Impact of BRCA status on outcomes and survival in high-risk early breast cancers

Background: Relationship between the presence of the BRCA mutation (BReast CAncer) and outcomes is unclear, especially in high-risk breast cancers. The aims were to describe clinical and pathological outcomes considering mutational status and to assess the prognostic impact of germinal BRCA mutated status (BRCAm) in this high-risk population. Methods: A multi-center retrospective cohort of patients treated in Franche-Comté between 2003 and 2013 for an early breast cancer (eBC) by neoadjuvant and/or adjuvant chemotherapy was analyzed. Clinical and pathological outcomes were described and distributions were compared in regards of mutational status group performing Fisher exact tests. Kaplan-Meier method and log-rank tests were used to compare survival in terms of overall survival (OS. Univariate and multivariate Cox proportional hazards models were estimated for OS. Results: A total of 2,295 patients were included. Among them, 240 patients were tested (10.5%) including 60 patients diagnosed with BRCAm (2.6%). Among them, 36 were BRCA1 (1.6%), 22 BRCA2 (1%) and two BRCA1 and 2 (0.01%). Age at diagnosis (p < 0.0001), histological type (p = 0.0043), size (p = 0.0021), nodal status (p < 0.0001), histologic grade (p = 0.0009), triple negative status (p < 0.0001) and in situ component (p = 0.0163) were significantly different between BRCAm, BRCAwt and untested patients. BRCA1 mutated tumors were mostly triple negative tumors contrary to BRCA2 mutated tumors, which were mostly locally advanced luminal tumors. In multivariate analysis, OS was not associated with BRCAm status (p = 0.5690). Conclusions: Among this French cohort of high-risk eBC, incidence of BRACm cases was 2.6%. BRCA1 and BRCA2 breast cancers were two distinct tumors in term of pathological outcomes. BRCAm status had no significant impact on OS. Legal entity responsible for the study: CHU Besançon. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.