In this issue of American Family Physician, Shalauta and Saad¹ describe endoscopic screening for Barrett’s esophagus and esophageal adenocarcinoma in patients with reflux symptoms. This type of screening has been proposed in an effort to decrease the rate of death from esophageal adenocarcinoma. The concept is intuitively appealing—we know that gastroesophageal reflux disease (GERD) is associated with cancer, and we think that most cancers arise from Barrett’s esophagus. Why not use endoscopy for patients with GERD to find those who have Barrett’s esophagus, and then to follow those patients with Barrett’s esophagus to catch curable cancers? Unfortunately, as with most issues in medicine, the application of this simple concept is fraught with problems. Several barriers exist that make endoscopic screening, as currently practiced, a flawed concept.

Too Much Reflux

Epidemiologic studies suggest that as much as 14 percent of the adult population experience reflux symptoms weekly, and 40 percent of the adult population experience reflux symptoms monthly.^2,3 Even if endoscopic screening were limited to patients older than 50 years who experience weekly symptoms, more than 10 million persons in the United States would be eligible for endoscopic screening programs.⁴ Such a demand on a health care system already stressed in its ability to provide care is untenable.

Too Few Cancers

Although reflux is among the most common medical conditions in the United States, the cancer for which it is a risk factor, esophageal adenocarcinoma, is rare. About 50 percent of the projected 13,900 cases of esophageal cancers in the United States in 2003 were adenocarcinomas.⁵ Therefore, the risk of cancer to any given patient with reflux is miniscule, and has been suggested to be as low as 0.00065 to 0.00039 cases per patient with reflux annually.⁴ Subjecting millions of patients to upper endoscopy in an effort to find and prevent these cancers may not be worth the large expense and small rate of morbidity associated with the examinations. Although the incidence of this cancer is rising, the absolute numbers remain low.

Many Patients with Cancer Do Not Have Significant Reflux

Recent studies have demonstrated that up to 40 percent of patients who develop esophageal adenocarcinoma have no or trivial reflux symptoms.⁶ Presumably, if we use GERD symptoms to decide which patients will receive upper endoscopy screening, this 40 percent of patients would be excluded from screening programs and their poor outcomes would be unaffected by the availability of screening programs.

An Expensive, Unproven Screening Test

Ideally, screening tests should be cost effective, widely available, safe, and proven. Upper endoscopy is an expensive test that can be performed only by a limited number of highly trained professionals. Attempts to lessen the cost of screening examinations by using ultra-thin, unsedated endoscopy are promising, but not widely available.⁷ Furthermore, given the current screening parameters, endoscopic complications would outnumber the cancers detected.⁴ Finally, no prospective studies have demonstrated that screening endoscopy lengthens life or decreases the rate of cancer mortality in patients with reflux.

A Highly Prevalent, Poorly Predictive Precursor Lesion

Barrett’s esophagus is highly prevalent in the U.S. population; some estimate the prevalence to be 3 to 6 million persons.⁸ Although the risk of cancer is increased in patients with Barrett’s esophagus, even among those patients, the estimated cancer risk is approximately 0.005 cancers per patient-year.⁹ In other words, the vast majority of patients with Barrett’s esophagus will never develop cancer. These patients will go through periodic surveillance examinations and suffer other stigma of a chronic disease diagnosis without experiencing any benefits from the diagnosis of their Barrett’s esophagus. Because we currently cannot tell which patients with Barrett’s esophagus will progress to cancer, further risk stratification is impossible.

Given all of the above difficulties, it is unlikely that screening and surveillance upper endoscopy as currently practiced will do much to decrease the number of deaths from esophageal adenocarcinoma in the United States. Until we can improve risk stratification for this type of cancer among patients with reflux, scarce health care resources would best be diverted elsewhere. Screening for colorectal cancer, for instance, is an undersubscribed intervention that has proved effective in averting death from a much more common disease. It would be unfortunate if the best endoscopic test to prevent death from cancer among patients with reflux symptoms turned out to be a screening colonoscopy. Regardless, until these sizable conceptual problems with upper endoscopy screening are addressed and successfully resolved, this procedure should not gain large-scale acceptance. “Because we can” is an inadequate rationale for pursuing expensive, unproven endoscopic screening programs.