Breast-conserving surgery in BRCA1/2 mutation carriers: are we approaching an answer?

Approximately 10% of patients with breast cancer who are treated with breast-conserving surgery (BCS) develop an ipsilateral-breast tumor recurrence (IBTR). The optimal local therapy for women with BRCA-associated breast carcinoma remains controversial. We report the outcome of BCS in BRCA mutation carriers followed at a single institution.

A total of 54 women with BRCA1/2-associated breast cancer treated with BCS and whole breast radiotherapy were matched for age, tumor size, and time of surgery with 162 patients with sporadic breast cancer who had the same treatment between February 1994 and October 2007. Primary end points were cumulative incidence of IBTR and contralateral breast cancer (CBC). Median follow-up was 4 years for both groups.

Median age was 36 and 37 years for mutation carriers and controls, respectively; mean tumor size was 1.8 cm in carriers and 1.9 cm in controls. Ten-year cumulative incidence of IBTR was 27% for mutation carriers and 4% for sporadic controls (hazard ratio 3.9; 95% confidence interval 1.1-13.8; P = 0.03). Ten-year cumulative incidence of CBC was 25% for mutation carriers and 1% for sporadic controls (P = 0.03).

Our data suggest that IBTR risk after BCS in BRCA1/2 mutation carriers is increased compared with patients who have sporadic breast cancer. Likewise, the risk of CBC seems to be increased in this group. These risks and the likelihood of developing new primary tumors should be discussed with carriers interested in breast conservation as well as when choosing risk-reducing strategies.