TUMOR INFILTRATING LYMPHOCYTES PECULIARITIES IN DIFFERENT HISTOPATHOLOGICAL AND MOLECULAR SUBTYPES OF GASTRIC CARCINOMA.

Gastric carcinoma represents one of the major causes of cancer related mortality worldwide. Recently, immunotherapeutic means gave the new promise for the treatment of gastric carcinoma, although, not all patients benefit from this type of treatment. Tumor infiltrating lymphocytes (TILs) are considered as one of the promising prognostic and predictive biomarkers in solid tumors. However, the presence of TILs is not well characterised in different types of gastric cancer. The aim of our study was to characterise TILs profile in different histopathological and molecular subtypes of gastric carcinomas. We used standard haematoxylin and eosin staining (H&E) for evaluation of TILs and immunohistochemistry to detect molecular markers, including CDH1, Ki67, p53 and Her2. The results of our study revealed that TILs status varies significantly in different histological and molecular subtypes of gastric adenocarcinoma, which might be the reason for different prognosis in these patients. Also, high TILs status is significantly related to the presence of p53 mutations in both enteric type and diffuse type gastric carcinomas, which can be further explored for immunotherapeutic options in these patients.