Correlation between pre-treatment serum carcinoembryonic antigen levels and genotypes in a large population of Chinese people with advanced lung adenocarcinoma.

Background: A positive correlation between serum carcinoembryonic antigen (CEA) levels and epidermal growth factor receptor (EGFR) mutations has been reported in lung adenocarcinoma patients.

Aim: To investigate retrospectively whether serum CEA levels are also associated with genotypes in a large population of advanced lung adenocarcinoma.

Methods: A large cohort of 701 patients with advanced lung adenocarcinoma was studied retrospectively.

Results: EGFR mutations were found in 47.5% (333/701) of advanced lung adenocarcinoma patients, being identified at high frequencies in never-smokers, females, and in patients with abnormal pre-treatment serum CEA levels (53.1% vs 37.5%, P < 0.001). In contrast, anaplastic lymphoma kinase gene rearrangements were found in 7.8% (55/701) of patients, being identified at high frequencies in younger patients, and in patients with normal CEA levels (11.5% vs 5.8%, P = 0.012). Serum CEA levels were divided into four groups: <5, 5-19, 20-99 and ≥100 ng/mL. The rate of EGFR mutations significantly increased as the serum CEA levels increased (37.5%, 49.5%, 53.9% and 57.7%, respectively, P < 0.001). Anaplastic lymphoma kinase gene rearrangements showed the opposite result (11.5%, 7.1%, 5.7% and 4.1%, respectively, P = 0.044). A multivariate analysis revealed that higher pre-treatment serum CEA levels were independently associated with EGFR mutations (95% CI: 1.291-2.487, P < 0.001), but normal serum CEA levels were independently associated with anaplastic lymphoma kinase gene rearrangements (95% CI: 0.275-0.842, P = 0.010).

Conclusion: Our study demonstrated that a significant association exists between the serum CEA levels and genotypes in patients with advanced lung adenocarcinoma.