The reasons for finding cancer in pancreatic surface nodule after gastric cancer surgery include metastasis of gastric cancer to pancreas, pancreatic cancer itself, metastasis of other cancers and so on. 1. Stomach cancer metastasis: distant metastasis occurs when cancer develops into advanced stage, and this kind of metastasis can be transferred to all parts of the body, including liver, lungs, bones, etc. Surgery for stomach cancer can only remove the lesions in the stomach, and recurrence and distant metastasis may occur after the surgery. 2. Own cancer: when cancer occurs in the pancreas itself, it is possible to see cancer in the surface nodules, which is found late and has a very poor prognosis. 3. Metastasis from other cancers: for example, lung cancer and liver cancer may have pancreatic metastasis in the late stage. When the above situations occur, you must go to the hospital for diagnosis and clarification of whether it is primary or metastasis, and then according to the condition, you should carry out treatment under the guidance of professional doctors.