Clinical and morphological heterogeneity of diffuse gastric cancer

Abstract

Introduction. Despite various diagnostic testing and treatment options, stomach cancer ranks 5th in terms of global morbidity among all cancers. Diffuse gastric cancer occurs more frequently in younger patients and has a more aggressive course than the intestinal type. Modern ideas about the etiology, pathogenesis, and molecular structure of a tumor allow us to take a new look at diffuse gastric cancer in the light of revised classifications, recommendations, as well as approaches to the interpretation of morphological research data. Therefore, the study aimed to conduct a multifactorial analysis of patients with diffuse gastric cancer. Materials and methods. The study included 124 patients with diffuse gastric cancer. Clinical data (medical histories, protocols of endoscopic and surgical operations, sex, and age groups) and the primary tumor localization were analyzed. We formed a group of 25 observations out of 124 patients. In the group, we carried out a range of diagnostic measures: histological, histochemical, immunohistochemical, and molecular assays, as well as PCR testing. Results. In the group of 124 patients, the age of men averaged 67.5 (±12.4) years and that of women, 71 (±15.41) years. The malignant tumors were more frequently detected in distal parts of the stomach. In the group of 25 patients, Helicobacter pylori were present only in 2 cases. We detected the Epstein-Barr virus in 11 patients out of 25 using real-time PCR method. A study of the immunophenotype of diffuse gastric cancer using a wide panel of antibodies demonstrated heterogeneity of expression in both components of a malignant tumor. The expression of CK7, Muc1, Muc2, and Muc5AC markers in patients with a microsatellite unstable molecular subtype was noteworthy. Conclusion. The immunophenotypic heterogeneity of diffuse gastric cancer requires further research. It is necessary to create a standardized pathology evaluation protocol, including molecular and immunohistochemical tests that is the basis for modern management of cancer patients with diffuse gastric cancer. Keywords: gastric cancer, surgical pathology, immunohistochemistry, molecular genetics