局所進行性前立腺癌における根治的放射線外照射治療後の再発に対する救済ホルモン治療の臨床的検討

Abstract

Fifty-three patients with biochemical relapse (BCR) after receiving external beam radiotherapy (EBRT) against locally advanced prostate cancer (stage III : International Union Against Cancer [UICC] 6th edition) between September 1997 and January 2006 at our institution, who were treated with salvage hormonal therapy (HTx), were followed for a mean period of 75.5 months. There was progression to castrationresistant prostate cancer (CRPC) during the follow-up period in 17 patients (32.0%). The median time to CRPC after initial HTx was 17 months. Univariate analysis revealed that time to BCR after EBRT was significantly associated with progression to CRPC (p＝0.022), while PSA-doubling time just before salvage HTx was marginally associated with irradiation dose (p＝0. 088, p＝0.128 respectively). Multivariate analysis showed that time to BCR after EBRT was the only significant predictor of progression to CRPC (p＝ 0.035, Hazard ratio ; 0.252, 95% confidence interval ; 0.070-0.905) conclusion, time to BCR after EBRT might be a good predictor for the efficiency of salvage HTx after EBRT against locally advanced prostate cancer.