A novel method for downstream characterization of breast cancer circulating tumor cells following CellSearch isolation

Table 3 Patient data for in vivo validation procedures

Patient no.	Primary tumor phenotype	Metastasis phenotype	Number of CTCs*	CTC phenotype ^§
1	ER⁺/HER2⁻	ER⁻/HER2⁻	48	ER⁻/HER2⁺
2	ER⁺/HER2⁻	n/a	35	ER⁻/HER2⁻
3	ER⁺/HER2⁻	ER⁺/HER2⁻	3	n/a^‡
4	n/a	ER⁺/HER2⁻	12	ER⁺/HER2⁻
5	ER⁻/HER2⁺	n/a	111	ER⁻/HER2⁻
6	ER⁻/HER2⁺	n/a	311	ER⁻/HER2⁻
7	ER⁺/HER2⁻	ER⁺/HER2⁻	107	ER⁺/HER2⁻
8	ER⁺/HER2⁻	ER⁺/HER2⁻	0	Negative control
9	ER⁺/HER2⁻	ER⁺/HER2⁻	0	Negative control

*As defined by CellSearch, single samples assessed 0–6 months from initiation of therapy against metastatic disease.
^§Phenotype according to CTC-DropMount. Criteria for biomarker positivity were ≥1 ER⁺ CTC, and ≥1 HER2⁺ CTC.
^‡In this patient no CTCs were identified following secondary staining.
Patients 8, and 9 were selected as negative controls. Neither of these patients had detectable CTCs following secondary staining.

ISSN: 1479-5876