Loss to follow‐up of minorities, adolescents, and young adults on clinical trials: A report from the Children's Oncology Group

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.