Topoisomerase II immunostaining as a prognostic marker for survival in ovarian cancer

Objective. This study aimed to evaluate topoisomerase II compared to Ki-67 expression as a marker for tumor behavior and for prognosis of patients wit h ovarian cancer. Methods. In order to screen for potential prognostic markers, two groups of patients with advanced stage (FIGO stages III and IV) epithelial ovarian c arcinoma were selected based on differences in survival (mean survival, 11 years versus 2 years). Pathology slides were reviewed, and immunohistochemi stry using antibodies to topoisomerase II and Ki-67 was performed on the or iginal cell blocks. No patients were lost to follow-up. Results. Detectable expression of topoisomerase II was present in 70.0 +/- 30.3% of cells in patients with rapidly progressing disease, compared to on ly 12.3 +/- 12.4% of cells in long-term survivors (P = 0.0001). Ki-67 expre ssion was also more frequent in short-term survivors compared to long-term survivors, but the difference was less prominent than with topoisomerase II (P = 0.01), Specificity and sensitivity as prognostic factors reached 88.2 and 93.8% for topoisomerase II, compared to 55.6 and 88.2% for Ki-67, Conclusions. Topoisomerase II expression as detected by immunohistochemistr y in tumor samples emerged as a promising clinically relevant biomarker for survival in advanced epithelial ovarian-cancer. (C) 2001 Academic Press.