Table 2.
Direct methods for detection of circulating tumor cells (CTCs) in primary lung cancer
| Method and study | Patients | Positivity | CTC count | Specificity | Comments |
|---|---|---|---|---|---|
| Cytelligen: Negative immunomagnetic selection with anti-CD45 Ab followed by CK8/18/19 immunostaining | |||||
| Wu21 | SCLC and NSCLC | 85% (35/41) (CTC ≥ 1) 83% (CTC ≥ 2) |
90% (28/31) (CTC ≥ 1) 97% (30/31) (CTC ≥ 2) |
||
| MAINTRAK: Positive immunomagnetic selection with anti-epithelial Ab followed by laser scanning cytometry | |||||
| Rolle22 | NSCLC (Stage I–III) | 86% (25/29) |
|||
| CellSearch: Positive immunomagnetic selection with anti-EpCAM Ab followed by morphological confirmation with staining for cytokeratins (positive in cytoplasm), DAPI (positive in nucleus), and CD45 (negative) | |||||
| Sawabata23 | NSCLC (Stage I) | 11% (1/9) | 0–10 cells/7.5 mL |
||
| Hou24 | SCLC | 86% (43/50) LD: 65% ED: 100% |
28 cells/7.5 mL (median) (0–44896) 2 (0–91) 237 (1–44896) |
CTC count decreased with chemotherapy *Prognostic (univariate) |
|
| Tanaka25 | SCLC and NSCLC | ||||
| CTC-chip: Capture with microposts coated with anti-EpCAM antibodies | |||||
| Nagrath26 | NSCLC | 100% (55/55) | 155 cells/1.0 mL (mean) (5–1281) |
EGFR-gene mutations detected from CTCs27 | |
Abbreviations: CK, cytokeratin; Ab, antibody; SCLC, small cell lung cancer; NSCLC, non-small cell lung cancer; EpCAM, epithelial cell adhesion molecule; ED, extended disease; LD, limited disease; EGFR, epithelial growth factor receptor.