Clinical Validation of a Circulating Tumor Cell Assay Using Density Centrifugation and Automated Immunofluorescence
Daniel E Sabath1,2, Marie E Perrone1, Alisa Clein1
1Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA.
American Journal of Clinical Pathology
|April 23, 2022
Summary
A new circulating tumor cell (CTC) assay, RareCyte, shows comparable performance to the FDA-approved CELLSEARCH method. This validated CTC assay is ready for further clinical studies in cancer diagnostics.
Area of Science:
- Oncology
- Biotechnology
- Clinical Diagnostics
Background:
- The FDA-approved CELLSEARCH assay enriches circulating tumor cells (CTCs) using epithelial cell adhesion molecule expression.
- There is a need for validated CTC assays for clinical use.
Purpose of the Study:
- To validate the RareCyte CTC assay for clinical applications.
- To compare the performance of the RareCyte assay with the established CELLSEARCH method.
Main Methods:
- The RareCyte assay was validated using spiked cancer cell lines and 47 clinical samples.
- Specimens underwent buffy coat enrichment, immunofluorescent staining, and automated microscopy with computer-aided image analysis.
- Assay performance was evaluated for specificity, precision, linearity, recovery, and concordance with the CELLSEARCH assay.
Main Results:
- The RareCyte assay demonstrated 100% specificity for detecting spiked tumor cells.
- Linearity studies showed a strong correlation (R2=0.96) with high recovery rates.
- Clinical samples showed good correlation (R2=0.8) and 87.5% concordance with the CELLSEARCH assay.
Conclusions:
- The RareCyte CTC assay exhibits performance comparable to the FDA-cleared CELLSEARCH assay.
- The RareCyte assay is suitable for further clinical validation studies in cancer detection and monitoring.
