Immunohistochemical expression and prognostic significance of FAS and GLUT1 in bladder carcinoma

Background: Fatty Acid Synthase (FAS) and Human Erythrocyte Glucose Transporter 1 (GLUT1) are new markers involved in the biological activities of cancer cells. FAS is a multifunctional enzyme that synthesizes palmitate from acetylCoA and malonyl-CoA. GLUT1 is a transmembrane protein normally expressed in perineurium and erythrocytes. FAS and GLUT1 expression have been recently described in many aggressive tumors. We explored the immunohistochemical expression of FAS and GLUT1 in bladder carcinomas to reveal statistical associations with clinico-pathological features and recurrence. Materials and Methods: Thirty-one node-and distant metastasis-negative transitional cell carcinomas from patients with a five-year follow-up, were evaluated for FAS and GLUT1 expression. Results: Univariate analysis showed that low-grade, pTa stage and FAS-negative expression were associated with indolent tumors. Multivariate analysis showed that FAS expression (p=0.006) and pT1-2 stage tumors (p=0.001) were independent predictors of recurrence. Conclusion: Endogenous fatty acids are an exploitable storage of energy for aggressive human bladder carcinomas. Glucose uptake is not required by bladder tumors.