CEA levels in serum and BAL in patients suffering from lung cancer - Correlation with individuals presenting benign lung lesions and healthy volunteers

Background: Carcinoembryonic antigen (CEA) is a tumor marker belonging to the immunoglobulin gene superfamily of adhesion molecules. CEA is synthesized by epithelial and tumor cells. In this study, CEA levels in sera and bronchoalveolar lavage fluid (BAL) were measured in patients with malignant lung cancer and benign lung diseases. Methods: In the present study CEA was measured in serum using IRMA methods and in bronchoalveolar lavage of individuals undergoing fiberoptic bronchoscopy. Fifty patients with lung cancer (G1), 20 patients with benign lung lesions (G2), and a control group consisted of 20 individuals (G3) were enrolled in the study. Results: We found that serum CEA levels were significantly higher in G1 compared to G2 and G3 (p < 0.01). No significant difference in serum CEA levels was found between smokers and nonsmokers in any of the three groups studied. CEA was significantly higher in G1 BAL (p < 0.05) compared to G2 and G3 BAL. Furthermore, a statistically significant difference was found in CEA levels in BAL between smokers and nonsmokers of G2. Conclusions: CEA, levels in BAL of normal individuals may be influenced by smoking and other factors that affect lung epithelial cell function. Thus, CEA measurement in BAL alone has little value in the diagnosis of malignancy. BAL CEA levels in smokers of G2 are found significantly higher compared with nonsmokers of the same group and healthy individuals. Smokers of G2 have to be followed up carefully for the possibility of lung cancer growth.