Objective: This prospective study aimed to compare the diagnostic value of several tumor markers in blood and bronchoalveolar lavage (BAL) fluid in patients with lung cancer.
Methodology: Fifty-one patients diagnosed as cancer and 44 patients with a benign lung disease were included in the study. Blood and BAL fluid samples were collected from all subjects. Levels of carcinoembryogenic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), carbohydrate antigen 15-3 (CA 15-3) and lactate dehydrogenase (LDH) activity were determined in both samples. The sensitivity and specificity of the markers were analyzed by means of receiver-operating curves.
Results: Serum CEA and CA 15-3 levels were significantly higher in the malignant group (p<0.05), whereas CA 19-9 and LDH levels were comparable. Concentrations of CA 19-9, CA 15-3 and LDH in BAL fluid were higher in the malignant group compared to the benign group (p<0.05). CEA levels in BAL fluid did not differ between the two groups. The sensitivity and specificity of CEA, CA 19-9, CA 15-3 and LDH were calculated as 21-50%, 8.6-68.6%, 34.9-84-3% and 61-56% in the blood samples, respectively. In BAL fluid samples the sensitivity and specificity of CEA, CA 19-9, CA 15-3 and LDH were 81.8-45.1%, 29-69%, 81.8-68% and 70-25% in the same order. CA 15-3 levels displayed a high specificity both in BAL fluid and blood samples.
Conclusions: Although these markers are not hundred percent specific in the diagnosis of lung cancer, we suggest that measurement of CEA in BAL fluid and CA 15-3 assessment in both body fluids will be useful as complementary laboratory tests.