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

Background: Central nervous system is a common site of metastasis in NSCLC and confers worse prognosis and quality of life. The aim of this prospective study was to evaluate the prognostic significance of clinical-pathological factors (CPF), serum CEA levels, and EGFR and HER2 tissue-expression in brain metastasis (BM) and overall survival (OS) in patients with advanced NSCLC. Methods: 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. Results: 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. Conclusion: 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.