A Multinational, Multi-Institutional Study Assessing the Impact of Diabetes Mellitus on the Prognosis of Patients with Non-Muscle Invasive Bladder Cancer Treated with Bacillus Calmette-Guérin

The study aimed to examine the impact of diabetes mellitus type 2 (DMII) on the oncological outcomes of non-muscle invasive bladder cancer (NMIBC) treated with Bacillus Calmette-Guérin (BCG) using comprehensive real-world data. We performed an analysis of data on NMIBC patients treated with BCG from the United States (US) National Phase II BCG/Interferon (IFN) trial database (125 centers) and pooled databases from three tertiary care institutions: France (FR), Lebanon (LB) (2000-2021), and the US (University of Iowa) (2011-2021). There were 867 patients from the Phase II trial, 1232 from the FR/LB cohort, and 233 from the US (Iowa) cohort (n = 2332). DM II was reported in 13% of the Phase II trial cohort, 14.4% of the FR/LB cohort, and 33.5% of the US (Iowa) cohort. The median follow-up was 24 months in the Phase II trial cohort, 25 months in the FR/LB cohort, and 48 months in the US (Iowa) cohort. In multivariable Cox regression analyses, DMII was not significantly associated with recurrence or progression of the tumor in any of the cohorts included in this study. DMII may not be a clinical prognostic factor for NMIBC patients treated with BCG. Prospective evaluation is needed.