Comparison of Neoadjuvant vs Concurrent/Adjuvant Androgen Deprivation in Men with High-risk Prostate Cancer Receiving Definitive Radiation Therapy

Abstract

Purpose It is unknown whether there is a benefit to starting androgen deprivation therapy (ADT) prior to rather than concurrently with definitive radiation therapy in men with high-risk prostate cancer. We studied the National Cancer Data Base to determine whether the timing of ADT impacts survival. Methods Men diagnosed with high-risk prostate adenocarcinoma who received external beam radiation therapy (EBRT) to a dose of 70-81 Gy along with ADT from 2004-2011 were included. Those who started ADT 42-90 days before EBRT were identified as having received neoadjuvant hormonal therapy (N-HT) and those who received ADT from 14 days before their radiation until 84 days after the start of EBRT were categorized as receiving concurrent/adjuvant treatment (C-HT). We used the log-rank test to compare Kaplan-Meier survival curves and multivariable Cox regression to assess the impact of covariables on overall survival (OS). Results Among 11,491 included patients, those receiving N-HT were 1 year older ( p<0.001) and more likely to have Gleason 8-10 disease ( p = 0.01) and cT3-4 disease ( p = 0.002). Men receiving N-HT had a 5-year and median OS of 80.6% and 111.4 months, respectively, compared to 78.3% and 108.9 months, respectively, in those receiving C-HT ( p = 0.03). This benefit remained significant on multivariable analysis (hazard ratio 0.86, 95% confidence interval 0.77-0.96, p = 0.008). Duration of ADT was not available to report. Conclusions External beam radiation therapy with N-HT was associated with improved overall survival compared to C-HT. This study is hypothesis-generating and further studies are needed to best qualify the sequencing of hormone therapy with the duration of treatment.