Cancer has become more and more serious threat to people’s health in the past half century, and has become a common disease. There are 10 million new cancer patients and 6-7 million deaths from cancer in the world every year; there are about 1.6 million new cancer patients and 1.3 million deaths from cancer in China every year. Cancer is the first cause of death in developed countries and the second in developing countries. For this reason, cancer prevention and research is becoming a topic of increasing concern for scientists worldwide. However, cancer is not an incurable disease. In the past half century, human beings have done a lot of fruitful work on the prevention and research of malignant tumors, and have made remarkable progress, and have initially figured out the prevalence of various cancers. Due to the application of tumor markers, endoscopy, imaging and other technologies, many cancers have entered the stage of subclinical cancer diagnosis. The integrated application of surgery, radiation therapy, chemotherapy and biotherapy has made the former “terminal disease” become a preventable and curable disease today. Early diagnosis and early treatment of cancer have enabled more than 1/3 of patients to be cured. Correct understanding of tumor, alert to the early signs of cancer and timely diagnosis and treatment are the keys to cancer treatment. Correct understanding of tumor 1.What is tumor? Tumor is a new organism formed by the abnormal proliferation of certain body cells caused by the action of tumor-causing factors on the body. According to the different severity of tumors, they can be divided into benign tumors and malignant tumors. Malignant tumors originating from epithelial tissues are called carcinomas, and those occurring from mesenchymal tissues are called sarcomas. Both are commonly referred to as cancer. Cancer cells have biological characteristics such as autonomy, infiltration and metastasis. 2.What is the etiology of tumor? The occurrence of tumor is related to the internal and external factors of human, while it is increasingly related to the environment. Its etiology is generally divided into four categories: chemical (such as environmental pollution), biological (such as viruses), physical (such as electromagnetic radiation) and genetic (with familial nature). 3.How to prevent tumor? The rising incidence of malignant tumors is related to the increase of environmental pollution, lack or excess of nutrition, accelerated progress of population aging, and defects of lifestyle. A good environment and lifestyle can effectively prevent tumors. 4.How to treat tumor? According to the current level of medical technology in the world, there are four main methods to treat tumors: surgery, radiotherapy, chemotherapy and biological therapy. However, none of them can cure cancer independently and completely. Only the integrated therapy based on surgery, radiotherapy and chemotherapy is the best treatment for cancer at present. Ten early signs of cancer 1. Abnormal lumps in superficial parts of the body: malignant lymphoma, nasopharyngeal cancer, thyroid cancer, breast cancer, etc.; 2. Change in color and enlargement of moles or warts on the body surface: malignant melanoma; 3. Difficulty in swallowing and discomfort behind the sternum: esophageal cancer; 4. Persistent hoarseness, dry cough, blood in sputum: laryngeal cancer or lung cancer; 5. Loss of weight, anemia, change in stool habit, blood or mucus in stool Change in bowel habits, blood or mucus in stool: indicates colon cancer 6. Headache, tinnitus, hearing loss, blood in nasopharyngeal discharge: indicates nasopharyngeal cancer 7. Skin mucosal ulcers that do not heal: indicates skin cancer 8. Painless hematuria: may be kidney cancer or bladder cancer 9. Irregular vaginal bleeding: may occur in cervical cancer, endometrial cancer, ovarian cancer; 10. Unexplained fever: may be leukemia, malignant lymphoma, kidney cancer, etc.