Germline BRCA mutations in a large clinic-based cohort of patients with pancreatic adenocarcinoma

Abstract

Purpose The main purpose of this study was to determine the prevalence of pathogenic BRCA1 and BRCA2 mutations in a consecutively ascertained clinic-based cohort of patients with pancreatic ductal adenocarcinoma and describe the clinical and family history characteristics. Patients and Methods Unselected, consecutive, incident patients with pancreatic ductal adenocarcinoma were recruited at a single cancer center over a 2-year period. Participants provided blood for DNA analysis and cancer family history, and cancer treatment records were reviewed. DNA from all patients was analyzed by Sanger sequencing and multiplex ligation-dependent probe amplification for germline variants in BRCA1 and BRCA2. Results Three hundred six patients were eligible for analysis. Pathogenic germline BRCA mutations were identified in 14 patients (4.6%; 95% CI, 2.2% to 6.9%), including 11 patients with a BRCA2 mutation and three patients with a BRCA1 mutation. Having a cancer family history that met genetic testing criteria of the National Comprehensive Cancer Network or the Ontario Ministry of Health and Long-Term Care or self-reporting as Ashkenazi Jewish was significantly associated with BRCA mutation carrier status (P = .02, P < .001, and P = .05, respectively). However, the majority of the BRCA mutation-positive patients did not actually meet these genetic testing criteria. Conclusion Pathogenic BRCA mutations were identified in 4.6% of a large cohort of clinic-based patients. Considering the implications for family members of BRCA carriers, and possibly tailored chemotherapeutic treatment of patients, our finding has implications for broader BRCA genetic testing for patients with pancreatic ductal adenocarcinoma.