Serum CA 19-9 concentrations and computed tomography findings in patients with pancreatic carcinoma.

Carbohydrate antigen (CA) 19-9 is a new tumor marker, defined by a monoclonal antibody. Serum CA 19-9 concentrations and computed tomography (CT) findings were studied in 55 patients with histologically proven adenocarcinoma, and in 22 patients with chronic pancreatitis. CA 19-9 was useful in 83% of cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and serum CA 19-9 levels in pancreatic carcinoma were highly related to the size of tumors. Serum CA 19-9 levels greater than 37 U/ml were seen in patients with a tumor of less than 3 cm, 3 to 5 cm, and greater than 5 cm in diameter 13% (1/8), 90% (19/21), and 92% (24/26) of cases, respectively. Tumor location, however, was unrelated to serum CA 19-9 value. These results indicated that the measurement of serum CA 19-9 concentrations would be useful in most, if not all, cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and for the evaluation of tumor burden in patients with pancreatic carcinoma.