Generally speaking, there is no clinical statement about the two most obvious signs of gastric ulcer cancer. However, for patients with recurrent episodes and long duration of the disease, the risk of cancer is higher and attention should be paid. 1. Repeated attacks: ulcer cancer may be related to the erosion and stimulation of mucosal epithelium or glands at the edge of ulcers by gastric juice, repeated inflammation and regeneration and repair, therefore, patients with gastric ulcers not healed for a long period of time may have a higher chance of complication of cancer. 2. Long duration of disease: if the condition of patients with gastric ulcer still has no obvious improvement after 4-6 weeks of strict internal medicine treatment, it may suggest that there is a certain possibility of malignant transformation. In addition, there are many other manifestations that may indicate malignant transformation, such as loss of appetite, progressive emaciation, persistent positive fecal occult blood test, worsening of anemia, etc. Whether gastric ulcer is cancerous or not needs to be clarified through gastroscopy combined with biopsy. It is recommended that patients with gastric ulcer should be treated under the guidance of doctors, have timely review and good monitoring of their condition, so as to find out the changes in time and get diagnosed as early as possible.