Expression of Carbohydrate Antigens in Human Esophageal Squamous Cell Carcinoma: Prognostic Application and Its Diagnostic Implications

Background Tumor markers whose antigenic determinants have been demonstrated to consist of carbohydrates are probably one of the most extensive tools that have been used in routine cancer diagnosis. In this study, the relevance of carbohydrate antigen expression profile was examined in esophageal squamous cell carcinoma together with prognosis in 130 patients. Methods The expression of carbohydrate antigens was estimated immunohistochemically by anti–sialyl Lewis a (sialyl Le^a) and anti–sialyl Lewis x (sialyl Le^x) monoclonal antibodies, and correlation between their staining and clinicopathological status was examined. In addition, the correlation of both carbohydrate antigens expression was evaluated with microvessel density (MVD). Results Expressions of sialyl Lewis antigens and MVD were associated with several clinicopathological features that reflect the tumor aggressiveness in esophageal cancer. The 5-year survival rate of patients was found to be associated with expression of sialyl Le^a and sialyl Le^x antigens and with MVD; thus, all of them were revealed to be independent prognostic factors. Conclusions Combination of these factors offered a better prediction of prognosis of esophageal squamous cell carcinoma. Further, carbohydrate antigens represent a promising target for therapeutic approaches against the disease.