SERUM SIALYL-LEWIS X-I ANTIGEN LEVELS IN NONSMALL CELL LUNG-CANCER - CORRELATION WITH DISTANT METASTASIS AND SURVIVAL

To evaluate the correlation between serum levels of sialyl Lewis X-i a ntigen and distant metastasis and survival in patients with non-small cell lung cancer (NSCLC), we measured the serum levels of the tumor ma rker in 371 patients with untreated NSCLC, The sialyl Lewis X-i antige n level was measured using a RIA kit, In patients with adenocarcinoma or other NSCLC subtypes, there was a correlation between serum sialyl Lewis X-i antigen and stage of the disease (P = 0.0001 and P = 0.0015, respectively), Levels of the marker varied significantly depending on the number of metastatic organs in adenocarcinoma (P 0.0089) and in o ther NSCLC subtypes (P = 0.002), Univariate analysis showed that survi val of NSCLC patients with high (more than 100 units/ml) sialyl Lewis X-i antigen levels was significantly poorer than that of patients with low antigen levels (P = 0.0001), Multivariate analysis using Cox's pr oportional hazard model showed that high sialyl Lewis X-i antigen leve ls correlated significantly with poor survival (P = 0.004), Our data s uggest that a high serum level of sialyl Lewis X-i antigen seems to be an indicator of the presence of metastasis and might indicate the nee d for a careful investigation of all putative metastatic sites. The se rum levels of sialyl Lewis X-i antigen may reflect the extension of me tastasis and would be helpful in considering treatment options.