Familial pancreatic cancer (FPC) status as a clinical biomarker in patients receiving platinum-based systemic therapy: A case-control analysis.

Abstract

430 Background: Familial pancreatic cancer (FPC) is broadly defined as kindreds with at least a pair of first-degree relatives with pancreatic ductal adenocarcinoma (PDA). The role of DNA damage response agents, including platinum has not been well studied in this patient population. Methods: In this retrospective analysis, treatment details and clinical outcomes were analyzed in pts with FPC with advanced, unresectable or recurrent disease enrolled in the Ontario Pancreatic Cancer Study database. The primary outcome, overall survival (OS) was calculated from the initial diagnosis of advanced disease until death. 179 non-FPC patients from the COMPASS trial [NCT02750657] served as a control cohort all of whom had full molecular profiling and family history documented. OS between pts that received platinum-based therapy, and those that did not was compared using multivariable Cox proportional hazards model adjusting for age, sex, diagnosis year and FPC status. Interaction between FPC status and platinum was evaluated. Results: A total of 205 FPC pts were identified, 71% of pts had full germline testing and 16 (8%) had germline pathogenic variants in BRCA1/2. 104 (51%) were female and 101 (49%) male. Median age was 63 years (20-93) and 58 (28%) received platinum-based chemotherapy. Within the control arm (n=179), 71 (40%) were female, and 108 (60%) male; the median age was 64 years (29-84) and 106 (59%) received platinum-based therapy. In univariable analysis, median OS in pts with FPC was 16.9 months compared to 9.6 months (HR 0.46 [95% CI 0.37-0.58]). FPC patients receiving platinum had a superior median OS of 19 months compared to 15.5 months without platinum. In a multivariable analysis, both FPC (HR 0.33 [95% CI 0.21-0.51]) and receipt of platinum HR 0.53 [95% CI 0.38-0.73]) were prognostic. No interaction was seen with FPC and receipt of platinum (p=0.15). Conclusions: FPC status is prognostic but not predictive of platinum response in this study. Further molecular profiling of this unique cohort of patients will provide insights into putative predisposing germline alterations, and novel treatment strategies.