Mucosal Ablation in Patients with Barrett's Esophagus: Fry or Freeze?

Inhibition of BMP2 and BMP4 Represses Barrett's Esophagus While Enhancing the Regeneration of Squamous Epithelium in Preclinical Models

BACKGROUND & AIMS

Barrett's esophagus is considered to be a metaplastic lesion that predisposes for esophageal adenocarcinoma. Development of Barrett's esophagus is considered to be driven by sonic hedgehog mediated bone morphogenetic protein (BMP) signaling. We aimed to investigate in preclinical in vivo models whether targeting canonical BMP signaling could be an effective treatment for Barrett's esophagus.

METHODS AND RESULTS

Selective inhibition of BMP2 and BMP4 within an in vivo organoid model of Barrett's esophagus inhibited development of columnar Barrett's cells, while favoring expansion of squamous cells. Silencing of noggin, a natural antagonist of BMP2, BMP4, and BMP7, in a conditional knockout mouse model induced expansion of a Barrett's-like neo-columnar epithelium from multi-lineage glands. Conversely, in this model specific inhibition of BMP2 and BMP4 led to the development of a neo-squamous lineage. In an ablation model, inhibition of BMP2 and BMP4 resulted in the regeneration of neo-squamous epithelium after the cryoablation of columnar epithelium at the squamocolumnar junction. Through lineage tracing the generation of the neo-squamous mucosa was found to originate from K5+ progenitor squamous cells.

CONCLUSIONS

Here we demonstrate that specific inhibitors of BMP2 and BMP4 attenuate the development of Barrett's columnar epithelium, providing a novel potential strategy for the treatment of Barrett's esophagus and the prevention of esophageal adenocarcinoma.

Endoscopic Diagnosis and Management of Barrett's Esophagus with Low-Grade Dysplasia

Barrett's Esophagus is a common condition associated with chronic gastroesophageal reflux disease. It is well known that it has an association with a higher incidence of esophageal adenocarcinoma, but this neoplastic transformation is first preceded by the onset of low and high-grade dysplasia. The evaluation of low grade dysplastic esophageal mucosa is still controversial; although endoscopic surveillance is preferred, several minimally invasive endoscopic therapeutic approaches are available. Endoscopic mucosal resection and radiofrequency ablation are the most used endoscopic treatments for the eradication of low-grade dysplasia, respectively, for nodular and flat dysplasia. Novel endoscopic treatments are cryotherapy ablation and argon plasma coagulation, that have good rates of eradication with less complications and post-procedural pain.

Spray cryotherapy versus continued radiofrequency ablation in persistent Barrett's esophagus

Radiofrequency ablation (RFA) is the first-line treatment for flat Barrett's esophagus (BE) with dysplasia, however its role for persistent Barrett's esophagus (PBE) is unclear. PBE requires additional RFA sessions or application of cryotherapy to improve therapeutic response. We performed a retrospective cohort study evaluating cases of PBE treated by endoscopic eradication programs, with and without spray cryotherapy, and evaluated their safety and efficacy. We retrospectively identified patients with PBE, defined as ≤50% BE reduction or unchanged dysplasia after at least two RFA sessions. PBE was treated either by continued RFA (RFA Group) or converting to spray cryotherapy (CRYO Group), both followed by surveillance period. The rate of adverse events (AE), complete response of intestinal metaplasia (CRIM) and complete response of dysplasia (CRD) were recorded. A total of 46 patients, 23 per group, underwent 622 endoscopic therapies. Circumferential BE length was longer in the CRYO Group, but other baseline characteristics were similar, including maximal BE length. Esophageal strictures accounted for 14/16 total AE, 71% of which were RFA related, compared with 14% related to spray cryotherapy (P = 0.02). Overall CRIM/CRD rates in CRYO (83%) and RFA (96%) groups were not statistically different (P = 0.16), however cases in the CRYO Group required more treatment encounters (Median 19 vs. 12, P ≤ 0.01). Multimodal endotherapy is effective for eradicating PBE. Treatment programs incorporating spray cryotherapy are associated with less esophageal strictures but may require more treatment sessions to achieve eradication.

Endoscopic management of Barrett's esophagus: Western perspective of current status and future prospects

Barrett's esophagus (BE) is a precursor to esophageal adenocarcinoma and current practice is to establish endoscopic surveillance once diagnosed, in order to identify early dysplasia and neoplasia that has the potential to undergo endoscopic eradication therapy (EET). Before embarking upon EET the clinical team has a duty to consider all viable options and come to a plan based on recent evidence. The therapeutic approach varies greatly but largely adheres to the mantra of 'Detect-Resect-Ablate', in which high-quality endoscopy identifies BE associated pathology, associated lesions (if present) undergo safe endoscopic resection and remaining intestinal metaplasia in the esophagus is ablated to prevent recurrence of dysplasia. In this review, current practice, pitfalls, complications, and the future perspectives on practice in this field are discussed. The Western perspective is focused on here, with an outline of the differences in clinical practice with Asian nations and attempts to bridge these differences.

