Optimal combination of seven tumour markers in prediction of advanced stage at first examination of patients with non-small cell lung cancer.

Between Januaty 1996 and December 1999, we examined seven tumour markers (carcinoembryonic antigen (CEA), alpha feto protein (AFP), cancer antigen CAI9-9 (CA199), squamous cell carcinoma antigen (SCC), neuron-specific enolase (NSE), cancer antigen CA125 (CA125), cytokeratin 19 fragment (CYFRA)) in 312 patients (200 patients with adenocarcinoma (Ad); 112 patients with squamous cell carcinoma (Sq)). In Ad patients, CEA showed the highest positivity rate (46.5% of Ad patients) which rose as the stage advanced and was followed by CA125, the positivity rate of which also increased with the stage. All the Ad cases (35 out of 35:100%) with CA125 levels above 70 ng/ml were advanced (stage IIIB or IV), regardless of the other tumour markers. In Sq patients, the positivity rate of CYFRA (48.2%) was the second highest behind SCC (55.4%), but increased as the stage advanced. As regards the combinations of two markers, in Ad patients, both CYFRA and CA 125 showed significant supplementary value when used with CEA, even though CEA expression was absent. Furthermore, most ofthe CEA, CYFRA (25 out of 26:96.2%) and CEA, CA125 (38 out of 40:95.0%) double-positive Ad patients were also in the advanced stage. In Sq patients, no additional sensitivity and specificity in the prediction of advanced stage resulted from any combination of CYFRA with other markers. By selecting appropriate tumour markers in NSCLC patients, we can predict the stage of the lung cancer and utilize these markers as complementaty tools to establish indications for treatment.