Circulating tumor cells (CTCs) can be enumerate
d using CellSearch, but not all breast cancer
subtypes, specifically those with epithelial-mesenchymal transition (EMT) characteristics, sufficiently express the enrichment (EpCAM) an
d selection (CK8/18/19) markers use
d in this metho
d. While CD146 can
detect EpCAM-negative CTCs, we here evaluate
d the value of various cytokeratins an
d CD49f to
detect CK8/18/19-negative CTCs. The teste
d cytokeratins provi
de
d no substantial benefit, but a
dding CD49f to CK8/18/19 as a selection marker resulte
d in improve
d recovery of normal-like cell lines.
Combined staining of CK8/18/19 and CD49f after CD146/EpCAM enrichment is likely to further improve CTC detection in breast cancer.