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Esophageal cancer (or oesophageal cancer) is cancer arising from the esophagus—the food pipe that runs between the throat and the stomach.〔 Symptoms often include difficulty in swallowing and weight loss. Other symptoms may include pain when swallowing, a hoarse voice, enlarged lymph nodes (glands) around the collarbone, a dry cough, and possibly coughing up or vomiting blood.〔 The two main sub-types of the disease are esophageal squamous-cell carcinoma (often abbreviated to ESCC),〔Even by those using the British English spelling "oesophagus"〕 which is more common in the developing world, and esophageal adenocarcinoma (EAC), which is more common in the developed world. A number of less common types also occur.〔 Squamous-cell carcinoma arises from the epithelial cells that line the esophagus. Adenocarcinoma arises from glandular cells present in the lower third of the esophagus, often where they have already transformed to intestinal cell type (a condition known as Barrett's esophagus).〔 The most common causes of the squamous-cell type are: tobacco, alcohol, very hot drinks, and a poor diet.〔 The most common causes of the adenocarcinoma type are smoking tobacco, obesity, and acid reflux. The disease is diagnosed by biopsy done by an endoscope (a fiberoptic camera). Prevention includes stopping smoking and eating a healthy diet.〔〔 Treatment is based on the cancer's stage and location, together with the person's general condition and individual preferences. Small localized squamous-cell cancers may be treated with surgery alone with the hope of a cure. In most other cases, chemotherapy with or without radiation therapy is used along with surgery.〔 Larger tumors may have their growth slowed with chemotherapy and radiation therapy.〔 In the presence of extensive disease or if the affected person is not fit enough to undergo surgery, palliative care is often recommended.〔 Outcomes are related to the extent of the disease and other medical conditions, but generally tend to be fairly poor, as diagnosis is often late.〔 Five-year survival rates are around 13% to 18%.〔(【引用サイトリンク】url=http://seer.cancer.gov/statfacts/html/esoph.html )〕 As of 2012, esophageal cancer is the eighth-most common cancer globally with 456,000 new cases during the year.〔 It caused about 400,000 deaths that year, up from 345,000 in 1990.〔 Rates vary widely among countries, with about half of all cases occurring in China. It is around three times more common in men than in women.〔 ==Signs and symptoms== Prominent symptoms usually do not appear until the cancer has infiltrated over 60% of the circumference of the esophageal tube, by which time the tumor is already in an advanced stage. Onset of symptoms is usually caused by narrowing of the tube due to the physical presence of the tumor. The first and the most common symptom is usually difficulty in swallowing, which is often experienced first with solid foods and later with softer foods and liquids.〔 Pain when swallowing is less usual at first.〔 Weight loss is often an initial symptom in cases of squamous-cell carcinoma, though not usually in cases of adenocarcinoma. Eventual weight loss due to reduced appetite and undernutrition is common. Pain behind the breastbone or in the region around the stomach often feels like heartburn. The pain can frequently be severe, worsening when food of any sort is swallowed. Another sign may be an unusually husky, raspy, or hoarse-sounding cough, a result of the tumor affecting the recurrent laryngeal nerve. The presence of the tumor may disrupt the normal contractions of the esophagus when swallowing. This can lead to nausea and vomiting, regurgitation of food and coughing.〔 There is also an increased risk of aspiration pneumonia〔 due to food entering the airways through the abnormal connections (fistulas) that may develop between the esophagus and the trachea (windpipe).〔 Early signs of this serious complication may be coughing on drinking or eating. The tumor surface may be fragile and bleed, causing vomiting of blood. Compression of local structures occurs in advanced disease, leading to such problems as upper airway obstruction and superior vena cava syndrome. Hypercalcemia (excess calcium in the blood) may occur.〔 If the cancer has spread elsewhere, symptoms related to metastatic disease may appear. Common sites of spread include nearby lymph nodes, the liver, lungs and bone.〔 Liver metastasis can cause jaundice and abdominal swelling (ascites). Lung metastasis can cause, among other symptoms, impaired breathing due to excess fluid around the lungs (pleural effusion), and dyspnea (the feelings often associated with impaired breathing). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「esophageal cancer」の詳細全文を読む スポンサード リンク
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