Carbohydrate Antigen Sialyl-Lewis(a) (CA19-9)

Carbohydrate antigen sialyl-Lewis(a), also known as CA19-9 or sLe^a, is a tetrasaccharide carbohydrate structure that functions as a tumor-associated antigen. It is most widely recognized as a serum biomarker for cancers of the digestive tract, especially pancreatic ductal adenocarcinoma, but is also found in other malignancies such as colon and stomach adenocarcinomas. It acts primarily as a ligand for E-selectin, mediating adhesion between cancer cells and endothelium, a key step in tumor cell extravasation during metastasis.

Other names

Sialyl Lewis AsLe^a

Monoclonal antibodies targeting sLe^a have been explored for passive immunotherapy and active vaccination strategies.