Understanding Prescribing Differences Between Urologists and Medical Oncologists in the Management of Advanced Prostate Cancer

Introduction:The availability of oral therapies for advanced prostate cancer allows urologists to continue to care for their patients who develop castration resistance. We compared the prescribing practices of urologists and medical oncologists in treating this patient population.Methods:The Medicare Part D Prescribers data sets were utilized to identify urologists and medical oncologists who prescribed enzalutamide and/or abiraterone from 2013 to 2019. Each physician was assigned to one of 2 groups: enzalutamide prescriber (physicians that wrote more 30-day prescriptions for enzalutamide than abiraterone) or abiraterone prescriber (opposite). We ran a generalized linear regression to determine factors influencing prescribing preference.Results:In 2019, 4,664 physicians met our inclusion criteria: 23.4% (1,090/4,664) urologists and 76.6% (3,574/4,664) medical oncologists. Urologists were more likely to be enzalutamide prescribers (OR 4.91, CI 4.22-5.74, P < .001) and this held in all regions. Urologists with greater than 60 prescriptions of either drug were not shown to be enzalutamide prescribers (OR 1.18, CI 0.83-1.66, P = .349); 37.9% (5,702/15,062) of abiraterone fills by urologists were for generic compared to 62.5% (57,949/92,741) of abiraterone fills by medical oncologists.Conclusions:There are dramatic prescribing differences between urologists and medical oncologists. A greater understanding of these differences is a health care imperative.