Serum levels of CA-50, CA-19.9, CA-125, neuron specific enolase and carcinoembryonic antigen in lung cancer and benign diseases of the lung.

The serum levels of five markers (CA-50, CA-19.9, CA-125, Enolase (NSE) carcinoembryonic antigen (CEA) were studied in 96 lung cancer patients and in 60 patients with benign diseases of the lung: sensitivity was 0.44, 0.41, 0.54, 0.23 and 0.38 respectively; specificity was 0.67, 0.87, 0.47, 0.93 and 0.97 respectively. Serum levels of CA-125 over 20 U/ml were found in 74% of patients with acute pneumonia. A good parallel existed between the clinical evolution of lung cancer and the variations in the serum level of CA-50, CA-19.9 and NSE. Although the pretreatment result was elevated, successive assays of the marker allowed the clinical evolution to be followed. Conflicting results were found with CA-125 and to a lesser extent with CEA. A close correlation existed between the serum levels CA-50 and CA-19.9 in the 2 groups of patients. In the absence of a specific marker for lung cancer, complementary information can be provided by means of a simultaneous determination of CEA, NSE, CA-19.9--or CA-50--and CA-125.