Early salvage hormonal therapy for biochemical failure improved survival in prostate cancer patients after neoadjuvant hormonal therapy plus radiation therapy--a secondary analysis of irish clinical oncology research group 97-01.

ABSTRACT

PURPOSE: To assess the survival benefit of early vs late salvage hormonal therapy (HT), we performed a secondary analysis on patients who developed recurrence from Irish Clinical Oncology Research Group 97-01, a randomized trial comparing 4 vs 8 months neoadjuvant HT plus radiation therapy (RT) in intermediate- and high-risk prostate adenocarcinoma. METHODS AND MATERIALS A total of 102 patients from the trial who recurred were analyzed at a median follow-up of 8.5 years. The patients were divided into 3 groups based on the timing of salvage HT 57 patients had prostate-specific antigen (PSA)≤10 ng/mL and absent distant metastases (group 1, early), 21 patients had PSA>10 ng/mL and absent distant metastases (group 2, late), and 24 patients had distant metastases (group 3, late). The endpoint analyzed was overall survival (OS) calculated from 2 different time points date of enrolment in the trial (OS1) and date of initiation of salvage HT (OS2). Survival was estimated using Kaplan-Meier curves and a Cox regression model. RESULTS: The OS1 differed significantly between groups (P<.0005) OS1 at 10 years was 78% in group 1, 42% in group 2, and 29% in group 3. The OS2 also differed significantly between groups (P<.0005) OS2 at 6 years was 70% in group 1, 47% in group 2, and 22% in group 3. Group 1 had the longest median time from end of RT to biochemical failure compared with groups 2 and 3 (3.3, 0.9, and 1.7 years, respectively; P<.0005). Group 1 also had the longest median PSA doubling time compared with groups 2 and 3 (9.9, 3.6, and 2.4 months, respectively; P<.0005). On multivariate analysis, timing of salvage HT, time from end of RT to biochemical failure, and PSA nadir on salvage HT were significant predictors of survival. CONCLUSION: Early salvage HT based on PSA≤10 ng/mL and absent distant metastases improved survival in patients with prostate cancer after failure of initial treatment with neoadjuvant HT plus RT.