2-weekly versus 3-weekly docetaxel for metastatic castration-resistant prostate cancer: complete quality of life results from the randomised, phase-III PROSTY trial

Introduction: Treatment with 2-weekly docetaxel 50 mg/m² was shown to improve overall survival and was better tolerated than the standard 75 mg/m² 3-weekly regimen in men with metastatic castration-resistant prostate cancer (mCRPC) in the original randomised PROSTY trial. The aim of this study was to investigate, whether quality of life (QoL) effects would differ between the 2-weekly docetaxel 50 mg/m² regimen from the standard 3-weekly 75 mg/m² treatment. Materials and Methods: QoL data were collected with the Functional Assessment of Cancer Therapy–Prostate (FACT-P) and Functional Assessment of Cancer Therapy Advanced Prostate Symptom Index − 8 Item version (FAPSI-8). Pain was measured using the Visual Analogue Scale (VAS). A total of 743 forms from 163 patients were analysed in Arm A (2-weekly docetaxel), and 704 forms from 173 patients were analysed in Arm B (3-weekly docetaxel). The data were analysed using both the Wilcoxon signed rank test (with Holm–Bonferroni adjustment) and Mann–Whitney U models. Results: No major differences were found in total QoL. Total QoL was higher at month 8 in Arm B (p =.020), but this was reversed in the following month (p =.043), and no statistically significant differences were found during other months. Compared to Arm A, participants in Arm B had longer-lasting deterioration in FAPSI-8 scores and emotional well-being subdomain at the beginning of treatment (p <.05). Various one-month differences were found in FACT-P subdomains (except for functional well-being), and these favoured participants in Arm A, except for the prostate-cancer subdomain. There were no differences in pain. Conclusion: Based on our results, 2-weekly docetaxel was not inferior to 3-weekly docetaxel in terms of total health-related QoL and seemed to be superior at least in terms of the FAPSI-8 and emotional well-being subdomain in the first three to four months of treatment. More research on the topic is suggested to confirm the results.