Low free testosterone levels predict disease reclassification in men with prostate cancer undergoing active surveillance
Article first published online: 4 MAY 2014
© 2014 The Authors. BJU International © 2014 BJU International
Volume 114, Issue 2, pages 229–235, August 2014
How to Cite
San Francisco, I. F., Rojas, P. A., DeWolf, W. C. and Morgentaler, A. (2014), Low free testosterone levels predict disease reclassification in men with prostate cancer undergoing active surveillance. BJU International, 114: 229–235. doi: 10.1111/bju.12682
- Issue published online: 28 JUL 2014
- Article first published online: 4 MAY 2014
- Accepted manuscript online: 21 FEB 2014 09:14PM EST
- active surveillance;
- prostate cancer;
To determine whether total testosterone and free testosterone levels predict disease reclassification in a cohort of men with prostate cancer (PCa) on active surveillance (AS).
Patients and Methods
Total testosterone and free testosterone concentrations were determined at the time the men began the AS protocol. Statistical analysis was performed using Student's t-test and a chi-squared test to compare groups. Odds ratios (ORs) with 95% confidence intervals (CIs) were obtained using univariate logistic regression. Receiver–operator characteristic curves were generated to determine the investigated testosterone thresholds. Kaplan–Meier curves were used to estimate time to disease reclassification. A Cox proportional hazard regression model was used for multivariate analysis.
A total of 154 men were included in the AS cohort, of whom 54 (35%) progressed to active treatment. Men who had disease reclassification had significantly lower free testosterone levels than those who were not reclassified (0.75 vs 1.02 ng/dL, P = 0.03). Men with free testosterone levels <0.45 ng/dL had a higher rate of disease reclassification than patients with free testosterone levels ≥0.45 (P = 0.032). Free testosterone levels <0.45 ng/dL were associated with a several-fold increase in the risk of disease reclassification (OR 4.3, 95% CI 1.25–14.73). Multivariate analysis showed that free testosterone and family history of PCa were independent predictors of disease reclassification.
Free testosterone levels were lower in men with PCa who had reclassification during AS. Men with moderately severe reductions in free testosterone level are at increased risk of disease reclassification.