191 MET and nodal metastasis medical centers. Using a microtome, 3 mm thick whole tissue sections were cut for immunohistochemical analyses. D1C2 (Cell Signaling Technology®; Danvers, MA, USA) was used to detect C-terminal MET immunoreactivity according to the method described in our previous publications (17, 23). Membranous immunoreactivities obtained using D1C2 were characterized by assessing for four staining patterns: uniform negative, gradient towards the periphery, uniform positive and gradient towards the center according to the scoring system described in our previous publication (Figure 1) (17). Figure 1: photographs representing the defined staining patterns observed using D1C2 and corresponding HE section (10X and 20X objective). A. Uniform negative B. Gradient towards periphery. C. Uniform positive. The gradient towards center staining pattern was not observed. Association of MET positivity and DOI with LNM Analogous to the known association of ≥ 10% of the D1C2 uniform positive staining pattern with OS and DFS, it was assessed if ≥ 10% D1C2 uniform positivity (further on referred to as MET positivity) is associated with histopathologically proven LNM (cN0/pN+ and cN+/pN+) and occult LNM (cN0/pN+) using receiver operating characteristic (ROC) curve analysis (17). 6
RkJQdWJsaXNoZXIy MTk4NDMw