Abstract 2303: Entacapone and prostate cancer in patients with Parkinson’s disease: A large Veterans Health Administration study

Background: An increased risk of prostate cancer was observed in Parkinson’s disease (PD) patients treated with entacapone during a pre-approval randomized clinical trial. Objective: To investigate a potential association between entacapone use and prostate cancer in an ambulatory setting. Methods: Using data from the Department of Veterans Affairs (VA) healthcare system, new-user cohorts were created of PD patients treated with add-on entacapone or add-on dopamine agonist/monoamine oxidase B inhibitors between January 2000 and December 2014. Patients were followed on-treatment for occurrence of prostate cancer, identified via VA cancer registry linkage. Cox proportional hazards regression with time-dependent exposure was used to calculate hazard ratios (HR) and 95% confidence intervals (CI). Confounding was controlled by using inverse probability treatment weighting calculated from propensity scores. Results: Mean follow-up time was 3.1 and 4.0 years in the entacapone and control cohort, respectively. There were 17,666 subjects meeting study criteria (mean age, 74 (SD 8.6) years); the group treated with entacapone comprised 5,257 subjects. Twenty-three prostate cancers occurred in the entacapone cohort and 97 in the control cohort. The overall incidence of prostate cancer was 1.8 per 1000 person-years of risk. There was no difference in risk of prostate cancer between the cohorts for increased duration of entacapone intake (adjusted HR: 1.08; 95% confidence interval: 0.46-2.51 for cumulative exposure of ≥2 years). Time since starting drug therapy and cumulative dose (mg) were also examined. Conclusion: In this cohort of PD patients, extended duration of entacapone use was not associated with an increased incidence of prostate cancer. Note: This abstract was not presented at the meeting. Citation Format: Jacqueline M. Major, Francesca Cunningham, Diane Dong, Kunthel By, Kwan Hur, David C. Shih, Simone P. Pinheiro, Gerald D. Podskalny, David J. Graham. Entacapone and prostate cancer in patients with Parkinson’s disease: A large Veterans Health Administration study [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 2303. doi:10.1158/1538-7445.AM2017-2303