Reduced Expression Level of GPX2 in T1 Bladder Cancer and its Role in Early-phase Invasion of Bladder Cancer

BACKGROUND/AIM The role of glutathione peroxidase 2 (GPX2) expression in urothelial carcinoma (UC) is rarely reported. The aim of this study was to assess the expression status of GPX2 in UC of the bladder. MATERIALS AND METHODS We collected samples from 112 patients treated with radical cystectomy for immunohistochemical study. RESULTS Following immunohistochemical analysis of the specimens, 86 (76.8%) had weak GPX2 expression. In cases with consistent GPX2 expression within the same lesion, the levels of GPX2 showed significant decreases from pTa to pT1 (47.1%) compared to those from pT1 to pT2 (5.9%) (p=0.017). Specimens obtained with transurethral resection before cancer progressed to muscle invasive bladder cancer showed that pT1 had a lower expression for GPX2 than that of pTa (63.3% vs. 93.3%; p=0.009). CONCLUSION The decrease in GPX2 expression among those with UC of the bladder may be involved in the early step of cancer invasion.