Physical Activity, Occupational Sitting Time, and Colorectal Cancer Risk in the Netherlands Cohort Study

Abstract

We investigated occupational energy expenditure and sitting time in the longest held job (in men only), nonoccupational physical activity, and former sports participation in relation to colorectal cancer endpoints. The Netherlands Cohort Study includes 120,852 participants who completed a self-administered questionnaire in 1986 when they were aged 55–69 years. By 2002, 1,819 male and 1,366 female colorectal cancer cases were available for case-cohort analyses. In men, higher occupational energy expenditure levels and fewer occupational sitting hours were associated with decreased hazard ratios for colon cancer, particularly distal colon cancer (occupational energy expenditure of ≥12 vs. P for trend = 0.01; occupational sitting hours of 90 vs. ≤30 minutes/day, HR = 0.69, 95% CI: 0.50, 0.96; P for trend = 0.06), and rectal cancer (>90 vs. ≤30 minutes/day, HR = 0.59, 95% CI: 0.39, 0.90; P for trend = 0.02). In conclusion, regular long-term physical activity and fewer sitting hours may protect against colon cancer, particularly distal colon cancer; results for rectal cancer were mixed.