[Changes in serum prostate specific antigen and testosterone levels after chlormadinone acetate treatment in patients with benign prostatic hyperplasia : a prospective multicenter clinical study].

In this prospective multicenter study, we investigated the changes in serum prostate-specific antigen (PSA) and testosterone levels after treatment with antiandrogen chlormadinone acetate (CMA) in patients with benign prostatic hyperplasia (BPH). The inclusion criteria for the patients were as follows : PSA value of C10 ng/ml, maximum urine flow rate of ＜15 ml/s, estimated prostate volume of B20 ml, International Prostate System Score (IPSS) of B8, and IPSS-quality of life (QOL) index of B2. Of the 115 patients who registered, 114 qualified for this study. The patients were treated with CMA (50 mg/day) for 16 weeks ; this was followed by a no-CMA phase of 32 weeks. When compared with the baseline PSA level, the levels at 8 and 16 weeks of treatment had decreased by 56.4% (95% confidence interval [CI], 51.1-1.2) and 57.6% (95% CI, 52.3-62.4), respectively. Similarly, when compared with the baseline testosterone level, the levels at 8 and 16 weeks of treatment had decreased by 90.1% (95% CI, 87.8-91.9) and 84.4% (95% CI, 80.7-87.4), respectively. After treatment discontinuation, the PSA levels gradually increased and returned to baseline in 32 weeks. However, the testosterone levels returned to baseline in only 8 weeks. Although patients over 80 years of age showed a gradual decrease in these levels when compared with younger patients, the changes in the levels of PSA and testosterone were not affected by age. Thus, in order to use antiandrogen agents including CMA for treating BPH, we need to determine the PSA value that converted it into double.