Should all BRCA1 mutation carriers with stage I breast cancer receive chemotherapy?

Narod SA, Metcalfe K, Lynch HT, Ghadirian P, Robidoux A, Tung N, Gaughan E, Kim-Sing C, Olopade OI, Foulkes WD, Robson M, Offit K, Jakubowska A, Byrski T, Huzarski T, Sun P, Lubinski J.

Source

Women's College Research Institute, 790 Bay Street, Room 750, Toronto, M5G 1N8, Canada, steven.narod@wchospital.ca.

Abstract

To estimate the 15-year survival following a diagnosis of stage I breast cancer among women who carry a BRCA1 mutation and to determine predictors of mortality, including the use of chemotherapy. Patients were 379 women with stage I breast cancer for whom a BRCA1 mutation had been identified, in herself or in a close family member. Patients were followed for up to 15 years from the initial diagnosis of breast cancer. Survival rates were estimated for women by age, tumor size (≤1 cm; >1 cm), ER status (±), and by chemotherapy (yes/no). 42 women died of breast cancer in the follow-up period (11.2 %). Survival rates were similar for women with cancers of size 0-1.0 cm and size 1.1-2.0 cm. Of the 267 women in the study who used chemotherapy, 21 had died (7.9 %) compared to 21 deaths among 112 women who did not receive chemotherapy (18.8 %; p = 0.002). The 15-year survival was 89.4 % for women who received chemotherapy and was 73.1 % for women who did not receive chemotherapy (p = 0.08; log rank). The adjusted hazard ratio for death following a diagnosis of stage I breast cancer associated with chemotherapy was 0.53 (95 % CI 0.28-1.07; p value 0.06) after adjusting for age of diagnosis, tumor size, and estrogen receptor status. This was statistically significant only among women with ER-negative breast cancers (HR = 0.28; 95 % CI 0.10-0.79; p = 0.02). BRCA1 positive women who are treated for stage I breast cancer with chemotherapy have better survival than those who do not receive chemotherapy. The difference cannot be explained by other prognostic factors. All women with invasive breast cancer and a BRCA1 mutation should be considered to be candidates for chemotherapy.