Gastroenterologist Douglas Rex, MD, Distinguished Professor Emeritus of Medicine at Indiana University School of Medicine, Indianapolis, who was not involved in the study, told this news organization that he is not convinced that it is necessary or wise to use the margin-marking technique described in the paper over the current standard of care.
Dr. Rex explained that presently, physicians inject large lesions submucosally with fluid colored for contrast to delineate the margin of the polyp. This raises the question: if you can see the lesion well with that method, do you need to place the marks before you start around the border on the normal mucosa, as they did for the margin-marking group in this study?
Dr. Rex also noted that the researchers’ 29% control group recurrence rate is relatively high.
“Most of the evidence – if you look at the big meta-analyses – suggests that the recurrence rate with traditional methods is around 15%,” he said.
He added that even the recurrence rate in the current study’s active treatment arm is much higher than the 2%-5% rate seen in recent thermal ablation trials by Klein and colleagues and Sidhu and colleagues, both published in Gastroenterology.
“The methods described in those two papers should be considered the current standard of care,” Dr. Rex said. “Neither one of those involves this [margin-marking] method.”
Dr. Yang agrees that the Klein and Sidhu trials represent the standard of care, but he says it’s important to note that the 2% recurrence may not represent the actual practice of endoscopists of all skill levels.
“These are highly controlled studies coming from very experienced endoscopists,” he said.
“Our data are not trying to supplant what the high-quality studies on thermal ablation have shown. The point is to show that this is a concept that could potentially help,” he said.
“What I’m proposing is a potential alternative that could be better than that. Obviously, we won’t know until a comparative type of trial is performed.”
On that point, Dr. Yang and Dr. Rex agree.
Dr. Rex said that a randomized control trial would clarify some points and be useful to compare margin marking directly with the current standard of care, “which is to remove the whole thing and then burn up the margin.”
“Based on what we have seen so far, I would predict the current standard of care would have a very good chance of winning in terms of efficacy, because it’s hard to get lower than 2% [recurrence],” he said. “And it might well win with regard to safety, because burning the margin is at least theoretically safer than what they’re doing here.”
Dr. Rex said margin marking may be beneficial with the form of EMR that does not involve submucosal injection: underwater EMR. In underwater EMR, there’s no submucosal injection, and some people will mark the margin in those instances, he said.
“I do think it’s reasonable to do margin marking for underwater EMR,” Dr. Rex said.
Dr. Yang is a consultant for Boston Scientific, Olympus, Lumendi, and Steris. A coauthor is a consultant for Olympus, Boston Scientific, Cook Medical, Merit, Microtech, Steris, Lumendi, and Fujifilm. Another coauthor receives research grants from Steris and Cosmo/Aries Pharmaceuticals. Dr. Rex disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
