Barrett's esophagus is a condition in which the lining of the esophagus-the tube that carries food from your mouth down to your stomach-is replaced by a lining similar to that of the intestine. It's estimated that one out of every 100 people in the U.S. suffers from it, but many don't know it: It's a "stealth" syndrome, meaning it has no signs or symptoms. In fact, the average age at diagnosis is 50, but many people have had it for some time before getting properly diagnosed.

If it doesn't cause any outward problems, then why worry about Barrett's esophagus? Because people who have the condition are at greater risk for developing a kind of cancer called esophageal adenocarcinoma. It's estimated that 0.5 to 1 percent of people with Barrett's esophagus will develop esophageal adenocarcinoma.

Doctors recommend that certain people at higher risk for Barrett's esophagus, such as those who suffer acid reflux, undergo periodic testing to look for cancer or precancerous growths. This is an approach known as surveillance. The only way to definitively diagnose the disease is through an upper gastrointestinal (GI) endoscopy. This involves sedating the patient and inserting an endoscope-a flexible tube--down his throat. The endoscope has a small camera and a light and provides the doctor with a bird's-eye view of the esophageal tissue. Using a small device inserted through the endoscope, the doctor can remove small pieces of tissue for biopsies. Several biopsies must be performed because the disease can be missed if only one is done.

Since it can take years for cancer to develop in a person with Barrett's esophagus, doctors usually find precancerous cells first. This condition is known as dysplasia, and early treatment of it often can prevent full-blown cancer from developing. There are two ways in which dysplasia and cancer are typically treated. One is with photodynamic therapy. With this method, a light-sensitizing agent is injected into a vein, and one to three hours later, the patient receives laser therapy directly onto the site. The light-sensitizing agent, which is still active in the body, absorbs the light and produces a form of oxygen that kills cancer cells. Another type of treatment is endoscopic mucosal resection, in which the Barrett's tissue is cut out of the esophagus. This therapy is sometimes used in conjunction with photodynamic therapy. Removing the bulk of the esophagus surgically is occasionally recommended, but since most Barrett's esophagus sufferers are older and have additional medical problems, this treatment is not common.