Prevalence of BRCA1 and BRCA2 Germline Mutations in Vietnamese Patients With Triple-Negative Breast Cancer

Introduction Triple-negative breast cancer (TNBC) represents approximately 10-20% of all breast cancer cases and is frequently associated with BRCA1 mutations. Numerous studies from Western populations have investigated the prevalence of germline BRCA mutations in individuals with TNBC; however, the prevalence of BRCA1/2 mutations in TNBC patients varies widely between countries and from study to study. Evidence from Asian populations, particularly Vietnamese patients, remains limited. In this study, we determined the prevalence of germline BRCA1/2 mutations among unselected Vietnamese patients with TNBC and analyzed the clinicopathological features. Methods We conducted a single-center retrospective study of 68 women diagnosed with TNBC at the Vietnam National Cancer Hospital. Germline BRCA1 / 2 testing was performed by next-generation sequencing. Results Overall, 19 Vietnamese patients (27.9%) had BRCA1/2 mutations, with 14 (20.6%) in BRCA1 and 5 (7.4%) in BRCA2 . Three patients (4.4%) had variants of uncertain significance (2 BRCA1 mutations and 1 BRCA2 mutation). Thirteen distinct pathogenic or likely pathogenic variants (8 BRCA1 and 5 BRCA2 ) were found. Among patients diagnosed at ≤60 years, the prevalence of BRCA1/2 mutations was 32.0%. The average age at diagnosis for BRCA1/2 mutation carriers was notably lower than that observed in non-carriers (43.1 vs 51.7 years, P = .021). BRCA1/2 mutation carriers were also more frequently premenopausal (78.6% vs 43.9%, P = .025). Conclusions There is a high prevalence of BRCA1/2 mutations among TNBC patients in Vietnam. Women with TNBC in Vietnam should be screened for mutations in BRCA1/2 .