Evaluation and Prognostic Significance of Circulating Tumor Cells in Patients With Non–Small-Cell Lung Cancer

TLDR: CTCs are detectable in patients with stage IV NSCLC and are a novel prognostic factor for this disease, and further validation is warranted before routine clinical application.

Abstract: Purpose Lung cancer is the leading cause of cancer-related death worldwide. Non–small-cell lung cancer (NSCLC) lacks validated biomarkers to predict treatment response. This study investigated whether circulating tumor cells (CTCs) are detectable in patients with NSCLC and what their ability might be to provide prognostic information and/or early indication of patient response to conventional therapy. Patients and Methods In this single-center prospective study, blood samples for CTC analysis were obtained from 101 patients with previously untreated, stage III or IV NSCLC both before and after administration of one cycle of standard chemotherapy. CTCs were measured using a semiautomated, epithelial cell adhesion molecule–based immunomagnetic technique. Results The number of CTCs in 7.5 mL of blood was higher in patients with stage IV NSCLC (n = 60; range, 0 to 146) compared with patients with stage IIIB (n = 27; range, 0 to 3) or IIIA disease (n = 14; no CTCs detected). In univariate analysis, progression...