A retrospective feasibility study of biweekly, reduced-dose docetaxel in Asian patients with castrate-resistant, metastatic prostate cancer

Background: The aim of this retrospective study was to evaluate the clinical outcomes of reduced dose, biweekly docetaxel chemotherapy for Korean patients with castrate-resistant prostate cancer (CRPC). Methods: We retrospectively reviewed the medical records of 48 patients with metastatic CRPC who were treated with a biweekly regimen (intravenous docetaxel 40 mg/m(2) on day 1 plus prednisolone 5 mg twice daily) between 2012 and 2015 at Samsung Medical Center (Seoul, Korea). Prior to the adoption of a biweekly regimen in Oct 2013, our institutional standard chemotherapy was docetaxel 75 mg/m(2) every 3 weeks for patients with CRPC (n = 24). After Oct 2013, all chemotherapy-naive patients with CRPC received a 40 mg/m(2) biweekly regimen (n = 24). The primary end point was a PSA response, defined as a greater than 50% decline in PSA level from baseline. Results: The baseline characteristics of the patients in the two treatment groups were similar. The most common cause of treatment discontinuation was disease progression, which was exhibited by 17 patients (71%) in the 3-weekly group and 20 (75%) in the biweekly group. PSA responses were observed in 12 (50%) and 11 (46%) patients in the 3-weekly and biweekly groups, respectively (p = 0.683). Time to treatment failure (TTTF, 4.5 vs 3.9 months) and time-to-progression (TTP, 5.0 vs 4.2 months) were not significantly different between the 3-weekly and biweekly groups. Conclusions: Within the limitations of a retrospective study, the biweekly reduced dose docetaxel regimen was active and well-tolerated in Korean patients with metastatic CRPC.