CURRENT POINT OF VIEW ON PROGNOSTIC AND PREDICTIVE ROLES AND PRACTICAL APPLICATION OF HER2 RECEPTOR’S DETECTION. LITERATURE REVIEW

Human epidermal growth factor receptor HER2, a proto-oncogene involved in the proliferation and differentiation signaling pathway. The overexpression and amplification of the HER2 gene and their significance have been studied in breast cancer. Data on HER2 over expression in gastric cancer vary widely, and the value is presented by inconsistent disparate data. The interpretation of HER2 in gastric cancer differs from the evaluation in breast cancer. The purpose of this review is to summarize current data on the evaluation of HER2 in gastric cancer for the selection of targeted therapy. The search in modern databases of medical literature was carried out, more than 100 modern literary sources on the above-mentioned topic were studied and analyzed in detail and carefully. The most significant data on the evaluation of HER2 expression in gastric cancer and its prognostic and predictive value were selected and presented. Selected options evaluate the expression of HER2 receptor in operating and biopsy material of stomach cancer. Comparative data on the use of different antibody clones to solve the above problem are presented. The most frequent and important errors and possible interpretation disorders in the expression of HER2 in gastric cancer are analyzed. The use of transtuzumab for targeted therapy in gastric cancer makes it mandatory to test surgical and biopsy samples of gastric cancer to assess their expression of HER2. The development of various methods and the progress of molecular biology, however, the main role of the immunohistochemical method in solving this problem still left. Gastric cancer needs a single accessible standardized system for evaluating HER2 expression, and, most importantly, expert level interpretation of these results.