Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.NRG Oncology RTOG 0415 is a randomized phase III noninferiority (NI) clinical trial comparing conventional fractionation (73.8 Gy in 41 fractions) radiotherapy (C-RT) with hypofractionation (H-RT; 70 Gy in 28) in patients with low-risk prostate cancer. The study included 1,092 protocol-eligible patients initially reported in 2016 with a median follow-up of 5.8 years. Updated results with median follow-up of 12.8 years are now presented. The estimated 12-year disease-free survival (DFS) is 56.1% (95% CI, 51.5 to 60.5) for C-RT and 61.8% (95% CI, 57.2 to 66.0) for H-RT. The DFS hazard ratio (H-RT/C-RT) is 0.85 (95% CI, 0.71 to 1.03), confirming NI (P < .001). Twelve-year cumulative incidence of biochemical failure (BF) was 17.0% (95% CI, 13.8 to 20.5) for C-RT and 9.9% (95% CI, 7.5 to 12.6) for H-RT. The HR (H-RT/C-RT) comparing biochemical recurrence between the two arms was 0.55 (95% CI, 0.39 to 0.78). Late grade ≥3 GI adverse event (AE) incidence is 3.2% (C-RT) versus 4.4% (H-RT), with relative risk (RR) for H-RT versus C-RT 1.39 (95% CI, 0.75 to 2.55). Late grade ≥3 genitourinary (GU) AE incidence is 3.4% (C-RT) versus 4.2% (H-RT), RR 1.26 (95% CI, 0.69 to 2.30). Long-term DFS is noninferior with H-RT compared with C-RT. BF is less with H-RT. No significant differences in late grade ≥3 GI/GU AEs were observed between assignments (ClinicalTrials.gov identifier: NCT00331773).
Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2024 May 17 [Epub ahead of print]
W Robert Lee, James J Dignam, Mahul B Amin, Deborah W Bruner, Daniel Low, Gregory P Swanson, Amit B Shah, David D'Souza, Jeff M Michalski, Ian S Dayes, Samantha A Seaward, William A Hall, Paul L Nguyen, Thomas M Pisansky, Sergio L Faria, Yuhchyau Chen, Joseph P Rodgers, Howard M Sandler
Duke University Medical Center, Durham, NC., Department of Public Health Sciences, University of Chicago, Chicago, IL., Cedars-Sinai Medical Center, Los Angeles, CA., Emory University, Atlanta, GA., University of California, Los Angeles, Los Angeles, CA., Baylor Scott & White Healthcare Temple Clinic, Temple, TX., York Cancer Center, York, PA., London Regional Cancer Program, London, ON, Canada., Washington University School of Medicine, St Louis, MO., McMaster University, Hamilton, ON, Canada., Kaiser Permanente Northern California, Santa Clara, CA., Medical College of Wisconsin, Milwaukee, WI., Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, MA., Mayo Clinic, Rochester, MN., McGill University Health Center, Montreal, QC, Canada., University of Rochester Medical Center, Wilmot Cancer Institute, Rochester, NY., NRG Oncology Statistics and Data Management Center, Philadelphia, PA.