EFFECT OF COMBINED TRANSIENT ANDROGEN DEPRIVATION AND IRRADIATION FOLLOWING RADICAL PROSTATECTOMY FOR PROSTATIC-CANCER

Purpose: To evaluate whether transient androgen deprivation improves o utcome in patients irradiated after radical prostatectomy for locally advanced disease, persistent or rising postoperative prostate specific antigen (PSA), or local recurrence, Methods and Materials: Records of 105 consecutive patients who were treated with pelvic irradiation aft er radical retropubic prostatectomy between August 1985 and December 1 995 were reviewed. Seventy-four patients received radiation alone (mea n follow up: 4.6 years), and 31 received transient androgen blockade w ith a gonadotropin-releasing hormone agonist (4) androgen receptor blo cker (1) or both (24) beginning 2 months prior to irradiation (mean fo llow-up 3.0 years) for a mean duration of 6 months. Two of these patie nts were excluded from further analysis because they received hormonal therapy for more than 1 year. Patients received a prostatic fossa dos e of 60-70 Gy at 2 Gy per fraction; 48 patients also received pelvic n odal irradiation to a median dose of 50 Gy. Survival, freedom from cli nical relapse (FFCR), and freedom from biochemical relapse (FFBR) were evaluated by the Kaplan-Meier method. Biochemical relapse was defined as two consecutive PSA measurements exceeding 0.07 ng/ml. Results: At 5 years after irradiation, actuarial survival for all patients was 92 %, FFCR was 77%, and FFBR was 34%. FFBR was significantly better among patients who received transient androgen blockade before and during r adiotherapy than among those treated with radiation alone (56 vs. 27% at 5 years, p = 0.004). FFCR was also superior for the combined treatm ent group (100 vs. 70% at 5 Sears, p = 0.014). Potential clinical prog nostic factors before irradiation did not differ significantly between treatment groups, including tumor stage, summed Gleason histologic sc ore, lymph node status, indication for treatment, and PSA levels befor e surgery or subsequent treatment, Multivariate analysis revealed that transient androgen deprivation was the only significant predictor for biochemical failure. Conclusion: This retrospective study of irradiat ion after radical prostatectomy suggests that transient androgen block ade and irradiation may improve freedom from early biochemical and cli nically evident relapse compared to radiotherapy atone, although more prolonged follow-up will be needed to assess durability of impact upon clinical recurrence and survival rates. (C) 1998 Elsevier Science Inc .