Physical Activity and Colorectal Cancer Risk by Sex, Race/Ethnicity, and Subsite: The Multiethnic Cohort Study
Menée aux Etats-Unis auprès de 172 502 personnes âgées de 45 à 75 ans (durée moyenne de suivi : 16,8 ans), cette étude analyse, en fonction du sexe et de l'appartenance ethnique, l'association entre l'activité physique et le risque de cancer colorectal par sous-type anatomique (4 430 cas)
Physical activity has been associated with a lower risk of colorectal cancer. However, data is lacking on whether the association is consistent between sexes and across different races/ethnicities and anatomical subsites of tumors. We analyzed data from the Multiethnic Cohort in Hawaii and California, consisting of mostly African Americans, Native Hawaiians, Japanese Americans, Latinos, and whites aged 45-75 years at recruitment. During a mean follow-up of 16.8 years, 4,430 invasive adenocarcinoma cases of the colorectum were identified among 172,502 eligible participants. Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI). The multivariate-adjusted HR (95% CI) for the highest vs. lowest quintiles of physical activity (metabolic equivalent hours of moderate or vigorous activities per day) was 0.76 (0.66, 0.87) in men (P for trend <0.001) and 0.94 (0.80, 1.11) in women (P for trend = 0.53, P for heterogeneity by sex = 0.07). Sleeping and sitting hours were not associated with colorectal cancer risk both in men and women. In men, the inverse association was statistically significant among African Americans and Japanese Americans, for right colon and rectal cancer, and in all body mass index (BMI) groups, although heterogeneity tests were not significant across race/ethnicity or anatomical subsite of tumors. The findings confirm the inverse association between physical activity and colorectal cancer, which appears to be stronger in men, and suggest possible differences in the strength of the association by race/ethnicity and anatomical subsite of tumors.
Cancer Prevention Research , résumé, 2018