Progression free survival in patients with castrate resistant metastatic prostate cancer: Does sequence matter?

Abstract

356 Background: Approval of multiple therapeutic agents for castrate resistant prostate cancer (CPRPC) has improved survival and also quality of life. However, how to optimize sequencing is still an ongoing challenge for most clinicians. Methods: A retrospective chart review of patients treated with FDA approved regimens for castrate resistant prostate cancer from 2002 to 2017 at Mayo Clinical Florida was completed. Data on progression free survival of the various treatment sequences including abiraterone, docetaxel, and enzalutamide were reviewed. Results: One hundred patients were included in the study. Those on clinical trial were excluded. All patients were on LHRH agonist /antagonist and were continued while on the subsequent treatments. The first line therapy progression free survival (PFS) was 245 days with abiraterone acetate (AA), 307 days with enzalutamide (E) and docetaxel 285 days, respectively. The second line therapy PFS was 201 days with AA and 166 days with E. When AA was given after E PFS was 97 days and when E was given after AA the PFS was 68 days. E given after docetaxel resulted in a PFS of 390 days for one patient. Conclusions: In this chart review, enzalutamide had the longest PFS when used as the first line therapy and the PFS was improved when used as a second line after docetaxel. This retrospective review suggests therapy sequencing may be optimized to increase progressive free survival in patients with metastatic castrate resistant prostate cancer.