Evaluation of the relationship between CDK9 expression and prognostic parameters in epithelial ovarian tumours

Ovarian cancer is the seventh most common cancer in women worldwide. About %85 to 95 of these tumours originate from epithelial cells. Epithelial tumours usually occur in women older than 50 years. The incidence and mortality rates of ovarian cancer increase with age. Cyclin-dependent kinases are serine-threonine kinases involved in the regulation of cell cycle and transcription. Cyclin-dependent kinase 9 (CDK9) is critical in many important biological processes, including growth, differentiation and response to cell death. In this thesis study, it was aimed to compare CDK9 expression in epithelial ovarian cancer (EOC) with prognostic parameters and to investigate its relationship with prognosis. The study included 95 patients diagnosed with primary malignant epithelial ovarian carcinoma sent to the Laboratory of the Department of Medical Pathology of Fırat University Hospital between 2014 and 2022. The histological subtype range of the cases was as follows: 71 (74.7%) serous carcinoma, 11 (11.6%) endometrioid adenocarcinoma, 5 (5.3%) mucinous adenocarcinoma, 4 (4.2%) malignant Brenner tumour, 4 (4.2%) clear cell adenocarcinoma. Immunohistochemical CDK9 staining was applied to the sections made from the paraffin blocks of the cases. Total scores were calculated by multiplying the staining range and staining strength. The total score was 2 in 5.3%, 3 in 2.1%, 4 in 3.2%, 6 in 61.1% and 9 in 28.4% of the cases. According to the final score, 7.4% of the cases showed weak staining, 64.2% showed moderate staining and 28.4% showed strong staining. CDK9 final score and other prognostic values were statistically compared. No significant correlation was found between CDK9 expression and prognostic parameters. All cases included in the study were malignant and 92.6% of them showed moderate or strong staining, suggesting that CDK9 has a role in the pathogenesis of EOC and CDK9 inhibition can be used as an alternative treatment for EOC patients.