Correlation between serum CEA levels and EGFR mutations in Chinese nonsmokers with lung adenocarcinoma

Abstract

To evaluate the relationship between epidermal growth factor receptor (EGFR) mutations and serum carcinoembryonic antigen (CEA) levels in Chinese nonsmokers with pulmonary adenocarcinoma. We sequenced exons 18-21 of the EGFR gene in 98 cases. The patients were divided into two groups based on their pre-treatment serum CEA levels (below or above 5 ng/mL) for analyzing the correlations with EGFR mutations. Sixty-seven cases harbored EGFR mutations. The rates of EGFR mutations and exon 19 mutations in the high-CEA group (78.2% and 49.1%, respectively) were significantly higher those in the low-CEA group (55.8% and 20.9%, respectively). Serum CEA levels were found to be the only independent predictor of EGFR mutation (OR 2.837; 95% CI: 1.178-6.829) and exon 19 mutation (OR 3.618; 95% CI: 1.319-9.918). Furthermore, a higher serum CEA level was associated with a higher EGFR mutation rate and a higher exon 19 mutation rate: patients with serum CEA levels <5 ng/mL, ≥5 and <20 ng/mL, ≥20 ng/mL showed the EGFR mutation rate of 55.8%, 74.1%, 82.1%, respectively, and the exon 19 mutation rate of 20.9%, 40.7%, 57.1%, respectively. Patients with EGFR mutations displayed a significantly higher incidence of abnormal serum CEA levels (>5 ng/mL) than patients without EGFR mutations (64.2% vs 38.7%). Elevated serum CEA levels predict the presence of EGFR gene mutations in Chinese nonsmokers with pulmonary adenocarcinoma.