We also know that people with chronic heartburn — or gastroesophageal reflux disease, known as GERD — are at higher risk for esophageal cancer. Many doctors believe patients with a history of chronic heartburn for five years or more should be screened for precancerous changes in the lining of the esophagus — a condition known as Barrett's esophagus. It has been estimated that from 5 percent to 10 percent of Barrett's patients will go on to develop cancer. Eating a diet low in fruits and vegetables, or weighing more than your ideal weight, also has been linked with increased risk for esophageal cancer.

Most doctors agree that patients already diagnosed with Barrett's should get regular screenings for cancer. The more difficult question is who among GERD sufferers should undergo screening endoscopy. Some researchers have suggested a one-time screening for anyone who has chronic reflux, particularly if the problem is serious enough to warrant long-term drug therapy. Others believe only those at highest risk should be screened — men older than 40 who have suffered reflux symptoms at least twice a week for five years. Patients who develop GERD for the first time after age 65 also should consider screening.

One answer to the screening question is to perform a screening endoscopy at the same time a patient is undergoing a screening colonoscopy, which typically happens around the age of 50. The patient already is sedated and the gastroenterologist who performs the colonoscopy also typically specializes in endoscopy. Some studies have shown that Barrett's is detected in as many as one out of four patients screened this way.

Finding esophageal cancer early makes a dramatic difference in survival because patients can qualify for surgical removal of the esophagus and sometimes the surrounding lymph nodes. An April study published in the Journal of the American College of Surgeons reviewed the medical records of 263 patients who underwent the surgery from 1992 through 2002. The overall survival rate during the last five years of the study was 50.4 percent, and jumped to 81 percent for patients who were diagnosed at Stage I.

The results show patients can benefit from early detection, says Jeffrey H. Peters, surgery-department chairman at the University of Rochester Medical Center and a study co-author.

"I believe we should be screening high-risk populations," says Dr. Jeffrey H. Peters, surgery-department chairman at the University of Rochester Medical Center. "The principle is clear — the earlier you pick up a cancer the more likely you are to cure it. There's very little debate about that."