Adult survivors of childhood cancer face an increased risk of death. Whether exercise lowers that risk, as it does in other populations, is not known. Researchers examined the association between vigorous exercise in early adulthood, as well as changes in exercise over time, and mortality in long-term adult survivors of childhood cancer.

Subjects in this retrospective cohort study were cancer survivors who had been diagnosed with and received treatment for cancer between 1970 and 1999. They were all diagnosed before age 21 and had survived at least five years after the initial diagnosis. At enrollment and during follow-up, the 15,450 participants completed questionnaires assessing the total minutes of vigorous exercise they engaged in per week, expressed as metabolic equivalents of task (METs). Change in vigorous exercise was assessed in a subgroup of survivors.

Over a median follow-up of 9.6 years, there were 1,063 deaths, 811 from health-related causes, 120 from a recurrence or progression of primary disease, and 132 from external or unknown causes. At 15 years, the cumulative incidence of death from all causes was 11.7% at 0 MET-hours per week, 8.6% at 3 to 6 MET-hours per week, 7.4% at 9 to 12 MET-hours per week, and 8% at 15 to 21 MET-hours per week. There was a significant, nonlinear inverse association between exercise and all-cause mortality; similar relationships were observed with recurrence or progression of disease and health-related deaths. Increased exercise over eight years was associated with an adjusted 40% reduction in all-cause mortality, as compared with maintenance of low exercise.

The findings are consistent with earlier studies and support the recommendation of exercise for cancer survivors. Vigorous exercise for at least 40 minutes once a week may be an achievable goal for many survivors, the authors write.

REFERENCE