Treatment selection for men with metastatic prostate cancer who progress on upfront chemo-hormonal therapy

Androgen deprivation therapy plus docetaxel (D-ADT) increases overall survival (OS) in men with high-volume, metastatic hormone-sensitive prostate cancer (mHSPC). Although the vast majority of men initially respond to D-ADT, most will progress and develop castration-resistant prostate cancer (CRPC). Little is known about the optimal treatment sequence for men with progressive disease on D-ADT.

Retrospective analysis of consecutive mHSPC patients treated with ≥3 cycles of D-ADT at Cleveland Clinic and University of Wisconsin-Madison was undertaken. The primary end-points included radiographic progression free survival (rPFS) and OS with first-line treatment for metastatic CRPC (mCRPC).

Final analysis included 136 patients, median age 65 (range 35-86), 77% GS ≥ 8, and 79% with high-volume disease who received ≥3 cycles of docetaxel. Undetectable PSA values at 12 and 24 months were observed in 32% and 25% of patients, respectively. Median time to CRPC (biochemical, clinical, or radiographic) was 19.6 months (16.6-22.6). Sixty patients (44%) received ≥1 treatment for CRPC: 48 patients (80%) received a second-generation hormonal therapy (sHT). Among these, 22 received abiraterone acetate, 20 enzalutamide, and six a novel CYP-17 inhibitor on trial (ASN-001). Five patients (8%) received sipuleucel-T; four (7%) radium-223, five (8%) chemotherapy (two carboplatin-based, two single agent cabazitaxel, one single agent docetaxel) and three other. Patients receiving sHT as the first treatment for mCRPC had a median rPFS of 9.0 months (95%CI, 6.9-11.2) compared with 3.0 months (95%CI, 1.5-4.5) for patients who received a non-sHT (P = 0.024). The choice of first therapy for mCRPC was independent of GS (P = 0.909), visceral disease (P = 0.690) and time to CRPC (P = 0.844). Longer OS correlated with time to CRPC (P = 0.010) and first treatment for CRPC with sHT (P = 0.005).

For patients with progressive disease on D-ADT, subsequent treatment with a sHT is associated with a longer rPFS and OS.

The Prostate. 2018 Jun 07 [Epub ahead of print]

Pedro Barata, Hamid Emamekhoo, Prateek Mendiratta, Vadim Koshkin, Allison Tyler, Moshe Ornstein, Brian I Rini, Timothy Gilligan, Christos Kyriakopoulos, Jorge A Gracia

Department of Hematology and Medical Oncology, Taussig Cancer Institute Cleveland Clinic, Cleveland, Ohio., Department of Medicine, Division of Hematology and Oncology Carbone Cancer Center, University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin.