Free testosterone value before radical prostatectomy is related to oncologic outcomes and post-operative erectile function

PURPOSE: To investigate whether free testosterone (FT) prior to radical prostatectomy was related to post-operative oncologic outcomes, erectile function and continence. METHODS: The data of 586 patients with available information underwent treatment in our center was retrospectively reviewed. Total testosterone (TT) was tested by chemiluminescence immunoassay, and FT value was calculated using Vermeulen’s formula. Post-operative continence and erectile function were evaluated by the requirement of pad and the IIEF-5 score at 12 months. RESULTS: The median TT and FT value was 344 ng/dL (interquartile, IQR 314–374) and 6.9 ng/dL (IQR 6.4–7.3), and 106 patients (18.1%) and 152 patients (25.9%) were evaluated as having low TT and low FT based on current guidelines. Low TT and FT value were both related to older age (both p < 0.001), concomitant diabetes (p = 0.018 & 0.049), higher possibility of pre-operative erectile dysfunction (ED, both p < 0.001), higher pre-operative PSA value (both p < 0.001), higher clinical stage (both p < 0.001) and higher Gleason score in biopsy (both p < 0.001). Low FT was related to higher risk for pT3 (p = 0.020) and high Gleason score (p = 0.011) in logistic regression. The median follow-up duration was 52 moths (IQR 29–67) and FT was found to be an independent risk factor for biochemical recurrence (p = 0.005). In logistic regression TT was related to pre-operative ED (p = 0.010) and FT was related to post-operative ED (p = 0.001). CONCLUSION: Low FT value before radical prostatectomy was related to adverse pathological outcomes, biochemical recurrence and post-operative ED.