The prognostic significance of HER2 expression in urothelial carcinoma

HER2 (human epidermal growth factor receptor 2) is one of the proteins variably expressed in urothelial carcinoma, prompting its investigation as a potential predictive marker. HER2/neu (C-erbB-2), which is a member of the epidermal growth factor receptor (EGFR) family, is responsible for cell growth and proliferation by activating the tyrosine kinase pathway. Definition and diagnostic criteria Grade and stage were determined according to the World Health Organization (WHO) classification and TNM staging system.4 Recurrence was defined as the occurrence of a new tumour that is confirmed by biopsy three months after the first transurethral resection of bladder tumour, during follow-up.14 Progression was defined as recurrence with invasion into the muscularis propriae or beyond or distant metastasis, and / or death due to the disease, during follow-up.14 Immunohistochemical Studies HER2 immunohistochemistry (IHC) was performed on formalin-fixed, paraffin-embedded tissue whole section slides using DAKO anti-HER2/neu (Code A0485, rabbit polyclonal; pre-dilution; Dako Denmark) antibody and its kit (EnVision FLEX Mini Kit High pH (Dako AS Plus) on an automatic immunostainer (BenchMark XT, Ventana Medical Systems), according to the manufacturer's instructions. DISCUSSION Urothelial carcinoma has a worldwide regional variation in terms of incidence and mortality.1,3 A few studies conducted in the Asian region have demonstrated that bladder cancer incidence is highest among male with age at presentation between 60-65 years old with urothelial carcinoma being the most common histological type.18'20 Our findings exhibited similar clinicopathologic characteristics.