Patients with type 2 diabetes who were treated with pioglitazone (Actos) showed no increased risk of bladder cancer, according to a new analysis.

"The 10-year final analysis did not show any statistically significant findings of increased risk of bladder cancer with long term use of pioglitazone," according to a statement from Takeda Pharmaceuticals.

The study was conducted by the University of Pennsylvania and Kaiser Permanente Northern California.

As part of glucose control regimens, pioglitazone is an oral drug that lowers the amount of sugar in the blood. More specifically, the drug attaches to the insulin receptors on cells throughout the body and causes the cells to become more sensitive to insulin. Its use is not recommended in patients with class III or IV heart failure.

"The results of the study provide reassurance with regard to the use of pioglitazone and the risk of bladder cancer," said Tom Harris, who heads global regulatory affairs for Takeda, in the company statement.

Opposite findings

This finding contradicts an earlier analysis that showed a significantly higher incidence of bladder cancer in long-term pioglitazone users. That study, published in Diabetes Care, found an increased risk among patients who took the drug for more than two years. It involved more than 193,000 patients, 30,173 of whom had been treated with pioglitazone. Of all users, there were 90 cases of bladder cancer.

Following the publication of the interim analysis, the U.S. Food and Drug Administration added a warning about the risk of bladder cancer on the label of pioglitazone, and the drug was banned from use in France and Germany.

In addition, a meta-analysis of four randomized trials found an increased risk as well.

It's clear that further research is required to sort out the contradictions.

To learn more about bladder problems with diabetes:

Teaching Your Bladder to Behave
Diabetes and Overactive Bladder: 5 Signs You Need Treatment
Overactive Bladder? 8 Lifestyle Changes to Help Reduce Symptoms