Diabetes drug Actos linked to possible cancer risk

While the US Food and Drug Administration hasn't taken any action to restrict the use of Actos -- one of the most popular diabetes drugs -- both Germany and France suspended new prescriptions this week due to results from a new French study of 155,000 people taking Actos from 2006 to 2009. The study found about a 22 percent higher risk of bladder cancer in those taking Actos compared with diabetics taking other drugs.

"I think it’s worthwhile for patients to be aware of this issue," says Dr. Ken Snow, director of medical programs at the Joslin Diabetes Center. "But they also need to realize that diabetes patients are already at higher risk of bladder cancer," he adds, just by having the disease and it could be that those who were prescribed Actos also had some other health factor that made them more likely to develop the cancer than those not prescribed the drug.

The FDA began a review of Actos and bladder cancer last September after some initial data showed an increased risk in those who had been on the drug for longer durations and at higher doses. Since then, data have been conflicting.

One study conducted by Kaiser Permanente health plan found the risk of bladder cancer wasn't significantly higher in 30,000 Actos users compared with 160,000 other diabetics who didn't use the drug. That's a finding being highlighted by Takeda, maker of Actos. The company says the FDA has given no indication that it will restrict Actos.

On the other hand, a further analysis of the data recently published in the journal Diabetes Care found a 40 percent increased risk of bladder cancer in those patients who took the drug for at least two years.

"Short-term use of pioglitazone was not associated with an increased incidence of bladder cancer, wrote the study authors, "but use for more than 2 years was weakly associated with increased risk."

Until, the FDA moves to issue a statement either way on the potential bladder cancer risks, those on Actos should talk to their doctors about the drug's risks and benefits.