Detection of circulating tumor cells as a prognostic factor in patients undergoing radical surgery for non‐small‐cell lung carcinoma: comparison of the efficacy of the CellSearch Assay™ and the isolation by size of epithelial tumor cell method

Abstract

Comparison of the efficacy of different enrichment methods for detection of circulating tumor cells (CTCs) before radical surgery is lacking in non-small-cell lung carcinoma (NSCLC) patients. Detection and enumeration of CTCs in 210 consecutive patients undergoing radical surgery for NSCLC were evaluated with the CellSearch Assay TM (CS), using the CellSearch Epithelial Cell Kit, and by the isolation by size of epithelial tumor (ISET) method, using double immunolabeling with anticytokeratin and anti-vimentin antibodies. CTCs were detected in 144 of 210 (69%) patients using CS and/or ISET and in 104 of 210 (50%) and 82 of 210 (39%) patients using ISET and CS, respectively. Using ISET, 23 of 210 (11%) patients had vimentin-positive cells with cytological criteria of malignancy. Disease-free survival (DFS) was worse for patients with CTCs compared to patients without CTCs detected by CS alone (p < 0.0001; log rank 5 30.59) or by ISET alone (p < 0.0001; log rank 5 33.07). The presence of CTCs detected by both CS and ISET correlated even better with shorter DFS at a univariate (p < 0.0001; log rank 5 42.15) and multivariate level (HR, 1.235; 95% CI, 1.056-1.482; p < 0.001). CS and ISET are complementary methods for detection of CTCs in preoperative radical surgery for NSCLC. CTC detection in resectable NSCLC patients using CS and/or ISET could be a prognostic biomarker of great interest and may open up new avenues into improved therapeutic strategies for lung carcinoma patients.Despite the different therapeutic strategies developed to date, non-small-cell lung carcinomas (NSCLC) have poor prognosis, because overall survival after 5 years is 20-25% for all stages.

Detection of KRAS mutations in circulating tumor cells from patients with metastatic colorectal cancer

“…Counting was made per mL of blood. Cells were considered as CTCs if they were negative for CD45, have presented with hypercromatic nucleus, irregular shape, high cytoplasm nucleus ratio (>0.5) and nuclear size Although ISET has passed through technical, 27,28 and clinical validation, 32,34 we made our own tests of its sensitivity and specificity, as described previously by Chinen et al, (2014). 30 Briefly, we spiked different numbers of cells HCT 116 (colorectal carcinoma cell line) in 1 ml of blood from healthy subject.…”

Introducing, OncoTarget

“…Some reports found that the presence of Abbreviation: NOS (not otherwise specified) mesenchymal markers on CTCs has strongly associated with worse prognosis than those with the expression of CK alone, indicating that common identification based on epithelial marker may omit the most aggressive CTCsubset [28,29]. Vimentin has been regarded as a novel marker, with preferentially expressed in moderately and well-differentiated lung adenocarcinomas [30]. When analyzed by immune-fluorescent staining, EMT-related markers are frequently co-expressed with different CKs [31,32].…”

Critical issues in the clinical application of liquid biopsy in non-small cell lung cancer

“…Several studies associate CTC number to OS and/or PFS of metastatic NSCLC patients (32,33,48,57), meanwhile others do not find these associations (70,71). Many small trials have also demonstrated the association between CTC count and therapy efficacy, comparing the count before and after therapy (38,(72)(73)(74), or during target therapy, in order to detect the onset of resistance mutations (50,54,62,66,75).…”

“…EMT CTCs are documented in NSCLC (76), and low numbers of CTCs are observed with epithelial marker-dependent methods (13,33). Indeed, methods based on physical properties (48,49,53) or PCR-based methods (32), usually detect higher numbers of CTCs in lung cancer. However, so far, the FDA-cleared CellSearch ® assay, enriching and counting EpCAM+ CTCs (Table 1) has proved to identify 20-40% of CTC positive metastatic NSCLC patients (32,33,48,57).…”

“…Indeed, methods based on physical properties (48,49,53) or PCR-based methods (32), usually detect higher numbers of CTCs in lung cancer. However, so far, the FDA-cleared CellSearch ® assay, enriching and counting EpCAM+ CTCs (Table 1) has proved to identify 20-40% of CTC positive metastatic NSCLC patients (32,33,48,57). Moreover, a CTC positive status has been associated with a positive lymph node using this test (32,77).…”