CORRELATION OF NUCLEAR P53 IMMUNOREACTION WITH THE HISTOPATHOLOGIC FEATURES IN GASTRIC CARCINOMA

Background – Alteration in the expression of p53 tumor-suppressor protein is an event that occurs frequently in human cancer, but the practical implications of this phenomenon are yet to be fully exploited. The objective of this study was to determine the value of p53 accumulation as a marker of tumor progression and the relationship between p53 overexpression and clinicopathologic variables in gastric cancer. Methods – The expression of p53 was studied immunohistochemically in 52 gastric carcinomas using paraffin-embedded gastric tumor tissues. DO7, a monoclonal antibody to p53 protein, was used for the immunohistochemical analysis. The correlation between p53 expression in gastric tumor tissues and clinicopathologic variables was analyzed. Results – P53 positivity was found in 75% of gastric carcinoma cases. A significant correlation between the rate of p53 overexpression and tumor histologic type (p = 0.001), depth of invasion (p value = 0.037), and tumor grade (p = 0.000) was found in the gastric tumors. There was no significant association between p53 protein accumulation and lymph node status (p = 0.591). Conclusion – These results suggest that the preoperative assessment of p53 expression in gastric carcinomas can be helpful to identify patients at high risk of higher grades and more advanced tumors. P53 immunoreactivity cannot, though, predict lymph node status in patients with gastric carcinoma. Furthermore, p53 overexpression is related to gastric cancer progression.