In an analysis of the phase III NRG Oncology/RTOG 0815 study reported in the Journal of Clinical Oncology, Benjamin Movsas, MD, and colleagues found few differences in patient-reported outcomes among patients with intermediate-risk prostate cancer receiving short-term total androgen suppression (TAS) plus dose-escalated radiotherapy vs radiotherapy alone.
The trial showed no difference in overall survival—the study’s primary endpoint—with the addition of short-term TAS to radiotherapy, but benefits in other outcomes—including rates of metastases, prostate cancer–specific mortality, and prostate-specific antigen failure—were observed.
Benjamin Movsas, MD
In the multicenter trial, 1,492 patients with stage T2b-T2c, Gleason score 7, or PSA > 10 and ≤ 20 ng/mL were randomly assigned between September 2009 and March 2016 to receive dose-escalated radiotherapy with (n = 742) or without short-term TAS (n = 750). TAS consisted of 6 months of luteinizing hormone-releasing hormone agonist/antagonist therapy plus an antiandrogen. Radiotherapy was delivered via external-beam radiotherapy alone to 79.2 Gy or external beam to 45 Gy with a brachytherapy boost.
The patient-reported outcomes analysis population consisted of 420 eligible patients who agreed to participate: 205 in the TAS plus radiotherapy group vs 215 in the radiotherapy group. The primary patient-reported outcome instrument used was the Expanded Prostate Cancer Index Composite (EPIC-50); secondary instruments included the Patient-Reported Outcome Measurement Information System (PROMIS)-fatigue and EuroQOL 5-dimensions scale questionnaire (EQ-5D). Patient-reported outcome change scores calculated as the follow-up score minus the baseline score at the end of radiotherapy and at 6, 12, and 60 months were compared between groups.
Completion rates for EPIC were ≥ 86% through the first year of follow-up and 70% to 75% at 5 years. Changes from baseline in EPIC scores for the TAS plus radiotherapy vs radiotherapy alone groups showed statistically significant (P = .0125 to adjust for multiple comparisons) poorer outcomes in the TAS plus radiotherapy group in the hormonal domain at the end of radiotherapy and at 6 and 12 months (all P < .001) and in the sexual domain at the end of radiotherapy (P < .001) and at 6 (P < .001) and 12 months (P = .0014); all differences except those at 12 months were clinically meaningful. No statistically or clinically significant differences between groups were observed for the hormonal and sexual domains at 60 months. No statistical or clinically significant differences between groups at any time point were observed in the urinary and bowel domains.
EQ-5D scores exhibited little change from baseline in either group. PROMIS-fatigue scores worsened from baseline in both groups and were statistically, but not clinically, worse in the TAS plus radiotherapy group at the end of radiotherapy; thereafter, scores were similar between groups at 6, 12, and 60 months.
The investigators concluded, “Compared with dose-escalated radiotherapy alone, adding TAS demonstrated clinically meaningful declines only in EPIC hormonal and sexual domains. However, even these patient-reported outcome differences were transient, and there were no clinically meaningful differences between arms by 1 year.”
Dr. Movsas, of Henry Ford Cancer Institute, Detroit, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by grants from the National Cancer Institute. For full disclosures of the study authors, visit ascopubs.org.
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