Pre-cancerous means that the pathology has not yet reached the stage of cancer, and it belongs to pre-cancerous lesions. For example, atypical hyperplasia is categorized into mild, moderate and severe atypical hyperplasia. Severe atypical hyperplasia belongs to pre-cancerous lesions, i.e. pre-cancerous stage, while mild and moderate atypical hyperplasia belongs to benign lesions. Generally speaking, if further treatment is given before severe atypical hyperplasia develops, further development into precancerous stage can be avoided. For example, an inflammatory lesion in the stomach starts out as superficial gastritis, then gradually progresses to intestinal epithelial hyperplasia, and then further progresses to atypical hyperplasia. Severe atypical hyperplasia is precancerous and generally requires further treatment. For Helicobacter pylori infection in the stomach, anti-Helicobacter pylori treatment is needed, and attention should be paid to dietary modification at the same time. Early detection and early surgical treatment may have a good effect, so regular physical examination and review are important.