The Lauren Classification Highlights the Role of Epithelial- to-Mesenchymal Transition in Gastric Carcinogenesis: an Immunohistochemistry Study of the STAT3 and Adhesion Molecules Expression

Background & Aims: Despite some recent advances, gastric cancer remains an important cause of death at world level. This indicates an absence of therapeutic options, stemming from the limited understanding of the molecular mechanisms involved in carcinogenesis. Nearly fifty years ago Lauren classified gastric cancers, according to the morphological aspect, as intestinal or diffuse. The phenotype of the cells indicates the presence of different molecular mechanisms, which can be approached in the light of recent data and identified with the help of current techniques. The best described are the germline/somatic mutations or the hypermethylations of the E-cadherin 1 CDH1 gene promotor. Methods. We analyzed 195 gastric tumors,120 intestinal and 75 diffuse type, using immunohistochemistry (tissue microarray TMA method) for pStat3 Tyr705 , E-cadherin, α-catenin and β-catenin; 985 spots of gastric tumors, distributed on 4 TMA blocks were analyzed. For pStat3 Tyr705 we took the nuclear staining into account