• diabetes mellitus;
  • progression;
  • recurrence;
  • urinary bladder neoplasm

Objective:  The aim of the present study was to investigate the relationship between diabetes mellitus (DM) and tumor features in patients with non-muscle invasive bladder cancer (NMIBC).

Methods:  Data from 251 patients who underwent transurethral resection (TUR) for NMIBC from January 2000 to June 2010 were analyzed retrospectively. Patients were divided into two groups: Group I, 159 patients (63%) who did not have DM at the time of surgery; and (ii) Group II, 92 patients (37%) who had DM at the time of surgery. Recurrence- and progression-free survival was assessed in both groups. Preoperative HbA1c levels, as parameter of glycemic control, were determined in Group II patients, with patients divided into two subgroups: (i) HbA1c ≥7.0%; and (ii) HbA1c <7.0%. The clinical features of the bladder tumor were compared in these two subgroups.

Results:  Compared with Group I, Group II patients were older and had a higher rate of hypertension, recurrence, and progression (P < 0.05). Univariate survival analysis showed that gender, DM, smoking, and serum creatinine were associated with recurrence-free survival (P < 0.05), whereas DM, stage, grade, intravesical instillation, and serum creatinine were associated with progression-free survival. In multivariate survival analysis, DM was found to be an independent factor for recurrence- (hazard ratio [HR] 2.11; 95% confidence interval [CI] 1.4–3.2; P = 0.001) and progression-free survival (HR 9.35; 95% CI 3.1–28.6; P = 0.001). Furthermore, patients with HbA1c ≥7.0% exhibited a significantly higher rate of multiplicity (P = 0.001), tumor grade (P = 0.03), and intravesical treatment (P = 0.04).

Conclusions:  In conclusion, DM seems to be an independent predictor of recurrence- and progression-free survival in NMIBC patients. Further prospective studies are needed to establish the prognostic significance of postoperative glycemic control in this patient population.