Type 2 diabetes drugs not linked to bladder cancer

A new analysis of over one million people in six worldwide populations has found no link between the diabetes medicine pioglitazone and bladder cancer.
Previous studies had suggested a link between the two, with bladder cancer the ninth most common cancer in the world.
According to research published in Diabetologia, the cumulative use of pioglitazone or rosiglitazone, which are used to treat type 2 diabetes, was not associated with the risk of bladder cancer.
Diabetes medication study
This new study involved collecting data on prescriptions, cancer and mortality from people with type 2 diabetes across six populations: Manchester, Scotland, British Columbia, Finland, Rotterdam and the UK Clinical Practice Research Datalink.
This data was used to study the effect of pioglitazone and rosiglitazone exposure on incidences of bladder cancer, collated on 1.01 million people over 5.9 million person-years.
During a median follow-up duration of four to 7.4 years, there were 3,248 cases of incident bladder cancer found by the researchers. Only 117 cases in the patients with type 2 diabetes were ever exposed to pioglitazone.
“These data challenge the idea that pioglitazone causes bladder cancer,” said Helen Colhou, MD, of the University of Dundee, United Kingdom.
“Longer-term studies observational of real world exposure to diabetes drugs remain important, not just for this class of drugs, but other diabetes drugs too,” Colhoun said. “Such studies need to be careful to use methods that minimize biases.”