Section for epidemiology and medical statistics
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Congenital malformations and childhood cancer - gender differences

Recent research published in the International Journal of Epidemiology shows that there are gender differences in the connection between congenital malformations and childhood cancer.


Main content

Worldwide, approx. 400,000 children (0-19 years) are diagnosed with cancer each year. Having a congenital malformation is one of the strongest known risk factors for childhood cancer (cancer before the age of 20). This suggests a common cause. Few studies have previously examined whether there are gender differences in this context.

We combined data from national health registers in four Nordic countries in the period 1967 to 2014, and identified a total of 21,900 cases of childhood cancer. In addition, we included over 200,000 children and young people without cancer.

We found that children with malformations (other than chromosomal) had an almost twice increased risk of childhood cancer compared to children without malformations, while children with chromosomal defects had a 10-fold increased risk. We also found that the connection between congenital malformations and childhood cancer was generally stronger among girls than among boys. For girls with congenital malformations, the risk of childhood cancer was almost triple, while for boys it was double. However, the study did not substantiate the hypothesis that a congenital malformation is a strong mediator in the connection between gender and childhood cancer.

Read the article here: Sex differences in childhood cancer risk among children with major birth defects: a Nordic population-based nested case-control study