(HealthDay News) — For patients with type 2 diabetes newly treated with antidiabetic drugs, use of pioglitazone is associated with an increased risk of bladder cancer, with duration-response and dose-response correlations, according to a study published online in The BMJ.
Marco Tuccori, PhD, from the Jewish General Hospital in Montreal, and colleagues conducted a population-based study involving 145,806 patients newly treated with antidiabetic drugs from Jan. 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 of bladder cancer compared with other antidiabetic drugs (121.0 versus 88.9 per 100,000 person years; hazard ratio, 1.63; 95 percent confidence interval, 1.22 to 2.19). No increased risk of bladder cancer was seen for rosiglitazone (86.2 versus 88.9 per 100,000 person years; hazard ratio, 1.10; 95% confidence interval, 0.83 to 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 authors write. “The absence of an association with rosiglitazone suggests that the increased risk is drug specific and not a class effect.”