Proliferating cell nuclear antigen labeling index of preoperative biopsy specimens in gastric carcinoma with special reference to prognosis.

Abstract

Proliferating cell nuclear antigen (PCNA) is an auxiliary protein of DNA polymerase delta and is considered to correlate with the cell's proliferative state. Immunohistochemical methods with a anti-PCNA antibody (PC10) have particular advantages compared with other techniques because of the maintenance of the tissue architecture and simplicity of the methodology. The authors investigated the correlation between the tumor's proliferative activity and progression of gastric carcinoma using immunohistochemical staining with PC10. One hundred eighty-nine endoscopic biopsy specimens from patients with gastric carcinoma before operation were investigated by immunohistochemical study, using anti-PCNA monoclonal antibody (PC10). The correlation of PCNA labeling index (percentage of positive cells in more than 500 tumor cells) with various clinicopathologic factors and prognosis was studied. The PCNA labeling index became higher as the histologic stage increased. In patients with lymph node metastasis, vascular invasion, liver metastasis, and peritoneal metastasis, the labeling index was significantly higher. In patients with high PCNA labeling index (50% or greater), prognosis was significantly poorer than in those with a low index (less than 50%). The rate of disease recurrence after curative resection was significantly higher in patients with high PCNA grade group. As a result of this study, PCNA labeling index is suggested to be correlated with the depth of invasion, organ metastasis, vascular invasion, and tumor stage and to be effective as a prognostic factor.