The time it takes for cancer cells to form, which can range from a few months to a few years, is specifically related to the risk factors for the development of cancer. Cancer is a common malignant disease, and the occurrence of the disease is associated with a variety of factors. For example, the risk factors for stomach cancer include gene mutation, heredity, high salt diet, Helicobacter pylori infection, alcohol abuse, age over 50, and history of gastric disease. Therefore, people with more related high-risk factors may have a shorter time for cancer cell formation, which is a few months; on the contrary, it may be a few years. Therefore, in daily life, we can strive for early detection, early diagnosis and early treatment through regular medical checkups and timely standardized diagnosis and treatment in hospitals after finding discomfort, so as to obtain a better prognosis.