Glut 1 expression in transitional cell carcinoma of the urinary bladder is associated with poor patient survival

Cancer cells show increased glucose uptake compared to normal cells. Glut1 has been shown to be expressed in many human cancers, including transitional cell carcinoma of the urinary bladder (TCCB). The aim of this study was to determine the biologic significance of Glut1 expression, as determined by immunohistochemistry, in TCCB. Using the polyclonal anti-Glut1 antibody MYM, microwave-aided antigen retrieval, and standard immunoperoxidase ABC technique, we immunostained sections of formalin-fixed and paraffin-embedded tissue from cystectomy specimens from 40 patients with TCCB, who received no adjuvant therapy. The percent of positive cancer cells was scored on a semiquantitative scale as 1) 0%, 2) 1-10%, 3) 11-25%, 4) 26-50%, 5) 5.1-75%, and 6) > 75%. Statistical analysis was performed using the Kaplan-Meier survival method, the Log rank test, and Fisher's exact test. Glut1 immunoreactivity was detected in 58% of the cases. Glut1 expression in > 10% of cancer cells was associated with worse patient survival than expression in < 10% of the cancer cells (p = 0.0064). Tumors with > 10% Glut1-positive cancer cells were more likely to be of pT2 stage or higher than tumors with < 10% Glut1-positive cells (100% vs 68%, respectively, p = 0.0109), but showed no significant difference in the incidence of nodal metastasis (p = 0.4258). Our results suggest that Glut1 expression in TCCB is a marker of aggressive biologic potential in patients undergoing cystectomy.