Serum testosterone level as a predictor of biochemical failure after radical prostatectomy for localized prostate...

• To investigate serum testosterone levels as a predictor for biochemical failure (BF) after radical retropubic prostatectomy (RRP).

• Prospective cohort study with 227 patients and a median follow-up of 7.7 years. • Total serum testosterone was measured at diagnosis. • Primary endpoint: 5-year BF-free survival defined as first PSA > 0.2 ng/mL. • Testosterone was tested as a predictor of BF as a dichotomized and continuous variable.

• Median (range) age was 62 years (45-74), median PSA 9.9 ng/mL (0.4-96), and median testosterone was 14 nmol/L (2.2-40). • BF occurred for 57 patients (26%) within 5 years. • In multivariate analysis with age, PSA, and biopsy Gleason score, testosterone levels >11 nmol/L were an independent predictor for reduced risk of BF (hazard ratio, 0.53; 95% confidence interval, 0.31-0.90; P= 0.02). • When analyzed as a continuous variable, testosterone was not a statistically significant predictor of BF.

• Low pretreatment serum testosterone levels correlate with a higher risk of BF, and testosterone may possess biological information about prostate cancer progression potential, which makes it an independent predictor of biochemical failure after RRP.