Improving the yield of circulating tumour cells facilitates molecular characterisation and recognition of discordant HER2 amplification in breast cancer

• Published in: British journal of cancer Vol. 102; no. 10; pp. 1495 - 1502
• Main Authors: Flores, L M, Kindelberger, D W, Ligon, A H, Capelletti, M, Fiorentino, M, Loda, M, Cibas, E S, Jänne, P A, Krop, I E
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11-05-2010; Nature Publishing Group
• Subjects: 631/208/737/1505; 631/67/1857; 692/699/67; Antibodies; Automation; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Breast cancer; Breast Neoplasms - blood; Breast Neoplasms - genetics; Cancer Research; Cell adhesion & migration; Drug Resistance; Epidemiology; Epidermal growth factor; FDA approval; Female; Fluorescent Antibody Technique; Gene Amplification; Genes, erbB-2 - genetics; Gynecology. Andrology. Obstetrics; Humans; Immunomagnetic Separation - methods; In Situ Hybridization, Fluorescence; Lung cancer; Mammary gland diseases; Medical research; Medical sciences; Metastasis; Methods; Molecular Diagnostics; Molecular Medicine; Neoplastic Cells, Circulating; Oncology; Tumors; United States > US; lung cancer; FISH; circulating tumour cells; breast cancer; HER2; Human; Breast disease; erbB2 Gene; Breast cancer; Malignant tumor; Blood; Human Epidermal growth factor Receptor 2; Mammary gland diseases; Gene amplification; Cancerology; C-Onc gene; Fluorescence in situ hybridization; Genetics; Tumor cell; Protooncogene; Cancer
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/sj.bjc.6605676

Background:
Circulating tumour cells (CTCs) offer a non-invasive approach to obtain and characterise metastatic tumour cells, but their usefulness has been limited by low CTC yields from conventional isolation methods.
Methods:
To improve CTC yields and facilitate their molecular characterisation we compared the Food and Drug Administration-approved CellSearch Epithelial Kit (CEK) to a simplified CTC capture method, CellSearch Profile Kit (CPK), on paired blood samples from patients with metastatic breast (
n
=75) and lung (
n
=71) cancer. Molecular markers including Human Epidermal growth factor Receptor 2 (HER2) were evaluated on CTCs by fluorescence
in situ
hybridisation (FISH) and compared to patients’ primary and metastatic cancer.
Results:
The median cell count from patients with breast cancer using the CPK was 117
vs
4 for CEK (
P
<0.0001). Lung cancer samples were similar; CPK: 145 cells
vs
CEK:4 cells (
P
<0.0001). Recovered CTCs were relatively pure (60–70%) and were evaluable by FISH and immunofluorescence. A total of 10 of 30 (33%) breast cancer patients with HER2-negative primary and metastatic tissue had HER2-amplified CTCs.
Conclusion:
The CPK method provides a high yield of relatively pure CTCs, facilitating their molecular characterisation. Circulating tumour cells obtained using CPK technology demonstrate that significant discordance exists between HER2 amplification of a patient's CTCs and that of the primary and metastatic tumour.