title: Colorectal Cancer Epidemiology in the Nurses' Health Study.
abstract: OBJECTIVE
  To review the contribution of the Nurses' Health Study (NHS) to identifying risk and protective factors for colorectal adenomas and colorectal cancer (CRC).
  
  
  METHODS
  We performed a narrative review of the publications using the NHS between 1976 and 2016.
  
  
  RESULTS
  Existing epidemiological studies using the NHS have reported that red and processed meat, alcohol, smoking, and obesity were associated with an increased risk of CRC, whereas folate, calcium, vitamin D, aspirin, and physical activity were associated with decreased risk of CRC. Moreover, modifiable factors, such as physical activity, vitamin D, folate, insulin and insulin-like growth factor binding protein-1, and diet quality, were identified to be associated with survival among CRC patients. In recent years, molecular pathological epidemiological studies have been actively conducted and have shown refined results by molecular subtypes of CRC.
  
  
  CONCLUSIONS
  The NHS has provided new insights into colorectal adenomas, CRC etiology, and pathogenic mechanisms. With its unique strengths, the NHS should continue to contribute to the field of CRC epidemiology and play a major role in public health.
authors.affiliation: All authors are with the Departments of Nutrition and Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA. Edward L. Giovannucci is also with the Department of Medicine, Harvard Medical School, Boston.
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Lee
authors.affiliation: All authors are with the Departments of Nutrition and Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA. Edward L. Giovannucci is also with the Department of Medicine, Harvard Medical School, Boston.
authors.forename: NaNa
authors.initials: N
authors.lastname: Keum
authors.affiliation: All authors are with the Departments of Nutrition and Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA. Edward L. Giovannucci is also with the Department of Medicine, Harvard Medical School, Boston.
authors.forename: Edward L
authors.initials: EL
authors.lastname: Giovannucci
mesh_terms: D000328:Adult; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008019:Life Style; D008137:Longitudinal Studies; D008875:Middle Aged; D009726:Nurses; D011446:Prospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D016387:Women's Health