The Risk of Cancer in Patients with Congenital Heart Disease: A Nationwide Population-Based Cohort Study in Taiwan

Background
The relationship between congenital heart disease (CHD) and malignancies has not been determined. This study aimed to explore the association of CHD with malignancies and examine the risk factors for the development of cancer after a diagnosis of CHD.
Patients and Methods
This nationwide, population-based cohort study on cancer risk evaluated 31,961 patients with newly diagnosed CHD using the Taiwan National Health Insurance Research Database (NHIRD) between 1998 and 2006. The standardized incidence ratios (SIRs) for all and specific cancer types were analyzed, while the Cox proportional hazard model was used to evaluate risk factors of cancer occurrence.
Results
Among patients with newly diagnosed CHD regardless of ages, 187 (0.6%) subsequently developed cancers after a diagnosis of CHD. Patients with CHD had increased risk of cancer (SIR, 1.45; 95% CI, 1.25–1.67), as well as significantly elevated risks of hematologic (SIR, 4.04; 95% CI, 2.76–5.70), central nervous system (CNS) (SIR, 3.51; 95% CI, 1.92–5.89), and head and neck (SIR, 1.81; 95% CI, 1.03–2.94) malignancies. Age (HR, 1.06; 95% CI, 1.05–1.06) and co-morbid chronic liver disease (HR, 1.91; 95% CI, 1.27–2.87) were independent risk factors for cancer occurrence among CHD patients.
Conclusion
Patients with CHD have significantly increased cancer risk, particularly hematologic, CNS, and head and neck malignancies. Physicians who care for patients with CHD should be aware of their predisposition to malignancy after the diagnosis of CHD. Further studies are warranted to clarify the association between CHD and malignancies.