Lupo PJ, et al. - Through a large population-based registry study of more than 10,181,074 children in four states, researchers intended to find specific birth defect-childhood cancer associations and describe cancer risk in children by increasing number of nonchromosomal birth defects. An association of an increased number of nonchromosomal birth defects with a similar increase in the risk of cancer was noted. Hepatoblastoma and neuroblastoma were the two types of cancer most frequently correlated with nonchromosomal defects. Between specific birth defects and cancers, numerous significant and novel associations were recognized. The number of major birth defects diagnosed in children with nonchromosomal birth defects was significantly and directly associated with cancer risk. Hence, for children with birth defects, these conclusions could help in informing clinical treatment and could clarify mechanisms that lead to complex results.