Preoperative serum value of sialyl Lewis X predicts pathological nodal extension and survival in patients with surgically treated small cell lung cancer.

BACKGROUND AND OBJECTIVES

We investigated various tumor markers in patients with surgically treated small cell lung cancer (SCLC) to identify the markers closely correlated to pathological staging and to predict survival by retrospective analyses.

METHODS

Reviewing database records between 1990 and 2007 revealed 36 patients with SCLC, that were grouped according to clinical and pathological stages. Receiver operating characteristic (ROC) curves were calculated for serum levels of various tumor makers to predict the pathological stage. The cut-off value was calculated from the ROC curve of the significant marker. Survival in patient groups divided by the new cut-off value was calculated.

RESULTS

Serum levels of various tumor makers were not significantly different between the pathological stage groups, except for serum sialyl Lewis X (SLX). ROC curve of SLX was significantly correlated to pathological stages (P = 0.0136). The calculated SLX cut-off value was 25.1 U/ml, with 80% sensitivity and 70% specificity. Five-year survival of patients selected by this new cut-off was 82.5%, whereas that with the standard cut-off (38.0 U/ml) was 55.9%.

CONCLUSIONS

Serum SLX values were associated with pathological stage and survival after surgery in SCLC patients.