Relationship between serum carcinoembryonic antigen level and epidermal growth factor receptor mutations with the influence on the prognosis of non-small-cell lung cancer patients

Objective: To investigate the relationship between serum carcinoembryonic antigen (CEA) level and epidermal growth factor receptor (EGFR) gene mutations in non-small-cell lung cancer (NSCLC) patients and to analyze the influence of CEA level on postoperative survival time in lung cancer patients. Methods: A total of 296 patients who were treated in Thoracic Surgery Department of Henan Provincial Chest Hospital from September 2011 to September 2013 were recruited. The level of tumor markers, such as CEA, was determined before the surgery, and EGFR gene mutations were detected after surgery. Thereby, the relationship between tumor makers, including CEA, and EGFR mutation and its influence on prognosis could be investigated. Results: Among 296 patients, the positive rate of EGFR gene mutation was 37.84% (112/296); the mutation occurred more frequently in nonsmokers, adenocarcinoma patients, women, and patients aged<60 years (P<0.05). Both tumor markers and chemosensitivity indicators were related to the profile of EGFR mutations. Elevated squamous cell carcinoma and Cyfra21-1 as well as positively expressed ERCC1 were more common in patients with wild-type EGFR (P<0.05), whereas increased CEA level was observed more frequently in patients with EGFR gene mutation (P=0.012). The positive rate of EGFR gene mutations was higher as the serum CEA level increased, that is, the positive rate in patients with serum CEA level <5, 5-20, and >20 mu g/L was 39.81%, 45.32%, and 65.47%, respectively (P=0.004). Logistic regression analysis showed that CEA level was an independent factor in predicting EGFR gene mutations, and serum CEA level was also an independent factor in affecting the prognosis of NSCLC patients, as the overall 2-year survival rate was 73.86% in elevated CEA group and 86.43% in normal group (P<0.01). Conclusion: The prognosis of NSCLC patients receiving resection can be predicted according to serum CEA level, which is associated with EGFR mutations in NSCLC patients and provides a preliminarily guidance for EGFR mutations.