The incidence of esophageal adenocarcinoma has increased more than five-fold over the past four decades in the U.S. While the rate of rise in incidence of esophageal cancer has slowed somewhat in recent years, this malignancy is still associated with a dismal prognosis. Barrett’s esophagus, the precursor lesion to esophageal cancer, is easily identifiable on routine upper endoscopy and can be monitored for the development of precancerous changes. We generally assume that by performing endoscopic surveillance in our Barrett’s patients, we can detect high-grade dysplasia and esophageal cancer at early stages when it is still easily treatable. Therefore, shouldn’t we perform screening endoscopies with the goal of identifying all patients with Barrett’s esophagus?
While this line of reasoning seems logical, the issue is not at all straightforward, as multiple factors go into the decision to perform any type of screening test. While the incidence of esophageal cancer is rising, it is relatively low compared to other GI cancers such as colon or even pancreas. However, mortality in esophageal cancer is extremely high, and thus there may still be significant benefit to detection at early, asymptomatic stages. Another consideration is cost, including medical (from unnecessary tests or treatments), psychological (to the patient) and financial (to the health care system).
In the GI practice setting, we perform endoscopy not to screen for esophageal cancer but rather for Barrett’s esophagus, the precursor lesion. However, the overwhelming majority of Barrett’s patients will not progress: I tell my patients without dysplasia that, over the next five-to-10 years, they have only a 1 to 2 percent chance of developing esophageal cancer. By performing endoscopic surveillance, we subject our patients to numerous costly endoscopies when most will ultimately die from something other than esophageal cancer. On the other hand, an endoscopy is a relatively low-risk procedure, and maybe we can catch those unlucky progressors early simply through endoscopic surveillance. Interestingly, though, a recent well-conducted study examining data from Northern California showed that Barrett’s patients under surveillance did not have a decreased risk of death from esophageal adenocarcinoma compared to those who did not get surveillance. In other words, surveillance for these patients may have little if any benefit in terms of reducing the number of deaths due to esophageal cancer.
Should we screen women and non-Caucasians for Barrett’s esophagus?
As most gastroenterologists have recognized from clinical experience, Barrett’s esophagus is much more common in Caucasians and males. Let us assume for a moment that endoscopic surveillance is indeed beneficial. In general, cancer prevention efforts should be targeted to those patients at higher risk; there are more than 2,000 cases of male breast cancer per year, but we do not perform screening mammograms in men. The American Gastroenterological Association provides guidance in its medical position statement on the management of Barrett’s esophagus, suggesting that we screen patients who have risk factors for cancer.
Remarkably, nearly 90 percent of all esophageal adenocarcinoma cases occur in men. The incidence in Caucasians is also two-to-four times higher than in non-Caucasians. Risk factors also include central obesity, smoking and a history of reflux. While Caucasian males are clearly the highest risk group for esophageal cancer, we should not off-hand dismiss females and non-Caucasians from prevention strategies. A 60-year-old female with chronic GERD, central adiposity and a heavy smoking history potentially warrants screening.
Furthermore, screening low-risk groups is reasonable if the cost is minimal and we have a highly effective intervention, in this case to reduce deaths from cancer. Unfortunately, endoscopy is relatively expensive, and the benefit of surveillance (regardless of sex or race) is questionable. If we perform screening endoscopy on all patients, then a very large number of patients would need to be screened to possibly prevent a single death from esophageal adenocarcinoma.
A look ahead
Our views on screening for Barrett’s esophagus may change over the next several years. Use of cheaper, less invasive tests such as transnasal endoscopy or a brush cytology capsule on a string would resolve many screening cost issues. There is also a push in the field towards identifying markers of risk stratification, which would allow for interventions aimed at high-risk patients, who would theoretically derive the most benefit. The low-risk majority would then need little to no follow-up. If these developments come to fruition, then there may be increased enthusiasm for screening all populations. Until then, we should continue to individualize screening recommendations after assessing the likelihood of Barrett’s esophagus based on each patient’s risk factors, regardless of sex or race.
Julian A. Abrams a assistant professor of medicine and epidemiology, division of digestive and liver diseases, Columbia University Medical Center in New York, NY.
