Purpose: GnT-V is an enzyme that catalyzes beta1-6 branching of N-acetylglucosamine on asparagine (N)-linked oligosaccharides of cell proteins. GnT-V expression has been closely related to malignant potentials in colon cancer, brain cancer and hepatocellular carcinoma. We determined whether GnT-V expression is predictive of superficial bladder cancer recurrence.
Materials and methods: The cohort comprised 60 consecutive patients with first time superficial bladder cancer treated with transurethral resection. None of the patients received prophylactic intravesical therapy until recurrence. Paraffin embedded tumor specimens were immunohistochemically examined by the avidin-biotin peroxidase method using monoclonal antibody against GnT-V. Kaplan-Meier survival curves were generated to determine disease-free survival. Univariate and multivariate analyses were done to compare GnT-V expression to other clinical and pathological variables.
Results: GnT-V expression correlated inversely with tumor grade and stage. The positive incidence of GnT-V in G1 to G3 tumors was 7 of 9 (78%), 21 of 43 (49%) and 3 of 8 (38%), respectively. GnT-V was positive in 26 of 44 cases of pTa (60%) and in 5 of 16 of pT1 (31%) disease. The 31 patients with positive GnT-V expression had significantly higher disease-free survival than the 29 with negative GnT-V expression (log rank test p = 0.0034). Multivariate analysis revealed that patient age, pT, grade and negative GnT-V expression were independent predictors of recurrence (p = 0.015, 0.001, 0.019 and 0.011, respectively).
Conclusions: Immunohistochemical detection of GnT-V is an independent predictor of superficial bladder cancer recurrence.