Long-term attack on the gastric mucosa by attacking factors destroying the gastric mucosa can cause chronic non-specific lesions of the gastric mucosa: chronic non-atrophic gastritis, atrophic gastritis, heterogeneous hyperplasia of the gastric mucosa, epithelial hyperplasia of the gastric mucosa, and gastric cancer. The following is a discussion of the concept, cure factors, and treatment of these lesions. 1, chronic atrophic gastritis Definition of atrophy: gastric mucosal atrophy refers to the reduction of intrinsic glands, and there are two types of histology: (1) chemotropic atrophy: intrinsic glands of gastric mucosa are replaced by enteric or pseudopyloric chemotropic glands. (2) Non-chemoid atrophy: the intrinsic glands of the gastric mucosa are replaced by fibrous or fibromuscular tissue or inflammatory cell infiltration causing a decrease in the number of glands in the intrinsic layer. The diagnosis is mainly based on histopathological examination by biopsy. The causes of atrophic gastritis are: immune factors, bile reflux, biological factors (H. pylori infection), chemical factors (drugs, alcohol), etc. H. pylori infection causes active inflammation of the gastric mucosa, and after long-term infection, atrophy and enterosis of the gastric mucosa can occur in some patients. The coordinated action of patient, environmental and H. pylori factors determines the type and development of gastritis associated with H. pylori infection. H. pylori-associated chronic gastritis is divided into: total gastritis gastric sinus dominant and total gastritis gastric body dominant. 2, gastric mucosa intestinal epithelial hyperplasia gastric mucosa intestinal epithelial hyperplasia refers to the gastric mucosa epithelial cells are replaced by intestinal-type epithelial cells, that is, the appearance of epithelial cells in the gastric mucosa similar to the small intestine and large intestine mucosa, is a common lesion of the gastric mucosa, seen in a variety of chronic gastritis, to atrophic gastritis is more common. It originates from undifferentiated cells in the neck of the intrinsic gastric glands and, in normal times, it continuously differentiates into gastric mucosal cells to replenish the decaying gastric epidermal cells. Under the influence of pathological factors it can differentiate into intestinal-type epithelial cells, forming an intestinal metaplasia of the gastric mucosa. According to mucohistochemical staining, the metaplasia is divided into small intestinal metaplasia (complete intestinal epithelial metaplasia) and colonic metaplasia (incomplete intestinal epithelial metaplasia). Small intestinal type chemosis has no obvious precancerous possibility, while large intestinal type chemosis has a higher risk of gastric cancer. Moreover, the wider the distribution of intestinal chemosis, the greater the possibility of cancer. According to epidemiological survey, the risk of carcinoma is 33%. Gastric mucosal heterotypic hyperplasia Hyperplasia is a non-invasive epithelial change in the process of carcinoma formation. Heteroplasia is a benign tumor epithelial injury, which is a precancerous lesion. 3.Intraepithelial neoplasia Intraepithelial neoplasia refers to the tumor proliferation in the epithelium of gastric mucosa but not infiltrating into the mucosal lamina propria. It is an important precancerous lesion of gastric mucosa and represents the initial stage of tumor growth. Intraepithelial neoplasia is classified into 2 grades: low-grade and high-grade. Low grade intraepithelial neoplasia is defined as epithelial structural and cytological abnormalities confined to the lower half of the epithelium, corresponding to mild and severe heterogeneous hyperplasia of the gastric mucosa. High-grade intraepithelial neoplasia refers to the expansion of epithelial structural and cytological abnormalities to the upper half of the epithelium or even the whole layer, which corresponds to severe heterogeneous hyperplasia or carcinoma in situ. Low-grade intraepithelial neoplasia is mainly a slight change of mucosal structure, while high-grade intraepithelial neoplasia is a proliferating gland with obvious heterogeneity, but without interstitial infiltration. 4.Early gastric cancer refers to cancer cells confined to gastric mucosa or submucosa, regardless of the size of the lesion and the presence of lymph node metastasis. The longest survival period of intramucosal cancer is 21 years, and once the gastric cancer penetrates into the submucosa, the expected survival time is about 1 year. For progressive proliferative gastric cancer, it is 3-9 months. The rate of missing early gastric cancer is 25% for endoscopists who have been operating endoscopy for less than 10 years and 20% for endoscopists who have been operating endoscopy for more than 10 years. Regression and follow-up of precancerous lesions of gastric mucosa Cancer of gastric mucosa is a multi-step and progressive process, generally: chronic atrophic gastritis —- intestinal epithelial hyperplasia —– heterogeneous hyperplasia —– gastric cancer. Domestic follow-up of heterogeneous hyperplasia of gastric mucosa from 6 months to 8.3 years, 70.9% of heterogeneous hyperplasia regressed and 18% of aggravation and carcinoma, so that heterogeneous hyperplasia is reversible. The cancer rates of mild, moderate and severe heterogeneous hyperplasia were 1.7%, 9.8% and 42.1%, respectively. The time to carcinoma was 4.4 ± 4.52 years, 2.38 ± 0.51 years, and 1.28 ± 0.55 years for mild, moderate, and severe heterogeneous hyperplasia, respectively. Most of the gastric mucosal intraepithelial neoplasia are of low grade and can be reversed with appropriate treatment. However, they should be followed up regularly. Although high-grade intraepithelial neoplasia may also be reversed, it has a high possibility of developing into gastric cancer in the short term and should be actively followed up or endoscopically mucosal resected. Atrophic gastritis with intestinalization should be followed up about once a year, and those with mild heterogeneous hyperplasia and rejection of paracancer should be followed up once every 6-12 months according to clinical and endoscopic conditions. For severe heterogeneous hyperplasia, gastroscopy and pathology should be reviewed immediately, and endoscopic or surgical treatment should be performed if necessary. Early treatment of gastric mucosal lesions 1. reversal of atrophic gastritis and intestinal epithelial hyperplasia (1) eradication of H. pylori (2) antioxidant therapy (3) Cox-2 inhibitors (4) herbal medicine 2. treatment of low-grade intraepithelial neoplasia Can be treated conservatively with regular endoscopic biopsy. 3.High-grade intraepithelial neoplasia For high-grade intraepithelial neoplasia, surgery or endoscopic treatment can be performed according to the extent of the lesion, and endoscopic treatment is recommended if the extent is within 1 cm.