Expression of biliary antigen and its clinical significance in hepatocellular carcinoma

In order to classify the hepatocellular carcinomas (HCCs) which had diverse clinicopathologic characteristics, we divided HCCs into two groups accordi ng to the expression of biliary antigen on the basis of the hypothesis that the hepatocyte and biliary epithelial cell originate from the same precurs or cell, and then we investigated the clinical and pathologic characteristi cs in the two groups. Forty HCC cases with no preoperative treatment and at least two-year follow-up data were selected among 202 cases of HCC files f rom 1991 to 1995. Expression of biliary antigen (AE1, cytokeratin 19), p53, AFP, and Ki-67 in the tumor tissue were assessed by immunohistochemistry. Positive cytokeratin 19 was noted in one case (2.5%); AE1 was detected in 4 0% of patients; p53 was overexpressed in 20% of patients; and AFP was detec ted in 45% of patients. No statistical difference between the biliary antig en positive group (16 cases) and the negative group (24 cases) were noted i n terms of mean age, sex, presurgical serum AFP level, Child class, and tum or size. HBsAg positive race was 66.7% for the biliary antigen (-) group an d 93.8% for the biliary antigen (+) group with a statistically significant difference (p=0.048). The number of cases for Edmonson-Steiner grade I/II a nd III/IV were 15 and 9 in the biliary antigen (-) group, and 4 and 12 in t he biliary antigen (+) group, respectively, with a statistically significan t difference (p=0.024). The 1, 3 and 5-year disease-free survival races wer e 69.7, 40.9 and 40.9% for the biliary antigen (-) group and 73.7, 39.1, 39 .1% for the biliary antigen (+) group with no statistically significant dif ference. The 1, 3 and 5-year overall survival rates were 91.7, 73.8, 66.4% for the biliary antigen (-) group and 68.8, 34.4, 34.4% for the biliary ant igen (+) group, with a significantly greater overall survival rate for the biliary antigen negative group (p=0.045). Poor histopathological differenti ation, a high HBsAg positive rate and poor overall survival rate were noted in the biliary antigen positive group and the differences were statistical ly significant. In conclusion, HCCs with positive biliary antigen, which or iginates from more primitive cells, is suggested to he more aggressive than HCCs with negative biliary antigen.