Preventable fractions of colon and breast cancers by increasing physical activity in Brazil: perspectives from plausible counterfactual scenarios

Highlights • 12% of postmenopausal breast cancers and 19% of colon cancers are attributable to lack of physical activity in Brazil. • 1.3% of postmenopausal breast and 6% of colon cancers could be prevented by achieving the physical activity recommendation. • Other plausible counterfactual scenarios showed limited to moderate impact of physical activity on cancer prevention. • High levels of physical activity are required to obtain sizable impact on breast and colon cancer prevention.
Background Physical activity is associated with lower risk of colon and breast cancers. Herein we estimated preventable fractions of colon and breast cancers in Brazil by increasing population-wide physical activity to different counterfactual scenarios. Methods We used data from a representative national survey in Brazil and corresponding relative risks of colon and postmenopausal breast cancers from a meta-analysis. Estimated cancer incidence was retrieved from GLOBOCAN and Brazilian National Cancer Institute. Five counterfactual scenarios for physical activity were considered: (i) theoretical minimum risk exposure level (≥8,000 metabolic equivalent of tasks-minute/week – MET-min/week); (ii) physical activity recommendation (≥600 MET-min/week); (iii) a 10% reduction in prevalence of insufficient physical inactivity (