Logan Spector, Ph.D., assistant professor of pediatrics and cancer epidemiology researcher, and Kimberly Johnson, Ph.D., postdoctoral fellow in pediatric epidemiology, led the research team on this study.
"Our finding shows that although the absolute risk is low, advancing maternal age may be a factor and explain why, after other factors are adjusted for, some children get cancer," said Spector.
For the study, the researchers used information from birth registry records in New York, Washington, Minnesota, Texas, and California.
The study included the records of 17,672 children in those states diagnosed with cancer at ages 0-14 years between 1980 and 2004 and 57,966 children not diagnosed with cancer.
"We saw that the risk of 7 of the 10 most common childhood cancers increased slightly, about 7-10 percent, with every five-year increase in maternal age," Spector said.
The researchers noted the father's age did not seem to matter once the mother's age was taken into account.
Spector and Johnson say more research needs to be done on why the risk for childhood cancer increases with advancing maternal age. br>
Types of cancers most often affecting children include leukemia, lymphoma, central nervous system tumor, neuroblastoma, Wilms' tumor, bone cancer, and soft tissue sarcoma.
The results are published in the July 2009 issue of the journal Epidemiology.