Risk of Cancer Among Children and Young Adults With Congenital Heart Disease Compared With Healthy Controls.

Importance: Adult patients with congenital heart disease (CHD) have an increased incidence of cancer, presumably owing to repeated radiation exposure, genetic predisposition, or repeated stress factors during heart interventions. However, there are limited data on the risk of cancer in children and young adults with CHD compared with the general population. Objective: To determine the risk of developing cancer from birth to age 41 years among patients with CHD compared with healthy matched controls. Design, Setting, and Participants: This registry-based, matched, prospective cohort study in Sweden used data from the Patient and Cause of Death Registers. Successive cohorts of patients with CHD born from 1970 to 1979, 1980 to 1989, and 1990 to 1993 were identified. Each patient (n = 21 982) was matched for birth year, sex, and county with 10 controls without CHD from the general population (n = 219 816). Follow-up and comorbidity data were collected from 1970 until 2011. Data analysis began in September 2018 and concluded in February 2019. Main Outcomes and Measures: Risk of cancer among children and young adults with CHD and among healthy controls. Results: Among 21 982 individuals with CHD and 219 816 healthy matched controls, 428 patients with CHD (2.0%) and 2072 controls (0.9%) developed cancer. Among patients with CHD, the mean (SD) age at follow-up was 26.6 (8.4) years, and 11 332 participants (51.6%) were men. Among healthy controls, the mean (SD) age at follow-up was 28.5 (9.1) years, and 113 319 participants (51.6%) were men. By the age of 41 years, 1 of 50 patients with CHD developed cancer. The overall hazard ratio (HR) for cancer was 2.24 (95% CI, 2.01-2.48) in children and young adults with CHD compared with controls. Risk increased by each successive birth cohort to an HR of 3.37 (95% CI, 2.60-4.35) among those born from 1990 to 1993. The risk of cancer was similar in men and women with CHD (men: HR, 2.41; 95% CI, 2.08-2.79; women: HR, 2.08; 95% CI, 1.80-2.41). The HR for cancer among patients with CHD who underwent surgery was 1.95 (95% CI, 1.58-2.33) compared with controls; for patients with CHD who had not undergone surgery, the HR was 2.43 (95% CI, 2.12-2.76). According to a hierarchical classification, a significantly increased risk of cancer was found among patients with complex heart lesions, such as conotruncal defects (HR, 2.29; 95% CI, 1.62-3.25), compared with healthy controls. Conclusions and Relevance: Children and young adult patients with CHD had an increased risk of developing cancer compared with healthy matched controls, and the risk was significantly higher among patients with CHD from the most recent birth cohort. An increased risk of cancer in all CHD lesion groups was found, and a systematic screening for cancer could be considered for this at-risk group of patients.