Pathology of bladder cancer among diabetic patients undergoing radical cystectomy with a history of pioglitazone (Actos) use

BACKGROUND Prospective studies suggested an association between pioglitazone (Actos) use and the development of bladder cancer. Cancer pathology among pioglitazone users has not been characterized. We chose to compare the surgical pathology among diabetic users and non-users, as well as non-diabetic patients who underwent radical cystectomy for bladder cancer. METHODS Our single-center, prospectively-maintained bladder cancer database was reviewed. Patient demographics, surgical pathology, and outcomes were evaluated. Information regarding diabetic history and use of pioglitazone was determined from chart analysis and patient interview. RESULTS From April 2005 to October 2011, 204 patients undergoing radical cystectomy were identified. Of these, 33 (16.2%) were diabetic and 171 (83.8%) had no history of diabetes. Among diabetic patients, 9 (27.3%) had a history of pioglitazone use. Median duration of therapy was 14 (6-120) months. Pathology in non-diabetic patients was T1 in 17 (9.9%), T2 in 38 (22.2%), T3 in 44 (25.7%), and T4 in 31 (18.1%). Pathology among diabetic non-users was T1 in 1 (4.2%), T2 in 7 (29.2%), T3 in 7 (29.2%), and T4 in 4 (16.7%). Pathologic stage among diabetic users was T1 in 1 (11.1%), T2 in 3 (33.3%), T3 in 3 (33.3%), and T4 in 1 (11.1%). Lymph node involvement in non-diabetics, diabetic non-users, and diabetic users was 25.7%, 33.3%, and 33.3%, respectively. Cancer-specific death was seen in 60.3% of non-diabetics, 58.3% of diabetic non-users, and 75% of diabetic users. CONCLUSIONS Diabetics have similar stage distribution regardless of pioglitazone use. Lymph node metastases rates and cancer specific death were similar across all groups. Additional studies will serve to better characterize this relationship.