医学科普(英文)
Barrett' s esophagus---cancer risk and symptoms
发表者:常玉英 1200人已读
What is the risk of developing adenocarcinoma of the esophagus in Barrett's?
When patients with Barrett's esophagus are assessed as a group, the risk of cancer has been found to be as low as one in 300 patients yearly. This means that if we examined 300 patients yearly, one patient would be found to have cancer every year. What we really need to know, however, is the risk of cancer if NO DYSPLASIA is found after one or two years of surveillance. Our belief is that this risk would be much less than the previously-quoted figures of one in 300 patients yearly.
Among patients with high grade dysplasia, up to 50% may be found to have cancer. Therefore, the first order of management when high grade dysplasia is found is to exclude the presence of an adenocarcinoma.
Low grade dysplasia is much less threatening than high grade dysplasia, but we don't know just how much less. In fact, we don't have precise data to indicate just what the cancer risk is in patients with Barrett's and low grade dysplasia.
The diagnosis of dysplasia should be as precise as possible because this diagnosis can prompt a change in the treatment or the intensity of follow-up of patients with Barrett's esophagus. It requires a great deal of experience to be able to make a precise diagnosis of the presence and grade of dysplasia. Therefore, it is a common and useful practice to ask a second pathologist (or even a third, if necessary) to review the biopsies. The idea is to see if there is an agreement between the pathologists and/or to get a more experienced opinion about the presence and grade of dysplasia.
If a person has longer segment Barrett's, one would guess that the cancer risk is greater than with shorter segment Barrett's. The data, however, is controversial in this regard. For that reason, the current practice is to do endoscopic biopsy surveillance with similar frequency in patients with short and long segment Barrett's esophagus.
What are the symptoms of Barrett's esophagus?
Barrett's esophagus has no unique symptoms. Patients with Barrett's have the symptoms of GERD (for example, heartburn, regurgitation, nausea, etc.). The general trend is for Barrett's patients to have more severe GERD. However, not all Barrett's have marked symptoms of GERD, and some patients are detected accidentally with minimal or no symptoms of GERD.
Heartburn is a burning sensation behind the breastbone, usually in the lower half, but may extend all the way up to the throat. Sometimes, it is accompanied by burning or pain in the pit of the stomach just below where the breastbone ends. The second most common symptom is regurgitation (backup) of bitter tasting fluid. GERD symptoms often are worse after meals and when lying flat.
The refluxed, regurgitated fluid occasionally may enter the lungs or the voice box (larynx), resulting in what are called extraesophageal (outside the esophagus) symptoms (manifestations) of GERD. These symptoms include:
new onset adult asthma,
frequent bronchitis,
chronic cough,
sore throats, and
hoarseness.
For reasons not fully understoood, some GERD patients have minimal heartburn but experience other GERD symptoms, for example, extraesophageal symptoms.
GERD may result in strictures and ulceration of the esophagus. A stricture or narrowing is due to scarring (fibrosis) of the esophagus that may cause difficulty in swallowing (dysphagia). The dysphagia is sensed as a sticking (stopping) of solid food in the chest (in the esophagus), and liquids when the narrowing is severe. Strictures can be treated by stretching them with dilators during endoscopy. Untreated, strictures may promote more spillage of food and/or gastric fluids into the lungs. Uncommonly, massive gastrointestinal (GI) bleeding caused by inflammation of the esophagus may occur. Such bleeding results in vomiting of blood or passage of black or maroon stools. More commonly, however, an inflamed esophagus can cause slow bleeding that is detected when anemia (a low red blood cell count) is found and/or stools are tested for blood.
发表于:2011-11-08 17:50