253P Preliminary report on survival outcomes of BRCA mutation carriers with triple-negative breast cancer

Abstract

Background: A substantial proportion of triple-negative breast cancer (TNBC) patients harbors a germline BRCA1/2 mutation. However, the impact of these mutations on recurrence-free survival (RFS) and overall survival (OS) rates remains controversial.Methods: Medical records of women diagnosed with BC between January 2013 and 2020 in two centers located in Monterrey, Mexico were reviewed. Only stage I-III TNBC patients who had available genetic test results and at least 12 months of followup were considered eligible. Fisher's exact tests were used to evaluate differences between groups based on mutation status. Furthermore, RFS and OS were calculated using the KaplaneMeier method, employing the log-rank test for group comparisons.Results: A total of 279 patients were diagnosed with TNBC, of which 162 (58%) had undergone genetic testing. Of these, 106 patients were considered eligible. Overall, 58 (55%) were negative for germline mutations and 48 (45%) had pathogenic BRCA mutations (36 BRCA1 [34%] and 12 BRCA2 [11%]). The median follow up was 31 months. The estimated 2.5-years RFS was 81.9% (confidence interval [CI] 95% 63.8-91.5%) for BRCA1 carriers, 71.4% (CI95% 33.8-90.1%) for BRCA2 carriers and 73.7% (CI95% 58.8-83.9%) for non-carriers (p>0.05). The estimated 2.5-years OS was 91.2% (CI95% 75.1-97.1%) for BRCA1-mutated, 73.3% (CI95% 24.3-93.4%) for BRCA2mutated and 77.1% (CI95% 62.3-86.7%) for non-mutated patients (p>0.05).Conclusions: There was a higher prevalence of BRCA2 mutation carriers in our TNBC cohort compared to what has been previously reported in the literature. BRCA1/2 carrier status was not found to be associated with statistically significant differences in RFS or OS at 2.5 years. However, there was a notable difference in OS at 2.5 years between BRCA1 carriers and non-BRCA1 carriers. Longer follow-up is required to determine if the observed survival advantage in BRCA1 carriers is maintained.Legal entity responsible for the study: The authors.