Oestrogen receptor status and survival in women with BRCA2-associated breast cancer

To evaluate the predictors of mortality, including ER status, in women with a BRCA2 mutation and breast cancer.

Eligible participants were identified from within two longitudinal cohorts. These patients were selected because they were diagnosed with breast cancer between 1975 and 2015 and carried a BRCA2 mutation. Data were abstracted from the medical record and pathology report. We analysed the effects of ER status and other variables on breast cancer specific survival using a Cox proportional hazards model.

Three hundred ninety women with breast cancer and a BRCA2 mutation were included in the analysis. The mean follow-up time was 12.3 years (range 1-39 years) and 89 subjects died (22.8%). In the multivariate analysis, women with ER-positive tumours were more likely to die than women with ER-negative tumours (HR 2.08, 95% CI 0.99-4.36, p = 0.05), and this was of borderline significance. For the 233 women with ER-positive tumours the 20-year survival rate was 62.2%, compared to 83.7% for 58 women with ER-negative tumours (p = 0.03).

The majority of women with a BRCA2 mutation present with ER-positive breast cancer, and for these women, prognosis may be worse than for BRCA2 carriers with ER-negative breast cancer.