Background: Cancer of the esophagus is one of the most malignant tumors and has a poor prognosis. The p53 and retinoblastoma (RB) genes are involved in the regulation of cell population by suppressing cell proliferative activity. Our goal was to clarify whether expression of p53 and RB genes could be prognostic factors in squamous cell carcinoma of the esophagus.
Methods: Tumor samples taken from 73 patients undergoing subtotal esophagectomy were immunohistochemically stained for the p53 and RB genes. An image analyzer was used for quantitative assessment of the staining, and clinicopathologic characteristics of those patients were investigated.
Results: Patients in whom p53 expression was high had greater tumor diameter, deeper tumor invasion, and worse prognosis compared with patients in whom p53 expression was low. Patients in whom RB expression was low had a higher incidence of lymph node metastasis and more advanced disease than did those in whom RB expression was high. The combination of p53 and RB expression revealed that the cases with high p53 and low RB expression had significantly worse survival rates and deeper tumor invasion compared with other groups. In various clinicopathologic parameters, (e.g., age, sex, tumor-diameter, tumor type, location, differentiation, TNM classification, TNM stage) tumor type, tumor size, depth of invasion, lymph node involvement, distant metastasis, and combined p53 and RB expression showed significant differences in survival by univariate analysis. Among those six variables, only lymph node involvement showed an independent prognostic factor for survival (P = .0055) by multivariate analysis.
Conclusions: The combination of p53 and RB expression is not a prognostic indicator in the surgical treatment of esophageal cancer.