(4) patients with chronic pancreatitis, chronic pancreatitis is now considered to be an important precancerous lesion in a small number of patients, especially chronic familial pancreatitis and chronic calcific pancreatitis; (5) intraductal papillary mucinous tumors are also precancerous lesions; (6) patients with familial adenomatous polyposis; (7) patients with benign lesions who have undergone major distal gastrectomy, especially those who are more than 20 years postoperative; (8) high risk factors for pancreatic cancer include long-term smoking, heavy alcohol consumption, and long-term exposure to harmful chemicals. (8) High risk factors for pancreatic cancer include long-term smoking, heavy alcohol consumption and long-term exposure to harmful chemicals.