Major Birth Defects Could Increase the Risk of Cancer Later in Life

While the risk of developing cancer is 1.74 times greater for individuals born with major birth defects, that risk is highest in childhood but decreases slightly after age 20, according to a study published in The BMJ.

The authors of the study noted that being born with a birth defect is one of the strongest risk factors for childhood cancer, and that many associations between cancer and specific birth defects have already been made. To further investigate the risk of cancer beyond childhood adolescence, the authors analyzed data from nationwide health registries in Denmark, Finland, Norway and Sweden.

A total of 62,295 patients with cancer (cases) and 724,542 people without cancer (controls) were enrolled, all born between 1967 and 2014. The study specifically focused on the Nordic population, which reported a 3% rate of children being born with major birth defects in 2017. Entirely data driven, the study only drew from those who were diagnosed inpatient within the first year of life and excluded those individuals with minor birth defects.

The percentage of individuals with cancer who also had a major birth defect was 3.5%, compared to 2.2% in those without cancer. The data demonstrated that the risk of developing cancer was 1.74% greater in those with a major birth defect compared to those without.

When it comes to age, researchers found that the odds of those with birth defects developing cancer was greatest in children aged 0 to 14 (2.52 times higher) and declined, but remained 1.22 times higher in adults at age 20 and older with major birth defects.

The type of birth defect also had an impact on the risk and type of cancer an individual could develop. Those with congenital heart defects, defects of the genitals or nervous system and skeletal dysplasia (a group of conditions that affect bone development) continued to have a greater risk of cancer later in life. For example, the risk was higher in those with chromosomal anomalies and highest (5.53 times higher) for those with Down syndrome.

More specifically, people with non-chromosomal birth defects had a 54% increased risk of developing cancer, with the highest risks of cancers of urinary organs (70%), peripheral nerves and autonomic nervous system (40%) and central nervous system (30%). There was also an observed increased risk in cancers of digestive organs, soft tissue, genital organs, nose/sinuses, thyroid and other or unspecified cancers. For those with chromosomal anomalies, data showed an increased risk of cancers of lymphoid and hematopoietic tissue, and a high risk for acute myeloid leukemia.

The authors noted that the study was limited because it only included diagnoses made in the first year of life, and could also have missed some less visible birth defects that were diagnosed later in life.

But despite the study’s limitations, the authors highlighted the need for further research “that may offer important preventative opportunities and identify high-risk patient groups for enhanced targeted surveillance."

Finally, the authors noted that these findings could hold some clinical importance for health care providers who care for individuals with birth defects: “The most important implication of our results is to provide further rationale for additional studies on the molecular mechanisms involved in the developmental disruptions underlying both birth defects and cancer,” they wrote.

For more news on cancer updates, research and education, don’t forget to subscribe to CURE®’s newsletters here.