Racial Disparities in Childhood Cancer Survival and the Role of Time to Treatment

Background: Survival disparities of childhood cancers among racial and ethnic minorities continue to persist despite significant advancements in care. While partially mitigated when accounting for socioeconomic status (SES) and stage at diagnosis, the persistence of these disparities suggests that additional factors need investigation. There have been suggestions that delays in treatment may contribute to differences in mortality among pediatric and young adult cancer patients.

Methods: Using cancer registry data from the Surveillance, Epidemiology, and End Results (SEER) program, we investigated the role of time from diagnosis to treatment in racial survival disparities among patients diagnosed with a primary malignancy at ages 19 years and under. We compared mortality hazard ratios from regression models with and without time to treatment to assess its specific role in risk of mortality. We also compared race-specific unadjusted survival curves to those adjusted for other known determinants of survival, socioeconomic status and stage at diagnosis.

Results: A total of 47,661 patients were included in the analysis, with 24,696 (51.82%) Non-Hispanic White patients, 5,032 (10.56%) Non-Hispanic Black patients, 3,636 (7.63%) Non-Hispanic Asian/Pacific Islander patients, and 14,297 (30.00%) Hispanic patients. Overall, time to treatment had no statistically significant effect on survival, and it did not affect the risk of mortality in any race group. We then assessed the degree to which stage and SES contribute to known racial survival disparities and found there was partial reduction in survival gaps between minority racial groups compared to Non- Hispanic White patients for lymphomas, central nervous system cancers, and other solid tumors but not for leukemias.

Conclusions: Time from diagnosis to treatment does not appear to act as a significant driver of survival outcomes among children with cancer, and despite adjustment for socioeconomic status and stage, there remain significant racial survival disparities.