Aims: Medical radiological exposure is associated with an additional risk of cancer. Children with repaired congenital heart disease (CHD) are theoretically at a relatively greater cancer risk as the radiological exposure can be intensive in these patients. Chromosomal aberrations test (CA) and micronucleus assay (MN) in peripheral blood lymphocytes are biomarkers of chromosomal damage and intermediate endpoints in carcinogenesis.
Methods and results: The frequency of CA and MN was assessed in three groups of patients: Group I, 32 exposed patients (17 males, age=15.5+/-8.3 years) who underwent cardiac procedures employing ionizing radiation (mostly cardiac catheterization) for CHD between 1965 and 2000; Group II, 32 healthy age- and sex-matched subjects (17 males, age=14.1+/-12.3 years), and Group III, 10 newborn non-exposed patients (7 males) with CHD. Exposed patients of Group I had a mean value of 2.9+/-1.4 cardiac catheterization (range 1-5) procedures per person. The mean frequency of CA was higher in the exposed patients (Group I=2.8+/-1.9% vs. Group II=0.7+/-0.7%; vs. Group III=0.8+/-0.8%; P<0.0001). Similarly, the mean values of MN were higher in the exposed patients (Group I =12.3+/-5.1 per thousand vs. Group II=6.0+/-3.8 per thousand; vs. Group III=4.4+/-1.4 per thousand; P<0.0001).
Conclusion: Cardiac ionizing procedures are associated with a long-lasting mark in the chromosomal damage of exposed children with CHD.