Challenges in enumeration of CTCs in breast cancer using techniques independent of cytokeratin expression

• Published in: PloS one 2017-04, Vol.12 (4), p.e0175647-e0175647
• Main Authors: Castle, John, Morris, Karen, Pritchard, Susan, Kirwan, Cliona C
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Biology and Life Sciences; Biomarkers; Biomarkers, Tumor - genetics; Biomarkers, Tumor - metabolism; Blood; Blood circulation; Breast cancer; Breast Neoplasms - diagnosis; Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Breast Neoplasms - pathology; Cancer; Case-Control Studies; Cell adhesion & migration; Cell Count - instrumentation; Cell Count - methods; Cell migration; Cell Separation - instrumentation; Cell Separation - methods; Cytokeratin; Enumeration; Epithelial-Mesenchymal Transition - genetics; Estrogen Receptor alpha - genetics; Estrogen Receptor alpha - metabolism; False Positive Reactions; Female; Filtration - instrumentation; Filtration - methods; Histology; Hospitals; Humans; Identification; Immunocytochemistry; Immunohistochemistry; Keratins - genetics; Keratins - metabolism; Medical prognosis; Medical research; Medicine and Health Sciences; Mesenchyme; Metastases; Metastasis; Middle Aged; Morphology; Multiplexing; Neoplastic Cells, Circulating - metabolism; Neoplastic Cells, Circulating - pathology; Oncology; Prostate cancer; Research and Analysis Methods; Stem cells; Technology; Thrombosis; Tumors
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0175647

Given the current postulated plasticity between epithelial and mesenchymal states of migratory cancer cells the detection of non-epithelial CTCs is an important scientific and clinical goal. We used the filtration-based ISET technology to enrich circulating tumour cells (CTCs) in early breast cancer blood samples and identify them using a morphology-based immunocytochemistry (ICC) approach. We found greater numbers of putative CTCs by this approach than by the cytokeratin-based CellSearch technology, but a high number of CTC false positives were identified in healthy volunteer samples which were not reduced in successive blood draws. Preliminary work using an oestrogen receptor (ER)-based multiplex ICC method in metastatic breast cancer ISET samples indicated a low number of ER+ CTCs even at this advanced stage. This work highlights the challenges in enumerating CTCs without conventional epithelial markers.