Survivors of Childhood ALL Likely to Be Sedentary Adults

NEW YORK, July 25 -- Survivors of childhood acute lymphoblastic leukemia, particularly those treated with cranial radiotherapy, tend to lead a dangerously sedentary lifestyle as adults, found researchers here.

They are likely to exercise less than 2.5 hours a week and many reported no leisure-time physical activity over the course of a month, reported Kevin C. Oeffinger, M.D., of the Memorial Sloan-Kettering Cancer Center, and colleagues, in the July issue of Cancer Epidemiology, Biomarkers, & Prevention.

All this inactivity increases their risk of obesity, cardiovascular disease, and osteoporosis, they pointed out. The patients were treated in the 1970s and 1980s.

Survivors whose ALL therapy included more than 20 Gy of cranial radiotherapy were at the highest risk for a sedentary lifestyle, according to the findings.

Women who underwent cranial radiotherapy were twice as likely to meet CDC exercise recommendations and were about 86% more likely to report no exercise at all in the previous month compared with age matched controls, said Dr. Oeffinger and colleagues.

Dr. Oeffinger said the findings suggest that whole-brain radiation "has fundamentally altered something in the central nervous system that's leading to a decrease in levels of physical activity."

Dr. Oeffinger and colleagues assessed self-reported physical activity in 2,648 ALL survivors and compared their physical activity to the activity reported by age-matched controls culled from the 110,623 participants in the CDC's Behavioral Risk Factor Surveillance System Survey.

The mean age of survivors was 28.7 years and they were a mean of 23 years post-ALL diagnosis.

The CDC recommends that adults do 30 minutes of moderate exercise at least five days a week -- 2.5 hours a week -- or 20 minutes of vigorous exercise at least three days a week.

Compared with controls, ALL survivors were more likely to come up short on the CDC recommendations for physical activity (OR 1.44, 95% CI 1.32-1.57), Dr. Oeffinger said.

Moreover, 23% of ALL survivors said they didn't even participate in leisure time physical activities like golf or tennis in the past month versus 20% of the controls.

Women who had CRT had an OR of 2.07 for failure to meet CDC physical activity recommendations (95% CI, 1.67-2.56) for men the OR was 1.43 (95% CI, 1.16-1.76). And CRT was also associated with an increased risk for complete inactivity among both women (OR 1.86, 95% CI 1.50-2.31) and men (OR 1.84, 95% CI 1.45-2.32).

Dr. Oeffinger said the findings were particularly disappointing because research has shown that physical activity can undo risk -- particularly cardiovascular risk -- caused by ALL treatment.

"Small, incremental steps can make a big difference in improving health outcomes," he said.

The authors noted that the physical activity levels were based on self-reported data, which are subject to bias. Moreover, ALL survivors who were treated with cranial radiation may have cognitive defects that could "have resulted in differential reporting." Finally, ALL therapy has changed in recent years -- including lower dose cranial radiation. The findings were from data from survivors who were treated in the 1970s and 1980s.