The metastasis of pancreatic cancer in the late stage is due to the thin peritoneal membrane, except for the metastasis to the retroperitoneal and peri-pancreatic lymph nodes, the metastasis area varies according to the location of the tumor. Head cancer often metastasizes to the lymph nodes around the subpyloric and superior mesenteric arteries, while tail cancer metastasizes to the lymph nodes in the splenic hilum first, and the lymph nodes in the hepatic hilum are not uncommon. Finally, it can metastasize extensively to the lymph nodes around the celiac artery, the greater and lesser curvatures of the stomach and the peri-abdominal aorta, as well as to the mediastinal and supraclavicular lymph nodes. Grade I refers to metastasis to mediastinal and supraclavicular lymph nodes; grade II refers to metastasis to abdominal lymph nodes away from the head of the pancreas, and grade III refers to metastasis to lymph nodes in distant areas such as the supraclavicular area. If the pancreatic cancer lesion directly infiltrates the surrounding organs, it may lead to portal vein embolism and portal hypertension. Through hematogenous metastasis, the cancer metastasizes to the liver and then to the lung, and eventually to most organs in the periphery, such as bone, kidney, brain, adrenal gland and subcutaneous tissue, causing corresponding symptoms. If the cancer invades the abdominal plexus, it will metastasize along the lymphatic vessels around the retroperitoneal nerve, thus causing intractable back pain. Metastasis of pancreatic cancer in late stage 1. Direct infiltration: most often breaks into adjacent organs. Cancer of the head of pancreas can easily invade the lower end of common bile duct, portal vein, duodenum and transverse colon; cancer of the tail of pancreatic body can invade splenic vein, leading to portal vein embolism and portal hypertension; after the invasion of pancreatic peritoneum, cancer cells can be shed and cause intra-abdominal implantation metastasis. 2. Hematogenous metastasis: mostly through the vein to the liver and then to the lung, and eventually to most organs in the body such as bone, kidney, brain, adrenal gland and subcutaneous tissue. 3.Metastasis along the nerves: pancreatic head cancer is the most common one. As it invades the abdominal nerve plexus, it metastasizes along the lymphatic vessels around the retroperitoneal nerve (actually a special way of lymphatic metastasis), which leads to persistent back pain. Treatment of advanced metastasis of pancreatic cancer Since pancreatic cancer is usually found to be advanced, the chance of surgery is very small, and even if surgery is possible, most of them are only palliative surgery, and chemotherapy and radiotherapy are also insensitive to pancreatic cancer, which not only have poor effect, but also have toxic side effects that are often difficult to be tolerated by a weak body. Therefore, the treatment of advanced metastasis of pancreatic cancer generally adopts comprehensive treatment, advocating a combination of surgery, radiotherapy and bioimmunotherapy.