Application of serum NY-ESO-1 antibody assay for early SCLC diagnosis.

BACKGROUND NY-ESO-1 antibody is one of the cancer-related antibodies. The purpose of this study was to investigate the diagnostic role of the NY-ESO-1 humoral immune response in small cell lung cancer (SCLC). METHODS We recombined the recombinant protein of NY-ESO-1 antibody and NSE, analyzed them by Enzyme-linked immunosorbent assay, and then established the Receiver Operating Characteristic (ROC) curve to estimate the diagnostic value of NY-ESO-1 antibody, NSE and their combinations. RESULTS According to detection, the positive rate of NY-ESO-1 humoral immune response (26.3%), NSE (43.8%) and their combinations (10.5%) were all lower than the negative rate which indicated that the NY-ESO-1 antibody might be down-regulated in SCLC. And the positive rate wasn't related to clinicopathologic characteristics. The ROC curve demonstrated that with a 37.17% sensitivity and a 91.7% specificity along with a AUC of 0.619 for NY-ESO-1ab as well as with a 48.3% sensitivity and a 90.87% specificity along with a AUC value of 0.773 for NSE, their diagnostic value were both high. Besides, the diagnostic value of their combinations was also good for a AUC of 0.83 and a 69.12% sensitivity and a 91.8% specificity. There were significant difference of diagnostic value among three types above (NY-ESO-1 vs. NSE, P < 0.01; The Combinations vs. NY-ESO-1, P < 0.0001; and the Combinations vs. NSE, P < 0.04). CONCLUSION In conclusion, NY-ESO-1ab, NSE and their combinations all were important diagnostic markers for SCLC. Moreover, the diagnostic value of their combinations was higher than any single of them. And NY-ESO-1 humoral immune to NSE might be a potential diagnostic indicator in SCLC.