The authors report a population-based retrospective review of patients with mCSPC who received DOC from 04/2015 to 02/2017. Safety and clinical-effectiveness were evaluated.
A total of 183 records were identified; 156 patients received DOC in the mCSPC setting. Baseline characteristics included a median age of 67 years (range 44-86) and visceral metastases (mets) were present in 18%. 80% had high volume disease with 74% having > 3, and 54% > 10 bone mets; 76% had de-novo metastatic disease. All 6 planned DOC cycles were delivered to 126 patients (81%). Treatment was stopped early due to toxicity in 15 (10%), unrelated death in 1 (0.6%), patient preference in 5 (3%) or disease progression in 9 (6%) cases. Dose reductions and delays were required in 61 (39%) and 25 (16%) patients, respectively. Grade 3-5 adverse events were noted in 62 (40%) patients, with 28 (18%) due to febrile neutropenia (FN); there were no treatment-related deaths. Patients with FN had more bone mets (p = 0.046), but there was no difference in time from start of ADT to initiation of docetaxel, age, baseline performance status, PSA, or visceral involvement. PSA ≤ 0.2 ng/L was achieved in 41 (28%) patients after 6 months of ADT and maintained in 13 (8%) patients after 12 months. 41% of patients had developed castrate resistant prostate cancer (CRPC) within 1-yr, with a median time to CRPC of 14.3 months. Treatment for CRPC was given in 54 patients, with most of them receiving either abiraterone or enzalutamide (87%) with a PSA decline of over 50%.
The authors concluded that effectiveness of DOC with ADT in a general population of patients with mCSPC was associated with poorer outcomes and high rates of toxicity compared to the results reported in phase III studies. Response rates to first-line treatment for mCRPC with abiraterone or enzalutamide appear similar to those previously reported.
Presented by: Jean-Michel Lavoie, MD, Vancouver, Canada
Co Authors: Kevin Zou, Daniel Khalaf, Bernhard J. Eigl, Christian K. Kollmannsberger, Joanna Vergidis, Krista Noonan, Muhammad Zulfiqar, Daygen L. Finch, Kim N. Chi; British Columbia Cancer Agency - Vancouver Centre, Vancouver, BC, Canada; British Columbia Cancer Agency, Vancouver, BC, Canada; British Columbia Cancer Agency - Vancouver Island Centre, Victoria, BC, Canada; British Columbia Cancer Agency - Fraser Valley Centre, Surrey, BC, Canada; British Columbia Cancer Agency - Abbotsford Centre, Abbotsford, BC, Canada; British Columbia Cancer Agency - Centre for the Southern Interior, Kelowna, BC, Canada; BC Cancer Agency, Vancouver, BC, Canada
Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA