New Genetic Clues to Esophageal Diseases

July 26, 2011 -- Researchers have discovered three genetic mutations that may play a role in the development of esophageal diseases, a study shows.

The esophageal diseases that may be affected by the mutations include esophageal adenocarcinoma (EAC) -- a type of cancer of the esophagus -- and Barrett's esophagus (BE).

The study is published in the Journal of the American Medical Association.

"We are absolutely thrilled to now know three distinct genes that link to BE/EAC," study researcher Charis Eng, MD, PhD, chair of genomic medicine at the Cleveland Clinic, says in a news release. "This is essential for improving risk assessment, disease management, and saving lives."

The study, which was conducted at 16 centers around the U.S. between 2005 and 2010, involved 298 participants, each of whom had Barrett's esophagus, EAC, or both. Comparing that group to a group that did not have either disease, the researchers identified three major genes associated with both Barrett's esophagus and EAC: MSR1, ASCC1, and CTHRC1. Mutations of those genes were found in 11% of the participants.

One of the genes, MSR1, has been linked with inflammation, according to the study, and there's evidence that both Barrett's esophagus and EAC might be as well.

"More and more examples linking inflammatory and carcinogenic pathways, such as the cell cycle, are surfacing," the researchers write. They add that such evidence strengthens the case that MSR1 mutations play a role in the development of esophageal diseases.

Risk Factors for Esophageal Diseases

The majority of cases of Barrett's esophagus and esophageal cancer are not believed to be caused by genetic factors, the researchers write. The most common risk factors are age, smoking, heavy drinking, and being male.

Men are much more likely to develop cancer of the esophagus. According to the National Cancer Institute, 13,000 men are diagnosed with the disease each year, compared to 3,500 women. The disease is most common among people age 65 and older. This form of cancer is curable if caught at an early stage; however, most cases are not diagnosed until the disease has advanced, at which point, survival rates are quite low.

Barrett's esophagus, also much more common among men, most often occurs after age 50. It is usually preceded by gastroesophageal reflux disease (GERD), a common condition characterized by frequent heartburn.

Most people with Barrett's or GERD will not develop cancer. The researchers estimate that less than one-half of 1% of people with Barrett's esophagus will later be diagnosed with EAC.