title: Reduced risk of colorectal cancer with use of oral bisphosphonates: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The association between oral bisphosphonate (BP) intake and colorectal cancer (CRC) risk has been investigated in several recent studies with conflicting results. We summarized the evidence from the published studies in a categorical, dose-response meta-analysis.
  
  
  METHODS
  Relevant studies were identified by a search of MEDLINE and EMBASE databases through January 15, 2012. We included studies that reported effect size estimates with 95% CIs for the association between exposure to oral BPs and risk of CRC.
  
  
  RESULTS
  Three case-control studies with a total of 16,998 CRC cases and 108,197 controls and one cohort study with 94,405 individuals exposed to BPs and 283,181 unexposed to BPs were included in meta-analysis. The random effect model meta-analysis suggested reduced risk of CRC with exposure to oral BPs with pooled odds ratio (OR) of 0.87 (95% CI, 0.78 to 0.97). Significant inverse relationship was noted for 10 or more prescriptions categories, with pooled ORs of 0.71 (95% CI, 0.58 to 0.87). Similarly, the analysis for 1 to 3 years of use and more than 3 years of use of BPs suggested a significant inverse relationship, with pooled ORs of 0.76 (95% CI, 0.68 to 0.85) and 0.78 (95% CI, 0.61 to 0.99), respectively.
  
  
  CONCLUSIONS
  This meta-analysis suggests that the use of oral BPs at a dose of 10 or more prescriptions or 1 or more years of duration is associated with reduced risk of CRC. Further randomized controlled trials are needed to prove this association.
authors.affiliation: The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
authors.forename: Nirav
authors.initials: N
authors.lastname: Thosani
authors.forename: Sonali N
authors.initials: SN
authors.lastname: Thosani
authors.forename: Sheetanshu
authors.initials: S
authors.lastname: Kumar
authors.forename: Zoann
authors.initials: Z
authors.lastname: Nugent
authors.forename: Camilo
authors.initials: C
authors.lastname: Jimenez
authors.forename: Harminder
authors.initials: H
authors.lastname: Singh
authors.forename: Sushovan
authors.initials: S
authors.lastname: Guha
mesh_terms: D000284:Administration, Oral; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000517:prevention & control*; D004164:Diphosphonates / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D016017:Odds Ratio; D040242:Risk Reduction Behavior
chemical_list: D004164:Diphosphonates