Clinicopathological Significance of Serum NY-ESO-1 Antibodies in Patients with Gastric Cancer

Background: Although clinicopathological significance of serum NY-ESO-1 antibodies has been evaluated in patients with esophageal cancer, little information was available in the patients with gastric cancer. We, therefore, evaluated pathological and prognostic significance of serum NY-ESO-1 antibodies (s-NY-ESO-1-Abs) in patients with gastric cancer. Methods: Serum samples were obtained from 75 patients with gastric cancer before surgery. Serum samples were analyzed using an enzyme-linked immunosorbent assay system to detect s-NY-ESO-1-Abs. A cutoff optical density value was fixed at 0.165 (mean plus three standard deviations for serum samples from the healthy controls). Clinicopathological factors and patients prognosis were compared between seropositive and seronegative patients. Tissue microarray of surgically resected tumor specimens were evaluated for NY-ESO-1 immunoreactivities. Results: The overall positive rate for s-NY-ESO-1-Abs was 8% (4.9% of stage I, 0% of stage II, 13% of stage III, and 38% of stage IV patients). s-NY-ESO-1-Abs was significantly associated with distant metastases (P<0.001) and stage progression (P=0.005). Although seropositive patients showed worse survival rates than seronegative patients, the difference was not statistically significant (P=0.106). Based on the tissue microarray, the association between serum antibodies and immunoreactivities was not confirmed. Conclusions: Although s-NY-ESO-1-Abs was significantly associated with distant metastasis and tumor progression, the prognostic impact of s-NY-ESO-1-Abs was not found to be statistically significant. The association between immunoreactivities and autoantibodies reaction was not confirmed in the current study using tissue microarray.