Overview Esophageal cancer is a common malignant tumor, with the age of onset mostly above 35 years old and the highest death rate in the age group of 60-64 years old, and is a common disease among the elderly, with more men than women. There are obvious regional differences in the incidence of esophageal cancer, and China is one of the high incidence areas of esophageal cancer in the world, especially in the Taihang Mountains in North China, the Dabie Mountains at the junction of Hubei and Anhui, North Jiangsu, the Qinling Mountains, the junction of Fujian and Guangdong, and northern Sichuan. Etiology The etiology of esophageal cancer is not yet known exactly, but the following factors may be related to its occurrence. Nitrosamines: Nitrosamines are highly carcinogenic. The content of nitrosamines and their precursors in drinking water and commonly used foods, such as sauerkraut, fish sauce, shrimp paste, pickled vegetables, dried radish, etc., in high esophageal cancer-prone areas is significantly higher than that in low-prone areas. Mold: The rate of mold contamination is significantly higher in the food of people with high incidence of esophageal cancer, especially in the pickled by-products. Mold can also contribute to the increase of nitrite and secondary amine content in food. Bad lifestyle: long-term smoking and alcohol consumption are related to the development of esophageal cancer. According to some studies, the incidence rate of heavy drinkers is 50 times higher than that of basic non-drinkers; the incidence rate of heavy smokers is 7 times higher than that of basic non-smokers; the incidence rate of those who drink heavily and swallow is 156 times higher than that of those who do not drink or smoke, and the risk is greater for those who drink strong alcohol and smoke. Dietary habits: Excessively hot diet, too fast eating and too hard and rough food may be related to the occurrence of esophageal cancer. According to the survey, the incidence of esophageal cancer is higher among Japanese people who like to eat hot porridge and hot tea. Nutrition and trace elements: Esophageal cancer high incidence areas are generally in underdeveloped areas with poor land and poor nutrition, and the dietary structure is unbalanced, lacking animal protein, fresh vegetables and fruits, so their drinking water and diet often lack vitamins (especially vitamin B2, C and A), protein and essential fatty acids, and also lack trace elements such as molybdenum, zinc, iron, copper and manganese. The lack of these components can make the esophageal mucosa proliferate and interstitially change, which can further cause cancer. Genetic factors: Esophageal cancer has a significant phenomenon of family gathering, although research shows that it is mainly influenced by common living environment, but genetic factors cannot be completely excluded. Other factors: It has been reported that esophagitis and esophageal cancer are very closely related, and esophagitis caused by various reasons may be a pre-cancerous lesion of esophagus. Certain esophageal diseases, such as esophageal diverticulum, hiatal hernia, esophageal polyps, cardia loss retardation, or frequent exposure to asbestos, lead, silica, radiation, etc., may be related to the development of esophageal cancer. Clinical manifestations The symptoms of esophageal cancer gradually worsen with the development of the disease. In the early stage, there may be no symptoms or mild symptoms, such as stagnation or choking when swallowing food, foreign body sensation or rubbing sensation in the esophagus, tingling, burning sensation or other discomfort behind the sternum. The above symptoms are not unique to esophageal cancer, but can also occur in other esophageal diseases, so there is no need to be nervous. However, when such sensation occurs repeatedly within a period of time, it should be taken seriously and timely go to hospital for examination to clarify whether there is any lesion in the esophagus. Early diagnosis and early treatment of esophageal cancer can significantly improve the therapeutic effect. When esophageal cancer develops to the middle and late stage, typical dysphagia may appear, which is continuously and progressively aggravated: firstly, it is difficult to swallow dry solid food, then it develops to semi-liquid, and finally even water and saliva cannot be swallowed, and the patient gradually loses weight and becomes dehydrated. Patients in advanced stages may also have persistent chest or back pain, hoarseness, choking, vomiting blood or black stool. Once dysphagia occurs, the patient should go to the hospital immediately to avoid delaying the disease. Diagnosis For patients suspected of having esophageal cancer, barium swallow X-ray examination should be performed. For patients with esophageal cancer suggested by barium swallow X-ray examination, esophageal mesh exfoliation cell examination should be performed in the corresponding lesion