Abstract
BACKGROUND: The increasing number of childhood cancer survivors necessitates continued follow-up to monitor for long-term complications. Inequities in loss to follow-up for patients enrolled on pediatric clinical trials have not been well studied. METHODS: This was a retrospective study of 21,084 patients residing in the United States enrolled on phase 2/3 and phase 3 Children's Oncology Group (COG) trials between January 1, 2000 and March 31, 2021. Rates of loss to follow-up to COG were evaluated using log-rank tests and multivariable Cox proportional hazards regression models with adjusted hazard ratios (HRs). Demographic characteristics included age at enrollment, race, ethnicity, and zip code level socioeconomic data. RESULTS: Adolescent and young adult (AYA) patients 15-39 years old at diagnosis had an increased hazard of loss to follow-up compared to patients 0-14 years old (HR, 1.89; 95% confidence interval (CI), 1.76-2.02). In the overall cohort, non-Hispanic Blacks were found to have an increased hazard of loss to follow-up compared to non-Hispanic Whites (HR, 1.56; 95% CI, 1.43-1.70). Among AYAs, the highest loss to follow-up rates were among non-Hispanic Blacks (69.8% ± 3.1%), patients on germ cell tumor trials (78.2% ± 9.2%), and patients living in zip codes with a median household income ≤150% of the federal poverty line at diagnosis (66.7% ± 2.4%). CONCLUSIONS: AYAs, racial and ethnic minority patients, and those living in lower socioeconomic status areas had the highest rates of loss to follow-up among clinical trial participants. Targeted interventions are warranted to ensure equitable follow-up and improved assessment of long-term outcomes. PLAIN LANGUAGE SUMMARY: Little is known about disparities in loss to follow-up for pediatric cancer clinical trial participants. In this study, we found that participants who were adolescents and young adults when treated, those who identified as a racial and/or ethnic minority, or those residing in areas with lower socioeconomic status at diagnosis were associated with higher rates of loss to follow-up. As a result, the ability to assess their long-term survival, treatment-related health conditions, and quality of life is hindered. These findings suggest the need for targeted interventions to improve long-term follow-up among disadvantaged pediatric clinical trial participants.