Esophageal cancer poses a great threat to people, and the cure rate of esophageal cancer in early stage is high, but since it is hard to detect esophageal cancer in early stage, when patients notice it and go to the hospital for checkup, most of them are already in middle or late stage. 1.Patients with advanced esophageal cancer will be hindered in swallowing food. Due to the elasticity and expanding ability of esophagus, the symptom of difficulty in swallowing will appear when most of the esophagus is surrounded by cancer cells. Although the cancerous tumor of esophagus in the early stage is relatively small, but as the cancerous tumor increases, patients are often accompanied with inflammation of the esophageal wall, edema, spasm and so on, which can aggravate the difficulty in swallowing, therefore, the patients with esophageal cancer will have this kind of difficulty in the advanced stage. Therefore, esophageal cancer patients in the late stage have this kind of difficulty in swallowing, and it seriously affects the life of patients and brings great pain to them. 2. Esophageal cancer patients may have reflux when swallowing food. Food reflux in patients with advanced stage of esophageal cancer is often manifested in difficulty in swallowing with bleeding, and the reflux is not big, containing food and mucus, which is due to the rapid growth of cancer cells, resulting in narrowing of the esophagus. The so-called malignant disease is that, due to the rapid growth of malignant cells, patients with advanced esophageal cancer will have obstruction in esophagus, so that they can only consume their own nutrition, but they cannot get timely supplement, which will eventually lead to malignant disease with insufficient nutrition. 4. Infiltration of malignant tumors in patients with advanced esophageal cancer. Malignant tumors in patients with advanced esophageal cancer can infiltrate the esophagus and invade the mediastinum, trachea, bronchus, lungs, pericardium, large blood vessels and so on, which can cause mediastinitis, lung abscess, esophageal-tracheal fistula and fatal hemorrhage. This is very serious.