area, and most patients with esophageal cancer can be diagnosed based on this examination. These two examination methods are simple and effective, suitable for early detection and early diagnosis of esophageal cancer. For those who are highly suspected but not diagnosed, esophagoscopy and biopsy should be performed as soon as possible to understand the extent of lesion and make a clear diagnosis, while CT examination can understand the extent of outward invasion of esophageal cancer and whether there is lymph node metastasis in the mediastinum, which has reference significance in deciding surgery. If the supraclavicular or cervical lymph nodes are enlarged, puncture or biopsy can be taken to determine whether there is metastasis. The basic treatment of esophageal cancer is radical esophageal resection, lymph node dissection supplemented with radiotherapy or chemotherapy. In recent years, the treatment effect of esophageal cancer has been greatly improved, and early treatment is one of the important factors to improve the treatment effect. Early treatment is one of the important factors to improve the efficacy. Surgery is still the first choice for the treatment of esophageal cancer. At present, the five-year survival rate of early esophageal cancer after surgery can reach 90%. Generally speaking, surgery should be pursued for esophageal cancer that can be surgically resected, has no distant metastasis, and the systemic condition allows (no serious heart, lung or liver function damage). Surgery is to remove the diseased esophagus and cardia, and then reconstruct the digestive tract. In addition to complete removal of the tumor, radical esophageal cancer surgery also requires removal of lymph nodes in the paraesophagus, para-aorta, mediastinum and intra-abdominal cavity. With the innovation of surgical methods and the improvement of surgery-based comprehensive treatment, many esophageal cancers that were difficult or inoperable to be operated are gradually preferred to be treated surgically. The authors have also adopted active surgical treatment for esophageal cancer of the residual stomach after major gastrectomy and achieved satisfactory surgical results. For advanced esophageal cancer that has lost the chance of radical surgery or radiotherapy, surgery such as esophagogastric or esophagojejunostomy, gastrostomy or jejunostomy is feasible to relieve the difficulty of eating and improve the nutritional status, or to expand the stenosed esophagus by placing metal stents in the esophageal lumen through esophagoscopy, which is a simple method and can save the patient from the pain of surgery and improve the quality of life. Radiotherapy is also one of the treatment methods for esophageal cancer, except for cervical and top thoracic esophageal cancer, where radiotherapy is the main treatment method, but mostly combined with surgery. Extensively invasive and difficult-to-resect esophageal cancer can be treated with radiotherapy before surgery to shrink the cancer and metastatic lymph nodes, so as to improve the resection rate. For patients with cancer cells in the cut edge of postoperative pathological section, or tumor invading the esophageal epithelium and surrounding tissues, or accompanied by local lymph node metastasis, postoperative radiotherapy should be supplemented. For patients who are incompetent to undergo surgery for various reasons or are estimated to be inoperable, radiation therapy can be used directly. Chemotherapy is often used in combination with other therapies such as surgery and radiotherapy. Pre-operative chemotherapy can reduce the vitality of tumor cells and make them less likely to spread; post-operative chemotherapy can avoid the accelerated growth of cancer cells remaining in the body after the primary foci are removed and reduce the probability of metastasis. For patients who are already in advanced stage when found and have lost the opportunity of surgery or radiotherapy, the combination of chemotherapy with multiple drugs while giving nutritional support can improve the survival rate. In addition, traditional Chinese medicine treatment can relieve symptoms, promote immune function, improve tolerance to radiotherapy and chemotherapy, and serve as adjuvant therapy to other treatments. Biological therapy also has the effect of killing cancer cells and is under further research. Rehabilitation Patients with esophageal cancer need to insert gastrointestinal drainage tube from nasal cavity before surgery, through which gastrointestinal decompression can be performed, which can reduce gastric tension after surgery, facilitate anastomotic healing and prevent gastric dilatation from affecting respiratory and circulatory functions; by observing the amount and color of gastrointestinal drainage fluid, we can also understand the recovery of gastrointestinal function and the existence of anastomotic bleeding, stress ulcer and gastrointestinal infection. Fasting should