title: Metformin use and the risk of esophageal cancer in Barrett esophagus.
abstract: OBJECTIVE
  Diabetes mellitus is a significant risk factor for total cancer incidence and mortality. Metformin, a commonly used antidiabetic drug, has been shown to be protective against different types of cancers; however, its role in esophageal cancer is unknown. The goal of this study was to determine whether the use of metformin modifies the risk of development of esophageal adenocarcinoma in patients with Barrett esophagus.
  
  
  METHODS
  Patients with diagnoses of Barrett esophagus and esophageal cancer were identified during a 20-year period. Demographic and clinical data were collected. The outcome variable was esophageal adenocarcinoma. Univariate analysis was performed using two-sample t tests for continuous variables or the Fisher exact test for categorical variables. Multiple logistic regression analysis was then performed using the significant variables.
  
  
  RESULTS
  A total of 583 patients were identified with the diagnosis of Barrett esophagus or esophageal adenocarcinoma from 1992 to 2012. Of these, 115 had esophageal adenocarcinoma and 468 had Barrett esophagus. Age, smoking, and diabetes mellitus were found to be significant risk factors for the development of esophageal cancer with the following results: age (P < 0.001), smoking (P = 0.003), diabetes mellitus (P = 0.007). Statin use was protective against the development of cancer with P = 0.001. Metformin use was neither associated with an increased nor a decreased risk of esophageal cancer.
  
  
  CONCLUSIONS
  The three independent variables that predicted progression of Barrett esophagus to esophageal adenocarcinoma in our study were older age, smoking, and diabetes mellitus. Statin use showed protective effect against development of esophageal adenocarcinoma. Metformin use did not demonstrate any statistically significant protective effect.
authors.affiliation: From the Dayton VA Medical Center, and the Departments of Internal Medicine, Gastroenterology, and Pathology, Wright State University, Dayton, Ohio.
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Agrawal
authors.affiliation: From the Dayton VA Medical Center, and the Departments of Internal Medicine, Gastroenterology, and Pathology, Wright State University, Dayton, Ohio.
authors.forename: Piyush
authors.initials: P
authors.lastname: Patel
authors.affiliation: From the Dayton VA Medical Center, and the Departments of Internal Medicine, Gastroenterology, and Pathology, Wright State University, Dayton, Ohio.
authors.forename: Ayush
authors.initials: A
authors.lastname: Agrawal
authors.affiliation: From the Dayton VA Medical Center, and the Departments of Internal Medicine, Gastroenterology, and Pathology, Wright State University, Dayton, Ohio.
authors.forename: Neil
authors.initials: N
authors.lastname: Makhijani
authors.affiliation: From the Dayton VA Medical Center, and the Departments of Internal Medicine, Gastroenterology, and Pathology, Wright State University, Dayton, Ohio.
authors.forename: Ronald
authors.initials: R
authors.lastname: Markert
authors.affiliation: From the Dayton VA Medical Center, and the Departments of Internal Medicine, Gastroenterology, and Pathology, Wright State University, Dayton, Ohio.
authors.forename: William
authors.initials: W
authors.lastname: Deidrich
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001471:Barrett Esophagus / Q000150:complications / Q000473:pathology*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy*; D004938:Esophageal Neoplasms / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D011230:Precancerous Conditions / Q000150:complications / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin