Childhood Cancer Survivorship Globally

Abstract

Importance: As childhood cancer survival improves worldwide, supporting the growing survivor population, who are at increased risk of morbidity and mortality compared with the general population, is critical. No prior publications have summarized the landscape of childhood cancer survivorship research globally and encompassed high-income countries (HICs) and low-income and middle-income countries (LMICs). Objective: To describe the global distribution of childhood cancer survivorship research, including country of origin and study focus, with a systematic review. Evidence Review: The Global Index Medicus, CAB Direct, Embase, and PubMed were searched for childhood cancer survivorship studies published between January 1, 1980, and September 1, 2021. Included studies had full texts available and measured multimorbidity or classic survivorship outcomes in children who received a diagnosis of cancer when younger than 20 years. Two reviewers separately screened studies for eligibility. Studies were categorized by World Bank income group and World Health Organization region. Survivorship domains were classified using an existing framework and included mental, physical, or psychosocial health, recurrences and new cancers, and health promotion. Basic quality metrics were assessed, including sample size, source, and uncertainty reporting. χ2 And Fisher tests were used to compare income groups and regions, linear regression for associations between publication year and income group or study domains, and the Mann-Whitney U test for sample size. Findings: A total of 1558 studies were included from 43 countries and territories, with HICs and the combined World Health Organization American and European regions disproportionately represented (1478 [95.2%] and 1436 [92.5%], respectively, of all cohort and cross-sectional studies [n = 1553]). The proportion of LMIC studies increased over time. Physical effects predominated among survivorship domains studied, particularly in LMICs compared with HICs. In HICs, cohort and cross-sectional sample sizes were larger (median, 276.5 [IQR, 80.0-1732.5] vs 87.0 [IQR, 50.0-130.0]) and more often drawn from the entire population or multiple rather than single institutions. Conclusions and Relevance: This systematic review results suggest that the global compendium of childhood cancer survivorship data does not reflect the global population of survivors. Supporting survivorship research in diverse regions and areas of study is crucial to achieving equitable long-term outcomes globally.