Purification, partial characterization, and clinical evaluation of an adenocarcinoma-associated antigen.

The current investigation describes the purification and partial characterization of a new adenocarcinoma-associated antigen (ACAA). ACAA is a large molecular weight glycoprotein (Mr 790,000 by size chromatography on Sepharose CL-6B) that migrates in the alpha 1 region upon electrophoresis and is eluted from a DEAE-cellulose column at a 0.1 M NaCl concentration. ACAA is immunochemically and biochemically different from carcinoembryonic antigen, alpha-fetoprotein, pancreatic oncofetal antigen, human pancreatic tissue antigen, CA 19-9, ferritin, and acute-phase proteins. Assays for ACAA were carried out using a solid-phase sandwich enzyme immunoassay. The results indicate that ACAA is present in sera of all individuals. Patients with cancer have higher serum levels of ACAA than normal individuals. The greatest frequency of elevated serum values of ACAA was seen in patients with lung and pancreatic cancers followed by colorectal, breast, and prostate cancer. The measurement of ACAA levels may be valuable in the diagnosis and clinical management of patients with certain cancers.