UNC testing new treatment for Barrett’s esophagus
| September 08, 2006 | |
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UNC Hospitals is leading a nationwide clinical trial to compare the effectiveness of radiofrequency ablation against standard treatment for Barrett’s esophagus, a condition that can lead to deadly gastrointestinal cancer.
Barrett’s esophagus is a condition in which repeated acid reflux causes the cells that normally line the esophagus to be replaced by a different type of cell, similar to those normally found in the intestines. By itself Barrett’s is not a life-threatening problem, but a small percentage of people with Barrett’s will develop esophageal adenocarcinoma, an especially deadly form of cancer.
Radiofrequency ablation, a non-invasive technique that uses thermal energy, or heat, to destroy cells, is very effective at destroying abnormal cells in the esophagus. However, the technique has never been evaluated for treating dysplasia, a more advanced stage of Barrett’s esophagus in which the abnormal cells acquire precancerous traits.
Preliminary studies suggest radiofrequency ablation works in patients who have developed dysplasia, but the extent to which it corrects dysplasia is unclear, said Dr. Nicholas Shaheen, principal investigator and director of UNC’s Center for Esophogeal Diseases and Swallowing.
“We’re trying to answer two questions,” said Shaheen, also associate professor of medicine and epidemiology in UNC’s Schools of Medicine and Public Health. “Number one, in the patients that are getting radiofrequency ablation, is their dysplasia going away and staying away? And number two, is there a difference in terms of progression to cancer?”
The current standard of care for Barrett’s esophagus includes regular biopsies of the esophagus to determine whether or not the patient is progressing towards cancer, and medication to treat chronic heartburn or acid reflux disease. Newer treatments include photodynamic therapy or PDT, in use at UNC Hospitals since 2004, and radiofrequency ablation. Both PDT and radiofrequency ablation aim to prevent development of cancer by removing Barrett’s cells.
But there is little information on comparative standards such as the five-year survival rate for patients who receive ablation treatment because it is relatively new, Shaheen said.
The randomized trial will enroll about 120 patients nationwide. Two-thirds of the enrollees will receive radiofrequency ablation. The remaining one-third will receive a simulated or “sham” treatment, followed eventually by the real treatment.
The radiofrequency ablation system uses thermal energy provided by a set of electromagnetic coils on the surface of a balloon, Shaheen said. “The balloon is placed in the area of the esophagus where the offending cells are and the balloon is inflated. Energy is then passed through the electromagnetic coils and, because we know how far apart the coils are spaced and how much energy is being put through them, we get a very reliable depth of burn, such that you can kill cells only one or two layers deep.”
Radiofrequency ablation offers certain advantages over PDT for patients, Shaheen said. For example, two days before the PDT procedure, patients have to take a medication that makes them very sensitive to red light. The effects of this medication last for two or more months, and during this time patients have to avoid direct sunlight and cover all of their skin before going outdoors. Patients treated with radiofrequency ablation do not have to take this medication. In addition, PDT patients typically have to stay in the hospital overnight after their procedure, while radiofrequency ablation patients can go home the same day.
The trial is funded by BARRX Medical Inc., which manufactures the HALO360 radiofrequency ablation system.
For more information about the trial or treating Barrett’s esophagus, call Patty Prentice, UNC Division of Gastroenterology & Hepatology, at (919) 966-2513.
UNC Hospitals contact: Stephanie Crayton, (919) 966-2860, scrayton@unch.unc.edu. News Services contact: Becky Oskin, (919) 962-8596, becky_oskin@unc.edu. School of Public Health contact: Ramona DuBose, (919) 966-7467, ramona_dubose@unc.edu. |
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