Brain metastasis development and poor survival associated with carcinoembryonic antigen (CEA) level in advanced non-small cell lung cancer: a prospective analysis

In a prospective manner, we studied 293 patients with NSCLC in IIIB-IV clinical stage. They received standard chemotherapy. CEA was measured prior to treatment; EGFR and HER2 were evaluated by immunohistochemistry. BM development was confirmed by MRI in symptomatic patients.BM developed in 27, and 32% of patients at 1 and 2 years of diagnosis with adenocarcinoma (RR 5.2; 95% CI, 1.002–29; p = 0.05) and CEA ≥ 40 ng/mL (RR 11.4; 95% CI, 1.7–74; p < 0.01) as independent associated factors. EGFR and HER2 were not statistically significant. Masculine gender (RR 1.4; 95% CI, 1.002–1.9; p = 0.048), poor performance status (RR 1.8; 95% CI, 1.5–2.3; p = 0.002), advanced clinical stage (RR 1.44; 95% CI, 1.02–2; p = 0.04), CEA ≥ 40 ng/mL (RR 1.5; 95% CI, 1.09–2.2; p = 0.014) and EGFR expression (RR 1.6; 95% CI, 1.4–1.9; p = 0.012) were independent associated factors to worse OS.High CEA serum level is a risk factor for BM development and is associated with poor prognosis in patients with advanced NSCLC. Surface expression of CEA in tumor cells could be the physiopathological mechanism for invasion to CNS.Lung cancer is the first cause of cancer death in the world. Eighty five percent of patients are diagnosed yearly with non-small cell lung cancer (NSCLC). Despite efforts, innovations, and progress in diagnosis and treatment of these patients, overall survival (OS) at 5 years of diagnosis is only 15% [1].The central nervous system (CNS) is a devastating and frequent site of metastasis development in NSCLC. The reported incidence of CNS metastasis in patients with NSCLC is 54% [2] with an OS of <1 year after diagnosis [3-5]. Age [3], clinical stage [6], gender [7], and initial treatment period [8] are some of the reported with CNS metastasis development-related factors in patients with NSCLC; however, due to their lack of specificity, we are required to detect biomarkers to predict brain metastasis in patients with NSCLC.Carcinoembryonic antigen (CEA, CEA-related cell adhesion