Scott JM, et al. – In this multicenter cohort analysis, researchers investigated the potential association of vigorous exercise and change in exercise with mortality in adult survivors of childhood cancer using a questionnaire after a median follow-up of 10 years. They found a lower risk of mortality in adult survivors of childhood cancer in relation to vigorous exercise in early adulthood and increased exercise over 8 years.

Methods

• Study participants included 15,450 adult cancer survivors from pediatric tertiary hospitals in the United States and Canada who received a diagnosis of cancer before 21 years of age (1970-1999) and were enrolled in the Childhood Cancer Survivor Study, with follow-up through December 31, 2013.
• Included exposure was self-reported vigorous exercise in metabolic equivalent task (MET) hours per week.
• Using multivariable piecewise exponential regression analysis to estimate rate ratios, they evaluated the relationships between vigorous exercise and change in vigorous exercise and cause-specific mortality.
• All-cause mortality was the primary outcome.
• Cause-specific mortality (recurrence/progression of primary malignant neoplasm and health-related mortality) was Secondary end points.
• Through the National Death Index, outcomes were evaluated.

Results

• Among the 15,450 survivors, median age at interview of 25.9 years and were 52.8% male.
• A total of 1,063 (811 health-related, 120 recurrence/progression of primary cancer, 132 external/unknown causes) were reported during a median follow-up of 9.6 years.
• The cumulative incidence of all-cause mortality was 11.7% for those who exercised 0 MET-hours/week, 8.6% for 3-6 MET- hours/week, 7.4% for 9-12 MET- hours/week, and 8.0% for 15-21 MET- hours/week (P < 0.001) at 15 years.
• After adjusting for chronic health conditions and treatment exposures (P=0.02 for trend), they noted a significant inverse association across quartiles of exercise and all-cause mortality.
• Increased exercise (mean [SD], 7.9 [4.4] MET-hours/week) over an 8-year period was related to a 40% reduction in all-cause mortality rate vs maintenance of low exercise among a subset of 5,689 survivors.