title: Pioglitazone does not affect the risk of ovarian cancer: analysis of a nationwide reimbursement database in Taiwan.
abstract: BACKGROUND
  The association between pioglitazone and ovarian cancer has not been studied.
  
  
  METHODS
  The reimbursement databases of all Taiwanese patients with a diagnosis of diabetes and under oral anti-diabetic agents or insulin from 1996 to 2009 were retrieved from the National Health Insurance. An entry date was set at 1 January 2006 and a total of 546,632 female patients with type 2 diabetes were followed up for ovarian cancer incidence until the end of 2009. Incidences for ever-users, never-users and subgroups of pioglitazone exposure [using cutoffs of the Kaiser Permanente Northern California study and tertile cutoffs derived from the databases] were calculated and the hazard ratios were estimated by Cox regression in unadjusted, age-adjusted and fully adjusted models.
  
  
  RESULTS
  There were 30,783 ever-users and 515,849 never-users, with respective numbers of incident ovarian cancer of 49 (0.16%) and 946 (0.18%), and respective incidence of 43.08 and 51.47 per 100,000 person-years. The overall hazard ratios (95% confidence intervals) in unadjusted, age-adjusted and fully adjusted models were 0.822 (0.616-1.095), 0.823 (0.617-1.097) and 0.968 (0.718-1.305), respectively. In the dose-response analyses, none of the categories showed a significant hazard ratio, and all P-trends were >0.05 without statistical significance.
  
  
  CONCLUSIONS
  This study does not support a positive or negative association between pioglitazone use and ovarian cancer in female patients with type 2 diabetes.
authors.affiliation: Department of Internal Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Division of Endocrinology and Metabolism, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Division of Environmental Health and Occupational Medicine of the National Health Research Institutes, Taipei, Taiwan. Electronic address: ccktsh@ms6.hinet.net.
authors.forename: Chin-Hsiao
authors.initials: CH
authors.lastname: Tseng
mesh_terms: D000328:Adult; D000368:Aged; D016208:Databases, Factual; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D015994:Incidence; D007349:Insurance, Health, Reimbursement; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000453:epidemiology*; D000077205:Pioglitazone; D013624:Taiwan / Q000453:epidemiology; D045162:Thiazolidinediones / Q000627:therapeutic use*
chemical_list: D007004:Hypoglycemic Agents; D045162:Thiazolidinediones; D000077205:Pioglitazone
keywords: Diabetes mellitus; Incidence density; Ovarian cancer; Pioglitazone; Taiwan