Abstract 3073: Detection and isolation of circulating tumor cells in ovarian cancer: Principles and methods

Objective: The quantitative and qualitative analysis of circulating tumor cells (CTCs) aids in diagnosis of disease, prognosis, disease recurrence, and therapeutic response in several cancers. However, detection and isolation of CTCs from the blood circulation is a difficult task because of their scarcity and the lack of reliable markers to identify these cells. Especially, in epithelial ovarian cancer, there is a little reported data for CTCs and their CTCs has been defined to the EpCAM+ cells, even though EpCAM+ cells are just a few in ovarian cancer. The aim of this study is to investigate the effective principles and methods to detect and isolate CTCs through novel markers in ovarian cancer. Methods: CTC analysis was performed in the spiking test to find cancer cells in the human serum mixed with WBCs. Four cell lines including OVCAR3, SKOV3, SNU8 and SNU251 were used and primary cancer cells from 4 patients were analyzed. Cancer cells were isolated on the basis of cell size by filtration through CytoGen capture device, followed by identification according to validated immunocytochemistry based on the expression of DAPI, CD45, EpCAM, CK, CA-125 and HE4. Results: We obtained cancer cells more than 90% based on the cell size by filtration. Immunocytochemistry confirmed the epithelial origin through the expression of CK and EpCAM in cancer cell lines. The rate of expression was 35-99 % for CK and 1-99 % for EpCAM. A small number of cancer cell lines expressed CD45 that is the marker of WBC. The expression of CA-125 and HE4 showed their ovarian origin. The rate of expression was 7-98 % for CA-125 and 40-99 % for HE4 in cancer cell lines. Primary cancer cells were detected most effectively as the method of combination with 4 markers, including DAPI, CD45, EpCAM and HE4. Conclusion: Our findings provide the first evidence for effective methods to detect and isolate CTCs in ovarian cancer. Combination of DAPI, CD45, EpCAM and HE4 could be a useful marker to support CTCs research in epithelial ovarian cancer. Citation Format: Shin-Wha Lee, Ha-Young Lee, Jin-Young Mo, Byung Chul Kim, Eun Hye Kim, Yong-Man Kim. Detection and isolation of circulating tumor cells in ovarian cancer: Principles and methods. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3073. doi:10.1158/1538-7445.AM2014-3073