Cancer Risk in Adults With Congenital Heart Disease

Study Questions:

What is the association between low-dose ionizing radiation (LDIR) from cardiac procedures and cancer in adults with congenital heart disease (ACHD)?

Methods:

The study made use of province-wide administrative databases as well as the Quebec Congenital Heart Disease Database. Cumulative numbers of LDIR-related cardiac procedures were measured for each patient until 1 year before time of cancer diagnosis or administrative censoring. To determine the association between LDIR exposure and cancer risk, a nested case-control study was conducted and cancer cases were matched with controls based on sex, CHD severity, birth year, and age.

Results:

The study included 24,833 ACHD patients aged 18-64 years from 1995-2009. During the follow-up period, 602 cancer cases were observed (median age, 55.4 years), with a cumulative incidence of cancer estimated up to age 64 of 15.3% (95% confidence interval [CI], 14.2-16.5). Cases had more LDIR-related cardiac procedures than controls (1,410 vs. 921 per 1,000 ACHD patients, p < 0.001). Cumulative LDIR exposure was independently associated with cancer (odds ratio, 1.08 per procedure; 95% CI, 1.04-1.13).

Conclusions:

This large population-based study documented an association between LDIR-related cardiac procedures and incident cancer in the ACHD population.

Perspective:

Patients with CHD often undergo multiple diagnostic and therapeutic procedures that involve exposure to ionizing radiation. This is the first large population to document the association between radiation exposure as related to cardiac procedures and cancer later in life. Prospective studies will be important to confirm these findings. This finding is particularly important with the increasing use of prolonged complex interventional catheterization procedures such as transcatheter pulmonary valve implantation, which can involve significant radiation exposure, particularly when done in conjunction with additional interventions on the pulmonary arteries. Physicians involved with cardiac imaging should be sensitive to the issue and use the lowest reasonable radiation dose. Physicians involved in the longitudinal care of patients with CHD should also be sensitive to the cumulative lifetime radiation exposure of ACHD patients.

Keywords: Cardiac Imaging Techniques, Cardiology Interventions, Cardiotoxicity, Catheterization, Heart Defects, Congenital, Neoplasms, Radiation, Radiation Effects, Risk, Secondary Prevention


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