Circulating Endothelial Cells (CECs) as Potential Predictive/Prognostic Biomarkers in Ovarian Cancer

Anti-angiogenic agents, such as Bevacizumab, have demonstrated survival benefits in ovarian cancer, particularly in patients at high risk of disease progression. However, these therapies are costly, associated with potential side effects, and may negatively impact quality of life, benefiting only specific patient subgroups. Therefore, identifying reliable, predictive, and prognostic biomarkers that can be seamlessly integrated into clinical practice is essential to optimize patient selection. Circulating endothelial cells (CECs)-mature endothelial cells shed from vascular walls following blood vessel damage-represent a promising biomarker for monitoring vascular injury, treatment response, and disease recurrence. While flow cytometry offers a rapid, cost-effective, and standardized approach for CEC enumeration, methodological variability across laboratories has historically limited its clinical utility. To overcome this, this study utilizes a standardized flow cytometry protocol (developed by Beckton Dickinson and the SCENIC consortium) combining DNA staining with a dried, pre-titrated 5-antibody panel to ensure consistent and reproducible CEC quantification. Additionally, emerging evidence suggests that specific microRNA (miRNA) expression profiles in primary tumor tissue and plasma reflect vascular damage and response to anti-angiogenic therapy. This study aims to evaluate the predictive and prognostic role of CEC counts (at baseline and post-treatment) in ovarian cancer patients receiving standard chemotherapy with or without Bevacizumab. Furthermore, it seeks to explore the correlation between baseline CEC levels and the expression of selected miRNAs in plasma and primary tumors.

Inclusion Criteria for Healthy Donors: * Healthy adults caucasian female * Non-smoker * Normal blood pressure values * Normal complete blood count (CBC) * Normal blood chemistry values Inclusion Criteria for Cancer Patients: * Caucasian * Patients with confirmed histological diagnosis of ovarian carcinoma (all histotypes) * Treatment-naive or with disease recurrence occurring more than 12 months after the start of therapy * Normal systolic and diastolic blood pressure values, no cardiovascular comorbidities * Written informed consent Exclusion Criteria: Exclusion Criteria for Healthy Donors: * Diabetes * Hypertension * Active infectious states or chronic inflammatory diseases * Active or previous malignancies * Pharmacological treatment completed less than 48 hours prior * Statin treatment * Endometriosis * Cardiovascular disease / Heart disease * End of menstrual cycle less than 15 days prior * Non-fasting subjects * Obesity * Hypercholesterolemia * Active gastric or duodenal ulcer * Positive serology for HIV, Hepatitis A, B, or C infection