Circulating free testosterone is an independent predictor of advanced disease in patients with clinically localized prostate cancer.

PURPOSE

To evaluate the clinical value of the pre-treatment calculated free testosterone (fT), total testosterone (tT), sexual hormone-binding globulin (SHBG) and estradiol (E2) levels as potential predictors of pathological stage and grade in patients with clinically localized prostate cancer.

METHODS

Preoperative sex hormone serum levels were prospectively measured in 137 patients who underwent radical prostatectomy at the University Hospital Ulm from February 2011 to February 2012. We related sex hormone levels to clinicopathologic data including tumour stage, Gleason score and prostate specific antigen (PSA). (Non)parametric statistical tests and receiver operating characteristics (ROC) analyses were performed.

RESULTS

Preoperative serum fT levels were significantly associated with advanced disease (pT3-4 and/or pN+; p = 0.047) and lymph node involvement (pN+) (p = 0.027). Patients with low (<0.047 μg/l) vs. normal fT values (≥0.047 μg/l) were associated with higher tumour stage (p = 0.049), positive lymph node status (pN+ , p = 0.038) and advance disease (p = 0.016). Moreover, low tT values (≤0.193 μg/l; p = 0.018) and elevated SHBG levels (>48.4 nmol/l, p = 0.043) correlated with a higher Gleason score. Conversely, E2 levels were not associated with tumour stage or grade. Applying multivariate analysis, unlike tT, SHBG, and E2 levels, low fT levels were a significant independent predictor of advanced disease (relative hazard ratio 3.05, p = 0.028).

CONCLUSIONS

Low pre-treatment fT levels were significantly associated with tumour stage and extraprostatic tumour spread and might-in addition or combination with PSA-serve as a useful prognostic parameter for prostate cancer patients prior to radical prostatectomy.