Socio-economic and geographic survival disparities among children with lymphoma in the USA.

Abstract

e22005 Background: The effect of socioeconomic status (SES) and place of residence on cancer survival has been extensively studied among adults. There is, however, a lack of research examining the role of SES and geography on survival of lymphoma in pediatric oncology. Hence, this study aimed toevaluate the role of SES on survival among children diagnosed with Hodgkin and Non-Hodgkin Lymphoma in the USA, and whether these differences varied by place of residence. Methods: The study is a population-based longitudinal study using the 2006-2020 SEER Research Plus Specialized Data with Census Tract Attributes. Internal Classification of Diseases (ICD)-0-3 topography codes C71.0 to C71.9 were used to select primary cases of malignant Hodgkin and non-Hodgkin lymphoma cases diagnosed at age 0-19 years from 2006-2020. Survival months were calculated from the date of cancer diagnosis to the date of cancer death or last follow-up or date of death from other causes, whichever occurred first. Rural/urban residence was classified using Rural Urban Continuum Codes. SES was measured as a composite pre-calculated through a factor analysis using seven indicators of neighborhood socioeconomic status. The index is a 5-level variable categorized into quintiles, with quintile 1 being the lowest SES quintile and quintile 5, the highest. Other variables included stage at diagnosis, age, gender, histology, and race/ethnicity. Chi-square tests were used to assess differences in demographic characteristics of study participants by rurality. Cause-specific Cox-proportional hazard models were used to examine the hazard of death by SES adjusting for race/ethnicity, age, gender, stage at diagnosis, and histology. An interaction term was added to test if the effect of SES differed by place of residence. The proportional hazard assumptions were tested using Schoenfeld residuals. Results: Among 12,659 children included in the study, 10.25% were from rural counties. Among children from lowest SES (level 1), 33.31% were from rural counties and 17.66% from urban counties. There was no difference in survival for both Hodgkin and non-Hodgkin lymphoma by rural/urban residence. Survival rate, however, differed by SES, even after adjusting for covariates. The hazard of death was 1.54 (95% CI: 1.14-2.07), 1.81 (95% CI: 1.41-2.33), 1.72 (95% CI: 1.34-2.19) and 1.47 (95% CI: 1.16-1.87) for SES levels 1, 2, 3 and 4, respectively, compared to the highest SES level (level 5). The interaction term between SES and rurality was not significant, indicating that the effect of SES did not differ by rural/urban residence. Conclusions: SES was significantly associated with the hazard of death for Hodgkin and non-Hodgkin lymphoma. Survival did not differ by place of residence. Interventions that address individual and neighborhood level socio-economic factors may reduce survival disparities among children diagnosed with lymphoma.