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 h epatocellular carcinoma. The aim of this study was to determine the diagnos tic usefulness of the quantitative measurement of telomerase activity in sm all liver tumors, which has not Set been established. Methods: Fifty-eight liver specimens from tumorous and non-tumorous portion s of 29 small liver tumors equal to or less than 3.0 cm were obtained by ul trasonography-guided liver biopsy and of these, 25 were diagnosed as hepato cellular carcinoma and four as adenomatous hyperplasia. The telomerase acti vities in these specimens and control specimens were examined quantitativel y 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 3.5+/-7.4 AU. The mean telomerase activity in 13 tumors e qual to or less than 2 cm in diameter was 77.1+/-133.7 AU and that in 16 tu mors more than 2 cm was 152,7+/-215,2 AU, The mean telomerase activity in t he 4 adenomatous hyperplasias was 5.5+/-4.5 AU; those of hepatocellular car cinoma 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 hepatocell ular carcinoma compared to adenomatous hyperplasia and non-neoplastic tissu e, indicating that the quantitation of telomerase activity would be useful for the diagnosis of small hepatocellular carcinoma.