Congenital anomaly and cancer may have some shared genetic and/or environmental fac-
tors that may influence the risk of occurrence. A malformation may also cause physiologic or
lifestyle changes that may impact on cancer risk [
13
,
14
]. Dysregulation of human development
probably plays a vital role in the etiology of cancer among patients with birth defects [
15
–
17
].
Previous studies have shown that patients with congenital anomalies have increased risk of de-
veloping cancer, such as leukemia, lymphoma, brain tumor, neuroblastoma, germ cell tumor,
retinoblastoma, and soft tissue sarcoma [
14
–
16
,
18
–
25
]. Most of these studies have focused on
the association of all categories of congenital anomalies with cancer. Congenital cardiovascular
anomaly, a major subgroup of congenital anomalies, is the most frequent type of birth defects
that also have a cancer diagnosis [
20
]. A few studies discuss the individual association of CHD
with cancer occurrence, but not all categories of congenital anomalies are included and the re-
sults have been conflicting [
14
,
20
,
26
–
29
]. Furthermore, previous studies do not explore the as-
sociation between age at CHD diagnosis, gender, duration of follow-up, co-morbidities, and
medical radiation examination among CHD patients, and cancer risk.