Recent research links the diabetes drug pioglitazone with an increased risk of bladder cancer.
The nested case-control study analyzed data from 115 727 patients in the United Kingdom who were newly treated with diabetes drugs between 1988 and 2009. Researchers reported an 83% increased risk of bladder cancer in those who had ever taken pioglitazone, which translates into a rate of 74 cases per 100 000 person-years. Even though that's similar to the rate among people at least 65 years old in the United Kingdom—73 per 100 000 person-years—the study participants were younger (mean age, 64.1 years) and so at less risk of developing bladder cancer. Investigators also found that in patients taking the drug for 2 years or longer, the bladder cancer rate was 88 cases per 100 000 person-years and 137 per 100 000 in patients with a cumulative dose totaling 28 000 mg or more (Azoulay L et al. BMJ. doi: 10.1136/bmj.e3645 [published online May 31, 2012]).
Voelker R. Diabetes Drug Is Linked With Bladder Cancer Risk. JAMA. 2012;307(24):2577. doi:10.1001/jama.2012.7131