title: Long-term use of antibiotics and risk of colorectal adenoma.
abstract: Recent evidence suggests that antibiotic use, which alters the gut microbiome, is associated with an increased risk of colorectal cancer. However, the association between antibiotic use and risk of colorectal adenoma, the precursor for the majority of colorectal cancers, has not been investigated.
  
  
  
  We prospectively evaluated the association between antibiotic use at age 20-39 and 40-59 (assessed in 2004) and recent antibiotic use (assessed in 2008) with risk of subsequent colorectal adenoma among 16 642 women aged ≥60 enrolled in the Nurses' Health Study who underwent at least one colonoscopy through 2010. We used multivariate logistic regression to calculate ORs and 95% CIs.
  
  
  
  We documented 1195 cases of adenoma. Increasing duration of antibiotic use at age 20-39 (ptrend=0.002) and 40-59 (ptrend=0.001) was significantly associated with an increased risk of colorectal adenoma. Compared with non-users, women who used antibiotics for ≥2 months between age 20 and 39 had a multivariable OR of 1.36 (95% CI 1.03 to 1.79). Women who used ≥2 months of antibiotics between age 40 and 59 had a multivariable OR of 1.69 (95% CI 1.24 to 2.31). The associations were similar for low-risk versus high-risk adenomas (size ≥1 cm, or with tubulovillous/villous histology, or ≥3 detected lesions), but appeared modestly stronger for proximal compared with distal adenomas. In contrast, recent antibiotic use within the past four years was not associated with risk of adenoma (ptrend=0.44).
  
  
  
  Long-term antibiotic use in early-to-middle adulthood was associated with increased risk of colorectal adenoma.
authors.affiliation: Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Yin
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Kana
authors.initials: K
authors.lastname: Wu
authors.affiliation: Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Raaj
authors.initials: R
authors.lastname: Mehta
authors.affiliation: Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: David A
authors.identifier: 0000-0002-8813-0816
authors.initials: DA
authors.lastname: Drew
authors.affiliation: Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Mingyang
authors.initials: M
authors.lastname: Song
authors.affiliation: Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Lochhead
authors.affiliation: Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Long H
authors.initials: LH
authors.lastname: Nguyen
authors.affiliation: Food Science and Technology Department, University of Nebraska, Lincoln, Nebraska, USA.
authors.forename: Jacques
authors.initials: J
authors.lastname: Izard
authors.affiliation: Yale Cancer Center, New Haven, Connecticut, USA.|Department of Medicine, Yale School of Medicine, New Haven, Connecticut, USA.|Smilow Cancer Hospital, New Haven, Connecticut, USA.
authors.forename: Charles S
authors.initials: CS
authors.lastname: Fuchs
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, USA.|Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.|Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Garrett
authors.affiliation: Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.|Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Curtis
authors.initials: C
authors.lastname: Huttenhower
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts, USA.|Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA.|Division of MPE Molecular Pathological Epidemiology, Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Shuji
authors.initials: S
authors.lastname: Ogino
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.|Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, USA.|Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Edward L
authors.initials: EL
authors.lastname: Giovannucci
authors.affiliation: Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA.|Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.|Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Chan
mesh_terms: D000236:Adenoma / Q000139:chemically induced / Q000453:epidemiology / Q000451:nursing* / Q000473:pathology; D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D003113:Colonoscopy / Q000451:nursing*; D015179:Colorectal Neoplasms / Q000139:chemically induced / Q000453:epidemiology / Q000451:nursing* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D015399:Nursing Research; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013997:Time Factors; D014481:United States / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents
keywords: ANTIBIOTICS; COLONIC MICROFLORA; COLORECTAL ADENOMAS; INFLAMMATION