Immunohistochemical Study of p53 and c-erbB-2 Oncoproteins in Gastric Adenocarcinoma

ABSTRACT

The prognosis for gastric adenocarcinoma has been found to be related to several factors such as depth of invasion, inflammatory reaction, lymph node metastasis, pathological stage, DNA ploidy, amplification of proto-oncogene, and tumor suppressor gene. This study was performed to investigate the expression rate of p53 protein and c-erbB-2 oncoproteins in gastric adenocarcinoma, and correlation among clinicopathologic parameters, p53 protein and c-erbB-2. The p53 protein and c-erbB-2 oncoproteins were immunohistochemically stained in the tissue specimens of 36 advanced adenocarcinoma and 15 early adenocarcinoma. The results were summarized as follows; 1) Positive reaction for c-erbB-2 oncoprotein revealed an intense brown granular staining predominantly at the tumor cell membrane, with some cell exhibiting a cytoplasmic staining as well. The surrounding mucosal epithelial cells and protein cells around tumors revealed positive reaction. Positive reaction for p53 protein revealed an intense brown granular staining in tumor nuclei. 2) Twenty four of 51 cases(47%) for p53 protein and 11 of 51 cases(22%) for c-erbB-2 oncoprotein of gastric adenocarcinoma revealed positive reaction. 3) There was no significant difference in the expression of p53 protein and c-erbB-2 according to lymph node metastasis, depth of invasion and Laurens' classification. 4) Five of 51 cases(10%) simultaneously revealed c-erbB-2 oncoprotein overexpression associated with p53 protein expression, and 21 of 51 cases(41%) simultaneously revealed negative reaction for c-erbB-2 oncoprotein and p53 protein. There was no correlation between c-erbB-2 oncoprotein overexpression and p53 protein expression. In summary, p53 and c-erbB-2 oncoprotein were seen in 47% and 22% of gastric adenocarcinoma, respectively. They were not correlated with depth of invasion, lymph node metastasis and Laurens' classification.