NY-ESO-1 expression and its serum immunoreactivity in esophageal cancer

Purpose. NY-ESO-1, a member of the cancer/testis antigen (CTA) family, elicits humoral and cellular immune responses in patients with advanced cancer. Unresectable or metastatic esophageal carcinoma patients do not benefit from the present multimodality treatment regimens in terms of survival. The objectives of this study were to analyze the antibody response to NY-ESO-1 antigen in patients with esophageal cancer and to determine the potential of NY-ESO-1 for use in tumor-specific immunotherapy. Methods. Serum from 69 patients with esophageal cancer was investigated for antibody production against NY-ESO-1 by Western blot analysis. Also analyzed by immunohistochemistry were 56 tissue samples from these patients for NY-ESO-1 protein expression. Results. NY-ESO-1 protein expression was found in 18 of 56 (32%) esophageal carcinomas. Serum immunoreactivity specific for NY-ESO-1 was found in 9 patients (13%) of whom 8 were in the advanced stage (stages III and IV). There was no relationship between clinicopathologic features and serum immunoreactivity for NY-ESO-1. NY-ESO-1 protein expression was detected in three of five antibody-positive patients whose tissue was available for analysis. Survival analysis showed no significant difference between antibody-positive and antibody-negative patient groups. Conclusions. A humoral immune response to NY-ESO-1 antigen was established in patients with advanced esophageal cancer. NY-ESO-1 is a good candidate for vaccine-based immunotherapy for advanced esophageal carcinoma.