be performed for 3 to 5 days after surgery. During this period, gastrointestinal decompression is continued, the gastric tube is kept open, and nutritional support such as glucose solution, amino acid solution, fat emulsion, electrolytes, and vitamins are supplemented via intravenous. The gastric tube can be removed when gastrointestinal peristalsis is restored and the anus is exhausted in 3 to 4 days after surgery. Generally, around the 5th postoperative day, we start to eat fluids by mouth, including drinking water, juice, vegetable soup, milk, etc., about 100 ml each time, 6-7 times a day, the amount gradually increases, and gradually add fish soup and meat soup, avoid greasy. About the 7th to 9th day after surgery, semi-liquid diet can be gradually added, such as steamed egg, cereal porridge, rice porridge, rotten noodles, etc. About one month after surgery, you can transition to soft food or even normal diet. The diet should pay attention to less and more meals, chew and swallow slowly, food should be light, fresh, nutritious and easy to digest, and smoking and alcohol are prohibited. Some patients have acid reflux, easy to be full and other discomforts after esophagectomy because the cardia was removed during the surgery, which cannot effectively stop the food and gastric juice in the gastrointestinal tract from refluxing into the esophagus and the gastrointestinal emptying function is weakened after the surgery, besides eating less and more meals, they should also pay attention to not lying down to eat, not lying down immediately after meals, taking appropriate walks to promote gastrointestinal peristalsis, padding the upper body when sleeping, taking some digestive drugs, gastrointestinal and acid control drugs. Patients with esophageal cancer should be followed up regularly for a long time after surgery and do some necessary examinations. Patients who receive chemotherapy should have blood tests to understand the white blood cells and liver and kidney functions before each chemotherapy. Esophageal cancer surgery is very traumatic and is often supplemented with chemotherapy or radiotherapy after surgery, which requires a period of recuperation and recovery. After these treatments are over, patients should rest for 2-3 months and gradually return to work depending on their physical condition, and can generally perform any work except for heavy physical labor. Patients should have a correct understanding of their condition, build up confidence, maintain optimism and actively cooperate with treatment, which is very beneficial to recovery. Prevention The occurrence of esophageal cancer may be due to the long-term effect of various carcinogenic factors, which leads to chronic inflammation and hyperplasia of epithelial tissue, developing from simple hyperplasia to atypical hyperplasia, from mild to severe, and finally forming esophageal cancer. Therefore, severe atypical hyperplasia of esophageal epithelium is a precancerous state. This is a process from quantitative to qualitative change, which may take 20 to 30 years. It is possible to reverse this process, and effective preventive measures can prevent the occurrence of cancer. In view of the etiology and process of esophageal cancer, prevention can be started from the following aspects: ① Improve water quality and prevent water pollution. Reduce the content of nitrite in drinking water and add trace elements to drinking water. ②Improve food structure and change bad eating habits. Vegetables and fruits contain a large number of natural anti-mutagenic substances and B vitamins have a reversal effect on esophageal epithelial hyperplasia, should eat more fresh vegetables and fruits, pay attention to coarse grains with fine grains, increase multivitamin intake. Eat less pickled products such as sauerkraut, shrimp paste and pickled vegetables, do not eat moldy food, quit smoking and alcohol. ③Treat esophageal epithelial hyperplasia and diseases related to the occurrence of esophageal cancer. We should treat esophageal epithelial hyperplasia with Chinese and western drugs to block the process of cancer, and treat esophagitis, white spot, diverticulum, cardia loss retardation, esophageal scar stenosis, etc. in time. Esophageal cancer mostly occurs in arid and sparse vegetation areas, and the soil and water lack many kinds of trace elements, so the vegetation should be increased through grass cultivation and afforestation to maintain the soil and water and improve the soil, and change the dry land to paddy field in conditional areas, change the crop structure to match coarse and fine grains, grain and vegetables, and promote trace element fertilizers. ⑤ Popularize cancer prevention knowledge, people with factors that predispose to esophageal cancer or people with family history should follow up regularly, go to hospital for examination in time with symptoms, and strive to achieve early detection, early diagnosis and early treatment.