More scientific data has solidified the association between Actos, a popular prescription drug used to treat type 2 diabetes, and bladder cancer.
The new study found that people who suffer from diabetes already have a 40 percent higher risk for bladder cancer. Taking Actos (pioglitazone) adds a 22 percent increased risk to an already-high occurrence for bladder cancer, explains Jeffrey A. Johnson, the lead researcher on the study that appeared July 3, 2012, in the Canadian Medical Association Journal.
The Canadian study involved data from more than 2.6 million people. After starting an Actos treatment regimen, 3,643 of those people with type 2 diabetes developed bladder cancer.
Johnson said it’s not clear yet how Actos raises the risk of bladder cancer, according to the National Institutes of Health. He did say that some animal studies suggest that the drug could cause crystals to form that irritate the bladder, which could affect the development of cancer in that organ.
Type 2 Diabetes and Actos
Type 2 diabetes is defined as the condition when a patient cannot produce enough insulin or cannot process the insulin produced by the body. Insulin is the body’s hormone that stabilizes the blood sugar, or glucose.
Actos, which is a drug in the thiazolidinedione class, is used to help adults regulate their levels of blood sugar when diet and exercise alone do not work. The drug is designed to make cells more sensitive to insulin. However, insulin also is a growth hormone. Cancer cells have insulin receptors, which allow them to use the additional insulin to grow.
Johnson stated that because Actos, and other thiazolidinedione drugs, reduce the amount of insulin the body needs, he concludes in the study that the bladder cancer would have to be the result of a direct effect of the medication.
Actos Repeatedly Linked to Bladder Cancer
Another recent Canadian study found that taking Actos for two years can double a patient’s risk of developing bladder cancer. Data from more than 115,000 diabetes patients was analyzed in the study published May 31 in the British Medical Journal (BMJ). The abstract states, “The safety of pioglitazone, an oral antidiabetic agent in the thiazolidinedione class, is controversial.”
Further evidence of the health risk linked to taking Actos was revealed a year ago. On June 15, 2011, the U.S. Food and Drug Administration (FDA) issued a safety alert, stating that the use of Actos for more than one year may be associated with an increased risk of developing bladder cancer. The agency based its warning on the five-year interim results of a decade-long study being conducted by Actos manufacturer Takeda Pharmaceuticals. In 2011, the FDA also required medicines containing pioglitazone to include a warning about the increased risk of bladder cancer.