Oligosaccharide Le(a)-Le(x): a cell surface marker for carcinomas derived from embryonic endoderm.

An immunohistochemical evaluation of Le(a)-Le(x) expression by adenocarcinomas of the biliary tree, pancreas, colon and stomach was undertaken as examples of epithelial tumors derived from embryonic endoderm. This complements previous studies showing that Lea-Lex was present on the cell surface of non-small cell lung carcinomas, some non-lung carcinomas, and is a prognostic marker for squamous cell lung carcinomas. All of the tumor specimen evaluated were positive and no expression of Le(a)-Le(x) was detected in derivatives of neural, connective or muscle tissues. These findings indicate that it could be informative to examine the biological significance of Le(a)-Le(x) not only in carcinogenesis but during embryogenesis, as well.