Ki-67 immunostaining and DNA flow cytometry as prognostic factors in epithelial ovarian cancers

Samples from malignant epithelial ovarian tumors were examined for expression of Ki-67, DNA ploidy and S-phase fraction (SPF). In addition, normal ovary, benign and borderline tumors were immunostained with Ki-67 to examine its role in ovarian carcinogenesis and to estimate the prognostic significance. For both Ki-67, ploidy and SFP a significant correlation to survival in malignancy was observed. Furthermore, SPF above 10% showed significant correlation to decreased survival in both stage subgroups I-II and III-IV, while for aneuploidy a decrease in survival could be detected only in localized disease. Ki-67 expression was present in tumor cells in the main part of borderline and malignant tumors and even in 2 benign counterparts, which might indicate an active state in these commonly believed dormant neoplasms. In the malignant group the Ki-67 correlation to survival seemed to be independent of staining intensity, although the observed decay in survival seemed to be faster in the strongly stained group.