Prognostic and predictive value of serum carcinoembryonic antigen levels in advanced non-small cell lung cancer patients with epidermal growth factor receptor sensitive mutations and receiving tyrosine kinase inhibitors

BACKGROUND Despite the widespread use of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced or recurrent non-small cell lung cancer (NSCLC), no biomarkers for predicting the efficacy of EGFR-TKIs in patients with EGFR-sensitive mutations have yet been identified. The purpose of our study was to explore the effect of baseline serum tumor markers in stage IIIB/IV NSCLC patients treated with EGFR-TKIs. METHODS One hundred and seventy-seven patients with stage IIIB/IV NSCLC who harbored EGFR-sensitive mutations and were treated with EGFR-TKIs were retrospectively reviewed. Their levels of CEA, CYFRA 21-1, NSE and CA199 were measured before treatment with EGFR-TKIs. RESULTS The response rate for all patients was 54.8%, with a median progression-free survival of 6.6 months and overall survival of 14.8 months. In univariate analyses, patients with CEA levels below the cutoff point (10 ng/ml) had higher RR, better PFS, and better OS than those with CEA levels above 10 ng/mL (RR: 69.2% vs. 43.4%, p= 0.001; mPFS: 7.8 months vs. 5.3 months, p=0.029; mOS: 18.8 months vs. 11.8 months, p=0.000). The baseline serum CEA level was an independent factor for RR (odds ratio [OR] =0.322, p=0.001), PFS (hazard ratio [HR] =1.45, p=0.025), and OS (HR=2.133, p=0.000). CONCLUSION Our study suggests that baseline serum CEA levels may play a role in predicting the efficacy of EGFR-TKIs in stage IIIB/IV NSCLC patients with EGFR-sensitive mutations who are treated with EGFR-TKIs.