(OR06-04-23) Objectively Measured Physical Activity and Risk of Colorectal Cancer: Evidence From the UK Biobank Cohort Study

Objectives: We investigated the associations between objectively measured physical activity (PA) and colorectal cancer incidence, including cancer at the proximal and distal colon and rectum.

Methods: We studied 87,347 male and female participants in UK Biobank who did not have cancer at recruitment. Exposure variables included total PA, moderate to vigorous PA (MVPA), and light, moderate and vigorous PA measured using a wrist accelerometer. Incident colorectal cancer (fatal and non-fatal) and its subtypes were the outcomes. The associations were investigated using Cox proportional hazards models and adjusted for socio-demographics, lifestyle factors, adiposity and multimorbidity.

Results: The median follow-up was 5.3 years (Interquartile range 4.8 to 5.3 years). In the most adjusted model, participants in the highest tertile of total PA had a lower risk of colorectal (HR: 0.78, 95% CI%: 0.62; 0.99) and colon cancer (HR: 0.74, 95% CI: 0.55; 0.99) compared to those in the lowest tertile. For moderate-to-vigorous PA the cancer risk for those in the highest tertile was lower for colorectal (HR: 0.66, 95% CI: 0.46; 0.80), proximal colon (HR: 0.40, 95% CI: 0.34; 0.81) and colon (HR: 0.52, 95% CI: 0.24; 0.90) cancer compared with the least active individuals. Light PA was only associated with lower risk of proximal colon cancer (HR: 0.67, 95% CI: 0.47; 0.97).

Conclusions: This study showed that objectively measured physical activity is associated with a lower risk of colorectal cancer and site-specific colorectal cancer, independent of adiposity and lifestyle factors. Strategies for the prevention of colorectal cancer should include increasing physical activity levels among the population, but especially among high risk individuals.

Funding Sources: S.P.-S. received financial support from the Chilean Government for doing her PhD (ANID-Becas Chile).