Aberrant expression of p53 and retinoblastoma gene products in human esophageal squamous cell carcinoma

: The aberrant expression of p53 and RB proteins was investigated by immunohistochemistry in 73 patients with esophageal SCC, who underwent esophageal resection. Fresh tumor tissues from 21 patients were also tested for p53 mutations in exons 4 through 9 by direct sequencing. Positive nuclear staining with p53 antibody in cancer cells was found in 49.3% (36/73) of the tumors. Mutations in the p53 gene were detected in 66.7% (14/21) by direct sequencing. Nuclear staining with RB antibody in cancer cells was diffuse in 11.0% (8/73) and heterogeneous in 57.5% (42/73) of cases. Ten patients with p53-positive but RB-negative tumors had a significantly higher incidence of stage IV disease than the other patients studied. In addition, 8 patients with tumors with diffuse nuclear staining for RB antibody had a significantly lower survival rate than the other patients. These findings demonstrate that aberrant expression of RB and/or p53 protein is frequent in human esophageal SCC, and is probably associated with tumor progression and unfavorable prognosis.