Thiazolidinediones might might raise bladder cancer risk. please advise.?

Answer still unclear: Thiazolidinediones (tzd), used in the treatment of diabetes, have complex effects on the proliferation of cells. Early reports showed that tzds caused bladder cancer to occur in rats. Other studies showed that no cancers occurred in tzd treated mice. In humans, and in cell culture, it may be that tzd actually helps to eliminate bladder cancer and is being investigated as a potential treatment.