The Effect of Treatment Sequence on Overall Survival for Men With Metastatic Castration-resistant Prostate Cancer: A Multicenter Retrospective Study.

Introduction: We aimed to evaluate the treatment sequence for patients with metastatic castration-resistant prostate cancer (mCRPC) in real-world practice and compare overall survival in each sequential therapy.

Patients And Methods: We retrospectively evaluated 146 patients with mCRPC who were initially treated with androgen deprivation therapy as metastatic hormone-naive prostate cancer in 14 hospitals between January 2010 and March 2019. The agents for the sequential therapy included new androgen receptor-targeted agents (ART: abiraterone acetate or enzalutamide), docetaxel, and/or cabazitaxel. We evaluated the treatment sequence for mCRPC and the effect of sequence patterns on overall survival.

Results: The median age was 71 years. A total of 35 patients received ART-ART, 33 received ART-docetaxel, 68 received docetaxel-ART, and 10 received docetaxel-cabazitaxel sequences. The most prescribed treatment sequence was docetaxel-ART (47%), followed by ART-ART (24%). Overall survival calculated from the initial diagnosis reached 83, 57, 79, and 37 months in the ART-ART, ART-docetaxel, docetaxel-ART, and docetaxel-cabazitaxel, respectively. Multivariate Cox regression analyses showed no significant difference in overall survival between the first-line ART (n = 68) and first-line docetaxel (n = 78) therapies (hazard ratio [HR], 0.84; P = .530), between the ART-ART (n = 35) and docetaxel-mixed (n = 111) sequences (HR, 0.82; P = .650), and between the first-line abiraterone (n = 32) and first-line enzalutamide (n = 36) sequences (HR, 1.58; P = .384).

Conclusion: The most prescribed treatment sequence was docetaxel followed by ART. No significant difference was observed in overall survival among the treatment sequences in real-world practice.