Objective: The p21 gene is thought to play a central role in tumor suppression. The aim of this study was to examine the clinicopathological role of p21 and p53 in esophageal squamous cell carcinomas.
Methods: The expression of p21 and p53 proteins in 153 Chinese patients (131 men, 22 women) with resected esophageal squamous cell carcinomas was investigated by the immunohistochemical method. Correlation between p21 and p53 expression and clinicopathological features was examined.
Results: The expression of p21 and p53 was detected in 70% and 64% of the tumors, respectively. The staining of p21 and p53 was also found in squamous carcinoma in situ, dysplasia, and nontumor epithelium. p21 expression was often weak in the suprabasal cells and found in better differentiated tumors. There was no significant correlation between the expression of p21 and the abnormal accumulation of p53. The prognosis of the patients depended on the size, stage, and p21 expression of the lesion. In stage III lesions with tumor diameter < or = 7.5 cm (n = 93), patients with loss of p21 expression had better survival. The survival rates of patients were worse if they had expression of both p21 and p53.
Conclusions: Thus, p21 and p53 had prognostic value for esophageal squamous cell carcinomas. Loss of p21 expression was shown without p53 alternations, indicating that other mechanisms are also involved in turning off the gene. The pattern of p21 and p53 expression predicts an aggressive clinical course of esophageal squamous cell carcinomas.