Crisler, Katia M.

ABSTRACT Purpose Despite 5‐year survival rates of over 90% among children and adolescents/young adults (CAYAs) with classic Hodgkin lymphoma (cHL), 15%–20% relapse after frontline therapy. Prior analysis of frontline Children's Oncology Group (COG) clinical trials demonstrated that, despite similar rates of relapse, non‐Hispanic Black (NHB) and Hispanic (vs. non‐Hispanic White [NHW]) patients experienced higher post‐relapse mortality. It is unknown whether post‐relapse disparities persist when second‐line treatment is delivered in a cooperative group trial setting. We examined overall survival (OS) by race and ethnicity in CAYAs enrolled in COG trials for relapsed/refractory (r/r) cHL. Methods A pooled analysis of individual‐level data from CAYAs (≤ 29 years) receiving therapy for r/r cHL on COG clinical trials (2001–2016) was conducted. The Kaplan–Meier method estimated 3‐year OS by racial and ethnic groups. Cox regression models examined associations of race and ethnicity and OS, adjusted for age, insurance, first versus ≥2 relapse, and time from initial diagnosis to relapse trial enrollment. Results Among 175 CAYAs treated on COG trials for r/r cHL (5.7% Asian or Pacific Islander, 14.9% Hispanic, 14.3% NHB, 61.7% NHW, 3.4% other), at median follow‐up of 4.9 years, 3‐year OS was 82.1% (95% confidence interval [CI], 75.3%–87.1%) and did not differ by race and ethnicity ( p = 0.36). In multivariable analyses, shorter time from diagnosis to relapse trial enrollment ( p = 0.01) and ≥2 relapses (vs. first, p = 0.004) conferred worse OS, with no significant effect of race and ethnicity ( p = 0.43). Conclusion Post‐relapse survival did not differ by race and ethnicity among CAYAs enrolled in COG trials for r/r cHL, suggesting access to clinical trials may mitigate OS disparities.