Androgen deprivation therapy (ADT) should be considered a critical component of treatment for men with intermediate- and high-risk prostate cancer regardless of radiotherapy delivery method, according to new research.
Prior research has shown that the addition of ADT or a brachytherapy boost to external beam radiotherapy (EBRT) have been beneficial for men with localized prostate cancer. However, practice patterns indicate that men who receive a brachytherapy boost are significantly less likely to receive ADT.
William C Jackson, MD, department of radiation oncology, University of Michigan, and colleagues performed a network meta-analysis to compare the predicted outcomes of a randomized trial of EBRT plus ADT vs EBRT plus a brachytherapy boost. Researchers identified six randomized trial comparing EBRT with or without ADT (number of patients = 4663) and three randomized trials comparing EBRT with or without ADT and with or without a brachytherapy boost (number of patients = 718). All studies reported on overall survival (OS).
Standard fixed-effects meta-analyses were performed for each comparison, and a meta-regression was conducted to adjust for use and duration of ADT, researchers noted. Results of the study were published in the Journal of Clinical Oncology (online May 12, 2020; doi:10.1200/JCO.19.03217).
Dr Jackson and colleagues found that the addition of ADT to EBRT improved OS (hazard ratio, 0.71; 95% CI, 0.62-0.81), whereas the addition of a brachytherapy boost did not significantly improve OS (hazard ratio, 1.03; 95% CI, 0.78-1.36).
Similarly, network meta-analysis showed that EBRT plus ADT had improved OS compared with EBRT plus a brachytherapy boost (hazard ratio, 0.68; 95% CI, 0.52-0.89).
Furthermore, Bayesian modeling demonstrated an 88% probability that EBRT plus ADT results in superior OS compared with EBRT plus a brachytherapy boost.
“Our findings suggest that current practice patterns of omitting ADT with EBRT plus brachytherapy may result in inferior OS compared with EBRT plus ADT in men with intermediate- and high-risk prostate cancer,” authors of the study concluded. “ADT for these men should remain a critical component of treatment regardless of radiotherapy delivery method until randomized evidence demonstrates otherwise.”—Zachary Bessette
