Benchmark xt

Tissue samples from TURBTs were fixed in 10% neutral formalin solution and embedded in paraffin blocks. Immunohistochemical analysis was performed with the automated system BenchMark XT (Ventana BenchMark XT, Roche, Mannheim, Germany). Deparaffinization was performed with a combination of heat, a mild detergent solution (EZ prep), and spin-mixing. The Optiview DAB IHC Detection Kit, an indirect biotin-free system, was used to detect the primary antigens in paraffin sections. HER2 protein expression was studied with the prediluted VENTANA anti-HER-2 antibody (clone 4B5; Roche). This rabbit monoclonal antibody is directed against the internal domain of HER-2 protein. The staining was membranous, allowing a semi-quantitative detection of HER-2 antigen. Only membrane staining was scored according to the same standard criteria used in breast cancer.^{4 (link)} HER-2 positivity was assessed using the following scoring system:
0: no staining was observed or membrane staining that was incomplete and faint/barely perceptible was found in ≤10% of tumor cells; 1+: incomplete membrane staining that was faint/barely perceptible in >10% of tumor cells (Figure 1); 2+: weak to moderate complete membrane staining was observed in >10% of tumor cells (Figure 2); 3+: circumferential membrane staining that was complete and intense was observed and in >10% of tumor cells (Figure 3).^{4 (link)}