Swanson, Gregory P

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 ).

Abstract Data on long-term follow-up for definitive therapy of prostate cancer are limited, especially for radiation therapy. Either surgery or radiation was used in 322 patients for treatment with curative intent, and follow-up was for a minimum of 15 years. Overall survival was nearly identical to that in an age-matched cohort. 5-, 10-, and 15-year recurrence-free survival rates were 77%, 63% and 53%, respectively. Grade and stage were significant prognostic factors for both recurrence and survival. More than 60% of the initial failures were local, and more than 25% of the failures occurred after 10 years. Radiation therapy was used in 137 patients with clinically staged disease. Radical retropubic prostatectomy and perineal prostatectomy were performed in 133 and 44 patients, respectively. In this group, pathological staging was used. Survival rates for surgically treated patients were better than those in the cohort population. In conclusion, overall long-term follow-up demonstrates that definitive treatment does not have an adverse effect on survival from prostate cancer. Local recurrence is a frequent cause of failure. Caution must be used in interpreting any prostate study with less than 10 years of follow-up, because 25% to 50% of the failures occur after that time.