Liver cancer: cirrhosis Cirrhosis may be a precancerous lesion of liver cancer. There is a typical three-step process of liver cancer, i.e. hepatitis-cirrhosis-liver cancer. About 70% of primary liver cancers occur on the basis of cirrhosis, and in addition about 40% of cirrhosis combined with liver cancer in China. Therefore, patients with cirrhosis should receive timely and standardized treatment. Gastric cancer: chronic atrophic gastritis Chronic atrophic gastritis may be a precancerous lesion of gastric cancer. Most patients with chronic gastritis receive timely and regular treatment with combined Chinese and Western medicine, the effect is relatively good and will not cause cancer. However, some gastric cancers coexist with or occur on the basis of certain benign lesions such as chronic atrophic gastritis, and most of these gastric diseases have existed for a long time, which makes patients relax their vigilance of gastric cancer more easily. To confirm whether there is stomach cancer, gastroscopy must be performed. Kidney cancer and bladder cancer: painless hematuria Painless hematuria may be an early symptom of kidney cancer and bladder cancer. In a few cases, painless hematuria may also be a symptom of prostate cancer. As long as hematuria occurs, regardless of whether the volume is high or low, even if it is not painful and occurs only once in a long time, you should be highly alert and should go to a specialist in a large hospital for examination as early as possible. Cervical cancer: virus-induced cervical erosion Virus-induced cervical erosion may be a precancerous lesion of cervical cancer. “Cervical erosion” is a phenomenon on the surface of the cervix, not a disease. If there is no specific clinical manifestation, it usually does not require treatment. The symptoms of early cervical cancer and precancerous lesions are similar to those of “cervical erosion”, so blind treatment may cause the spread of cancer. women after 21 years old should undergo cervical smear examination once a year, and after 30 years old, HPV (human papillomavirus) examination can be combined. Lymphoma: painless swollen lymph nodes Lymphoma most often begins with swollen lymph glands (nodes), especially in the neck, armpits or groin. If the lymph nodes are swollen in one or more places with hard texture but no pain, you should be concerned about lymphoma, and it is better to go to hospital for examination in time. Lung cancer: lung nodules Most lung nodules are benign, and only a small percentage of them are precancerous lesions or lung cancer. If lung nodules are found, do not be overly alarmed and do not ignore them. They should be diagnosed in time to clarify their nature and be observed or treated according to the actual situation. Lung nodules are in many cases only inflammatory lesions. This disease is more prevalent in people over 40 years of age, so this group, or those at high risk with a family history of the disease, should try to have low-dose spiral CT screening for early lung cancer once a year. Bowel cancer: adenomatous intestinal polyps Intestinal polyps are a type of lesion in which the mucosal surface in the lumen of the large intestine is elevated, resulting in local hyperplasia. Among them, inflammatory intestinal polyps, misshapen polyps and lymphatic polyps are not related to intestinal cancer; proliferative intestinal polyps and adenomatous intestinal polyps are closely related to intestinal cancer. Especially adenomatous polyps are “time bombs” and need to be removed by surgery in time. Patients with intestinal polyps should stay away from cooking methods such as frying, smoking, baking and alcohol and tobacco.