Clinical evaluation of pancreatic cancer-associated mucin expressing CA19-9, CA50, Span-1, sialyl SSEA-1, and Dupan-2.

We have previously described the purification and partial characterization of a new pancreatic cancer-associated antigen, a pancreatic cancer-associated mucin expressing CA19-9, CA50, Span-1, sialyl SSEA-1, and Dupan-2. This study describes the clinical evaluation of various assay systems for this antigen which depend on measuring respective serum levels. Elevated levels of antigen were detected in the sera from both patients with malignant and non-malignant diseases. However, elevated serum levels of CA19-9 and Lewisa and Lewisb epitopes on moieties were restricted to pancreatic and biliary tract cancers, although adequate sensitivity was not attained. Coordinate evaluation of these three markers improved the sensitivity to some extent without loss of specificity for the diagnosis of pancreatic and biliary tract cancers, because of the heterogeneity of the coexpression of these epitopes. We developed additional assay systems with a combination of this antigen and two lectins (Bauhinia purpurea (BPA) and Vicia villosa (VVA)). Elevated levels of BPA- and VVA-reactive antigens were detected in 41% and 31%, respectively, of pancreatic cancer sera samples. Few patients with chronic pancreatitis had an elevated serum level of either antigen, and higher elevated levels of these markers were restricted to the sera of patients with malignancies. Our results suggest that this antigen is found in the sera of patients with various conditions and in the sera of normal subjects but that antigens bearing CA19-9 or Lewisa or Lewisb epitopes and an altered carbohydrate structure recognized by BPA and VVA lectins are preferentially present in the sera of patients with pancreatic and other malignancies.