Purpose: The p53 gene and its family are important factors for carcinogenesis, prognosis, and chemoresistance in esophageal squamous cell carcinoma. A recently identified ribonucleotide reductase, p53R2, is regulated by p53 for supplying nucleotides to repair damaged DNA. In the present study, we analyzed the expression and clinicopathologic significance of p53 and p53R2 in esophageal squamous cell carcinoma.
Experimental design: We immunohistochemically investigated the relationship between p53 and p53R2 expressions in surgical specimens of primary tumors in 222 patients with esophageal squamous cell carcinoma.
Results: The positive expression rate of p53 was 47.1% and that of p53R2 was 61.7%. Positive p53R2 expression was significantly correlated with depth of invasion, lymph node metastasis, stage, and poor prognosis. In the p53-negative group, the 5-year survival rate was better in patients with negative p53R2 expression than in those with positive p53R2 expression. Multivariate analysis indicated that the negative expression of both p53 and p53R2 was an independent prognostic factor along with tumor depth nodal metastasis and stage.
Conclusions: We showed that positive p53R2 expression was related to tumor development and that alteration of p53R2 expression in p53-negative tumors was closely related to prognosis. Evaluation of the expressions of p53 and p53R2 proteins should be useful for determining the tumor properties, including prognosis, in patients with esophageal squamous cell carcinoma.