The Presence of Small-Size Circulating Tumor Cells Predicts Worse Prognosis in Non-Small Cell Lung Cancer Patients.

CONTEXT.— Most patients with non-small cell lung cancers (NSCLC) are diagnosed at advanced stages. The 5-year survival rate of patients with advanced lung cancer is less than 20%, which makes lung cancer the leading cause of cancer-related deaths worldwide. OBJECTIVE.— To identify indicators that can predict the prognosis of lung cancer patients. DESIGN.— To determine the correlation between circulating tumor cells (CTCs), circulating tumor-derived endothelial cells (CTECs), and their subtypes and the prognosis of patients with NSCLC, 80 patients with lung cancer were recruited and 48 patients who met the enrollment criteria were selected in this study. Peripheral blood was collected from the enrolled patients before any treatment and analyzed by the subtraction enrichment and immunostaining-fluorescence in situ hybridization technique to determine the correlation between CTCs and CTECs and lung cancer disease progression and to identify prognostic indicators. RESULTS.— In all patients, the positive rate of CTCs was 100% and the positive rate of CTECs was 81.3%. The CTEC positivity rate was higher in late-stage patients than in early-stage patients (P = .03). Patients with advanced or lymph node metastases had a higher rate of small-size CTC positivity than those with early or no lymph node metastases. Large-size CTEC positivity was higher in patients with advanced NSCLC than in early-stage patients. Patients with ≥1 small-size CTC had shorter progression-free survival, and it was an independent prognostic factor. CONCLUSIONS.— Small-size CTCs are a reliable prognostic indicator and a probable predictor of the severity of disease in NSCLC patients.