Role of Increased DNA Synthesis Activity of Hepatocytes in Multicentric Hepatocarcinogenesis in Residual Liver of Hepatectomized Cirrhotic Patients with Hepatocellular Carcinoma

To examine whether the marked increase in DNA synthesis of hepatocytes in cirrhotic liver might elicit multicentric hepatocarcinogenesis, we examined the relationship between new development of hepatocellular carcinoma (HCC) and the bromodeoxyuridine (BrdU) labeling index (LI) of hepatocytes in the residual liver of hepatectomized patients with liver cirrhosis (LC) and HCC. Eighteen hepatectomized patients with LC and HCC, whose resected liver revealed neither portal nor hepatic vein invasion by histologic examination, were studied (to exclude cases with intrahepatic metastasis). DNA synthesis activity of hepatocytes from the residual cirrhotic liver was measured by a BrdU/anti-BrdU in vitro method. The incidence of HCC recurrence was studied during a 3-year follow-up period. Among 18 patients, 9 patients had recurrence and 9 did not. The average BrdU LI in the recurrent patients was 2.6 +/- 1.3% and was significantly higher than that in patients without recurrence (1.4 +/- 0.5%, P < 0.05). All five patients who had a BrdU LI of 2.4% or above showed recurrence within 3 years, as compared with 4 of 13 (30.8%) patients with BrdU LI of less than 2.4% (P < 0.05). Our data indicate that abnormally high DNA synthesis in hepatocytes in the background cirrhosis might lead to the development of multicentric carcinogenesis in human cirrhotic liver, and in the residual cirrhotic liver of hepatectomized patients with HCC and LC, it may be a predictor of new development of HCC.