Glycosylation is among the most common post translation modifications of 
proteins in humans. Decades of research have demonstrated that aberrant 
glycosylation can lead to malignant degeneration. Glycoproteomic studies in the 
past several years have identified techniques that can successfully characterize 
a glycan or glycan profile associated with a high-grade dysplastic or malignant 
state. This review summarizes the current glycomic and glycoproteomic literature 
with specific reference to esophageal cancer. Esophageal adenocarcinoma 
represents a highly morbid and mortal cancer with a defined progression from 
metaplasia (Barrett's esophagus) to dysplasia to neoplasia. This disease is 
highlighted because (1) differences in glycan profiles between the stages of 
disease progression have been described in the glycoproteomic literature; (2) a 
glycan biomarker that identifies a given stage may be used as a predictor of 
disease progression and thus may have significant influence over clinical 
management; and (3) the differences in glycan profiles between disease and 
disease-free states in esophageal cancer are more dramatic than in other 
cancers.