Background: Pre-treatment androgen levels are associated with overall survival (OS) in patients with metastatic castration-resistant prostate cancer (CRPC) treated with androgen synthesis inhibitors. The current study sought to determine whether pre-treatment serum androgens predict clinical outcome among patients with metastatic CRPC treated with docetaxel chemotherapy. Materials and Methods: Data were obtained from 1050 men who were chemotherapy-naive prior to treatment with docetaxel, prednisone, and either bevacizumab or placebo (CALGB 90401). Pretreatment serum assays for testosterone, androstenedione, and dehydroepiandrosterone (DHEA) were performed with tandem liquid chromatography-mass spectrometry. Results: Median values for testosterone, androstenedione, and DHEA were 1.00, 13.50, and 8.12 ng/dL, respectively. The median was used to define the midpoint between low and high values. In univariate analysis, median OS for low versus high levels was 21.4 and 24.2 months for testosterone, 23.8 and 21.9 months for androstenedione, and 20.2 and 25.2 months for DHEA (P = NS). In multivariable analysis of all androgens, baseline DHEA was prognostic of ≥ 50% PSA decline from baseline (P =.008). In multivariable analysis adjusting for 10 known prognostic values and prior ketoconazole use for metastatic CRPC, a 10-unit increase in baseline testosterone increased risk of death (hazard ratio, 1.11; 95% confidence interval, 1.01-1.23; P =.039), whereas a 10-unit increase in androstenedione lowered risk of death (hazard ratio, 0.92; 95% confidence interval, 0.88-0.97; P =.001). Conclusion: Consistent with prior studies, higher androstenedione levels in patients with metastatic CRPC treated with docetaxel are associated with improved survival. However pretreatment levels of other androgen levels are associated with varied effects on clinical outcome in chemotherapy-treated patients.
- Castration resistant prostate cancer
- Prognostic biomarker
- Serum androgens