Rosiglitazone may reduce thyroid cancer risk in patients with type 2 diabetes.
BACKGROUND
Whether rosiglitazone use in patients with type 2 diabetes may affect thyroid cancer risk has not been investigated.


METHODS
The reimbursement databases of all diabetic patients under oral anti-diabetic agents or insulin from 1996 to 2009 were retrieved from the National Health Insurance of Taiwan. An entry date was set at 1 January 2006, and 887,665 patients with type 2 diabetes were followed for thyroid cancer incidence until the end of 2009 for ever-users, never-users, and subgroups of rosiglitazone exposure using tertile cut-offs for time since starting rosiglitazone, duration of therapy, and cumulative dose. Hazard ratios were estimated by Cox regression.


RESULTS
There were 103,224 ever-users and 784,441 never-users, with respective numbers of incident thyroid cancer of 84 (0.08%) and 764 (0.10%), and respective incidence of 23.12 and 28.09 per 100,000 person-years. The overall multivariable-adjusted hazard ratio was not significant. However, in dose-response analyses, the adjusted hazard ratios (95% confidence intervals) were significant for the third tertile of duration of therapy (≥ 14 months) and cumulative dose (≥ 1,800 mg) for age ≥ 50 years: 0.53 (0.31-0.89) and 0.50 (0.29-0.87), respectively.


CONCLUSIONS
This study suggests that rosiglitazone use in patients with type 2 diabetes may reduce the risk of thyroid cancer.
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 , and Division of Environmental Health and Occupational Medicine of the National Health Research Institutes , Taipei , Taiwan.
Chin-Hsiao
CH
Tseng
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D000077154:Rosiglitazone; D013624:Taiwan; D045162:Thiazolidinediones / Q000627:therapeutic use*; D013964:Thyroid Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D016896:Treatment Outcome
D007004:Hypoglycemic Agents; D045162:Thiazolidinediones; D000077154:Rosiglitazone