If you get heartburn regularly, is cancer of the esophagus next? Some drug advertisements imply as much. Many heartburn sufferers believe so. Even insurance companies have taken notice. But epidemiologist Nicholas Shaheen says the correlation is not so simple.

Heartburn is the most common symptom of acid reflux disease—a weakening of the lower esophageal valve, which lets stomach acid flow into the esophagus. Eating spicy, acidic, and fatty foods can aggravate the condition, as can too much caffeine, tobacco, overeating, and lying down after a meal. About eighty-seven million Americans experience reflux weekly. In 2005, about eight thousand people were diagnosed with esophageal adenocarcinoma—one of two rare but deadly esophageal cancers. These numbers suggest that only .009 percent of weekly reflux sufferers will get adenocarcinoma.

Yet Shaheen says that many doctors and patients overuse endoscopy—insertion of a camera down the throat—because they think it will protect people from cancer. Endoscopies are safe, Shaheen says, but they are expensive, and there’s a small risk of complications. There’s also no strong evidence that they save lives, he says.

“We can’t scope everyone with reflux,” he says. “That’s nearly half the adult population.”

Although the risk of getting cancer is low, one reason acid reflux has gained attention among gastroenterologists is that the number of adenocarcinoma cases has increased 300 to 500 percent over the past thirty to forty years.

So Shaheen’s goal is to educate patients while researching the upward trend, which may be linked to the increase in obesity. In a large research study, he and his team found that people who carry weight in the abdomen get precancerous changes of the esophagus more often than people who carry weight in their hips and buttocks. Men tend to carry weight in their abdominal area, and men are eight times more likely to get esophageal cancer than women. Weight-related pressure on the diaphragm may push acid through the lower esophageal valve. But people who carry weight in the abdomen also produce more insulin and insulin-like growth factor, which have been associated with other types of cancer in overweight people. Shaheen also found other demographic predictors: overweight white men over sixty, for example, face the greatest risk.

But even if patients develop Barrett’s esophagus—a precancerous condition where typical esophagus cells change into intestinal-type cells—the chances of getting cancer are still slim. Shaheen found that only one-half of 1 percent of Barrett’s patients develop cancer each year. When surveyed, his own patients—whom Shaheen tries to keep well-informed—thought that 8 percent of Barrett’s patients get cancer. Patients at another hospital thought the risk was 24 percent.

Barrett’s esophagus, Shaheen says, has not been demonstrated to reduce life expectancy. But when he found the cellular change in an otherwise healthy forty-three-year-old man, the patient’s insurance rate more than doubled. Shaheen wrote letters to twenty insurance companies as part of a study. Only one agreed to change its policy.

“A lot of people have become very alarmist in the way they emphasize the esophageal cancer risk,” Shaheen says. “In reality, it’s important to know some of the risk factors, and we need to follow these worrisome trends, but it’s just not all that common. So the main reason to get treated for your heartburn is not because you are going to die of cancer; it’s because heartburn really affects quality of life and we can make it better.”