Serological test of carbohydrate antigen CA50 in patients with cancer of the digestive tract

: In order to determine the clinical usefulness of carbohydrate antigen CA50 as a marker for cancers of the digestive tract, an attempt was carried out to measure the CA50 levels (normal level less than or equal to 18.1 U/ml) in sera of patients with various diseases of the digestive tract including pancreatic cancer. In patients with pancreatic cancer, the frequency of elevation of CA50 was 85.7% (6/35), which was the highest frequency of elevation, and a serum level of over 1,000 U/ml was observed in 6 (17.1%) of these 35 pancreatic cancer patients. Furthermore, patients with gall bladder carcinoma, hepatocellular carcinoma and gallstones showed relatively high frequencies of elevation. On the other hand, the maximum level of CA50 in serum was 41 U/ml in patients with benign pancreatic disease. Therefore, it was thought that CA50 was able to differentiate pancreatic cancer from benign pancreatic disease in patients with pancreatic disease with extremely high levels of CA50. The serum level of CA50 showed significant correlation with that of CA19-9. This study suggested that CA50 might be a potentially useful marker.