The establishment of population‐based birth defects surveillance programs provides an opportunity to systematically evaluate the risk of cancer among children with specific birth defects avoiding the bias of surveys conducted in genetics clinics.
PURPOSE: Determine the association between specific birth defects and childhood cancer to aid in the discovery of previously unrecognized genetic syndromes.
METHODS: We examined cancer risk in a population‐based cohort of children with and without birth defects born between 1992 and 2011 by linking data from the Michigan Birth Defects Registry, the Michigan Cancer Surveillance Program, and birth records from the Michigan Department of Community Health. Incidence rate ratios and 95% confidence intervals were calculated to determine the risk of cancer among children with all reported birth defects.
RESULTS: We identified a birth cohort of 2,566,771 live births for the study period. There were 225,599 infants with birth defects and a total of 4,354 children with cancer. Overall, children with birth defects were three times more likely to be diagnosed with cancer compared to their unaffected contemporaries (IRR=3.24, 95% CI: 3.02‐ 3.47). The risk of childhood cancer was seen among most birth defects including: central nervous system defects (IRR=4.28, 95% CI: 3.48‐5.27); eye and ear defects (IRR=2.02, 95% CI: 2.02, 95% CI: 1.55‐2.65); cardiac and circulatory defects (IRR=2.22, 95% CI: 1.93‐2.56); and gastrointestinal defects (IRR=3.05, 95% CI: 2.48‐3.76). Not surprisingly children with an underlying chromosomal abnormality at a high cancer risk (IRR=7.81, 95% CI: 6.36‐9.59). The only birth defect evaluated where there was not an association with childhood cancer was oral clefts (IRR=1.11, 95% CI: 0.60‐ 2.06).
CONCLUSIONS: Children with birth defects are at an increased risk of developing cancer. These results are consistent with previous studies and reinforce the utility of record linkages between population‐based registries for epidemiologic assessments. The specific associations will allow molecular studies to determine if common developmental pathways underlie the etiology of birth defects and childhood cancer.
