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Adaptation of Semiautomated Circulating Tumor Cell (CTC) Assays for Clinical and Preclinical Research Applications
Published on: February 28, 2014
External quality assurance of circulating tumor cell enumeration using the CellSearch(®) system: a feasibility study
Jaco Kraan1, Stefan Sleijfer, Michiel H Strijbos
1Department of Medical Oncology, Erasmus Medical Center, Rotterdam, The Netherlands. j.kraan@erasmusmc.nl
Cytometry. Part B, Clinical Cytometry
|February 22, 2011
Summary
External quality assurance (EQA) for circulating tumor cell (CTC) detection using CellSearch® is feasible. Harmonizing CTC enumeration across laboratories is crucial, as image interpretation remains a key source of variation.
Area of Science:
- Oncology
- Laboratory Medicine
- Quality Assurance
Background:
- Circulating tumor cells (CTCs) are critical biomarkers for cancer detection and monitoring.
- The CellSearch® system is a widely used method for CTC enumeration.
- Standardization of CTC detection across multiple laboratories is essential for reliable clinical application.
Purpose of the Study:
- To assess the feasibility of an external quality assurance (EQA) program for the CellSearch® assay.
- To evaluate inter-laboratory, inter-assay, and inter-instrument variation in CTC detection.
- To identify sources of variability in CTC enumeration and image interpretation.
Main Methods:
- A multicenter study involving 14 independent laboratories.
- Distribution of blood samples from cancer patients and controls for CellSearch® analysis.
- Assessment of between-operator variability through blinded image interpretation via a website.
Main Results:
- Shipment and storage did not affect CTC values.
- Low between-instrument (CV < 12%) and between-assay (CV ≤ 20%) variation demonstrated high reproducibility.
- High between-laboratory variation (45-64% CV) was primarily attributed to image interpretation, especially with apoptotic cells.
Conclusions:
- An EQA program for CTC detection using CellSearch® is feasible and necessary.
- Continued EQA is vital for harmonizing CTC enumeration across laboratories.
- Addressing variability in image interpretation is key to improving CTC detection consistency.
