Evolution of expression of hepatitis B surface and core antigens (HBsAg, HBcAg) in resected primary and recurrent hepatocellular carcinoma in HBsAg carriers in Taiwan. Correlation with local host immune response.

Abstract

Studies were conducted on the evolution of hepatitis B virus (HBV) surface and core antigens (HBsAg and HBcAg) in the tumors of both primary and recurrent hepatocellular carcinoma (HCC) in 27 HBsAg carriers; these were followed for up to 8 years after the resection of the primary tumor. Twenty-seven primary and 34 recurrent tumors were included. HBV antigens were detected in the tumor of the primary HCC in ten cases (37%): six (22.2%) had both antigens (Group I) and four (14.8%) had HBsAg alone (Group II). The remaining 17 cases were negative for both antigens (Group III). Intrahepatic tumor recurrence occurred in 17 cases; both HBcAg and HBsAg were found in the recurrent HCC in four of five HBcAg-positive cases (Group I). In contrast, HBcAg was detected in none of the other 12 cases (Group II, 0 of one; Group III, 0 of 11), and HBsAg in only one (Group II, 0 of one; Group III, one of 11), P less than 0.03 and P less than 0.02, respectively. Groups I, II, and III had extrahepatic recurrence in two, four, and seven cases, respectively. HBcAg was detected in none, while HBsAg was found in only one case (7.7%). The frequent detection of both antigens in the primary HCC and even in the intrahepatic recurrences suggests that HBV replication in HCC may occur more commonly than previously perceived, especially in the small HCC. Failure to detect HBV antigens in the extrahepatic recurrences suggests that the switch-off of the viral gene expression, particularly the core gene, may be an event related to the extrahepatic growth of HCC. HBV antigen expression in HCC is associated with more evident lymphocyte infiltration; this local host immune response may in turn result in a negative selection and expansion of the antigen-negative HCC cell clones. This suggestion is in accord with the fact that HBV antigens, particularly HBcAg, are rarely detected in advanced HCC.