In the development of a cancer, unlimited cell proliferation has been believed to play an important role. In addition, a programmed cell death called apoptosis, which is regulated by several oncogenes and tumor suppressor genes, has been suggested to be another important different pathway of carcinogenesis. Recently, several reports on cell proliferation capacity and apoptosis in the development of human liver disease have been published, bur the cell proliferation index and its relationship between the expression of the bcl-2 and p53 genes involving apoptosis has not yet been discussed in view of the clinical differences of primary and metastatic liver cancer. In this study, we investigated the cell proliferation index and expression of p53 and bcl-2 in the tumorous and non-tumorous portions of both hepatocellular carcinoma and metastatic liver cancer. The expression of p53 was observed in both hepatocellular carcinoma and metastatic liver cancer, but bcl-2 expression was observed neither in hepatocellular carcinoma nor in metastatic liver cancer. In hepatocellular carcinoma, the p53 positive group showed a higher Ki-67 score (cell proliferation index) and more tumor numbers than the p53 negative group (p < 0.05). In metastatic liver cancer, the results were the same as in hepatocellular carcinoma (p < 0.05). However, we could not correlate the p53 expression and its prognostic significance in hepatocellular carcinoma.
