Pancreatic oncofetal antigen and carbohydrate antigen 19-9 in sera of patients with cancer of the pancreas.

Pancreatic oncofetal antigen (POA) and carbohydrate antigen 19-9 (CA 19-9) were measured in the sera of 23 patients with cancer of the pancreas to determine the true positive rates of these cancer markers. In one group of unselected pancreatic cancer patients (n = 9), both tests showed above-normal results in three patients and both gave values that were within reference limits in three other patients. Two of the three remaining patients had increased CA 19-9 but normal POA values, and one patient had increased POA but normal CA 19-9 concentrations in serum. In another group of 14 pancreatic cancer patients, selected on the basis of increased concentrations of POA in serum, the CA 19-9 values were increased in eight. In four patients who had progressive disease, the concentrations of both markers increased with time in one patient, only POA in one, and only CA 19-9 concentration in another. (The fourth patient had increased but stable concentrations of POA and CA 19-9 in serum.) These data suggest that serum POA and CA 19-9 measurements should be used in combination in the evaluation of patients with cancer of the pancreas.