title: Effect of metformin on the incidence of head and neck cancer in diabetics.
abstract: BACKGROUND
  The purpose of this study was to examine the effect of metformin on head and neck cancer in patients with diabetes.
  
  
  METHODS
  We compared 66,600 patients, all with diabetes and all newly diagnosed with head and neck cancer in 2002. Half were being treated with metformin for diabetes (Met(+) ) and half were not (Met(-) : controls). All were matched for comorbidities (obesity, coronary artery disease, hyperlipidemia, and hypertension), sex, and age. The risk of head and neck cancer at the end of 2011 was determined.
  
  
  RESULTS
  The incidence of head and neck cancer was 34% lower in the Met(+) cohort than in the Met(-) cohort (adjusted hazard ratio [HR] = 0.66; 95% confidence interval [CI] = 0.55-0.79). The risks for oropharyngeal cancer (adjusted HR = 0.66; 95% CI = 0.17-0.74) and nasopharyngeal carcinoma (NPC; adjusted HR = 0.50; 95% CI = 0.31-0.80) were significantly lower in the Met(+) cohort than in the Met(-) cohort.
  
  
  CONCLUSIONS
  Metformin is associated with a lower risk of developing head and neck cancer in patients with diabetes.
authors.affiliation: Department of Ophthalmology, Chi Mei Medical Centre, Liou-Ying, Tainan City, Taiwan.
authors.forename: Yung-Chang
authors.initials: YC
authors.lastname: Yen
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, California.
authors.forename: Charlene
authors.initials: C
authors.lastname: Lin
authors.affiliation: Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, Canada.
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Lin
authors.affiliation: Department of Otolaryngology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.|Department of Otolaryngology, Chi Mei Medical Center, Tainan, Taiwan.
authors.forename: Yung-Song
authors.initials: YS
authors.lastname: Lin
authors.affiliation: Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan.|Department of Hospital and Health Care Administration, Chia-Nan University of Pharmacy and Science, Tainan, Taiwan.
authors.forename: Shih-Feng
authors.initials: SF
authors.lastname: Weng
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D016022:Case-Control Studies; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D018572:Disease-Free Survival; D005260:Female; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D015994:Incidence; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D016012:Poisson Distribution; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D016019:Survival Analysis; D013624:Taiwan / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D007004:Hypoglycemic Agents; D008687:Metformin
keywords: diabetes; head and neck cancer; metformin; nasopharyngeal carcinoma; oral cancer