Long-Term Health Outcomes in Male Survivors of Childhood Cancer After Hematopoietic Stem Cell Transplantation: A Registry-Based Study

Late effects are a major concern after pediatric hematopoietic stem cell transplantation (HSCT), but data on health outcomes beyond early adulthood remain scarce. This study assessed long-term morbidity and mortality in one of the earliest childhood cancer cohorts treated with HSCT. The study comprised 52 male childhood cancer survivors (survival ≥5 years), treated with HSCT in 1983-2001 at a median age of 6.1 years, and 257 matched population controls. Finnish national healthcare registries provided data on prescription drug purchases, reimbursements for chronic diseases, hospitalizations, and late mortality. Median follow-up was 24.9 years. Compared to population controls, survivors had increased risk for diabetes (HR 16.4, 95% CI 4.33-61.8), severe hypertension (HR 11.4, 95% CI 3.42-37.8), purchases of lipid-lowering drugs (OR 13.5, 95% CI 4.87-41.3), and purchases of antihypertensives (OR 2.58, 95% CI 1.28-5.12). HSCT survivors had also higher risk for hospitalizations due to cardiovascular diseases (HR 6.13, 95% CI 1.52-24.7) and neurological conditions (HR 4.79, 95% CI 1.73-13.2). New diagnoses of epilepsy and secondary neoplasms emerged beyond 20 years post-transplantation. Chronic graft-versus-host disease was associated with increased purchases of thyroxine, growth hormone, and lipid-lowering drugs. Given the high risk for diabetes, hypertension, and dyslipidemia, proactive cardiovascular risk assessment is essential in long-term care after pediatric HSCT. The occurrence of late-onset complications underscores the importance of structured lifelong follow-up.