Study Links Birth Defects and Cancer Risk Among Children

Children with certain types of birth defects may face an increased risk of childhood cancers, according to the findings of new research.

In a study published last week in the medical journal JAMA Oncology, researchers indicate that the risk of developing certain cancers may increase between 2 to 12 times, depending on the type of birth defect the child experienced.

Researchers from Baylor College of Medicine conducted a study using a population based registry of more than 10 million children born from 1992 to 2014 in four states. They assessed cancer risk among children identified using pooled statewide data on births, birth defects, and cancer from Texas, Arkansas, Michigan, and North Carolina.

Children were followed until 18 years of age, and a total of 40 specific birth defect-childhood cancer associations were identified.

Research indicated the cancer risk increased with the increasing number of major non-chromosomal birth defects.

Children with chromosomal birth defects, such as Down’s syndrome, are 11 times more likely to be diagnosed with cancer.

However, children with non-chromosomal birth defects, where there is no known genetic cause, also faced an increased risk of developing cancer by the age of 18. In fact, they were 2.5 to 4 times more likely to develop cancer.

Non-chromosomal birth defects affect more children than defects linked specifically to chromosomes. These defects often don’t have an identifiable cause and amount to roughly 70% of all birth defects.

The study also indicated that children with four or more non-chromosomal birth defects were nearly 6 times more likely to be diagnosed with cancer compared to those without birth defects.

“These findings could inform clinical treatment for children with birth defects and may elucidate mechanisms that lead to these complex outcomes.” wrote study authors.

Many childhood chromosomal defects have known cancer risks. For example, the trisomy 21 chromosome defect has a documented link to acute leukemia. However, many non-chromosomal defects don’t have definitive genetic causes and are harder to link to increased risks of cancer. Yet, the findings of this study showed there is a greater link between the two.

The cancers most frequently associated with non-chromosomal defects were hepatoblastoma, a type of liver cancer, and neuroblastoma, cancer that begins in the adrenal glands.

While children with non-chromosomal defects faced an increased risk, the absolute risk remains low at 1%.

Birth defects affect roughly 1 in 33 children. It is a broad term for a range of abnormalities occurring at birth. Sometimes that includes changes to body parts, such as a misshapen toe, or larger changes, like changes to the brain.

Researchers believe many childhood cancers begin to develop in utero. The link between birth defects and childhood cancer may indicate the two have a common origin occurring during fetal development while the fetus is still in the womb.

This is the largest study to evaluate the development of cancer in children with birth defects.