Serum levels of CA-50, CA-19.9, CA-125, CA-15.3, enolase and carcino-embryonic antigen in non neoplastic diseases of the lung.

There is not as yet a specific marker for lung cancer. We tested the specificity of six serum markers using radio-immunological assays (CA-50, CA-19.9, CA-125, CA-15.3, Enolase, CEA) in 60 patients with non-neoplastic diseases of the lung (COPD: 28 patients, acute pneumonia: 23 patients, allery: 9 patients). No correlation was found between the percentage of false positivities on the one hand, and sex, age and smoking habits on the other. CA-125 proved to be positive in 74% of acute pneumonia cases. The rate of false positive values is low with CEA (3.3%), Enolase (6.7%) and CA-15.3 (5%) and therefore the cut-off value we chose for these markers was adequate. This is not the case with CA-50, CA-19.9 and CA-125, for which we observed a high rate of false positive values (33.3%, 13.3% and 53.3% respectively) and for which higher cut-off values must be adopted.