A new study published this month in the Journal of the National Cancer Institute found that thiazolidinediones (TZDs) can increase a patient’s risk of bladder cancer. Researchers from the University of Pennsylvania Perlman School of Medicine found that patients taking TZDs had a two- to three-fold higher risk of bladder cancer than those taking sulfonylureas. TZDs account for about 20 percent or more of antidiabetic drugs in the United States, and sulfonylureas are also more commonly used. The authors say the study is important because people with diabetes themselves have a slightly higher risk of bladder cancer than the general population. While 30 out of 100,000 people in the general population will develop bladder cancer, the incidence of bladder cancer in people with diabetes is typically 0.04%. The authors of the study analyzed 60,000 people with type 2 diabetes from the UK’s Health Improvement Network database. The authors found that patients taking TZDs such as pioglitazone or rosiglitazone had two to three times the risk of having bladder cancer for five years or more than those taking sulfonylureas. Patients taking TZDs for five years or more will have bladder cancer in 170 out of every 100,000 patients. About 60 out of every 100,000 patients taking sulfonylureas like glibenclamide develop bladder cancer. Diabetes is one of the most common global chronic diseases, with approximately 285,000,000 people living with diabetes worldwide. Clinicians take many factors into account when giving medications to patients with diabetes, and these new study data provide clinicians with very important information. Ronac Mamtani, MD, PhD, lead author of the study and a faculty member in the Hematology-Oncology subspecialty at the University of Pennsylvania Abmussen Cancer Center, said our study suggests that concerned diabetic physicians should also be aware of any bladder-related symptoms in their patients, such as hematuria, and take further steps to evaluate these symptoms. Since Avandia was found to be associated with serious cardiovascular disease, most U.S. patients no longer take it, but Actos remains the ninth most commonly prescribed drug in the United States. The drug has become the most common choice for patients with type II diabetes when their condition can no longer be controlled with the first-line drug Metformin. Based on previous data on the safety risks for patients taking Actos, the FDA had warned that Actos could be linked to bladder cancer. France and Germany have withdrawn the drug from the market. As the first study to analyze the risk of bladder cancer in patients taking both classes of TZDs and taking sulfonamides, it also ranks among the many pieces of evidence against the use of TZDs. ”This risk for both classes of TZD drugs appears to be very common. We had compared the risk of bladder cancer in patients taking each class of such drugs, giving us some necessary information, because safety warnings for drugs are only useful if doctors are aware of the same risks of alternative drugs. “We believe our study will help physicians and patients weigh the potential benefits and risks of different diabetes drug therapies when choosing between them,” Mamtani said.