Contact: Ronald Brown, PhD, ABPP
(843) 876-1522
brownron@musc.edu

Cancer Treatment May Cause Learning Problems in Children

Children with leukemia who undergo a particular form of chemotherapy run the risk of learning problems later in life, new research suggests. The decline in learning abilities may not show up for years.

Twenty-six cancer sufferers, ages 2 to 15 years, were assessed annually for four years after diagnosis. Sixteen of the youngsters had leukemia and were treated with central nervous system chemotherapy. Other cancers affected the remaining 10 children. The treatments for the children with other cancers differed from those used by the leukemia patients. Within a few years, the two groups posted starkly different results on cognitive and academic tests, with the first group lagging further and further behind.

"The results suggest that the deterioration of functioning may not necessarily become evident until several years after treatment has been completed," said Ronald Brown, PhD, ABPP, head of the study. The research team included scientists from the Medical University of South Carolina, University of Adelaide, Australia, and the Women's and Children's Hospital, also in Adelaide.

Cognitive and academic tests varied by the age of each child. Researchers converted the results into a comparative scale. IQ scores of the kids who had not had central nervous system chemotherapy improved in four years from a baseline average of 110.3 to 123.9. This reflects typical childhood development. Children who had the treatment actually lost ground. Their scores fell in four years, from 112.5 to 104.0. By the third year, differences were quite apparent, as these youngsters scored significantly lower in spelling, reading, and arithmetic. In reading, the significant gap continued into the next year.

As parents agonize over which cancer treatment to authorize, scientists strive to better understand the effects. By the year 2000, one in 1,000 young adults will be a survivor of childhood cancer. Radiation therapy's harmful effects on cognitive abilities are well documented. Evidence of learning difficulties from central nervous system chemotherapy surfaced much more recently.

Most leukemia patients in this study underwent this particular cancer treatment for nearly two years. The delays in mental impairment may have something to do with the prolonged exposure, according to Brown. "The findings underscore the need for ongoing and careful monitoring of children's cognitive and academic functioning throughout treatment and well into the late-effects period," Brown concluded.

The study appears in the October issue of the Journal of Developmental and Behavioral Pediatrics. The research was supported by the National Health and Medical Research Council, the Anti-Cancer Foundation of South Australia, and the Channel Seven Children's Research Foundation of South Australia, Inc.

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The Journal of Developmental and Behavioral Pediatrics is published bimonthly by the Society for Developmental and Behavioral Pediatrics. For information about the journal, contact Mary Sharkey at (212) 595-7717.