Can't-Miss Highlights From ACG 2023: Part 2

This transcript has been edited for clarity.

Hello. I'm Dr David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia.

Welcome back to part 2 of this series featuring highlights from the American College of Gastroenterology (ACG) 2023 annual meeting.

New Findings for Multitarget Stool Tests

I want to resume our overview with two studies looking at stool-based testing for colon cancer screening.

The first of these was presented by Dr David Lieberman from Oregon Health & Science University.^[1] He and his colleagues assessed a new multitarget stool RNA test called Colosense. They recruited approximately 8300 participants from 49 US states, so there was no demographic bias here.

The test was 94% sensitive for detection of colon cancer. Interestingly, it was 100% sensitive for early-stage (stage I) colon cancers, of which there were 12 cases. The sensitivity for detecting advanced adenomas was 45%, and 51% for advanced adenomas > 2 cm. The specificity overall for no findings was 87%.

It's interesting that the maintenance of sensitivity was observed across all the age groups. Investigators speculated that this was likely because the stool DNA — used in the current version of the Cologuard test — is subject to methylation. The methylation patterns may change with age and that may impact the sensitivity of detection, which is something that they didn't see in this particular study.

Turning now to Cologuard, Dr Tom Imperiale presented^[2] the next generation of this multitarget stool DNA test, which was compared with noninvasive fecal immunochemical testing (FIT). Using a next-generation panel that combined three novel methylated DNA markers with FIT, they enrolled 26,758 patients. Investigators were trying to improve Cologuard's specificity, which previous studies had shown to be 87%.

The specificity did increase from the 87% observed in previous studies to 91% with the next-generation Cologuard. Specificity for no findings was 90% in the previous Cologuard studies and 93% in this study. The sensitivity for cancer detection increased by 2%, from 92% to 94%. Improvements for high-grade dysplasia were even a little better, increasing from 69% to 75%, and advanced precancerous sensitivity increased from 42% to 43%.

I think this will be a study that will lead to them getting an approval. They'll likely swap the current test out for the new panel as this product moves forward.

Superiority of Nasal Spray vs Orally Administered Metoclopramide

The diabetic gastroparetic population has a significant problem when it comes to incremental costs attributable to relapsing outpatient and inpatient visits, and certainly ER visits.

This led to the idea that intranasal administration of metoclopramide would provide a more predictable delivery and absorption.

Dr Richard McCallum presented results comparing nasal spray administration of metoclopramide with oral use of metoclopramide.^[3] Using a cohort comparison design, he and his colleagues reported that there was indeed a significant reduction in overall medical costs using intranasal administration. The total healthcare costs were nearly $15,000 cheaper. The cost of the drug itself was higher but was not significant overall between sites where it was used.

This has short-term implications for our practices. Intranasal metoclopramide was approved in 2020, and I think it is something that we could use more often.

Skin Glue for Prevention of Fluid Leaks Following Therapeutic Paracentesis

We've all performed paracentesis on patients when they have a large volume of ascites. Risk for leaking can make this problematic sometimes. This can occur even when using the best techniques of tunneling in submucosally and then a couple centimeters in and down, followed by keeping them right-side down to potentially decrease the risk from the left abdominal type of approach, and potentially even using ultrasound as well.

There was an interesting poster offering a new strategy for reducing abdominal paracentesis leaks.^[4] Investigators evaluated the use of 2-octyl cyanoacrylate, or "skin glue," which you may be familiar with for its use in gastric varices. Patients were randomized to alternating weeks of glue vs no glue, with investigators following measuring fluid leakage after paracentesis. There was a significant reduction in leakage during procedures using the glue (5% vs 22.3%).

These findings might be something to consider implementing, given that this product is available now. It certainly makes sense to do this, especially if you have somebody who has had a leak in the past and you may be trying to mitigate that and keep them from returning to the ER.

Although we should consider the cost of 2-octyl cyanoacrylate, the incremental costs from ER visits and hospitalization likely offset that.

Vaccine Considerations in Patients With IBD

We aggressively try to immunize our patients with IBD, many of whom may also be elderly or immunocompromised on top of that.

A noteworthy study^[5] looked at how we approach patients with IBD regarding the use of new respiratory syncytial virus (RSV) vaccines. The incremental risk of RSV was studied in 206,000 patients with IBD and over 4 million from a non-IBD cohort. The IBD cohort had a 2.24 increased odds ratio for risk of developing RSV.

The new RSV vaccine is out, and we should really be applying this to our overall vaccination strategy in a very aggressive and appropriate way for those with IBD.

Developing a Consensus on FMT in IBD

The final study that I want to highlight relates to a concept that we see more and more about, which is microbial involvement in IBD.

Investigators provided a poster^[6] sharing results from a meta-analysis of intestinal microbiota transplant (also referred to as fecal microbiota transplant or FMT) for IBD, in particular in patients with ulcerative colitis. They evaluated six medical databases and identified 10 randomized controlled trials. In performing their meta-analysis, they found that the value of fecal transplant was evident for ulcerative colitis.

This would certainly be something worth speaking with your patients about. Although it's not approved for use at present, we're seeing incremental value of this.

To that end, the most recent issue of Gut shared guidelines from the first Rome consensus conference on fecal transplant in IBD. The guideline authors concluded that it was potentially effective in IBD for ulcerative colitis. There's mild evidence of this and a strong recommendation that it should still be investigated.

It was the opposite finding for Crohn's disease. There was really no evidence of effectiveness. Most of the trials were not randomized controlled trials but rather pilot studies or anecdotal studies. And there was no evidence for pouchitis.

The new guidance on fecal transplant from this presentation, taken in tandem with the most recent Rome consensus, gives us much to think about.

In summary, ACG 2023 offers data with lots of potential implications. Some of these findings are ready for prime time now, and for others, we'll anxiously await the manuscripts to see these wonderful presentations in full display.

I'm Dr David Johnson. Thanks again for listening.

David A. Johnson, MD, a regular contributor to Medscape, is professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia, and a past president of the American College of Gastroenterology. His primary focus is the clinical practice of gastroenterology. He has published extensively in the internal medicine/gastroenterology literature, with principal research interests in esophageal and colon disease, and more recently in sleep and microbiome effects on gastrointestinal health and disease.

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