Persistence and adherence to androgen deprivation therapy in men with prostate cancer: an administrative database study

Background The aim of this study was to assess adherence to and persistence with androgen deprivation therapy (ADT) in a large cohort of prostate cancer (PCa) patients selected from an administrative database, with special attention to elderly patients. Methods Patients treated with LHRH analogues, LHRH antagonists, the novel androgen antagonist enzalutamide, and the CYP17 inhibitor abiraterone were included spanning the years 2011-2017. Descriptive statistics were used to analyze persistence and adherence in older patients stratified by age (46-55, 56-65, 66-75, 76-85, and >85 years). The effect of persistence duration on overall survival in super-elderly patients was analyzed by the Kaplan-Meier method, together with the influence of multiple prescriptions on overall survival. Results A total of 1160 male patients were treated with ADT. Of these, 1075 were given LHRH analogues, 80 LHRH antagonists, 14 novel androgen antagonists, and 109 the CYP17 inhibitor. Median adherence values were 0.93, 0.97, 0.95, and 0.99 respectively. The highest persistence was recorded for LHRH analogues/antagonists (24 months), followed enzalutamide and abiraterone (8 months). A total of 107 patients (9.2%) were classified as super-elderly (age range 85-97 years). Median persistence and OS in this group were 13 months and 29 months, respectively. The adherence was 0.92. Overall survival was significantly associated with additional prescriptions for other conditions-indications (P=0.0047) but not with differences in adherence rates (P=0.98). Conclusions Our data showed high adherence and persistence rates in men on ADT. The overall survival in the super-elderly is not influenced by persistence and/or adherence but rather by coprescriptions.