Rotter, David

e16012 Background: 75–85% of bladder cancer patients present with non-muscle invasive disease (NMIBC). While transurethral resection of bladder tumors (TURBT) is the initial standard treatment for visible lesions, there is variation in the utilization of adjuvant intravesical treatments in the real world. This study aims to assess current treatment patterns in privately insured NMIBC patients. Methods: Bladder cancer patients were identified from Truven MarketScan Commercial and Medicare Supplemental databases using ICD-9/ICD-10 codes. In the absence of tumor staging information, patients were considered to have NMIBC based on diagnosis of CIS or an algorithm centered on the use of TURBT, intravesical treatments and absence of immediate progression to muscle invasive disease. Patients were included in the final cohort if they had one year of continuous insurance coverage prior to index diagnosis, and were without any bladder cancer treatment during this period. Results: 18,683 patients met the eligibility criteria and had a median follow-up of 23 months; the mean age was 68.6 years and 75% were male. The median time from diagnosis to TURBT was 8 days. 54% of the cohort had an intravesical treatment (35% specifically with Bacillus Calmette–Guérin (BCG), with median time from TURBT of 69 days). 77% of BCG-treated patients received 5 or more administrations during induction. However, only 22% of patients received maintenance BCG after induction. 16% of the total cohort developed a recurrence or progression during the available follow-up; five percent underwent a cystectomy, while seven percent were diagnosed with metastatic disease. Only 4% of patients with 5 or more BCG administrations during induction met the definition for being BCG-unresponsive; this is influenced by the low adherence to BCG maintenance protocol. Conclusions: Only a third of NMIBC patients are given intravesical BCG treatment. Adherence to BCG maintenance protocols is suboptimal. Rates of cystectomy/ exenteration are low, suggesting patients’ preference of bladder preservation and the unmet need for new bladder-sparing alternatives.

Abstract Purpose: Growing mechanistic and epidemiologic evidence suggests that both metformin and statins have anti-cancer effects and are associated with reduced pancreatic cancer mortality. However, the joint effect of combination statin/metformin on pancreatic cancer mortality is unknown. By applying a robust analytic approach, we aim to examine the association between metformin and/or statin use and overall survival in a large cohort of patients with primary pancreatic adenocarcinoma (PDAC). Patients and Methods: 12,572 elderly patients with primary PDAC diagnosed between 2008 and 2012 were identified by using the Surveillance, Epidemiology, and End Results (SEER), and the detailed information on metformin and statin use was extracted from Medicare Part D. A Cox proportional hazard model with time-varying covariate adjusted for the propensity score was applied to assess the association of metformin and /or statin use with overall survival while controlling for potential confounders. Results: Of total 12,572 PDAC patients (median age = 76 years), 11,526 (91.77%) patients died before the study ended with a median follow-up of 3.8 months (interquartile range: 1.4-10.1). By the time-varying covariate analysis, statin use was significantly associated with an improved overall survival [Hazard ratio (HR), 0.938; 95% confidence interval (CI), 0.898 to 0.979], and more pronounced in post-diagnosis statin users (HR, 0.693; 95% CI, 0.555 to 0.864). However, metformin use was not significantly associated with overall survival (HR, 1.011; 95% CI, 0.939 to 1.091), neither in pre-diagnosis users (HR, 1.015; 95% CI, 0.970 to 1.061) nor in post-diagnosis users (HR, 0.990; 95% CI, 0.866 to 1.131). Additionally, no superior beneficial effect was observed for dual users (HR, 0.998; 95% CI, 0.947 to 1.053). Conclusions: Exposures to statin, not metformin, was significantly associated with reduced overall mortality of PDAC, indicating potential benefits of statin use on improving survival among PDAC patients. Further prospective validation is required to confirm these findings. Citation Format: Jian-Yu E, Shou-En Lu, Yong Lin, Judith M. Graber, David Rotter, Lanjing Zhang, Gloria M. Petersen, Kitaw Demissie, Grace Lu-Yao, Xiang-Lin Tan. Effects of concomitant metformin and statins on overall survival of pancreatic cancer patients: results from SEER-Medicare data analyses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3288. doi:10.1158/1538-7445.AM2017-3288

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 ages 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, 4,506 (35.84%) had used statin alone, and 2,445 (19.45%) were dual users. Statin use was significantly associated with improved overall survival [HR, 0.94; 95% confidence interval (CI), 0.90–0.98], and survival was more pronounced in postdiagnosis 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 anticancer effects of statins. Cancer Epidemiol Biomarkers Prev; 26(8); 1225–32. ©2017 AACR.