In a Children’s Oncology Group (COG) study reported in the Journal of Clinical Oncology, Kahn et al found that event-free survival in pediatric and adolescent patients with Hodgkin lymphoma was similar by race and ethnicity in COG trials, but that adjusted overall survival was better in white patients, reflecting increased postrelapse mortality in nonwhite patients.
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The study was a pooled analysis using individual-level data from 1,605 patients aged > 1 to 21 years old enrolled in phase III trials for low-, intermediate-, and high-risk Hodgkin lymphoma from 2002 to 2012. Event-free survival and overall survival were compared between non-Hispanic white and nonwhite patients. Cox proportional hazards for survival were estimated for de novo and relapsed Hodgkin lymphoma, with adjustment for demographics, disease characteristics, and therapy.
Event-Free, Overall, and Postrelapse Survival
At median follow-up of 6.9 years, the cumulative incidence of relapse was 17%. Unadjusted 5-year event-free survival and overall survival rates were 83% and 97% among all patients.
No significant difference in 5-year event-free survival was observed for white patients vs nonwhite patients in unadjusted analysis (82% vs 84%, P = .62) or adjusted analysis (hazard ratio [HR] = 0.92, P = .60). No significant difference in 5-year overall survival was observed for white patients vs nonwhite patients in unadjusted analysis (98% vs 96%, P = .06). However, in multivariate analysis, nonwhite patients had significantly increased risk of mortality (HR = 1.88, P = .031).
Among patients with relapse, 5-year post-relapse survival probabilities were 90% in non-Hispanic white patients, 66% in non-Hispanic black patients, and 80% in Hispanic patients (overall P < .01). Compared with non-Hispanic white children, Hispanic and non-Hispanic black children had 2.7-fold (95% confidence interval = 1.2–6.2) and 3.5-fold (95% CI = 1.5–8.2) higher hazard of postrelapse mortality, respectively.
The investigators concluded: “In patients who were treated for de novo [Hodgkin lymphoma] in contemporary Children’s Oncology Group trials, [event-free survival] did not differ by race/ethnicity; however, adjusted [overall survival] was significantly worse in nonwhite patients, a finding driven by increased postrelapse mortality in this population. Additional studies examining treatment and survival disparities after relapse are warranted.”
Justine M. Kahn, MD, of the Department of Pediatrics, Columbia University Irving Medical Center, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by National Cancer Institute grants, St Baldrick’s Foundation, Lymphoma Research Foundation, and others. For full disclosures of the study authors, visit jco.ascopubs.org.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.