| NEW YORK
NEW YORK (Reuters Health) - While people with chronic acid reflux are more likely to develop throat, or esophageal, cancer, a new study suggests the risk is far too low to warrant routine screening for the cancer.
Researchers say the findings should reassure people with heartburn that their odds of developing esophageal cancer are minimal.
"For women and younger men, the absolute risk of esophageal cancer is quite low and probably not something they need to worry about," said lead researcher Dr. Joel H. Rubenstein, of the University of Michigan Medical School in Ann Arbor.
And even for patients at relatively greater risk -- men older than 60 with weekly heartburn or other symptoms -- there is still too little evidence to recommend routine screening for the cancer.
Gastroesophageal reflux disease, or GERD, is considered a prime risk factor for esophageal cancer. The disorder, whose primary symptom is frequent heartburn, allows stomach acids to back up into the esophagus, where it can damage the lining and, in a small number of cases, lead to cancerous changes.
Because of that, doctors commonly recommend that people with long-standing, frequent heartburn be screened for pre-cancerous changes with a camera-equipped scope that is threaded down the esophagus, a so-called upper endoscopy.
There are, however, no guidelines that specifically advise such screening.
The central problem is that while about 60 million Americans experience heartburn at least once a month and 15 million have daily symptoms, only 16,600 Americans were expected to be diagnosed with esophageal cancer this year.
So even though people with GERD are at relatively greater risk than others, the odds of any one person with frequent heartburn developing esophageal cancer would likely still be very low.
The new study, published in the American Journal of Gastroenterology, showed just that.
Using information from a U.S. government cancer registry and other public data, Rubenstein's team estimates that for women of any age with GERD, the risk of esophageal cancer is "extremely low." Among 60-year-old women with weekly heartburn, for instance, there would be four cases of the cancer per 100,000 women per year.
In general, a woman's risk of esophageal cancer was on par with a man's breast cancer risk.
Men younger than 50 with GERD also had a very low risk of esophageal cancer: among 35-year-olds, for example, the rate was one out of 100,000. But it rose as men aged. Among 70-year-old men with weekly heartburn, the yearly rate of esophageal cancer would be 61 per 100,000.
That's still only a third of the rate of colon cancer in this age group, but high enough that the researchers said it might warrant screening. However, there is no strong research evidence that screening for esophageal cancer curbs deaths from the disease.
"It's quite controversial whether screening is effective," Rubenstein said. "We just don't have good-quality evidence that it works."
The rarity of esophageal cancer, even in people with GERD, is the key obstacle to conducting clinical trials to test whether screening cuts death rates from the cancer, Rubenstein said. A trial would have to include huge numbers of patients to show a statistically important effect.
So why not undergo esophageal cancer screening just to be safe? Because like all screening tests, it carries risks, Rubenstein said.
For instance, a false-positive result would create needless anxiety and be followed up with unneeded testing. And the screening endoscopy itself can have complications, such as perforation of the esophagus or reactions to the drugs used during the procedure.
Those risks are small, Rubenstein pointed out. But the likelihood of cancer is so low in women and younger men, he said, that the risks of screening probably outweigh any potential benefit.
For older men with frequent heartburn, Rubenstein said that screening might be a reasonable option, but that is something they would have to discuss with their doctors. "It comes down to a personal decision," he said.
"The strength of this study is that a clinician sitting down with a patient can now give them a better estimate of their individual risk of esophageal cancer," said Dr. Richard Sampliner, a gastroenterologist at the University of Arizona in Tucson.
Sampliner pointed out, though, that individuals vary in their anxiety over the cancer -- if, for instance, they've known someone who died of the disease -- and some people with GERD will push to "be scoped."
He also noted that while esophageal cancer is uncommon, it is often deadly, especially when diagnosed at later stages.
Of people diagnosed when the cancer has spread to nearby lymph nodes, about 19 percent are alive five years later. That figure is 37 percent when the cancer is still confined to the original site, and only three percent if it has spread to distant sites in the body at the time of diagnosis.
Rubenstein stressed that anyone with GERD who does develop potential symptoms of esophageal cancer, like unintentional weight loss, vomiting or difficulty swallowing, should not hesitate to see their doctor.
SOURCE: link.reuters.com/qux32r American Journal of Gastroenterology, online December 7, 2010.