Diabetes is an Important Risk Factor for Metastasis in Non- Muscle-Invasive Bladder Cancer

Background: Epidemiological evidence indicates that individuals with diabetes mellitus (DM) may have a modestly increased risk of bladder cancer. In the present study, we aimed to show any association between DM and risk of metastasis in patients with non-muscle-invasive bladder cancer (NMIBC). Materials and
Methods: We retrospectively analyzed 698 patients between January 2007 and December 2014 who were diagnosed with and underwent transurethral resection of bladder tumors (TUR-BT). Comparisons of means was conducted by independent samples t test, and relations between categorical variables were investigated by non-parametric chisquare test. A p value of 0.05 was accepted as statistically significant in comparisons.
Results: We analyzed 418 patients with non muscle invasive bladder cancer. 123 of whom were diabetic and 295 non-diabetic. In diabetic patients, 13 were N1 stage and 11 M1 stage. When compared with non diabetic patients that was statistically significant (p<0.001). TNM stages were more advanced in diabetic patients (p<0.001), but concurrent CIS (p=0.1) and squamous metaplasia did not significantly differ between diabetic and non diabetic cases (p=1).
Conclusions: Diabetic patients with non-muscle-invasive bladder cancer may suffer metastases earlier than expected although they are non invasive. Therefore such patients must be followed-up carefully and early cystectomy decision may be necessary. Further prospective studies with more patients are needed to confirm these findings.