Publication Abstract

Authors: E JY, Lu SE, Lin Y, Graber JM, Rotter D, Zhang L, Petersen GM, Demissie K, Lu-Yao G, Tan XL

Title: Differential and joint effects of metformin and statins on overall survival of elderly patients with pancreatic adenocarcinoma: a large population-based study.

Journal: Cancer Epidemiol Biomarkers Prev :-

Date: 2017 Jun 15

Abstract: BACKGROUND: Published evidence indicates that individual use of metformin and statin is associated with reduced cancer mortality. However, their differential and joint effects on pancreatic cancer survival are inconclusive. METHODS: We identified a large population-based cohort of 12,572 patients aged 65 years or older with primary pancreatic ductal adenocarcinoma (PDAC) diagnosed between 2008 and 2011 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Exposure to metformin and statins was ascertained from Medicare Prescription Drug Event files. Cox proportional hazards models with time-varying covariates adjusted for propensity scores were used to assess the association while controlling for potential confounders. RESULTS: Of 12,572 PDAC patients, 950 (7.56%) had used metformin alone, 4506 (35.84%) had used statin alone, and 2445 (19.45%) were dual users. Statin use was significantly associated with improved overall survival [hazard ratio (HR), 0.94; 95% confidence interval (CI), 0.90 ̶ 0.98], and survival was more pronounced in post-diagnosis statin users (HR, 0.69; 95% CI, 0.56 ̶ 0.86). Metformin use was not significantly associated with overall survival (HR, 1.01; 95% CI, 0.94 ̶ 1.09). No beneficial effect was observed for dual users (HR, 1.00; 95% CI, 0.95 ̶ 1.05). CONCLUSIONS: Our findings suggest potential benefits of statins on improving survival among elderly PDAC patients; further prospective studies are warranted to corroborate the putative benefit of statin therapy in pancreatic cancer. IMPACT: Although more studies are needed to confirm our findings, our data add to the body of evidence on potential anti-cancer effects of statins.