1471P Overall survival by BRCA and ATM mutation status in patients with metastatic pancreatic cancer: Findings from the PRIOR-2 study

Recent research suggests a role for BRCA1/2 or ATM gene mutations in metastatic pancreatic cancer (mPC) as predictive marker of clinical benefit from platinum-based chemotherapy and targeted therapies. However, there is little data on the prognostic impact BRCA/ATM mutation all-cause overall survival mPC. In this retrospective cohort study, we identified patients aged ≥18 years with mPC (≥2 PC diagnoses within 90 days plus ≥1 diagnosis ≥2 note mentions disease) Optum’s de-identified electronic health record (EHR) database (1/1/2011 – 6/30/2020; N=42.5M total lives). Index date was first diagnosis/note mention disease. Patients >1 other type 12-month baseline were excluded. stratified by status followed up to 36 months assess (OS). Death captured EHR linked social security obituary data. Survival differences evaluated using Kaplan-Meier log-rank test Cox Proportional-Hazards model, adjusting demographics, comorbidities, factors, frailty, number site metastases. Among 17,359 mPC, 546 (3.1%) tested BRCA/ATM: 182 (33.3%) BRCA+/ATM+ (POS), 94 (17.2%) BRCA-/ATM- (NEG) 270 (49.5%) unknown status. POS NEG 66% 60% female; mean (SD) age 65.1 (11.0) 63.3 (10.5) years, respectively. Baseline Charlson Comorbidity Score 6.3 (2.3) 6.2 (2.3), There few meaningful factors at baseline. index dates prior 7/1/2019 (to allow least one year post-index data; n=216), 1-year OS rates not significantly different between (60%) (64%) (p=0.29); unadjusted hazard ratio (HR) 1.28 (95% CI =0.80–2.05); adjusted HR 1.10 0.60–2.04). no statistically significant demographic, without mutation. Additional needed evaluate association survival.