Abstract

p53 is a tumor suppressor gene product identified in a wide variety of tumors. Studies have shown that wild-type p53 has an inhibitory effect on cell proliferation and transformation. Point mutations result in a mutant p53 protein with an altered conformational structure and an increased half life. Mutant p53 protein accumulates within the malignant cells where it is readily detected. Accumulation of mutant p53 protein is believed to be a common feature of malignant disease, and is a new parameter to evaluate the cell biology and prognosis of cancer. Factor VIII-related antigen is one of the three functional components of the antihemophiliac factor. It is synthesized in endothelial cells of blood vessel and is widely used as a nearly specific marker to evaluate the differentiation of endothelial cells. There was a clear distinction between a stage without neovascularization, which correlated with a paucity of metastasis, and a stage in which increasing neovascularization correlated with a rising rate of metastasis. Therefore the authors asked whether the extent of angiogenesis and p53 expression in advanced gastric carcinoma(AGC) and early gastric carcinoma(EGC) of the diffuse type and the intestinal type correlated with nodal status. To investigate whether tumor angiogenesis and p53 expression affect nodal metastasis or not, the authors counted tumor microvessels of 66 patients. (40 cases of AGC- 20 cases of nodal metastasis and 20 cases of no metastasis, 26 cases of EGC- 6 cases of nodal metastasis and 20 cases of no metastasis). Highlighting of the vessels by immunohistochemical staining for factor VIII-related antigen and assessment of p53 expression were done. As a result, of the 28 cases of the diffuse type, only two were positive for p53, but, of the 38 cases of the intestinal type, 20 cases were positive for p53. Nevertheless, no correlation was found between p53 protein accumulation and lymph node metastasis. The degree of tumor angiogenesis in lymph node free group is higher than in lymph node metastasis group. In conclusion, p53 mutations seem to play a role in oncogenesis only in the intestinal type of gastric carcinomas, however, p53 protein accumulation has no prognostic value in gastric carcinoma, but, tumor angiogenesis is a suspected predictor for patient's prognosis.

• Keywords: p53, Angiogenesis, Gastric cancer, Prognosis