Elevated serum sialyl Lewis X-i antigen levels in non-small cell lung cancer with lung metastasis

To evaluate the relationship between serum levels of sialyl Lewis X-i antigen and lung metastasis in patients with non-small cell lung cancer (NSCLC), we measured the serum level of the antigen in 299 patients with untreated locally advanced or metastatic NSCLC. Before treatment, serum levels of sialyl Lewis X-i antigen were significantly higher in patients with lung metastasis than in those without lung metastatis (p = 0.0001). Of 201 patients without lung metastasis at the time of primary diagnosis, 121 patients died between July 1987 and December 1995. Serum levels of sialyl Lewis X-i antigen in 21 patients who developed lung metastasis during the period were significantly higher than those in 100 patients who did not develop lung metastasis (p = 0.0171). Our results suggested that sialyl Lewis X-i antigen might be a good indicator for the presence or development of lung metastasis, and it might provide clinical information about the management of patients with NSCLC.