Effects of thiazolidinedione in patients with active bladder cancer

Objective To examine the influence of perioperative thiazolidinedione (TZD) on cancer‐specific outcomes in patients with diabetes mellitus (DM) undergoing radical cystectomy (RC) for urothelial carcinoma (UC). Patients and Methods A retrospective cohort of 173 patients with DM undergoing RC from 2005 to 2010 was identified. Of those, 53 were on TZD treatment at the time of RC, with 33 patients taking pioglitazone. Baseline clinicopathological characteristics, as well as cancer‐specific survival (CSS), recurrence‐free survival (RFS), and overall survival (OS) were compared between the patients on and off TZD therapy at the time of RC. In subgroup analysis, outcomes in patients specifically taking pioglitazone at the time of RC were compared to those not on a TZD. Results Baseline clinicopathological characteristics were similar between patients on and off TZD therapy at the time of RC. Overall, the median CSS rate was not reached in either group (P = 0.7). The estimated 5‐year CSS was 67.8% in the non‐TZD group and 66.3% in the TZD group. On multivariate analysis incorporating patient age, pathological T‐staging, and adjuvant chemotherapy, TZD use was found not to be a significant predictor for CSS (hazard ratio 1.20, 95% confidence interval 0.66–2.17; P = 0.5). Additionally, RFS (P= 0.3) and OS (P = 0.2) were also similar between the two groups without adjusting for other variables. Comparison between patients taking pioglitazone vs patients not taking TZD yielded similar CSS (P = 0.2), RFS (P = 0.5), and OS (P= 0.2). Conclusions CSS, as well as RFS and OS after RC were not compromised in patients on TZD therapy at the time of RC. Additional investigation is warranted in patients with non‐muscle‐invasive bladder cancer and muscle‐invasive bladder cancer undergoing bladder‐sparing procedures to assess the safety of using TZD in the setting of active UC.