Quantitative evaluation of telomerase activity in small liver tumors: analysis of ultrasonography-guided liver biopsy specimens

Background/Aims: Telomerase activity which restores the length of telomere repeat arrays is frequently detectable in various malignancies, including hepatocellular carcinoma. The aim of this study was to determine the diagnostic usefulness of the quantitative measurement of telomerase activity in small liver tumors, which has not yet been established. Methods: Fifty-eight liver specimens from tumorous and non-tumorous portions of 29 small liver tumors equal to or less than 3.0 cm were obtained by ultrasonography-guided liver biopsy, and of these, 25 were diagnosed as hepatocellular carcinoma and four as adenomatous hyperplasia. The telomerase activities in these specimens and control specimens were examined quantitatively by telomeric repeat amplification protocol with standard control. Results: The mean telomerase activity in cirrhosis without liver tumor was 0.4±0.6 (±S.D.) arbitrary units (AU) and that in 29 non-tumorous parts of the tumors was 4.5±7.4 AU. The mean telomerase activity in 13 tumors equal to or less than 2 cm in diameter was 77.1±133.7 AU and that in 16 tumors more than 2 cm was 152.7±215.2 AU. The mean telomerase activity in the 4 adenomatous hyperplasias was 5.5±4.5 AU; those of hepatocellular carcinoma with Edmondson-Steiner classification I, II, III and IV were 49.6±47.4 (n=10), 240.1±273.6 (n=9), 119.2±174.6 (n=4) and 144.6±80.2 (n=2) AU, respectively. Conclusions: The telomerase activity was significantly higher in hepatocellular carcinoma compared to adenomatous hyperplasia and non-neoplastic tissue, indicating that the quantitation of telomerase activity would be useful for the diagnosis of small hepatocellular carcinoma.