There are several possible scenarios of elevated CA 19-9 glycoconjugate antigen: 1. Most patients with pancreatic cancer have significantly higher serum CA 19-9 levels. 2. CA 19-9 levels may also be elevated in hepatobiliary tract cancer, gastric cancer and colorectal cancer. 3. Low concentration increase and transient increase can be seen in chronic pancreatitis, gallstone disease, liver cirrhosis, diabetes, etc. CA 19-9 is a marker for pancreatic cancer, cholangiocarcinoma and colon and rectal cancer (the threshold value of positive serum CA 19-9 is 37kU/L). 1. 85%-95% of patients with pancreatic cancer are positive. CA19-9 concentration will decrease after tumor resection, and then increase, it can indicate recurrence. 2.The positive rate of colorectal cancer, gallbladder cancer, cholangiocarcinoma, liver cancer and gastric cancer is also high, and if CEA and AFP are detected at the same time, the positive detection rate can be further increased. 3, benign diseases such as pancreatitis, jaundice, CA19-9 concentration can also be increased, but often “transient”, and its concentration is mostly less than 120kU / L, must be distinguished. What should I do if CA199 is occasionally found to be elevated during physical examination? Gastroscopy, abdominal enhancement CT, ultrasound gastroscopy, etc. are recommended to check for possible malignant tumors, especially for tumors of the gastrointestinal tract, biliary tract and pancreas. 2.PET/CT examination is also feasible for patients with conditions. 3. If no obvious neoplastic disease is found after a series of examinations, regular monitoring of CA199 is recommended. If there is a persistent rise, further investigation is needed.