The Significance of Serum Carcinoembryonic Antigen in Lung Adenocarcinoma

BACKGROUND: A raised carcinoembryonic antigen (CEA) may be associated with significant pathology during the postoperative follow-up of lung adenocarcinoma. METHODS: We reviewed the medical records of 305 patients who underwent surgical resections for primary lung adenocarcinoma at a single institution between April 2006 and February 2013. RESULTS: Preoperative CEA levels were significantly associated with age, smoking history, pathologic stage including pT (pathologic tumor stge), pN (pathologic nodal stage) and overall pathological stage, tumor size and differentiation, pathologically positive total lymph node, N1 and N2 lymph node, N2 nodal station (0/1/2=1.83/2.94/7.21 ng/mL, p=0.019), and 5-year disease-free survival (0.591 in group with normal preoperative CEA levels vs. 0.40 in group with high preoperative CEA levels, p=0.001). Preoperative CEA levels were significantly higher than postoperative CEA levels (p<0.001, Wilcoxon signed-rank test). Postoperative CEA level was also significantly associated with disease-free survival (p<0.001). A follow-up serum CEA value of >2.57 ng/mL was found to be the appropriate cutoff value for the prediction of cancer recurrence with sensitivity and specificity of 71.4% and 72.3%, respectively. Twenty percent of patients who had recurrence of disease had a CEA level elevated above this cutoff value prior to radiographic evidence of recurrence. Postoperative CEA, pathologic stage, differentiation, vascular invasion, and neoadjuvant therapy were identified as independent predictors of 5-year disease-free survival in a multivariate analysis. CONCLUSION: The follow-up CEA level can be a useful tool for detecting early recurrence undetected by postoperative imaging studies. The perioperative follow-up CEA levels may be helpful for providing personalized evaluation of lung adenocarcinoma.