Use of circulating tumor cells in prospective clinical trials for NSCLC patients - standardization of the pre-analytical conditions.
BACKGROUND
Circulating tumor cells (CTCs) hold potential for noninvasive diagnosis, prognosis and prediction testing in non-small cell lung cancer (NSCLC) patients. Minimizing degradation or loss of CTCs is pivotal for detection and profiling of the low abundance and fragile CTCs, particularly in clinical trials. We prospectively investigated (NCT02372448) whether a new blood collection device performed better compared to commonly used K3EDTA tubes, when subjected to long-term sample storage.


METHODS
Blood samples were drawn into K3EDTA and blood collection tubes (BCT) (Streck), and filtered by the Isolation by SizE of Tumor/Trophoblastic Cells (ISET® system), for CTC detection in two study populations of NSCLC patients; the training set of 14 patients with stage II/IV NSCLC, and the validation set of 36 patients with stage IV NSCLC). MET expression was evaluated by immunocytochemistry (ICC) and anaplastic lymphoma kinase (ALK) gene rearrangement by break-apart fluorescence in situ hybridization (FISH) on ISET-enriched CTCs.


RESULTS
Blood processed after 24 h and 48 h in BCT tubes showed stable CTCs counts and integrity, whereas CTCs in K3EDTA tubes showed an altered morphology in all patients. CTCs recovered in BCT or K3EDTA tubes at 24 and 48 h were evaluable by ICC for MET expression and by FISH for ALK rearrangement.


CONCLUSIONS
The BCT tubes gave a high yield and preserved the integrity of CTCs after 24 and 48 h of storage at room temperature, which facilitate their molecular characterization in NSCLC patients entering clinical trials.
['Ilie|Marius|M|http://orcid.org/0000-0002-2014-1236', 'Hofman|Véronique|V|', 'Leroy|Sylvie|S|', 'Cohen|Charlotte|C|', 'Heeke|Simon|S|', 'Cattet|Florian|F|', 'Bence|Coraline|C|', 'Lalvée|Salomé|S|', 'Mouroux|Jérôme|J|', 'Marquette|Charles-Hugo|CH|', 'Hofman|Paul|P|', '|||']
D000328:Adult D002289:Carcinoma, Non-Small-Cell Lung D002474:Cell-Free System D002986:Clinical Trials as Topic D004492:Edetic Acid D005260:Female D006801:Humans D017404:In Situ Hybridization, Fluorescence D008175:Lung Neoplasms D008297:Male D008875:Middle Aged D009360:Neoplastic Cells, Circulating D011446:Prospective Studies
circulating tumor cells non-small cell lung cancer (NSCLC) K3EDTA BCT Isolation by SizE of Tumor/Trophoblastic Cells (ISET) stability