There are many tumor-associated antigens that are considered to be related to pancreatic cancer, including CA19-9, carcinoembryonic antigen (CEA), pancreatic embryonic antigen (POA), pancreatic cancer-associated antigen (PCAA), CA242, etc. Carcinoembryonic antigen: It is a glycoprotein isolated from colorectal cancer tissues and lacks specificity for the diagnosis of pancreatic cancer. The prognosis of pancreatic cancer can be estimated by observing the dynamic change of CEA, which can be reduced to normal after tumor resection, and can be increased again when pancreatic cancer recurs. Pancreatic embryonic antigen: It is an antigen extracted from fetal pancreas and pancreatic cancer tissues, and recent experiments have demonstrated that the specificity of POA is not high. The measurement of POA can also be used to monitor the effectiveness of pancreatic cancer treatment. The antigen associated with pancreatic cancer is mainly found in the ductal epithelial cells of pancreatic cancer, but it can also be found in many tissues of normal people. However, the positive rate of pancreatic cancer is significantly higher than that of other tumor patients and the normal population. (1) Blood and urine amylase, blood glucose and glucose tolerance. (2) Pancreatic cancer and other pancreatic diseases may also have elevated serum and urinary amylase and lipase, abnormal blood glucose and glucose tolerance, and indirectly affect the function of the liver. (3) Liver function tests. (4) In pancreatic cancer, due to obstruction of bile duct or liver metastasis and other liver dysfunction, serum aminotransferases can exceed 500u. The measurement of transpeptidase has a certain reference value for the diagnosis of pancreatic body tail cancer. (5) Exocrine function examination of the pancreas. (6) Enzyme examination: When pancreatic cancer occurs, some enzyme changes may occur, but these changes are not specific, i.e. many cancers or diseases may also have similar changes, so it is only for clinical reference, however, it has some reference value for determining benignity and malignancy and prognosis. 3. Histological/cytological examination Even with preoperative/intraoperative pathological confirmation, patients should be reminded that there may be a 10% chance that resection was done in the case of benign lesions; on the contrary, because of the hard texture of pancreatic cancer, a negative fine needle aspiration cytology does not completely exclude the possibility of pancreatic cancer, especially when the CT scan suggests a more definite lesion. If neoadjuvant chemotherapy is being considered, histopathological confirmation must be obtained. Diagnostic options include fine-needle aspiration cytology guided by multiple routes such as ultrasound, CT, EUS, and ERCP.