Cancer mortality in children surviving congenital heart interventions: A study from the Pediatric Cardiac Care Consortium.

Introduction: Children with congenital heart defects (CHD) have shorter life expectancy than the general population. Previous studies also suggest that patients with CHD have higher risk of cancer. This study aims to describe cancer-related mortality among patients with a history of CHD interventions using the Pediatric Cardiac Care Consortium (PCCC), a large US cohort of such patients.

Methods: We performed a retrospective cohort study of individuals (<21 years) who underwent interventions for CHD in the PCCC from 1982 to 2003. Patients surviving their first intervention were linked to the National Death Index through 2020. Multivariable models assessed risk of cancer-related death, adjusting for age, sex, race, and ethnicity. Patients with/without genetic abnormalities (mostly Down syndrome [DS]) were considered separately, due to expected differential risk in cancer.

Results: Among the 57,601 eligible patients in this study, cancer was the underlying or contributing cause of death for 208; with 20% among those with DS. Significantly increased risk of cancer-related death was apparent among patients with DS compared to the non-genetic group (aHR: 3.63, 95% confidence interval [CI]: 2.52-5.24, p < .001). For the group with non-genetic abnormalities, the highest association with cancer-related death compared to those with mild CHD was found among those with more severe CHD (severe two-ventricle aHR: 1.82, 95% CI: 1.04-3.20, p = .036, single-ventricle aHR: 4.68, 95% CI: 2.77-7.91, p < .001).

Conclusions: Patients with more severe forms of CHD are at increased risk for cancer-related death. Despite our findings, we are unable to distinguish whether having CHD raises the risk of cancer or reduces survival.