Survival by Race and Ethnicity in Pediatric and Adolescent Patients With Hodgkin Lymphoma: A Children's Oncology Group Study

Abstract

Purpose: Population-based studies of children and adolescents with Hodgkin lymphoma (HL) report a survival disadvantage in nonwhite-non-Hispanic black (NHB) and Hispanic-patients. Whether disparities persist after adjustment for clinical and treatment-related variables is unknown. We examined survival by race/ethnicity in children receiving risk-based, response-adapted, combined-modality therapy for HL in contemporary Children's Oncology Group trials.

Patients and methods: This pooled analysis used individual-level data from 1,605 patients (younger than age 1 to 21 years) enrolled in phase III trials for low-risk (AHOD0431), intermediate-risk (AHOD0031), and high-risk (AHOD0831) HL from 2002 to 2012. Event-free survival (EFS) and overall survival (OS) were compared between non-Hispanic white (NHW) and nonwhite patients. Cox proportional hazards for survival were estimated for both de novo and relapsed HL, adjusting for demographics, disease characteristics, and therapy.

Results: At median follow up of 6.9 years, cumulative incidence of relapse was 17%. Unadjusted 5-year EFS and OS were 83% (SE, 1.2%) and 97% (SE, < 1%), respectively. Neither differed by race/ethnicity. In multivariable analyses for OS, nonwhite patients had a 1.88× higher hazard of death (95% CI, 1.1 to 3.3). Five-year postrelapse survival probabilities by race were as follows: NHW, 90%; NHB, 66%; and Hispanic, 80% (P < .01). Compared with NHW, Hispanic and NHB children had 2.7-fold (95% CI, 1.2 to 6.2) and 3.5-fold (95% CI, 1.5 to 8.2) higher hazard of postrelapse mortality, respectively.

Conclusion: In patients who were treated for de novo HL in contemporary Children's Oncology Group trials, EFS did not differ by race/ethnicity; however, adjusted OS 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.

FIG 1.

Cohort selection. COG, Children’s Oncology Group; HL, Hodgkin lymphoma.

FIG 2.

Kaplan-Meier curves for (A) event-free survival (EFS) and (B) overall survival (OS) in non-Hispanic white (NHW) versus nonwhite (non-Hispanic black and Hispanic) patients with de novo Hodgkin lymphoma.

FIG 3.

Kaplan-Meier curves for postrelapse survival in non-Hispanic white (NHW), non-Hispanic black (NHB), and Hispanic patients. Time zero is the date of relapse.