Esophageal cancer metastasis is the most common clinical symptom in the middle and late stages, cancer cells can spread and metastasize through many different ways, and the common metastases are mainly in the following four forms: 1. Blood-borne metastases of esophageal cancer: Blood-borne metastases of esophageal cancer usually occur in advanced cases, and the metastatic sites are liver, lung, bone, kidney, adrenal gland, pleura, etc., with liver metastases and lung metastases being the most common, and some patients may die due to local comorbidity, tracheal fistula, bleeding and malignant quality. There are also some esophageal cancer patients died due to local comorbidity obstruction, tracheal fistula, hemorrhage and cachexia. Lymph node metastasis of esophageal cancer: Lymphatic metastasis of esophageal cancer is more common, and it is generally believed that lymph node metastasis of esophageal hypofractionated squamous carcinoma or undifferentiated carcinoma is earlier, and the metastasis site is related to the direction of esophageal lymphatic drainage. 3.Metastasis of esophageal cancer: The underlying cells of the epithelium beside the esophagus become cancerous or in situ, which is one of the ways of surface spread of cancer. Cancer cells often do not infiltrate into the lymphatic vessels of the lamina propria of esophagus. Esophageal cancer can spread along the wall of the esophagus, and its spread is much more distant than that seen by the naked eye. In order to reduce the risk of inadequate resection, the surgical resection should exceed 300px of the upper edge of the tumor as seen by the naked eye, and inadequate resection is an important cause of local recurrence. Direct infiltration of esophageal cancer into surrounding organs: Upper esophageal cancer can invade larynx, trachea and soft tissues of neck, and even invade bronchus to form broncho-esophageal fistula; it can also invade thoracic duct, odd vein, pulmonary hilum and lung tissue, and some of them can invade aorta to form esophage-aortic fistula, causing life-threatening hemorrhage; lower esophageal cancer can often involve cardia and pericardium, etc. No matter what form of esophageal cancer metastasis occurs, it is very harmful to patients, so patients with esophageal cancer must pay attention to it after it occurs. What are the hazards of esophageal cancer? Here is a detailed introduction for you. 1.Esophageal cancer patients are very prone to vomiting blood and blood in stool, which are mainly caused by tumor ulceration; because of cancer cell metastasis and may cause vocal cord paralysis and hoarseness; 2.Esophageal cancer may easily metastasize to press and invade trachea and bronchus, causing shortness of breath and irritating dry cough; 3.Cancer cells invade phrenic nerve, vagus nerve and brachial plexus nerve, which will cause diaphragm paralysis, accelerated heart rate and abnormal arm pain; 4.If If the tumor compresses the superior vena cava, it will easily cause superior vena cava compression syndrome; if it metastasizes to the lung, brain, liver and other important organs of human body, it will cause jaundice, ascites, liver failure, respiratory difficulty, and even coma and other serious complications.