Physical activity and risks of breast and colorectal cancer: a Mendelian randomisation analysis

Abstract Physical activity has been associated with lower risks of breast and colorectal cancer in epidemiological studies; however, it is unknown if these associations are causal or confounded. In two-sample Mendelian randomisation analyses, using summary genetic data from the UK Biobank and GWA consortia, we found that a one standard deviation increment in average acceleration was associated with lower risks of breast cancer (odds ratio [OR]: 0.51, 95% confidence interval [CI]: 0.27 to 0.98, P-value = 0.04) and colorectal cancer (OR: 0.66, 95% CI: 0.48 to 0.90, P-value = 0.01). We found similar magnitude inverse associations for estrogen positive (ER +ve ) breast cancer and for colon cancer. Our results…

• CI
  Centre International de Recherche sur le Cancer
• CR
  Cancer Research UK

  Awards: C18281/A19169, A19169, C18281
• NI
  National Institute for Health and Care Research

  Award: C18281/A19169
• DO
  Department of Health and Social Care
• NC
  National Cancer Institute