Possible genetic basis for Barrett’s esophagus and esophageal cancer (adenocarcinoma)
(28 May 2006: VIDYYA MEDICAL NEWS SERVICE) -- Two new Mayo Clinic studies draw attention to the risk factors and possible genetic basis for Barrett’s esophagus and esophageal cancer (adenocarcinoma). These studies will be presented Monday, May 22, and Tuesday, May 23, in Los Angeles at Digestive Disease Week® 2006.
According to G. Richard Locke III, M.D., and Yvonne Romero, M.D., Mayo Clinic gastroenterologists and co-authors of one study, the incidence of esophageal cancer is increasing at what has been called an “epidemic” rate, but the cause for this increase is uncertain. Their team studied 186 cases of esophageal and stomach cancer (adenocarcinoma) and found a significant association between esophageal cancer and gastroesophageal reflux disease, also known as acid reflux.
According to Dr. Locke, the research strengthens the understanding of the connection between acid reflux and esophageal cancer.
“But only about 5 percent of individuals who experience acid reflux will develop Barrett’s esophagus,” says Dr. Romero. “And once Barrett’s esophagus is diagnosed, patients have a 30- to 125-fold increased risk of developing esophageal cancer.”
Barrett’s esophagus is a condition that occurs when acid reflux stimulates changes in the lining of the esophagus so that it resembles the lining of the intestines. Currently, the only way to identify Barrett’s esophagus is by performing an endoscopy.
“Acid reflux is such a common problem that it is unrealistic to perform an endoscopic examination on everyone who experiences it,” explains Dr. Locke. “Thus, in order to learn what’s causing this increase in esophageal cancer, we first need to know what’s causing Barrett’s esophagus and whether there are any genetic risks for which acid reflux patients could be screened.”
A second study, led by Dr. Romero, examined that question.
Her team discovered strong evidence for susceptibility genes in familial Barrett’s esophagus and esophageal cancer (adenocarcinoma). The genetic linkage analysis was performed on 278 people in 31 families with two or more members affected by Barrett’s esophagus, with or without esophageal cancer.
“Our research found areas on a chromosome that appear to be important for Barrett’s esophagus and esophageal cancer -- so we’re on the right path,” says Dr. Romero. “Our next step is to look at 94 additional families to identify the particular genes associated with these disorders. Eventually, we’d like to develop a blood test for Barrett’s esophagus to identify who has this precancerous lining early in their disease course, to ultimately prevent it from escalating into esophageal cancer.”
Co-authors of these studies include Sarah Crane, M.D.; William Harmsen; Nancy Diehl; Alan Zinsmeister, Ph.D.; Joseph Melton III, M.D.; Nicholas Talley, M.D., Ph.D.; Joshua Slusser; Mariza de Andrade, Ph.D.; Julie Cunningham, Ph.D.; Teresa Zais; Debra Geno; Gloria Petersen, Ph.D., and the Barrett’s Esophagus Genomic Study Group; all of Mayo Clinic in Rochester, Minn.
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