LOS ANGELES (AP) - Zapping away abnormal, precancerous cells in the throat may lower the risk of later developing esophageal cancer, the first major study to test this technique finds.

In a study of 127 people suffering from a heartburn-related problem known as Barrett's esophagus, only about 1 percent who had a procedure that uses heat to burn off precancerous spots went on to develop cancer over the next year. That's compared with more than 9 percent of those who got a fake treatment in which no cells were destroyed.

Barrett's esophagus occurs when stomach acid backs up into the throat, causing the normal lining to be replaced by abnormal growth. Barrett's sufferers are 30 times more likely than others to develop esophageal cancer, one of the deadliest forms of the disease.

Scientists do not know what causes esophageal cancer, but some suspect smoking, drinking and obesity may play a role. The American Cancer Society estimates 16,470 people will be diagnosed with the disease this year, and incidence has been rising.

Doctors typically perform down-the-throat exams and surgically remove the esophagus in severe cases of Barrett's. A less drastic alternative, which has been available since 2005, uses a device down the throat and radiofrequency energy to destroy precancerous cells.

In the study published in Thursday's New England Journal of Medicine, Barrett's patients who had signs of precancerous cells were treated with the device or given a sham procedure that did not involve heat.

After a year, 77 percent who had the procedure were free of precancerous spots compared with 2 percent who got the fake treatment.

More Barrett's patients who underwent the heat procedure had pain for about a week afterward. One in the heat group suffered gastrointestinal bleeding and five developed narrowing of the esophagus.

Still, the study had a low complication rate, Dr. Jacques Bergman of the Academic Medical Center in Amsterdam wrote in an accompanying editorial.

The study was led by Dr. Nicholas Shaheen of the University of North Carolina at Chapel Hill. Several researchers and Bergman have received grants from or have other financial ties to Sunnyvale, Calif.-based Barrx Medical Inc., which makes the device and paid for the research.

The procedure, which takes about 30 minutes and is done in outpatient offices, costs about $2,000. It is covered by Medicare and most insurance plans.

However, it's not for everybody with Barrett's: Not all have precancerous cells and Bergman said it is too early to recommend it to Barrett's sufferers who show no signs of abnormal spots.

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