Low MIB-1 labeling index in anti-HCV positive hepatocellular carcinoma

It has been reported that hepatitis C virus-related hepatocellular carcinoma (HCC) patients survive longer than hepatitis B virus-related patients. In this study, since HCC patients positive for anti-HCV antibody had significantly longer disease-free survival (p<0.05), we evaluated the proliferative activity of 58 resected HCCs and the status of their viral infections. Ki-67 (MIB-1) immunostaining, argyrophilic nucleolar organizer regions and c-myc gene amplification were examined as parameters of proliferation, and p53 overexpression was examined in relation to clinicopathologic features and prognosis. Thirty-nine patients with HCC (67%) were positive for anti-HCV antibody alone, five (9%) were negative for both anti-HCV and HBV antibodies, two (3%) were positive for both anti-HCV and HBV antibodies, and 12 (21%) had HBsAg alone. HCC patients with anti-HCV antibody had a lower MIB-1 labeling index (LI) than HCC patients negative for the antibody (p<0.05), irrespective of the serum HBsAg status. However, there was no significant correlation between anti-HCV antibody and other proliferative parameters. MIB-1 could simply be related to cellular proliferation. On the other hand, the other parameters may be related to tumor progression as well as proliferation. HCV-related HCC does have lower proliferative activity and a better prognosis.