Sakineh Amoueian - Professor of Pathology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, IR Iran
Armin Attaranzadeh - Fellowship of Molecular Pathology and Cytogenetics, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, IR Iran
Mehdi Montazer - Fellow of Molecular Pathology and Cytogenetics, Shiraz University of Medical Sciences, Shiraz, Iran
Arash Akhavan Rezayat - Student Research Committee, Gastrointestinal and Fatty Liver Research Center, Faculty of Medical Sciences, Mashhad University of Medical Sciences, Mashhad, IR Iran
Amir Behforouz - Student Research Committee, Gastrointestinal and Fatty Liver Research Center, Faculty of Medical Sciences, Mashhad University of Medical Sciences, Mashhad, IR Iran
Fatemeh Sobhani - Resident of pathology, Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, IR Iran

Background: Gastric cancer has a high mortality rate and often has a poor treatment outcome. The HER2/neu gene target therapyhas been known as a potential way for treatment.Objectives: The goal of our study was assessment the relation between chromogenic in situ hybridization (CISH) and immunohistochemistry(IHC) methods in determining the best diagnostic method for gastric cancer.Methods: In this historical cohort study, 50 gastric cancer samples were analyzed by CISH and IHC. The relation between clinicalpathologicalparameters of HER2/neu was also analyzed. Alive patients were followed from 2009 through 2012 for the main outcomes(mortality). The results of these two methods, in terms of sex, age, tumor size, grading, staging, tumor location, metaplasia,presence of necrosis and ulceration, vascular invasion, the TNM system, mucin or signet producing adenocarcinoma cells and patientsurvival rates were compared.Results: There was no significant difference between IHC and CISH regarding the sex, age, tumor size, grading, staging, tumor location,metaplasia, presence of necrosis and ulceration, vascular invasion, the TNM system, mucin or signet producing adenocarcinomacells and patient survival rates. Comparison of TNMscores by these two methods showed no significant relationship betweenIHC and staging, but a statistically significant difference between CISH and different N staging, (P < 0.05) was assessed.Conclusions: Comparison between IHC and CISH showed the only significant relationship between CISH and different N staging.Therefore, low amplified CISH was a better diagnostic method for gastric cancer, compared to low expression in IHC.

Stomach Neoplasms, Immunohistochemistry, Chromogenic In Situ Hybridization, erbB-2, HER2/neu