title: In vitro validation of an ultra-sensitive scanning fluorescence microscope for analysis of circulating tumor cells.
abstract: Analysis of circulating tumor cells (CTC) holds promise of providing liquid biopsies from patients with cancer. However, current methods include enrichment procedures. We present a method (CytoTrack), where CTC from 7.5 mL of blood is stained, analyzed and counted by a scanning fluorescence microscope. The method was validated by breast cancer cells (MCF-7) spiked in blood from healthy donors. The number of cells spiked in each blood sample was exactly determined by cell sorter and performed in three series of three samples spiked with 10, 33 or 100 cells in addition with three control samples for each series. The recovery rate of 10, 33 and 100 tumor cells in a blood sample was 55%, 70% and 78%, percent coefficient of variation (CV%) for samples was 59%, 32% and 18%, respectively. None of the control samples contained CTC. In conclusion, the method has been validated to highly sensitively detect breast cancer cells in spiking experiments and should be tested on blood samples from breast cancer patients. The method could benefit from automation that could reduce the CV%, and further optimization of the procedure to increase the recovery.
authors.affiliation: Department of Clinical Biochemistry, Hilleroed Hospital, Hilleroed.
authors.forename: Thore
authors.initials: T
authors.lastname: Hillig
authors.forename: Ann-Britt
authors.initials: AB
authors.lastname: Nygaard
authors.forename: Laura
authors.initials: L
authors.lastname: Nekiunaite
authors.forename: Jörg
authors.initials: J
authors.lastname: Klingelhöfer
authors.forename: György
authors.initials: G
authors.lastname: Sölétormos
mesh_terms: D001943:Breast Neoplasms / Q000097:blood / Q000378:metabolism / Q000473:pathology; D002452:Cell Count; D002469:Cell Separation; D005260:Female; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006801:Humans; D007211:Indoles; D007633:Keratins / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000378:metabolism; D061986:MCF-7 Cells; D008856:Microscopy, Fluorescence / Q000295:instrumentation*; D009360:Neoplastic Cells, Circulating / Q000378:metabolism / Q000473:pathology*
chemical_list: D005456:Fluorescent Dyes; D007211:Indoles; C007293:DAPI; D007633:Keratins; D017493:Leukocyte Common Antigens; C516769:PTPRC protein, human
keywords: CTC; Circulating tumor cells; CytoTrack; cancer