title: Aspirin use and the risk of prostate cancer: a meta-analysis of 24 epidemiologic studies.
abstract: OBJECTIVE
  Several epidemiologic studies were performed to clarify the protective effect of regular aspirin use on prostate cancer risk; however, the results remain controversial. Therefore, we conducted this meta-analysis to assess the association between regular aspirin use and risk of prostate cancer.
  
  
  METHODS
  Electronic databases including PubMed, EMBASE and Cochrane Library were searched between January 1966 and April 2013 to identify eligible studies. Pooled relative ratios (RRs) and 95 % confidence intervals (CIs) were computed to assess the influence of aspirin use on prostate cancer risk. All statistical tests were two-sided.
  
  
  RESULTS
  A total of 24 observational studies including 14 case-control studies and 10 cohort studies were eligible for this meta-analysis. Regular aspirin use was associated with reduction in overall and advanced prostate cancer risk (pooled RR 0.86, 95 % CI 0.81-0.92; pooled RR 0.83, 95 % CI 0.75-0.91, respectively). When we restricted our analyses to studies with long-time regular aspirin use (equal or more than 4 years), reverse association became stronger (pooled RR 0.82, 95 % CI 0.72-0.93; pooled RR 0.70, 95 % CI 0.55-0.90, respectively).
  
  
  CONCLUSIONS
  Our findings suggest that regular, especially long-time regular aspirin use may reduce the risk of overall and advanced prostate cancer. Considering the limitation of included studies, further well-designed large-scaled cohort studies and RCTs are required to draw more definitive conclusions.
authors.affiliation: Department of Urology, Shanghai Tenth People's Hospital, Tongji University, 301 Yanchang Road, Shanghai, 200072, China.
authors.forename: Tian-Bao
authors.initials: TB
authors.lastname: Huang
authors.forename: Yang
authors.initials: Y
authors.lastname: Yan
authors.forename: Zhui-Feng
authors.initials: ZF
authors.lastname: Guo
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Zhang
authors.forename: Huan
authors.initials: H
authors.lastname: Liu
authors.forename: Jiang
authors.initials: J
authors.lastname: Geng
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Yao
authors.forename: Jun-Hua
authors.initials: JH
authors.lastname: Zheng
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D016021:Epidemiologic Studies; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000517:prevention & control*; D018570:Risk Assessment
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin