As reported in JAMA Oncology by Mark K. Buyyounouski, MD, MS, and colleagues, the phase III NRG-GU003 trial showed noninferiority of hypofractionated postprostatectomy radiotherapy (HYPORT) vs conventionally fractionated postprostatectomy radiotherapy (COPORT) for genitourinary (GU) and gastrointestinal (GI) symptoms at 2 years postsurgery in patients with prostate cancer.
Mark K. Buyyounouski, MD, MS
Study Details
In the trial, 296 patients with prostate-specific antigen (PSA) levels ≥ 0.1 ng/mL postprostatectomy with pT2/3pNX/0 disease or PSA levels < 0.1 ng/mL with either pT3 disease or pT2 disease with a positive surgical margin were enrolled at sites in the United States and Canada. Patients were randomly assigned between June 2017 and July 2018 to receive HYPORT at 62.5 Gy in 25 fractions (n = 144) or COPORT at 66.6 Gy in 37 fractions (n =152). The primary endpoints of the study were 2-year changes in score from baseline for GI and GU domains of the Expanded Prostate Cancer Composite Index questionnaire.
Key Findings
At 2 years, differences in mean changes in GU and GI scores for HYPORT were noninferior to those for COPORT, using noninferiority margins of differences of −5 and −6, respectively. Mean (standard deviation [SD]) changes in GU scores were −5.01 (15.10) for HYPORT and –4.07 (14.67) for COPORT (P = .005); mean (SD) changes in GI scores were −4.17 (10.97) for HYPORT and −1.41 (8.32) for COPORT (P = .02).
At the end of radiotherapy, mean GU change scores did not differ between the HYPORT group and the COPORT group, and no significant differences were observed at 6 or 12 months. At the end of radiotherapy, mean GI change scores showed statistically and clinically poorer results for the HYPORT group vs the COPORT group (−15.52 [18.43] vs −7.06 [12.78], P < .001). No significant differences were observed at 6 or 12 months.
At 2 years, there was no significant difference between the HYPORT group and the COPORT group in terms of biochemical failure, defined as PSA levels ≥ 0.4 ng/mL and rising (12% vs 8%, P = .28).
The investigators concluded: “In this randomized clinical trial, HYPORT was associated with greater patient-reported GI toxic effects compared with COPORT at the completion of radiotherapy, but both groups recovered to baseline levels within 6 months. At 2 years, HYPORT was noninferior to COPORT in terms of patient-reported GU or GI toxic effects. HYPORT is a new acceptable practice standard for patients receiving postprostatectomy radiotherapy.”
Dr. Buyyounouski, of the Department of Radiation Oncology, Stanford University School of Medicine, is the corresponding author of the JAMA Oncology article.
Disclosure: The study was supported by grants from NRG Oncology Operations and the National Cancer Institute. For full disclosures of the study authors, visit jamanetwork.com.
