title: Male pattern baldness and risk of colorectal neoplasia.
abstract: BACKGROUND
  Male pattern baldness is positively associated with androgens as well as insulin-like growth factor 1 (IGF-1) and insulin, all of which are implicated in pathogenesis of colorectal neoplasia.
  
  
  METHODS
  From 1992 through 2010, we prospectively followed participants in the Health Professionals Follow-Up Study. Hair pattern at age 45 years was assessed at baseline with five image categories (no baldness, frontal-only baldness, frontal-plus-mild-vertex baldness, frontal-plus-moderate-vertex baldness, and frontal-plus-severe-vertex baldness). Cancer analysis included 32 782 men and used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted to men who underwent at least one endoscopy over the study period, adenoma analysis included 29 770 men and used logistic regressions for clustered data to estimate odds ratios (ORs) and 95% CIs.
  
  
  RESULTS
  Over the mean follow-up of 15.6 years, 710 cases of colorectal cancer (478 for colon, 152 for rectum, and 80 unknown site) developed. Significantly increased risks associated with frontal-only baldness and frontal-plus-mild-vertex baldness relative to no baldness were observed for colon cancer with respective HR being 1.29 (95% CI, 1.03-1.62) and 1.31 (95% CI, 1.01-1.70). Over the 19-year study period, 3526 cases of colorectal adenoma were detected. Evidence for an increased risk of colorectal adenoma relative to no baldness was significant with frontal-only baldness (OR, 1.16; 95% CI, 1.06-1.26) and borderline insignificant with frontal-plus-severe-vertex baldness (OR, 1.14; 95% CI, 0.98-1.33).
  
  
  CONCLUSIONS
  Subtypes of male pattern baldness at age 45 years were positively associated with colorectal neoplasia. Future studies are warranted to confirm our results and to determine the predictive value of male pattern baldness to identify those at high risk for colorectal neoplasia.
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.|Department of Epidemiology, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: N
authors.initials: N
authors.lastname: Keum
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.|Department of Epidemiology, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.|Department of Epidemiology, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Family Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: S M
authors.initials: SM
authors.lastname: Park
authors.affiliation: Department of Biostatistics, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: B
authors.initials: B
authors.lastname: Rosner
authors.affiliation: Department of Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Fuchs
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.
authors.forename: K
authors.initials: K
authors.lastname: Wu
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.|Department of Epidemiology, Harvard T.H. Chan School of Public Health, Building 2, 3rd Floor, 665 Huntington Avenue, Boston, MA 02115, USA.|Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.|Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: E L
authors.initials: EL
authors.lastname: Giovannucci
mesh_terms: D000328:Adult; D000368:Aged; D000505:Alopecia / Q000150:complications*; D015179:Colorectal Neoplasms / Q000209:etiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012306:Risk