The relationship between total and free serum testosterone and the risk of prostate cancer and tumour aggressiveness

OBJECTIVE: To analyse the relationship between the levels of total and free serum testosterone and the risk of prostate cancer and tumour aggressiveness. PATIENTS AND METHODS: Total and free serum testosterone were determined in 478 patients consecutively assessed by transrectal ultrasonography-guided prostate biopsy because of an abnormal digital rectal examination and/or serum prostate-specific antigen (PSA) level of >4.0 ng/mL. Tumour aggressiveness was assessed according to serum PSA level, biopsy Gleason score and clinical stage in the subset of 216 patients with cancer (45.2%). We also compared prostate cancer risk and tumour aggressiveness in 80 hypogonadal patients (16.7%) and 398 eugonadal patients (83.3%). RESULTS: The median total serum testosterone level in patients without and with prostate cancer was 466.0 and 466.5 ng/dL, respectively (P > 0.05); the median levels of free serum testosterone were 9.9 and 10.0 pg/mL, respectively (P > 0.05). The cancer detection rate in hypogonadal patients was 41.3% (33/80) and 46.0% in eugonadal patients (183/398) (P > 0.05). The median level of total testosterone was 433 ng/dL in patients with low-risk prostate cancer, 467 ng/dL in those with intermediate-risk tumours and 468 ng/dL in those with high-risk tumours (P > 0.05); the median levels of free testosterone were 9.4, 9.8 and 10.3 pg/mL, respectively (P > 0.05). CONCLUSIONS: Prostate cancer risk and tumour aggressiveness are not related to serum levels of total and free testosterone, but hypogonadal patients do not have a greater risk of prostate cancer and tumour aggressiveness.