To investigate the prevalence and cause of early discontinuation (DC) of androgen receptor inhibitor(ARi) in advanced prostate cancer (PCa) patients. Additionally, to study the effect of changing ARi versus dose reduction on duration of treatment (DOT).
A retrospective cohort study of 333 patients with advanced PCa who started ARi between 2016 and 2020 was performed. ARi medication, treatment duration, reason for DC, stage of PCa, PSA, Gleason score, and prior PCa treatments were collected. The cohort was divided into 2 subgroups, patients that stayed on one medication (Group A) vs patients who changed ARi medication (Group B). Student's t-test, Chi-square test, and Kaplan-Meier survival analysis were performed.
At one year 28.8% of patient's had discontinued ARi. Reasons for DC were side effects (34.4%), death (34.4%), and cancer progression (18.8%). DOT was 13 months for enzalutamide, 13.7 months for abiraterone, 7.6 months for darolutamide, and 12.1 months for apalutamide. Average DOT for patients with a dose change was 13.4 months, similar to those without dose change at 13.9 months (p=0.630). DOT was 12.7 months in group A versus 19.8 months in group B (p = 0.001).
In our study population discontinuation of ARi is higher than reported in the published trials. Providing patients with an alternative ARi is associated with an increase in DOT while dose reduction is not. It is important for clinicians to understand the causes of early discontinuation to develop strategies to maximize duration of therapy for management of advanced PCa patients.
Urology. 2023 Jan 02 [Epub ahead of print]
David Gangwish, Bernadette M M Zwaans, Paul Miriani, Wesley Dejoie, Andrina Ajo, Connor Ervin, Jeff Sarazin, Jason Hafron
Department of Urology, Beaumont Health System, 3601 W 13 Mile Rd, Royal Oak, MI 48073. Electronic address: ., Department of Urology, Beaumont Health System, 3601 W 13 Mile Rd, Royal Oak, MI 48073; Oakland University William Beaumont School of Medicine, 586 Pioneer Dr, Rochester, MI 48309., Michigan Institute of Urology, 130 Town Center Drive, Suite 101, Troy, Michigan 48084., Department of Urology, Beaumont Health System, 3601 W 13 Mile Rd, Royal Oak, MI 48073; Oakland University William Beaumont School of Medicine, 586 Pioneer Dr, Rochester, MI 48309; Michigan Institute of Urology, 130 Town Center Drive, Suite 101, Troy, Michigan 48084.