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

Aim: To evaluate the relationship between epidermal growth factor receptor (EGFR) mutations and serum carcinoembryonic antigen (CEA) levels in Chinese nonsmokers with pulmonary adenocarcinoma. Methods: We sequenced exons 18-21 of the EGFR gene in 98 cases. The patients were divided into two groups based on their pretreatment serum CEA levels (below or above 5 ng/mL) for analyzing the correlations with EGFR mutations. Results: 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 than 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%). Conclusion: Elevated serum CEA levels predict the presence of EGFR gene mutations in Chinese nonsmokers with pulmonary adenocarcinoma.