(HealthDay News) — For patients with type 2 diabetes newly treated with antidiabetic drugs, use of pioglitazone is associated with an increased risk for bladder cancer, with duration-response and dose-response correlations, according to a study published in The BMJ.
Marco Tuccori, PhD, from the Jewish General Hospital in Montreal, and colleagues conducted a population-based study involving 145 806 patients with type 2 diabetes newly treated with antidiabetic drugs from January 1, 2000, to July 31, 2013. The correlation between pioglitazone use and incident bladder cancer was examined.
The researchers found that 622 patients were newly diagnosed with bladder cancer during 689 616 person years of follow-up (crude incidence, 90.2 per 100,000 person years). Pioglitazone correlated with increased risk for bladder cancer compared with other antidiabetic drugs (121.0 vs 88.9 per 100 000 person years; hazard ratio, 1.63; 95% CI, 1.22-2.19).
No increased risk for bladder cancer was seen for rosiglitazone (86.2 vs 88.9 per 100 000 person years; hazard ratio, 1.10; 95% CI, 0.83-1.47).
For pioglitazone, but not rosiglitazone, there were duration-response and dose-response correlations.
“Pioglitazone is associated with an increased risk of bladder cancer,” the researchers wrote. “The absence of an association with rosiglitazone suggests that the increased risk is drug specific and not a class effect.”