Survival outcomes of radiotherapy with or without androgen-deprivation therapy for patients with intermediate-risk prostate cancer using the National Cancer Data Base

Abstract

Purpose: Presently no reported prospective, randomized trials have clearly defined the role of androgen-deprivation therapy (ADT) for patients with intermediate-risk prostate cancer in the setting of radiation therapy (RT) dose escalation. This study׳s objective was to evaluate the survival benefit of adding ADT to high-dose RT for patients with intermediate-risk prostate cancer using the National Cancer Data Base.

Materials and methods: The National Cancer Data Base was queried for patients with intermediate-risk prostate cancer treated from 2004 to 2006, with available data for Gleason Score, prostate-specific antigen, TNM staging, and receipt of radiation and ADT. Start of RT was within 1 to 180 days of ADT; radiation included external beam alone (≥70Gy) or external beam RT plus brachytherapy boost. Overall survival was evaluated using multivariate (MVA) Cox regression and propensity score-matched (PSM) analyses.

Results: A total of 14,126 patients were included of which 7,568 (53.6%) received no ADT and 6,558 (46.4%) received ADT. Median follow-up was 85.8 months (6.0-119.9mo). Median RT dose was 75.6Gy in 42 fractions. Under MVA, the addition of ADT for patients with intermediate-risk prostate cancer had no overall survival benefit compared with RT alone (hazard ratio [HR] = 0.97, P = 0.316). PSM also confirmed no survival benefit with the addition of ADT for the entire intermediate-risk cohort (HR = 0.98, P = 0.560). On subset analysis, those with 3 intermediate-risk factors had a survival benefit with the addition of ADT on both MVA (HR = 0.69, P = 0.037) and PSM (HR = 0.61, P = 0.026). Limitations include retrospective design and incomplete data on the type of ADT and duration.

Conclusions: With the exception of men who present with all 3 intermediate-risk factors, a significant association with decreased all-cause mortality risk and ADT was not observed for patients with intermediate-risk prostate cancer.

Keywords: Androgen-deprivation therapy; Hormones; Intermediate-risk; NCDB; Prostate cancer; Radiation therapy.