title: Initial metformin or sulphonylurea exposure and cancer occurrence among patients with type 2 diabetes mellitus.
abstract: OBJECTIVE
  This was a retrospective cohort study of type 2 diabetes patients, to evaluate the association between initial metformin or sulphonylurea treatment and cancer incidence.
  
  
  METHODS
  Patients identified in the UK Clinical Practice Research Datalink (CPRD), previously General Practice Research Database, during 1995-2008 who were initially stabilized on OHA monotherapy, including metformin, sulphonylurea, thiazolidinediones (TZDs) or meglitinides, were included in the cohort. New diagnoses of cancer, including malignant solid tumours and haematological malignancies, occurring during the follow-up were identified from the cohort. Age-standardized incidence rates were estimated and compared between metformin and sulphonylurea exposure groups.
  
  
  RESULTS
  The age standardized incidences of cancer were 7.5 and 8.5 per 1000 person-years for the metformin and sulphonylurea exposure groups, respectively. After adjusting for potential confounders, the hazard ratios (HR) for malignant solid tumours and haematological malignancies were 1.06 (95% CI: 0.98, 1.15) and 0.98 (95% CI: 0.67, 1.43) for sulphonylurea group as compared to the metformin group, respectively. For individual cancers, the HRs were 1.17 (95% CI: 0.95, 1.44), 1.04 (95% CI: 0.83, 1.31) and 0.88 (95% CI: 0.71, 1.11) for colorectal cancer, breast cancer and prostate cancer, respectively.
  
  
  CONCLUSIONS
  This study provides evidence that cancer incidence in the first few years after starting metformin or sulphonylurea therapy in type 2 diabetes patients is not much affected by choice of hypoglycaemic drug class.
authors.affiliation: Department of Epidemiology, University of Medicine and Dentistry of New Jersey-School of Public Health, New Brunswick, NJ, USA. hqiu@its.jnj.com
authors.forename: H
authors.initials: H
authors.lastname: Qiu
authors.forename: G G
authors.initials: GG
authors.lastname: Rhoads
authors.forename: J A
authors.initials: JA
authors.lastname: Berlin
authors.forename: S W
authors.initials: SW
authors.lastname: Marcella
authors.forename: K
authors.initials: K
authors.lastname: Demissie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001549:Benzamides / Q000008:administration & dosage / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000453:epidemiology; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000009:adverse effects*; D015994:Incidence; D008297:Male; D008687:Metformin / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology; D011471:Prostatic Neoplasms / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D013453:Sulfonylurea Compounds / Q000008:administration & dosage / Q000009:adverse effects*; D045162:Thiazolidinediones / Q000008:administration & dosage / Q000009:adverse effects*; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D001549:Benzamides; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones; C030516:meglitinide; D008687:Metformin