Some Children Have Greater Cancer Risks

Childhood cancer more common in children with some birth defects

(RxWiki News) Moms-to-be naturally worry about the health of their babies. By and large, this worry is a waste of energy. However, birth defects do occur in about three out of every 100 infants. And some of these babies may also be at risk for other health problems.

A new study found that children with certain types of birth defects had a three-fold higher rate of developing cancer before the age of 15 than children born with no birth defects.

The researchers discovered that these risks were higher in children with unusual birth defects, and the lead author of the study cautioned that parents shouldn’t be unduly worried about these findings because cancer in kids is very rare.

"Set up regular doctor visits during your pregnancy."

Lorenzo Botto, MD, professor of pediatrics at the University of Utah School of Medicine, and colleagues studied thousands of children and adolescents with and without birth defects to look at their rates of childhood cancer.

The researchers looked at major birth defects that affected various parts of the body and were not caused by genetic changes. The technical term for these conditions is “structural non-chromosomal birth defects.”

The study also included kids with Down’s syndrome, which is caused by a genetic change — an extra chromosome — and limits intellectual abilities.

The researchers looked at a wide range of birth defects that appear throughout the body — from the eyes and brain to the heart and the kidneys.

The study included 44,151 youngsters with birth defects and 147,940 kids who were not born with any health problems. The children were from Arizona, Iowa and Utah, and were between the ages of 0 and 14.

The study uncovered that kids with birth defects were nearly three times more likely to develop cancer than were children without birth defects.

Still, the numbers were quite small in both groups, with a cancer rate of 33.8 per 100,000 person-years among kids with birth defects, compared to 11.7 per 100,000 person-years among children without birth defects.

Person-years are a statistical figure based on the number of people observed multiplied by the number of years observed. So, 10,000 people observed for 10 years equals 100,000 person-years.

Only specific birth defects had higher cancer rates. These defects included microcephaly (abnormally small head), cleft palate (roof of mouth not fully formed) and certain eye, heart and kidney defects.

The most common types of cancers seen in the children with birth defects are those that develop while the baby is still in the womb.

These include extremely rare cancers, such as neuroblastoma, a cancer of nerve tissue that’s diagnosed in about 1,000 American children a year; hepatoblastoma, a liver tumor seen in less than 100 children each year; and nephroblastoma, a kidney tumor that affects about 500 children annually.

Cancer risks were not higher for those with certain common birth defects, including hypospadias (a condition in male babies where the urethra, the tube that carries urine out of the body, is on the underside of the penis instead of at the tip), cleft lip (split in the lip) with or without cleft palate, and hydrocephalus (fluid on the brain which enlarges the head).

Confirming what other studies have shown, the researchers found that children with Down’s syndrome have cancer risks 14 times higher than children without the condition. Kids with Down’s syndrome were most vulnerable to blood cancer, specifically leukemias.

Cancer risks were highest in the first 3 to 5 years of life.

"It's reassuring that many of the common major birth defects are not associated with any increase in cancer risk," Dr. Botto said in a prepared statement. "Our study helps to identify who is, and who is not, at increased risk for cancer, and this information can be used to focus future research on potential genetic or environmental factors that contribute to cancer risk."

This study was published recently in PLOS ONE.

This research was supported by the National Cancer Institute’s, the Utah Department of Health and the University of Utah. The research was also supported by the Centers for Disease Control and Prevention (CDC), National Center on Birth Defects and Developmental Disabilities Grant.

No conflicts of interest were declared.

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Review Date: 
August 15, 2013