Birth defects and cancer are the third and ninth leading causes of mortality globally. However, if birth defects are associated with the risk of cancer or not is uncertain. The objective of this study is to evaluate the association between birth defects and the risk of cancer from birth to adulthood.

This population-based nested control study included a total of 62,295 cancer cases and 724,542 frequency-matched controls. The frequency of birth defects in patients with cancer was considered. The primary objective of the study was the relative risk of cancer and their relationship with birth defects estimated as odds ratios (OR).

A total of 2,160 individuals with cancer (3.5%) and 15,826 frequency-matched controls (2,2%) had major birth defects. When compared with people with birth defects, the OR for those without them was 1.74. The OR was further lowered (1.54) for individuals with non-chromosomal birth defects. However, the OR of cancer was directly proportional to the number of defects and age. Birth defects associated with higher cancer risk were skeletal dysplasia, chromosomal anomalies, genital organ defects, and congenital heart defects.

The research concluded that individuals with birth defects persisting into adulthood were at higher risk of developing cancer.