Generally speaking, in situ cancer will not recur after surgery, because in situ cancer is a tumor confined to the mucosal layer only. If the surgery is clean, there will be no tumor tissue left locally, and regular review of gastroscopy and colonoscopy is sufficient. However, it is uncertain whether there are new tumors in the surrounding tissues, so it is necessary to avoid tumor-inducing factors as much as possible, for example, do not eat too spicy food, such as chili, spicy strips, spicy hot pot, etc., try not to drink drinks containing alcohol, and do not eat pickled foods, such as pickled sauerkraut and pickled bean curd, which can easily induce tissue cancer and form cancer. Patients can consume more fruits rich in vitamins, such as apples and kiwis, etc., green vegetables rich in fiber, such as spinach, etc., and high quality protein, such as fresh fish and fresh shrimp, etc., which are all helpful to health. At the same time, you can also appropriately increase physical exercise and maintain a cheerful mood, all of which can inhibit the new growth of tumor.