Carbohydrate antigen 19-9 is most valuable as a serum marker for pancreatic and biliary cancer, but increased concentrations occur in several other gastrointestinal malignancies. A carbohydrate antigen 19-9 value of >1,000 U/ml usually indicates a digestive cancer and has been reported to have a specificity greater than 99% for pancreatic cancer; nevertheless, false-positive results owing to be...

Carbohydrate antigen (CA) 19-9 identified by a murine monoclonal antibody against a colorectal carcinoma antigen is thought to be a sialylated Lewis (Le)a blood group antigen and occurs in high concentration in serum of patients with pancreatic carcinoma. This study was designed to identify the relationship between Lewis antigens and CA 19-9 in patients with pancreatic cancer. The following ana...