THE RELATION OF TUMORAL P53 IMMUNOREACTIVITY, CELL PROLIFERATION RATE AND MICROVESSEL DENSITY WITH THE PATHOLOGICAL STAGE IN ADVANCED STAGE GASTRIC CARCINOMA

Abstract

As it is universally accepted, pathological staging is the primary prognostic determinant for advanced gastric carcinoma which is associated with high mortality. Moreover, some morphological features of the primary tumor have adjunctive prognostic importance. More distinct histological parameters, which can be detected preoperatively, would help to assess the prognosis and to decide the primary treatment modality more precisely. This study was performed to determine the expressions of p53tumor suppressor gene protein, proliferating cell nuclear antigen (PCNA) and micro vessel density in advanced gastric cancers by immunohistopathological methods. The impact of these parameters on staging and morphological features of the turner was also determined. Forty-three patients who were operated upon the diagnosis of gastric cancer are included in the study. The clinical records, operation notes, specimen reports and histological slides of each patient were obtained retrospectively. Tumours were grouped according to their pathological stages, and also to their macroscopic and microscopic features. One paraffin block of each tumor was selected to be assessed for theirp53, PCNAandCD34 expressions by Immunohistochemical methods. Tumors were further divided into either negative or positive groups according to their p53 immunoreactivity. Separately, PCNA index was determined for each tumor by calculating the ratio of tumor cells which has immunoreactivity with the monoclonal antibody against PCNA over 1000 tumor cells at any site on the slide. The endothelial cells were highlighted by anti-CD34 antibody and this procedure was followed by calculation of angiogenesis index by counting the immunoreactive cell groups at areas involving the most distinct small sized vascular structure expression, As a result, in stage IV gastric carcinomas, p53 immunoreactivity and PCNA index were found to be significantly high when compared to other stages. We observed significantly higher PCNA index in tumors of ulcerative and diffuse infiltrative type when compared to polipoid and fungating types. There was a significant increase in angiogenesis index which was similar to the elevation of PCNA index in advanced stages of gastric carcinomas. These immunohistochemical markers may be useful in determining the stage of the tumor. In the light of these findings, we state that detecting these biological parameters maybe helpful in having an idea about the prognosis and deciding on the most appropriate primary treatment modality.