SAN DIEGO — Ablative therapies are a promising alternative to esophagectomy for treating patients with high-grade dysplasia associated with Barrett's esophagus, Dr. Kenneth K. Wang said at a meeting jointly sponsored by the AGA Institute and the Japanese Society of Gastroenterology.
One reason to consider ablation is that esophagectomy has high mortality. A study showed that the mortality is 20% in hospitals that perform fewer than two esophagectomies per year, compared with about 8% in hospitals that perform more than 19 esophagectomies per year (N. Engl. J. Med. 2002;346:1128–37). “There's a learning curve to esophagectomies,” said Dr. Wang, who directs the Barrett's Esophagus Unit at the Mayo Clinic in Rochester, Minn.
In addition, new Barrett's disease can occur after esophagectomy for high-grade dysplasia. One study of 40 patients who underwent esophagectomy found that 29% had erosive esophagitis and 40% had a columnar esophagus (Br. J. Surg. 2003;90:1120–8). “So you have to be aware that if you subject these patients to esophagectomy, it may not be the best thing, even if they're young,” he said.
One ablative option includes endoscopic mucosal resection using a cap-fitted endoscope. The most difficult part of this procedure is forming the snare around the loop of the cap, but this is improved with a newer band ligation device, Dr. Wang said.
Another option is circumferential endoscopic mucosal resection, which involves removing the index lesion as well as the Barrett's epithelium. “You can take out the whole Barrett's segment this way,” he said. “However, there is a bit of residual. It's very hard to take out the entire esophageal mucosa in a piecemeal fashion.”
One study of 35 Barrett's patients who underwent circumferential endoscopic mucosal resection found that 6% had residual high-grade dysplasia and 17% had residual intestinal metaplasia (Gastrointest. Endosc. 2003;57:854–9).
With this technique, “there's a lot of scarring, so you have to use repeated mucosal resection,” Dr. Wang said. In one study, treatment for 1 of 10 patients could not be completed because of scarring (Gastrointest. Endosc. 2006;63:847–52).
Overall, the results of endoscopic mucosal resection techniques “are pretty good,” he said. One study of 19 Barrett's patients with high-grade dysplasia and 96 with early cancers found a local remission rate of 98%. However, because the researchers removed only high-grade dysplastic lesions, metachronous lesions occurred in 30% of patients over 34 months (Euro. J. Gastroenterol. Hepatol. 2002;14:1085–91). “Even though the treated area looks good and histology is improved, there are the same genetic defects in the areas around the treated site that must be dealt with,” Dr. Wang explained.
Complications occurred in 10% of the patients—mainly bleeding and stenosis.
Photodynamic therapy (PDT) is also being used to treat high-grade dysplasia and cancer associated with Barrett's. This technique “probably has the longest track record,” Dr. Wang said. “It's very easy to do and takes about 5 minutes of photoradiation time.”
In a trial presented at the 2006 Digestive Disease Week, researchers randomized 208 patients to either continued surveillance or PDT. At 24 months, 77% of those in the PDT group had elimination of high-grade dysplasia, compared with 39% of those in the surveillance arm.
The 5-year clinical response data showed that 52% of those in the PDT group had completely normal mucosa, compared with 7% in the surveillance arm.
Dr. Wang added that three Markov models have all shown “that PDT is more cost effective than surgery or surveillance.”
Other available techniques include multipolar electrocoagulation and argon plasma coagulation. Results from one randomized study of 52 patients suggest that the efficacy of these two techniques is about the same. The endoscopic and histologic ablation rates for patients who underwent multipolar electrocoagulation were 88% and 81%, respectively; the endoscopic and histologic ablation rates for patients who underwent argon plasma coagulation were 81% and 67%, respectively.
These techniques “are not perfect,” Dr. Wang said. “There are always bits of Barrett's left, and you still have to continue surveillance.”
New alternatives expected to hit the market soon include devices that use cryotherapy and radiofrequency to ablate Barrett's tissue.
Whether physicians implement ablative techniques into their practice or not “depends on a lot of factors,” he said. “It depends on your expertise and that of the surgeons in your institution. It depends on the patients, how long their longevity is, whether or not they're going to be willing to come back to you, and the length of the Barrett's segment.”
Dr. Wang disclosed that he has received research support from Axcan and BarRx and served as a paid consultant for InScope.