Does presence of prostate cancer affect serum testosterone levels in clinically localized prostate cancer patients?

The relationships between serum level of testosterone (T) and prostate cancer (PCa) are complex. The present study evaluated whether presence of PCa alters serum T levels. Subjects were 125 patients with clinically localized PCa treated using radical prostatectomy (RP), for whom pretreatment T levels were recorded. We investigated clinical and pathological factors such as pretreatment serum T level, age, pretreatment prostate-specific antigen, Gleason score and pathological stage. Serum T and human luteinizing hormone (LH) levels before and after RP were then compared in 118 of the 125 patients. Mean pretreatment T level was significantly higher in patients with organ-confined PCa (pT2; 4.03+/-1.50 ng ml(-1)) than in patients with nonorgan-confined cancer (pT3; 3.42+/-1.06 ng ml(-1); P=0.0438). No association existed between pretreatment serum T level and pathological Gleason score. After RP, serum T level (5.60+/-1.90 ng ml(-1)) was significantly elevated compared to preoperative level (3.89+/-1.43 ng ml(-1); P<0.0001). In parallel, significant increases were seen in postoperative serum LH level (6.86+/-3.64 ng ml(-1)) compared to preoperative level (5.11+/-2.47 ng ml(-1); P=0.0001). In contrast, differences in serum T levels according to pathological stage disappeared postoperatively (P=0.5513). Significant increases in serum T and LH levels were seen after RP, compared to preoperative levels in parallel. This study suggests that serum T levels are altered by the presence of PCa, supporting the possibility that PCa may inhibit serum T levels with negative feedback in the hypothalamic-pituitary axis.