Diagnostic value of CYFRA 21-1 and carcinoembryonic antigen in diagnosis of operable lung cancer from benign lung disease.

Background: Lung cancer is sometimes difficult to differentiate from benign lung diseases with nodular shadow in imaging scan. In these cases, exploratory operation is needed for the patients with highly suspected malignant disease. Therefore, there is an urgent demand to differentiate the benign lung disease from malignant lung nodules rather than invasive method. Aim: We evaluated the diagnostic value of two tumor markers in distinguishing operable lung cancer from benign lung disease. Materials and Methods: The serum levels of carcinoembryonic antigen (CEA) and CYFRA 21-1 were retrospectively analyzed in 236 lung cancer patients and 44 patients with benign lung disease. These benign lung diseases were presented with evidence of a high likelihood of having lung cancer. After surgical operation, diagnosis of lung cancer and benign lung disease were confirmed by histological examination. Results: We found that the average level of tumor marker in operable lung cancer patients was higher than those in patients with benign lung disease. CYFRA 21-1 sensitivity and specificity for lung cancer diagnosis was 37.3% and 90.9%, respectively, while that for CEA was 22.0% and 90.9%. The combined value for the sensitivity and specificity of these two tumor markers was 47.5% and 81.8%, respectively. Conclusion: Our results indicate that the combination of these two tumor markers resulted in higher sensitivity compared to use CYFRA 21-1 or CEA along. Given its lower sensitivity and higher specificity, positive CYFRA 21-1 or positive CEA strongly supports lung cancer in patients with nodular shadow in imaging scan.