Value of carcinoembryonic antigen levels in predicting the efficacy of EGFR-TKI in advanced non-small cell lung cancer harboring EGFR mutations

Abstract

To explore the relevance of carcinoembryonic antigen (CEA) level and efficacy of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) in advanced non-small cell lung cancer (NSCLC) harboring EGFR mutations. Between September 2010 and December 2013, 170 NSCLC patients harboring EGFR mutations receiving EGFR-TKI treatment at pulmonary medicine department of Shanghai Chest hospital were retrospectively screened. They were screened for clinical characteristics, efficacy of EGFR-TKI, and tumor markers (CEA/cytokerantin-19-fragment CYFRA21-1) at an initial diagnosis. The cutoff value for CEA was 5 µg/L. The overall objective response rate (ORR) was 37.6% and disease control rate (DCR) 90.0%. Those with high CEA levels (>5 µg/L) had better DCR (94.3% vs 80.4%, P = 0.022). Univariate analysis showed that patients with high CEA levels ( ≥ 20 µg/L) had significantly longer progression-free survival (PFS) than those with low CEA level (HR = 1.444, 95%CI: 1.036-2.014, P = 0.030). HR value increased with rising CEA levels. No significant difference in PFS existed between high-CYFRA21-1 and normal-CYFRA21-1 groups (HR = 1.167, 95%CI: 0.840-1.622, P = 0.357). Close follow-ups were conducted for 51 patients on EGFR-TKI treatment. And their CEA levels was tested within one month after treatment. The patients in descending type group had longer PFS than other two types (HR = 7.344, 95%CI: 2.903-18.578, P < 0.001). CEA level has a close correlation with the efficacy of EGFR-TKI treatment. And a high CEA level may be a predictive marker for better response and longer PFS in advanced NSCLC.