Background and study objective: Serum sialyl Lewis X-i antigen has been shown to be one of the most specific markers for monitoring non-small cell lung cancer(NSCLC). We evaluated the correlation between serum levels of sialyl Lewis X-i antigen and mediastinal lymph node involvement in NSCLC patients.
Methods: One hundred patients with untreated NSCLC were included in this study. All the patients received surgical treatment and the lymph nodes were evaluated pathologically. Pretreatment sera from these patients examined for the levels of sialyl Lewis X-i antigen, using a radioimmunoassay.
Results: Serum levels of sialyl Lewis X-i antigen levels in patients with N2 were higher than those of N0-1(p = 0.0049). According to the receiver characteristic curve analysis, the recommended cut-off level of the antigen between N0-1 patients and N2 patients was 38.0 U/ml.
Conclusion: Measurement of serum levels of sialyl Lewis X-i antigen might provide preoperative information in patients with NSCLC.