Clinical symptoms are different due to different factors such as disease development, pathologic pattern, body reaction, etc. They are discussed below according to early, middle and late stages. Early esophageal cancer symptoms Clinical symptoms are often not obvious, mostly due to abnormal peristalsis or spasm of esophagus stimulated by local lesions, or due to local inflammation, erosion, superficial ulceration, tumor infiltration, which are often recurring, and the intervals can be asymptomatic for several years. The main characteristic symptom is retrosternal discomfort or dysphagia. The pain is burning, pins and needles, or pulling and rubbing pain, especially when eating rough, hot or irritating food. Food passes slowly with a mild choking sensation, and most progress slowly. Other rare symptoms include tightness behind the sternum, dryness and tightness in the pharynx, etc. 3%～8% of cases may not have any feeling. Typical symptoms of mid-stage esophageal cancer include progressive dysphagia. Due to the good elasticity and expansion ability of esophageal wall, when the cancer does not involve more than half of the esophagus circumference, the symptoms of dysphagia will not be significant yet. The degree of dysphagia is related to the type of pathology, with the constricted and medullary types being more severe than others. Symptoms or initial symptoms that are not dysphagia in about 10% of cases account for 20% to 40%, which causes delay in the diagnosis of esophageal cancer. Some patients have retrosternal or interscapular pain when swallowing food. According to the site of tumor, it is suggested that there has been external invasion caused by peri-esophagitis, mediastinitis or deep ulcer of esophagus. The pain caused by the tumor in the lower thoracic region may occur in the subxiphoid or epigastric region. If there is persistent chest and back pain, it is usually caused by invasion and/or compression of pleura and spinal nerves by the cancer. Esophageal cancer itself and inflammation can reflexively cause increased secretion of esophageal glands and salivary glands and reverse peristalsis through esophagus, which can cause choking and pneumonia. Symptoms of advanced esophageal cancer are mostly caused by compression and complications, and lymphatic and hematogenous metastasis can occur. If there is ulcer, inflammation or tumor invasion in the diseased section of esophagus, it will produce persistent hidden pain behind the sternum or back. If the pain is severe and accompanied by fever, one should be alert to whether the tumor has perforated or is about to perforate. Lymph node metastasis of cancer is often behind the attachment of sternocleidomastoid muscle in the upper part of the clavicle, and the left side is more than the right side. If it compresses the recurrent laryngeal nerve, hoarseness will occur; if it compresses the cervical sympathetic nerve, Horner’s syndrome will occur. Laryngitis due to inhalation inflammation can also cause hoarseness, and indirect laryngoscopy can help to identify it. Cough and dyspnea may occur when the trachea is compressed by the cancer. Sometimes, due to the high degree of obstruction of the esophagus, retrograde peristalsis occurs, causing the contents of the esophagus to be mistakenly aspirated into the airway, resulting in infection. Cancer tissue may invade mediastinum, trachea, bronchus and aorta, forming mediastinitis, tracheo-esophageal fistula, pneumonia, lung abscess and even fatal hemorrhage. The patient develops malnutrition, dehydration and other malignant diseases due to difficulty in swallowing. If there are metastases to important organs such as bone, liver and brain, bone pain, jaundice, ascites, coma and other symptoms may appear.