Prognostic significance of DNA topoisomerase IIalpha expression in human hepatocellular carcinoma

Background: The biological significance of the nuclear enzyme DNA topoisomerase 11 in hepatocellular carcinoma (HCC) remains unclear. Materials and Methods: Using immunohistochemical staining methods, we examined the clinical significance of topo Halpha (8D2) in surgically resected HCC, comparing the expression of both Ki-67 and p53, as well as various clinicopathological factors and prognosis. Results: The 70 HCC samples showed a positive,, but heterogeneous pattern. The mean topo Halpha labeling index (LI) was 14.1 +/- 15.1 %, and ranged from 0.2 to 55.6, and the median topo Halpha LI was 9.9%. The mean value of the topo Halpha LI in p53 positive HCC cases (25.6 +/- 17.4) was significantly higher than that in p53-negative cases (10.3 +/- 12.3). HCC patients with lower topo Halpha LI had significantly longer disease free survival and exhibited a longer cumulative survival period than did those with higher topo Halpha LI. Conclusion: Topo Halpha over-expression appears to be linked with a potentially aggressive tumor phenotype and may indicate tumor recurrence and cancer-related death in HCC.