SERUM CARCINOEMBRYONIC ANTIGEN LEVEL AS A PREDICTIVE MARKER FOR DISTANT METASTASIS IN NON-SMALL CELL LUNG CANCER

Aim: Elevated serum CEA (S-CEA) levels are sometimes attributable to the production of CEA by malignant cells, and in turn, the antigen itself can enhance the metastatic potential of malignant cells. We investigated the predictive role of S-CEA level for distant metastasis in nonsmall cell lung cancer (NSCLC).
Methods: Consecutive 116 NSCLC patients referred to our department were retrospectively investigated. S-CEA levels was compared according to age, gender, smoking habits, histological type, distant metastases and clinical disease stage in all patients.
Results: There were no significant relationship between S-CEA level and age, gender and smoking habits. There was significant difference in S-CEA level between M0 and M1 patients (p<0.001). S-CEA levels were not significantly different between symptomatic and silent metastases NSCLC patients (p=0.103). We could not find significant differences in S-CEA levels between T1-2 and T3-4 (p=0.141), N0-1 and N2-3 (p=0.672). In NSCLC, the area under the ROC curve was 0.728 (p<0.001), S-CEA threshold of 6.4 ng/mL has predictive sensitivity and specificity, for distant metastases as 69.8% and 73.0% respectively. In multivariate analysis including age, gender, smoking status, histologic type and S-CEA level that only S-CEA levels qualified as an independent predictive factor for distant metastases (p=0.001).
Conclusion: We conclude that S-CEA levels were significant for predicting distant metastases. High levels of S-CEA may be an indication to perform routine investigation of distant metastases even in the absence of symptoms and signs.