Serum carcinoembryonic antigen level is associated with epidermal growth factor receptor mutations in recurrent lung adenocarcinomas

BACKGROUND. The presence of epidermal growth factor receptor (EGFR) gene mutations is a good indicator of the clinical efficacy of gefitinib in patients with nonsmall cell lung cancer. It was recently reported that the serum carcinoembryonic antigen (CEA) level could be a predictive factor for the efficacy of gefitinib treatment; therefore, it is suggested that the EGFR gene mutation is associated with the serum CEA level. The current study analyzed the association between EGFR gene mutations and clinical features, including the serum CEA level, in patients with recurrent lung adenocarcinomas. METHODS. A total of 48 lung adenocarcinoma patients with postoperative disease recurrence who underwent chemotherapy were investigated. EGFR gene mutations at exons 18, 19, and 21 were measured using surgical specimens taken from the primary tumor. RESULTS. Mutations of the EGFR gene were detected in 25 of the 48 patients and the abnormal serum CEA concentration at the time of disease recurrence was found to be significantly associated with the incidence of EGFR gene mutations (P =.045). The rate of EGFR gene mutations significantly increased as the serum CEA level increased (serum CEA level; <5 vs ≥5 <20 vs ≥20 = 35% vs 55% vs 87.5%, respectively, P = .040). A multivariate analysis revealed that a higher serum CEA level at the time of disease recurrence is independently associated with EGFR gene mutations (P = .036) with an odds ratio of 4.70 (95% confidence interval, 1.1-21.1). CONCLUSIONS. The serum CEA level appears to be closely associated with the presence of EGFR gene mutations in patients with pulmonary adenocarcinomas.