title: Effect of Metformin and Statin Use on Survival in Pancreatic Cancer Patients: a Systematic Literature Review and Meta-analysis.
abstract: OBJECTIVE
  Current epidemiological studies report conflicting results for the effect of statin or metformin on pancreatic cancer overall survival. This literature review and meta-analysis summarize the studies reporting an association between statin or metformin use and overall survival of pancreatic cancer patients.
  
  
  METHODS
  We systematically searched for studies about the association between statin or metformin use and pancreatic cancer overall survival in electronic databases (PubMed, ISI Web of Science, MEDLINE, Cochrane, Scopus, Google Scholar). A meta-analysis based on hazard ratios (HRs) and 95% confidence intervals (CIs) was performed using random effect models. Heterogeneity between the studies was examined using I2 statistics, and sensitivity analyses were conducted to assess the robustness of the findings.
  
  
  RESULTS
  Of 116 statin-related articles identified, 6 retrospective cohort studies representing 12,057 patients were included. There was significant heterogeneity between studies. Statin use was associated with improved survival among pancreatic cancer patients (meta-HR = 0.75; 95% CI: 0.59, 0.90; P < 0.001). Of 311 metformin-related articles, 8 retrospective cohort studies and 2 randomized clinical trials, representing 3,042 patients were identified. Metformin use was associated with better overall survival among pancreatic cancer patients (meta-HR = 0.79; 95% CI: 0.70, 0.92, P < 0.001), and significant heterogeneity was observed between studies.
  
  
  CONCLUSIONS
  Our findings suggest that the improved survival time of pancreatic cancer patients are associated with statin or metformin use. Due to the multiple sources of heterogeneity of the original studies, these findings should be considered cautiously, and confirmed with larger prospective individual-level studies.
authors.affiliation: Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.|Department of Epidemiology, School of Public Health, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.
authors.lastname: Jian-Yu E
authors.affiliation: Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.|Department of Epidemiology, School of Public Health, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.|Environmental and Occupational Health Sciences Institute, Rutgers, The State University of New Jersey, United States.
authors.forename: Judith M
authors.initials: JM
authors.lastname: Graber
authors.affiliation: Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.|Department of Biostatistics, School of Public Health, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.
authors.forename: Shou-En
authors.initials: SE
authors.lastname: Lu
authors.affiliation: Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.|Department of Biostatistics, School of Public Health, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.
authors.forename: Yong
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.|Department of Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.
authors.forename: Grace
authors.initials: G
authors.lastname: Lu-Yao
authors.affiliation: Rutgers Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.|Department of Epidemiology, School of Public Health, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.|Department of Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ 08904, United States.
authors.forename: Xiang-Lin
authors.initials: XL
authors.lastname: Tan
mesh_terms: D016208:Databases, Factual; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008687:Metformin / Q000627:therapeutic use*; D016017:Odds Ratio; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D016016:Proportional Hazards Models; D015996:Survival Rate
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008687:Metformin
keywords: Statin; cancer drug; meta-analysis; metformin; overall survival; pancreatic cancer.