Efficacy and Adverse Events of Docetaxel for Metastatic, Hormone-sensitive Prostate Cancer Among Elderly Men: A Post Hoc Analysis of the CHAARTED Trial

Background: Combination therapy with docetaxel and androgen deprivation therapy (ADT) prolongs overall survival (OS) in men with metastatic hormone-sensitive prostate cancer. We assessed the benefits and adverse effects of docetaxel and ADT in relation to advancing age.

Methods: We performed a post hoc analysis of the CHAARTED trial comparing docetaxel and ADT vs. ADT alone (n = 773). Patients were stratified in age groups <60, 60-70, and >70 years old. Multivariable-adjusted progression-free survival (PFS) and OS were assessed using Kaplan-Meier curves and compared using multivariable Cox regressions with calculated interaction terms between age group and treatment arm. In the combination arm, the incidence of ≥1 adverse event (grade ≥3) and the number of adverse events per patient were compared for each age group using multivariable logistic and linear regressions, respectively.

Results: After adjusting for clinical variables, docetaxel's effect did not vary by age group for PFS and OS. There was no significant difference in the odds ratio of ≥1 adverse event (P > .1 for age groups 60-70 and >70 years old compared with <60 years old). However, men age >70 years old experienced +0.37 more adverse events per patient compared with men age <60 years old (95% CI, 0.11-0.64; P = .006).

Conclusions: PFS and OS were similar across age groups for the combination of docetaxel and ADT compared with ADT. Older men experienced a modest increase in adverse events per patient, highlighting the importance of balancing treatment benefits and adverse effects in this age group.