A retrospective feasibility study of biweekly docetaxel in patients with high-risk metastatic castration-naïve prostate cancer

Background: Results from randomized phase III trials have shown that thrice-weekly docetaxel added to androgen-deprivation therapy (ADT) has a significant impact on the survival of patients with metastatic castration-naïve prostate cancer (mCNPC) and established early chemotherapy as part of the standard of care for high-risk disease. Controversy remains, however, because some patients experience critical toxicities related to docetaxel. The purpose of the current study was to evaluate the feasibility and adverse events of biweekly-administered docetaxel in patients with previously-untreated, high-risk mCNPC. Methods: The study included 35 consecutive patients with high-risk mCNPC who received ADT plus docetaxel 40 mg/m ² . Oral prednisone 5 mg twice daily was also given. Treatment was repeated every two weeks for up to 12 cycles or until disease progression or unacceptable toxicity occurred. High-risk was defined as bone metastases beyond axial skeleton and/or visceral disease. Results: The included patients' median age was 68 years (range: 31-86 years) and 17 (49%) had visceral metastases. Biweekly docetaxel was generally well-tolerated; the most commonly observed adverse events, considering those of all grades, included alopecia (74%), nail changes (42%), and constipation (31%). Hematologic adverse events were infrequent, and no patient received hematopoietic growth factors. One patient died after the fourth cycle due to respiratory failure, which occurred as a complication of pneumonia. Among the 35 patients, 28 completed the planned 12 cycles of biweekly docetaxel. Prostate-specific antigen response (> 50% decrease from baseline) was recorded in 33 patients (94%), and the radiologic response rate was 49%. Median progression-free survival was 13.6 months (95% confidence interval: 6.7-20.4). Conclusion: ADT plus biweekly-administered docetaxel appeared to be tolerated and effective in patients with high-risk mCNPC.