Common clinical malignant tumors can be classified according to their locations, mainly as follows: 1. Gastrointestinal tumors: the most common clinically, including esophageal cancer, cardia cancer, gastric cancer, liver cancer, colon cancer, rectal cancer, and some hepatic duct cancer; 2. Lung cancer, which is more common clinically and currently has the highest incidence rate; 3. Breast cancer, cervical cancer, ovarian cancer, and vulvar cancer, which are commonly found in female patients; 4. Head and neck tumors. including thyroid cancer, laryngeal cancer, oral cancer; 5, brain tumor, glioma. The most common lung cancer has a high incidence rate in both men and women, especially in urban areas, and the incidence rate is higher than that in rural areas. The clinical manifestations of lung cancer are mainly cough and blood in sputum; esophageal cancer is mainly due to dysphagia and progressive swallowing obstruction, which can be easily detected clinically through gastroscopy; many patients have rectal cancer due to change in stool characteristics, resulting in more frequent stools or blood in stools. Gastrointestinal tumors are most prevalent in rectal cancer, gastric cancer and colorectal cancer.