ASTRA Study: Circulating Tumor Cells in Blood of Patients With High-Grade Serous Ovarian Cancer

This prospective, single-arm interventional diagnostic study evaluates circulating tumor cells (CTCs) in patients with high-grade serous ovarian cancer (HGSC). The study is designed to characterize the morphological and immunophenotypic features of CTCs and to assess their association with clinical and prognostic parameters. Eligible participants include adult women with histologically confirmed high-grade serous ovarian cancer (FIGO stage III or IV) undergoing first-line platinum-based systemic therapy. As part of the study protocol, an additional 10 mL peripheral blood sample is collected prior to initiation of systemic therapy. In participants with detectable CTCs at baseline, a second additional 10 mL blood sample is collected before cycle 4 of systemic therapy to evaluate treatment-related changes in CTC count and characteristics. Circulating tumor cells are isolated using the Parsortix size-based microfluidic system, which preserves cellular morphology. Isolated cells are processed into cytospin preparations and analyzed using cytology staining, immunocytochemistry, and immunofluorescence methods. CTCs are evaluated for number, presence of single cells and clusters, and expression of epithelial and mesenchymal markers. Megakaryocytes and other non-tumor cells are assessed to ensure accurate cell classification. Clinical data, including tumor stage, laboratory parameters (e.g., CA125 and immune-inflammatory indices), treatment information, and outcome data, are obtained from medical records. Progression-free survival and overall survival are assessed using clinical follow-up data and the national cancer registry. Statistical analyses include descriptive statistics, correlation analyses between CTC findings and clinical parameters, and survival analyses using Kaplan-Meier methods and multivariable Cox regression models. This study provides detailed insight into circulating tumor cells in high-grade serous ovarian cancer and explores their potential role as prognostic biomarkers and tools for future clinical and translational research.