THE PROGNOSTIC SIGNIFICANCE OF P53 OVEREXPRESSION IN METASTATIC LYMPH NODES OF ESOPHAGEAL CARCINOMAS AND ASSOCIATION WITH CELL PROLIFERATION AND APOPTOSIS

Abstract

The p53 overexpression is not always correlated with the clinicopathologic features or clinical outcome of esophageal cancer patients. The incidence of lymph node metastasis is the most significant prognostic factor, but the molecular genetic events including p53 overexpression in metastatic lymph node have remained unclear. The aim of this study was to investigate the prognostic significance of p53 overexpression in lymph node metastatic tumors in comparison with primary tumors and the relationship between p53 overexpression and proliferative activity or apoptosis. We performed immunohisto- chemical analysis for both p53 protein and proliferating cell nuclear antigen (PCNA) and in situ DNA nick end labeling method to detect apoptosis in 35 primary tumors and 25 metastatic lymph nodes. The p53 overexpression in lymph node metastatic tumors correlat- ed with shorter survival after operation in lymph node-positive cancer patients (p＜0.01). In primary tumors, there was no statistically significant difference for PCNA labeling index (LI) and apoptotic LI between p53-positive and negative tumors. In lymph node metastatic tumors, the PCNA LI of p53-positive tumors was significantly higher than that of p53- negative tumors (p＜0.04), and the apoptotic LI of p53-positive tumors tended to be lower than that of p53-negative tumors. The p53 overexpression is related to tumor cell prolifera- tion and inhibition of apoptosis in lymph node metastatic tumors, and p53 overexpression in metastatic lymph nodes may correlate with the malignant potential of esophageal carcinoma.