Sandeep Kumar Parvathareddy1, Abdul K Siraj1, Tariq Masoodi1, Padmanaban Annaiyappanaidu1, Ismail A Al-Badawi2, Fouad Al-Dayel3, Khawla S Al-Kuraya4. 1. Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, P.O. Box 3354, MBC#98 - 16, 11211, Riyadh, Saudi Arabia. 2. Department of Obstetrics & Gynecology, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. 3. Department of Pathology, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, 11211, Riyadh, Saudi Arabia. 4. Human Cancer Genomic Research, King Faisal Specialist Hospital and Research Center, P.O. Box 3354, MBC#98 - 16, 11211, Riyadh, Saudi Arabia. kkuraya@kfshrc.edu.sa.
Abstract
BACKGROUND: Cyclin-dependent kinase 9 (CDK9) has been shown to play an important role in tumorigenesis of several malignancies. However, the expression of CDK9 in ovarian cancer from Middle Eastern ethnicity remains unknown. METHODS: A tissue microarray of 441 epithelial ovarian cancer (EOC) samples was used to study the expression of CDK9 immunohistochemically and their clinico-pathological associations were determined. Cox proportional hazards regression model was used for univariate and multivariate analysis of recurrence-free survival. RESULTS: CDK9 over-expression was noted in 56.2 % (248/441) of EOCs and was associated with adverse clinico-pathological parameters such as distant metastasis (p < 0.0001), stage IV tumors (p < 0.0001), tumor recurrence (p = 0.0105) and high Ki-67 index (p < 0.0001). Importantly, CDK9 over-expression was an independent predictor of poor recurrence-free survival (Hazard ratio = 1.51; 95 % confidence interval = 1.15-1.98; p = 0.0030). We also found that CDK9 outperforms Ki-67 as a predictor of tumor recurrence in EOC. CONCLUSIONS: Our results show that CDK9 expression correlates with markers of advanced disease in Middle Eastern EOC and is also a prognostic marker. CDK9 overexpression also identifies a subset of patients with highest likelihood of recurrence across the patient cohort. These patients may benefit from additional alternative therapies targeting CKD9.
BACKGROUND:Cyclin-dependent kinase 9 (CDK9) has been shown to play an important role in tumorigenesis of several malignancies. However, the expression of CDK9 in ovarian cancer from Middle Eastern ethnicity remains unknown. METHODS: A tissue microarray of 441 epithelial ovarian cancer (EOC) samples was used to study the expression of CDK9 immunohistochemically and their clinico-pathological associations were determined. Cox proportional hazards regression model was used for univariate and multivariate analysis of recurrence-free survival. RESULTS:CDK9 over-expression was noted in 56.2 % (248/441) of EOCs and was associated with adverse clinico-pathological parameters such as distant metastasis (p < 0.0001), stage IV tumors (p < 0.0001), tumor recurrence (p = 0.0105) and high Ki-67 index (p < 0.0001). Importantly, CDK9 over-expression was an independent predictor of poor recurrence-free survival (Hazard ratio = 1.51; 95 % confidence interval = 1.15-1.98; p = 0.0030). We also found that CDK9 outperforms Ki-67 as a predictor of tumor recurrence in EOC. CONCLUSIONS: Our results show that CDK9 expression correlates with markers of advanced disease in Middle Eastern EOC and is also a prognostic marker. CDK9 overexpression also identifies a subset of patients with highest likelihood of recurrence across the patient cohort. These patients may benefit from additional alternative therapies targeting CKD9.