June 4 (UPI) -- Vigorous exercise has been linked to a lower risk of death in adult survivors of childhood cancer, according to a study.
Researchers at Memorial Sloan Kettering Cancer Center and several other hospitals in the U.S., Canada and Norway studied data on 15,450 adult cancer survivors, finding vigorous exercise in early adulthood over the course of eight years lowered their risk of death.
Data on the patients, who were diagnosed before age 21 at one of 27 pediatric tertiary hospitals between 1970 and 1999 and followed up with through 2013, was collected as part of the Childhood Cancer Survivor Study.
Findings from the new study were published Sunday in the Journal of the American Medical Association Oncology.
Healthy lifestyle behaviors that include regular exercise have been associated with substantial reductions in mortality, but it wasn't known whether that applies to adult survivors of childhood cancer.
Participants, who had a median age of 25.9 years, self-reported vigorous exercise in metabolic equivalent task hours per week.
During the median followup of 9.6 years, there were 1,063 deaths among the more than 15,000 participants, including 811 health-related, 120 recurrent or progressing cases of primary cancer and 132 external or unknown causes.
At 15 years, the all-cause mortality was 11.7 percent for those who exercised 0 hours, 8.6 percent for 3 to 6 metabolic equivalent task hours per week, 7.4 percent for 9 to 12 hours and 8.0 percent for 15 to 21 hours.
Exercising survivors were younger at cancer diagnosis, more likely to be nonsmokers and had a lower prevalence of cardiovascular risk factors and grade 3 to 4 chronic conditions.
Increased exercise over eight years was associated with a 40 percent reduction in all types of deaths compared with low exercise.
"Our findings indicate that regular vigorous exercise, as well as an increase in exercise, is associated with significant reductions in the risk of mortality in adult survivors of childhood cancer," the researchers wrote. "These findings may be of importance for the large and rapidly growing global population of adult survivors of childhood cancer at substantially higher risk of mortality due to multiple competing risks."