前立腺肥大症に対するアンチアンドロゲン剤の投与及び中断によるPSA値の変化

Abstract

PSA値が正常の前立腺肥大症の患者にアンチアンドロゲン製剤を投与し, これを中断しても腫瘍マーカーが前値以上に正常値を大きく越えて上昇するいわゆるリバウンド現象は生じないので, 中断後にPSAが高値を示す場合は前立腺癌の除外診断が重要である

We compared the prostate specific antigen (PSA) levels in benign prostatic hyperplasia (BPH) patients with antiandrogen chlormadinone acetate (CMA) or allylestrenol (AE) before and during the treatment. We also investigated the serial change of PSA levels before, during and after discontinuation of antiandrogen therapy. Fifty-one BPH patients with normal PSA levels were treated with CMA or AE for 16 weeks. The mean serum PSA level significantly decreased after the treatment from 1.9 +/- 1.0 ng/ml to 1.1 +/- 0.7 ng/ml (M +/- SD). We discontinued medication with informed consent and the patients were carefully monitored for another 16 weeks. Nineteen patients were followed for 32 weeks. The mean serum PSA level decreased significantly from 2.0 +/- 1.0 ng/ml to 1.1 +/- 0.5 ng/ml (M +/- SD) and recovered approximately to the pretreatment level (1.7 +/- 1.1 ng/ml) at the end of this study. We found only one patient whose PSA was slightly elevated to a subnormal range (4.3 ng/ml) after discontinuation of therapy. The other BPH patients with normal PSA levels showed no excessive increase in PSA levels beyond the normal limit after discontinuation of antiandrogen therapy compared with the pretreatment baseline. In conclusion, BPH patients with a marked increase in PSA after discontinuation of antiandrogen therapy should be checked for prostate cancer.