title: Circumcision and the risk of prostate cancer.
abstract: BACKGROUND
  Several lines of evidence support a role for infectious agents in the development of prostate cancer (PCa). In particular, sexually transmitted infections (STIs) have been implicated in PCa etiology, and studies have found that the risk of acquiring a STI can be reduced with circumcision. Therefore, circumcision may reduce PCa risk.
  
  
  METHODS
  Participant data collected as part of 2 population-based case-control studies of PCa were analyzed. Self-reported circumcision status, age at circumcision, and age at first sexual intercourse were recorded along with a history of STIs or prostatitis. Multivariate logistic regression was used to estimate the relative risk of PCa by circumcision status.
  
  
  RESULTS
  Data from 1754 cases and 1645 controls were available. Circumcision before first sexual intercourse was associated with a 15% reduction in risk of PCa compared to that of uncircumcised men (95% confidence interval [CI], 0.73-0.99). This risk reduction was observed for cases with both less aggressive (odds ratio, 0.88; 95% CI, 0.74-1.04) and more aggressive (odds ratio, 0.82; 95% CI, 0.66-1.00) PCa features.
  
  
  CONCLUSIONS
  Circumcision before first sexual intercourse is associated with a reduction in the relative risk of PCa in this study population. These findings are consistent with research supporting the infectious/inflammation pathway in prostate carcinogenesis.
authors.affiliation: Department of Urology, University of Washington School of Medicine, Seattle, WA, USA. jlwright@uw.edu
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Wright
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Lin
authors.forename: Janet L
authors.initials: JL
authors.lastname: Stanford
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002944:Circumcision, Male / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D011472:Prostatitis / Q000453:epidemiology; D012307:Risk Factors; D012725:Sexual Behavior; D012749:Sexually Transmitted Diseases / Q000453:epidemiology*