Adjuvant docetaxel without prednisone does not decrease the likelihood of biochemical progression of disease among men who have undergone radiation therapy (RT) intermediate- or high-risk prostate cancer (PCa) and are receiving androgen deprivation therapy, according to investigators.
The finding is from a phase 3 study in which Pirkko-Liisa Kellokumpu-Lehtnen, MD, of Tampere University Hospital in Tampere, Finland, and colleagues that included 376 patients who completed RT for intermediate- or high-risk PCa. They randomly assigned 188 patients to receive 6 cycles of adjuvant docetaxel without continuous prednisone and 188 to undergo surveillance. Neoadjuvant or adjuvant andogen deprivation therapy was mandatory for all patients. Of the 188 men in the docetaxel arm, 147 (78%) completed all 6 cycles of the drug.
Results showed that 58 patients in the docetaxel arm and 57 in the surveillance arm experienced the study’s primary end point of a 2 ng/mL or greater rise in PSA above nadir values, Dr Kellokumpu-Lehtnen’s team reported in European Urology. A Kaplan-Meier analysis revealed no significant difference in biochemical disease-free survival curves. On Cox multivariate analysis, the docetaxel and surveillance groups did not differ significantly with regard to PSA progression. The 5-year estimated biochemical progression rates were 31% in the docetaxel arm and 28% in the surveillance arm, the investigators reported.
“In conclusion, based on our current results, there is no evidence that adjuvant docetaxel with ADT after RT would provide a benefit for intermediate- or high-risk PCa patients in general clinical practice,” the authors concluded.
The median of age of patients in both study arms was 67 years. The median PSA level at baseline was 14.6 and 14.0 ng/mL in the docetaxel and surveillance arms, respectively.
Kellokumpu-Lehtinen PL, Hjälm-Eriksson M, Thellenberg-Karlsson C, et al. Docetaxel versus surveillance after radical radiotherapy for intermediate- or high-risk prostate cancer—Results from the prospective, randomised, open-label phase III SPCG-13 trial [published online August 20, 2019]. Eur Urol. doi: 10.1016/j.eururo.2019.08.010