Abstract P6-02-16: Breast cancer prognosis of germline BRCA1/BRCA2 mutation carriers of young women: a retrospective hospital-based cohort

Abstract

Abstract Background Studies evaluating prognostic impact of germline BRCA1/2 mutations (gBRCAm) on breast cancer patients reported controversial results. The primary aim of this study was to investigate outcomes of young gBRCAm patients with very early onset of breast cancer (< 30 years) compared with noncarriers. Methods In this retrospective study, 149 patients 30 years aged or younger at early breast cancer diagnosis between 2005 and 2019 were included in Oscar Lambret Center. Outcomes were overall survival (OS) and disease-free survival (DFS), defined as time from first diagnosis to first recurrence, second cancer or death from any cause, at 2 years, 5 years, and 10 years. Key patient data, kaplan-meier plots and outcomes were described by BRCA mutation status. Hazard ratios (HR) were calculated using Cox proportional-hazards models. Results Twenty-eight (18.8%) patients were gBRCAm carriers. The median follow-up was 6.5 years (IQR 0.25-16.5). Twenty-three deaths, 41 recurrences and 2 second cancers were reported. OS was 89.3% [70.4–96.4] in gBRCAm patients vs 99.1% [95% CI 93.9–99.9] in non-carriers patients at 2 years; 85.0% [64.7–94.1] vs 92.3% [85.1–96.1] at 5 years and 75.3% [52.5–88.3] vs 80.2% [66.6–88.7] at 10 years. There was no difference in OS between groups in multivariable analysis (HR=1.63 [0.55–4.77], p=0.37). Similar results were noted when comparing disease-free survival (HR=1.42 [0.64–3.11], p=0.38). Conclusions In this cohort of 149 patients with very early onset breast cancer, outcomes of gBRCAm mutation carriers did not differ from non-carriers when adjusted for others prognostic factors. Citation Format: Florent HEGO, Maël BARTHOULOT, Charles PIERARD, Audrey Mailliez. Breast cancer prognosis of germline BRCA1/BRCA2 mutation carriers of young women: a retrospective hospital-based cohort [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-02-16.