title: Reproductive factors and risk of colorectal polyps in a colonoscopy-based study in western Washington State.
abstract: Oral contraceptives (OC) are associated with a decreased risk of colorectal cancers; however, a recent study reported an increased risk of small colorectal adenomas associated with OC use. To determine if these results were replicable in a different study population, we investigated the relationship between OC use and other reproductive factors and risk of colorectal polyps in a case-control study in western Washington.
  
  
  
  Study participants were 24-79-year-old female enrollees at an integrated health care system in western Washington who were diagnosed as having adenomas (n = 299), serrated polyps (n = 337), both types of polyps (n = 105) or as polyp-free controls (n = 615) through an index colonoscopy and completed a structured interview to collect reproductive history information. Multivariable polytomous logistic regression was used to compare case groups to controls and to each other; odds ratios (OR) and 95% confidence intervals were estimated.
  
  
  
  There was no association between OC use, duration of use, or recency of use and the risk of either adenomas or serrated polyps [adjusted OR for OC ever use (95% CI) 0.85 (0.58-1.23) and 0.96 (0.66-1.40), respectively], and associations did not differ by lesion severity within the adenoma or serrated pathways. Further, no associations were observed between other reproductive factors and risk of colorectal polyp subtypes.
  
  
  
  Our results suggest that reproductive factors, including OC use, are not associated with early colorectal cancer precursor lesions.
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., M4-B402, PO Box 19024, Seattle, WA, 98109-1024, USA. shardika@fhcrc.org.|Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA. shardika@fhcrc.org.
authors.forename: Sheetal
authors.identifier: 0000-0003-0292-6168
authors.initials: S
authors.lastname: Hardikar
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., M4-B402, PO Box 19024, Seattle, WA, 98109-1024, USA.|Kaiser Permanente, Colorado Institute for Health Research, Denver, CO, USA.
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Burnett-Hartman
authors.affiliation: Group Health Research Institute, Seattle, WA, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Chubak
authors.affiliation: Department of Pathology, School of Medicine, University of Washington, Seattle, WA, USA.
authors.forename: Melissa P
authors.initials: MP
authors.lastname: Upton
authors.affiliation: Group Health Research Institute, Seattle, WA, USA.
authors.forename: Lee-Ching
authors.initials: LC
authors.lastname: Zhu
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., M4-B402, PO Box 19024, Seattle, WA, 98109-1024, USA.|Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA.|Centre for Public Health Research, Massey University, Wellington, New Zealand.
authors.forename: John D
authors.initials: JD
authors.lastname: Potter
authors.affiliation: Public Health Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., M4-B402, PO Box 19024, Seattle, WA, 98109-1024, USA.|Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA, USA.
authors.forename: Polly A
authors.initials: PA
authors.lastname: Newcomb
mesh_terms: D000236:Adenoma / Q000453:epidemiology; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003111:Colonic Polyps / Q000175:diagnosis / Q000453:epidemiology*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000453:epidemiology; D003276:Contraceptives, Oral / Q000008:administration & dosage; D005260:Female; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D017584:Reproductive History; D012307:Risk Factors; D014861:Washington
chemical_list: D003276:Contraceptives, Oral
keywords: Adenomas; Oral contraceptives; Reproductive factors; Serrated polyps