Risk of cancer in young and older patients with congenital heart disease and the excess risk of cancer by syndromes, organ transplantation and cardiac surgery: Swedish health registry study (1930–2017)

BACKGROUND: Increasing survival of patients with congenital heart disease (CHD) will result in an increased risk of age-dependent acquired diseases later in life. We aimed to investigate the risk of cancer in young and older patients with CHD and to evaluate the excess risk of cancer by syndromes, organ transplantation and cardiac surgery. METHODS: Patients with CHD born between 1930 and 2017 were identified using Swedish Health Registers. Each patient with CHD (n = 89,542) was matched by sex and birth year with ten controls without CHD (n = 890,472) from the Swedish Total Population Register. FINDINGS: 4012 patients with CHD (4·5%) and 35,218 controls (4·0%) developed cancer. The median follow-up time was 58·8 (IQR 42·4–69·0) years. The overall cancer risk was 1·23 times higher (95% confidence interval (CI) 1·19–1·27) in patients with CHD compared with matched controls, and remained significant when patients with syndromes and organ transplant recipients were excluded. The risk of cancer was higher in all CHD age groups, and in patients that underwent cardiac surgery during the first year after birth (Hazard Ratio 1·83; 95% CI 1·32–2·54). The highest risk was found in children (0–17 years), HR 3·21 (95% CI 2·90–3·56). INTERPRETATION: The cancer risk in patients with CHD was 23% higher than in matched controls without CHD. The highest risk was found in children and in the latest birth cohort (1990–2017). FUNDING: Funding by the Swedish state (Grant Number: 236611), the Swedish Research Council (Grant Number: 2019-00193), the Swedish Childhood Cancer Fund (Grant Number: SP2017-0012) and the Swedish Heart-Lung Foundation (Grant Number: 20190724).