Trial Information

Evaluation of the Value Forecasts of the Identification of the Circulating Tumoral Cells (CTC) in the Broncho-lung Carcinomas Not in Small Cells of Stages I and II by the Method ISET (Insulation by Size of Epithelial Tumor Cells)

Lung cancer is the most prevalent neoplasm and the major cause of tumor-related mortality
worldwide. Despite recent advances in the management of resected lung cancers (i.e., the use
of adjuvant therapy) and more effective treatments of metastatic tumors (i.e., molecular
targeted agents), the cure rate of patients with lung cancer remains low (. Histological
classification of lung tumors distinguishes small (SCLC) and non-small cell lung cancers
(NSCLC). Most NSCLC display three histological subtypes: adenocarcinoma, squamous cell
carcinoma and large cell carcinoma. The prognosis of these three NSCLC subtypes is quite
similar. In this regard, development and validation of new prognostic/predictive biomarkers
from tumor tissues and biological fluids is one of the more promising domain in
translational cancer research. However, the clinical impact of new biomarkers has to be
carefully validated, including for NSCLC. While pTNM staging is currently the only validated
prognostic factor used in NSCLC patients follow up and treatment, 25% to 50% of patients
with early-stage I NSCLC show tumor recurrence following extensive tumor resection,
indicating the urgent need of more sensitive prognostic markers. Furthermore, it has been
reported that the presence of occult metastatic disease correlates with disease recurrence
in stage I NSCLC patients. There is now a sizable body of evidence that metastases could
develop from circulating tumor cells (CTC) spread in blood before or during surgery . Thus,
sensitive and specific detection of CTC in blood is considered as a potentially relevant
predictive biomarker for patients with NSCLC. Indeed, the main goal for preoperative
detection of CTC is to identify patients with high risk of recurrence after surgery, in
order to perform more adapted therapeutic strategy. Despite several studies reported about
CTC detection, methodological aspects concerning sensitivity, specificity and
reproducibility have prevented a clear appraisal of their clinical impact. While RT-PCR and
immune-mediated methods can be very sensitive, specificity remains a critical issue for
these approaches as no transcript or antigen is known at present specifically recognizing
tumor cells from solid tumors . In this setting, cytopathological analysis of circulating
non hematological cells (CNHC), of epithelial (CEC) and endothelial (CEN-C) origin, isolated
according to their size (ISET, Isolation by Size of Epithelial Tumor cells) is considered a
promising approach, as CNHC enrichment is very sensitive and cell morphology is not damaged
allowing to apply classical cytopathological criteria to identify tumor cells. In this
regard, ISET technology has been previously reported to allow identification of CTC in
patients with liver and breast tumors. However, ISET method has never been used to detect
CTC in patients with NSCLC. The aim of this study is to determine the diagnostic potential
of ISET method for preoperative detection of CTC in NSCLC patients. For this purpose
cytomorphological criteria have been established by a group of 10 cytologists to classify
CNHC in 3 groups : i) CNHC with malignant features (CNHC-MF) , ii) CNHC with uncertain
features (CNHC-UMF), and, iii) CNHC with benign features (CNHC-BF). The presence and number
of these circulating cells are then correlated with pTNM, histological subtype, and
percentage of tumor cells into the primary tumors.