Prognostic role of circulating tumor cells in patients with EGFR-mutated or ALK-rearranged non-small cell lung cancer

Abstract

Background: Circulating tumor cell (CTC) counts at baseline and follow-up are an independent prognostic factor in patients receiving standard chemotherapy for non-small cell lung cancer (NSCLC). This study further explored the role of CTCs in EGFR-mutated and ALK-rearranged NSCLC patients administered targeted therapies as first-line treatment. Methods: CTCs were enumerated with a novel high-efficiency detection method from the blood of 43 patients with EGFR-mutated or ALK-rearranged NSCLC at baseline and at disease-progression. Patients were stratified into favorable and unfavorable groups with baseline CTC counts of < 8 or ≥ 8 CTCs/3.2 mL, respectively. Results: A total of 76.7% of the patients were positive for ≥ 2 CTCs /3.2 ml blood at baseline. The median progression-free survival (PFS) and overall survival (OS) rates of the favorable compared to the unfavorable group were longer (11.6 vs. 8.5 months, P = 0.004 for PFS; 21.00 vs. 17.7 months, P = 0.013 for OS). Multivariate analysis demonstrated that baseline CTC count was a strong predictor of PFS (hazard ratio 2.835; 95% confidence interval 1.240–6.483; P = 0.014) and OS (hazard ratio 3.317; 95% confidence interval 1.360–8.092; P = 0.008). Conclusion: Baseline CTC count could be a predictive biomarker for EGFR-mutated and ALK-rearranged NSCLCs, which allows for better guidance and monitoring of patients over the course of molecular targeted therapies.