Management of BRCA mutation carriers with pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis, with a 5-year survival rate of ≤7% across all stages. Most patients are diagnosed with advanced disease and median overall survival is limited. The limited success of conventional therapies for PDAC is at least partially attributable to its genetic heterogeneity. Extensive genomic efforts have been made to subtype PDAC. The DNA damage repair (DDR) deficiency subtype, also known as unstable genome/DSBR (DNA double-strand break repair) subtype, is one of the most clinically relevant biologic abnormalities in PDAC. Increased PDAC risk was found to be associated with inherited syndromes, which are present in approximately 10% of patients with PDAC. Recent updates to the ASCO and NCCN guidelines recommend risk assessment for all individuals with PDAC, irrespective of personal or family history or ethnicity. Germline BRCA mutations associated with DNA repair dysfunction is one of the best illustrations of actionable biologic subtypes in PDAC. This genetic alteration can indeed be targeted by PARP inhibitors (PARPi). Treatment implications for germline BRCA carriers with PDAC include the use of platinum-based therapy and the validation of PARPi administration as a maintenance strategy in platinum-sensitive patients. In the era of precision medicine, this is the first convincing example of targeting identified germline hereditary mutations in PDAC.