Improved enrichment of circulating tumor cells from diagnostic leukapheresis product

Michiel Stevens*, Anouk Mentink, Afroditi Nanou, Frank A.W. Coumans, Khrystany T. Isebia, Jaco Kraan, Paul Hamberg, John W.M. Martens, Leon W.M.M. Terstappen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

1 Citation (Scopus)
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The median number of circulating tumor cells (CTCs) detected in 7.5 mL of peripheral blood by CellSearch (PB-CS) in patients with metastatic prostate cancer is in the order of 1–10, which means many samples have insufficient tumor cells for comprehensive characterization. A significant increase is obtained through diagnostic leukapheresis (DLA), however, only 2%–3% of the DLA product can be processed per CellSearch test, limiting the gain. We processed aliquots from 30 DLA products of metastatic prostate cancer patients consisting of 0.2 × 109 leukocytes using CellSearch (DLA-CS) as well as the newly introduced reduced enrichment reagent protocol (RER), which uses 10-fold less enrichment reagents than DLA-CS. The number of tumor cells and the total number of captured cells were determined using the CellTracks Analyzer. Additionally, for six DLA samples, a 1.0 × 109 leukocyte aliquot was processed (RER+), using twofold less enrichment reagents than DLA-CS. A median 2.7-fold reduction in leukocyte co-enrichment was found between DLA-CS and RER methods without any loss in tumor cell recovery (Wilcoxon Signed Ranks Test, p = 0.953). Using 1.0 × 109 leukocyte aliquots a fourfold increase in tumor cells was found compared to DLA-CS and a 19-fold increase compared to PB-CS was obtained. The here-introduced RER protocol results in a higher final sample purity without any loss in tumor cell recovery while using 10-fold less CellSearch capture reagent. With this improved method, 26% of the leukapheresis sample can now be processed using reagents from a single CellSearch test, enabling the obtainment of a sufficient number of CTCs for comprehensive characterization in most metastatic prostate cancer patients.

Original languageEnglish
Pages (from-to)881-888
Number of pages8
JournalCytometry Part A
Issue number11
Early online date17 Jul 2023
Publication statusPublished - Nov 2023

Bibliographical note

Publisher Copyright:
© 2023 The Authors. Cytometry Part A published by Wiley Periodicals LLC on behalf of International Society for Advancement of Cytometry.

Funding information
Nederlandse Organisatie voor
Wetenschappelijk Onderzoek (NWO KWF
PICTURES), Grant/Award Number: 17915


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