...