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 per cent 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 per cent 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 today'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.