Three gene variants have been detected to be more profound in patients with esophageal cancer and Barret esophagus according to researchers. The incidence of esophageal adenocarcinoma (EAC) in the United States and Europe has increased a whopping 350% since 1970, with the cause uncertain. Esophageal adenocarcinoma is believed to be preceded by Barrett esophagus (BE).
Barrett esophagus is common, estimated to occur in 1 percent to 10 percent of the general population. This genetic discovery may lead to validation of how the conditions are spread from generation to generation and possibly open the door to innovative treatment methods.
The risk of malignancy is highest in the U.S. in Caucasian men more than 50 years of age with more than 5 years of symptoms. Current recommendations include routine endoscopy and biopsy (looking for dysplastic changes). If two endoscopies and biopsy sessions performed within 12 months are negative for dysplasia then surveillance can be performed every 3 years while the underlying reflux is controlled with proton pump inhibitor drugs in combination with measures to prevent reflux. For patients found to have low grade or high grade dysplasia close observation and repeat endoscopy and biopsies are indicated and the patient should be followed closely by a gastroenterologist.
The study states:
“Findings of germline [those cells of an individual that have genetic material that could be passed to offspring] MSRl and CTHRCl mutations were replicated in an independent validation series. These 3 genes together accounted for 11 percent of our cases, reflecting what is normally considered a moderate-to high-penetrance genetic load for a disease,” they write. “Nonetheless, future independent studies are needed to replicate our data in other patient populations to confirm the conclusions. Finding predisposition genes may improve premorbid risk assessment, genetic counseling, and management.”
The researchers add that larger cohort studies may be necessary to determine the usefulness of these genes and their variants in risk assessment and premorbid diagnosis.
Barrett’s esophagus is marked by the presence of columnar epithelia in the lower esophagus, replacing the normal squamous cell epithelium, an example of metaplasia. The secretory columnar epithelium may be more able to withstand the erosive action of the gastric secretions; however, this metaplasia confers an increased risk of adenocarcinoma.
The metaplastic columnar cells may be of two types: gastric (similar to those in the stomach, which is NOT technically Barrett’s esophagus) or colonic (similar to cells in the intestines). A biopsy of the affected area will often contain a mixture of the two. Colonic-type metaplasia is the type of metaplasia associated with risk of malignancy in genetically susceptible people.
The metaplasia of Barrett’s esophagus is grossly visible through a gastroscope, but biopsy specimens must be examined under a microscope to determine whether cells are gastric or colonic in nature. Colonic metaplasia is usually identified by finding goblet cells in the epithelium and is necessary for the true diagnosis of Barrett’s.
Treatment is determined by the cellular type of cancer (adenocarcinoma or squamous cell carcinoma vs. other types), the stage of the disease, the general condition of the patient and other diseases present. On the whole, adequate nutrition needs to be assured, and adequate dental care is vital.
If the patient cannot swallow at all, an esophageal stent may be inserted to keep the esophagus patent; stents may also assist in occluding fistulas. A nasogastric tube may be necessary to continue feeding while treatment for the tumor is given, and some patients require a gastrostomy (feeding hole in the skin that gives direct access to the stomach). The latter two are especially important if the patient tends to aspirate food or saliva into the airways, predisposing for aspiration pneumonia.
Sources:
Written by Sy Kraft