Head-to-head comparison of the impact of Aurora A, Aurora B, Repp86, CDK1, CDK2 and Ki67 expression in two of the most relevant gynaecological tumor entities.

Abstract

The dysregulation of cell cycle kinases plays a crucial role in carcinogenesis and the expression of various kinases has been attributed to aggressive tumor growth and an unfavourable prognosis in oncological patients. We, therefore, aimed to evaluate the expression of Ki67 among five additional cell cycle kinases in a collective of mammary and ovarian tumor specimens and to find a correlation with clinicopathological parameters. 76 mammary and 93 ovarian benign and malignant tumor samples were immunohistochemically stained and evaluated for the expression of Aurora A and B, Repp86, CDK1 and 2 (only breast specimens) and Ki67. The expression patterns of these cell cycle kinases were matched with retrospectively collected clinicopathological parameters. All examined cell cycle kinases accurately discriminated benign from malignant breast and ovarian tissues. In breast cancer, Aurora A and B-, Repp86-, CDK2- and Ki67-expression was inversely associated with ER expression. No correlation with the HER2-status was found in our collective. Importantly, we found a significant correlation between the expression of Aurora A and CDK1 and axillary lymph node metastasis in breast cancer. Furthermore, a shortened disease free survival (DFS) upon expression of Aurora B and CDK2 was shown in breast cancer patients. None of the cell cycle kinases was associated with predictive or prognostic factors in epithelial ovarian cancer. The prognostic value of the expression of Ki67 is overtrumped by alternative cell cycle kinases when it comes to prediction of axillary tumor spread and a shortened DFS, which might allow a further risk stratification in breast cancer patients.