Childhood brain tumor survivors may be vulnerable to physical declines associated with aging: Study

A large study focused on documenting the strength and fitness of childhood brain tumor survivors has found that many face health challenges as they age. The study led by St. Jude Children's Research Hospital investigators showed that although most participants were young adults in their 20s, many functioned like people in their 60s, making them less likely to live independently or attend college.

Kirsten Ness, Ph.D., St. Jude Epidemiology and Cancer Control department, said the findings underscore the need to work with current brain tumor patients to preserve and enhance their fitness and to develop strategies to help long-term survivors maximize their potential.

"If survivors were more fit, they might have better access to their communities. They might be able to get out more, find a job and live independently," said Ness, lead author of the study that was published recently in the journal Cancer.

Combination therapies have helped push overall cure rates for young brain tumor patients to nearly 70 percent. But many survivors are left with a variety of long-term emotional, intellectual and physical challenges.

"The survivors we tested were young adults, half between the ages of 18 and 22, but their muscle strength and fitness was similar to that of 60- to 65-year-olds," Ness said. "The findings indicate that childhood brain tumor survivors may be particularly vulnerable to the physical declines associated with aging, leaving them at higher risk for problems linked to inactivity, including osteoporosis and cardiovascular disease."

At St. Jude, work is already underway to modify current brain tumor treatments to save lives and reduce disability. Ness said reaching survivors scattered across the country will be a greater challenge, particularly for the estimated 20 percent who have vision and hearing problems or who suffered a loss of sensation that makes exercising more difficult. "This group needs targeted exercise strategies," she said.

This study included 78 adult survivors and an equal number of cancer-free recruits matched for age, sex and ZIP code. The survivors were treated at either St. Jude or the University of Minnesota Children's Hospital between 1970 and 2000. Nearly 85 percent were at least 10 years from learning they had an astrocytoma, medulloblastoma, ependymoma or another type of brain tumor. Surgery was the most common treatment. About two-thirds of survivors also underwent brain irradiation, and about 31 percent received chemotherapy.

Researchers traveled to participants' homes to conduct a variety of tests, focusing primarily on physical performance. Although some survivors were just as fit as their cancer-free peers, investigators found that as a group the survivors were weaker, less fit and more likely to be obese.

Age at diagnosis, rather than tumor type or other factors, was the only predictor of later weakness or poor endurance. Those at greatest risk were younger than age 5 at diagnosis, Ness said.