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.