Abstract 157P
Background
Breast cancer gene (BRCA) mutation carriers have an increased risk of developing breast cancer, and its prognostic impact is unclear. Presently, few studies excluded the effect of risk-reducing salpingo-oophorectomy (RRSO), which affects breast cancer prognosis. This study aimed to investigate whether BRCA mutation affects survival outcomes in patients with breast cancer, considering the prognostic effects of RRSO.
Methods
We enrolled patients diagnosed with invasive breast cancer and underwent BRCA testing at St. Luke’s International Hospital from 2003 to 2021. We divided the patients into three groups; BRCA1 mutation carriers (BRCA1+), BRCA2 mutation carriers (BRCA2+), and non-carriers. We compared the relapse-free survival (RFS), breast cancer specific survival (BCSS), and overall survival (OS) between BRCA carriers and non-carriers using the log-rank test and Cox proportional hazards model.
Results
Of the 1,114 women enrolled in the study, 87 (7.8%) were BRCA1+, 87 (7.8%) were BRCA2+, and 940 (84.4%) were non-carriers. The median age was 41 years (32–50) in BRCA1+, 44 years (33–55) in BRCA2+, and 45 years (21–83) in non-carriers. The median follow-up period was 5.1 years, 71 (6.4%) (6.9% in BRCA1+ and 10.8% in BRCA2+) local recurrence, 148 (13%) (8% in BRCA1+ and 16% in BRCA2+) distant metastasis, and 84 (7.5%) (5.7% in BRCA1+ and 10.3% in BRCA2+) death due to breast cancer were observed. In the analysis for all patients, BRCA carriers showed no significant difference on RFS, BCSS and OS compared to that of non-carriers. In the analysis for patients without RRSO, (46 in BRCA1+ and 51 in BRCA2+), BRCA2+ had worse RFS than that of non-carriers (4.9 vs 5.1 years, p = 0.017). In the multivariate analysis for patients without RRSO, adjusting the age, stage, histological grade, hormone receptor status, and HER2 receptor status, BRCA2+ showed an unfavorable outcome on RFS compared to that of non-carriers, though it was not statistically significant. (Hazard ratio 1.68, 95%CI 0.98–2.88, p = 0.059).
Conclusions
The study suggests that BRCA2 mutation may be a poor prognostic factor in breast cancer after adjusting for the effects of RRSO. This should be considered when making therapeutic strategies for BRCA mutation carriers.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.