Endoscopic Eradication Therapy for Barrett's Neoplasia: Where Do We Stand a Decade Later?

PURPOSE OF REVIEW

Barrett's esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), a cancer associated with increasing incidence and poor survival. Early identification and effective treatment of BE-related neoplasia prior to the development of invasive adenocarcinoma are essential to limiting the morbidity and mortality associated with this cancer. In this review, we summarized the recent evidence guiding endoscopic eradication therapies (EET) for neoplastic BE.

RECENT FINDINGS

New sampling technologies and the application of artificial intelligence (AI) systems have potential to revolutionize early neoplasia detection in BE. EET for BE are safe and effective in achieving complete eradication of intestinal metaplasia (CE-IM) and reducing the progression to EAC, a practice endorsed by all GI society guidelines. EET should be considered in patients with high-grade dysplasia (HGD), intramucosal carcinoma (IMC), and select cases with low-grade dysplasia (LGD). The increasing use of endoscopic submucosal dissection (ESD) in the West may allow EET of select cases with submucosal EAC. Post-EET surveillance strategies will continue to evolve as knowledge of specific risk factors and long-term neoplasia recurrence rates improve. In the last decade, major advancements in EET for neoplastic BE have been achieved. These now represent the standard of care in the management of BE-related dysplasia and intramucosal cancer.

A narrative review of Barrett's esophagus in 2020, molecular and clinical update

Barrett’s esophagus (BE) is a condition resulting from an acquired metaplastic epithelial change in the esophagus in response to gastroesophageal reflux. BE is the only known precursor lesion to esophageal adenocarcinoma, and can progress from non-dysplastic BE (NDBE) to low grade dysplasia (LGD) and high grade dysplasia (HGD), and ultimately invasive carcinoma. Although the risk of developing esophageal adenocarcinoma (EAC) in NBDE is less than 0.5% per year, there has been a rising incidence of EAC in Western countries, which continue to drive efforts to optimize screening and surveillance methods. The current gold standard for diagnosis is esophagogastroduodenoscopy (EGD), and there has been significant interest in alternative, minimally invasive methods for screening which would be more readily accessible in the primary care setting. Surveillance endoscopy in 3–5 years is recommended for NDBE given the low progression to EAC. The mainstay of treatment for LGD and HGD is endoscopic eradication therapy (EET). Visible lesions are treated with endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD). Radiofrequency ablation (RFA) is considered first line therapy for flat dysplastic BE and cryotherapy has shown promising results as an alternate form of treatment for of dysplasia. The molecular progression of BE to EAC is a complex process involving multiple pathways involving genetic and epigenetic modifications. Genomic studies have further led to the understanding of the complex molecular landscape that occurs early and late in the disease process. Promising biomarker panels have been investigated to help with the diagnosis of BE as well as aid in the risk stratification of BE during surveillance. In addition, clinical prediction models have been developed to categorize BE patients in low, intermediate, and high risk for progression to HGD and EAC. Further clinical and translational research is needed to help refine markers and techniques in diagnosis, screening, and surveillance.

Stretta procedure versus proton pump inhibitors for the treatment of nonerosive reflux disease: A 6-month follow-up

To compare the Stretta procedure with proton pump inhibitors for the treatment of nonerosive reflux disease (NERD).From July 2018 to April 2019, patients diagnosed with NERD and referred for treatment were enrolled. They were treated with either Stretta procedure or proton pump inhibitor (PPI) medication and followed-up for 6 months. The symptom control, quality of life, lower esophageal sphincter (LES) pressure, 24-hour pH parameters, PPI usage and satisfaction rate were evaluated. The complications were assessed. The outcomes of the 2 groups were analyzed and compared.Twenty-eight patients in the Stretta group and 21 patients in the PPI group completed the 6-month follow-up. No severe adverse events occurred in both groups. Both interventions were effective in improvement of symptom and quality of life. The symptom score improvement was significantly superior in the Stretta group compared to the PPI group (6.3 ± 3.4 vs 8.5 ± 4.1, P = .03). LES pressure increased significantly in the Stretta group compared to the PPI group (14.2 ± 4.4 mm Hg vs 10.0 ± 4.0 mm Hg, P < .01). Although both interventions improved 24-hour pH parameters, including number of acid episodes (P = .27), acid exposure time (P = .39), and DeMeester score (P = .28), no difference was found between the 2 groups. Complete PPI cessation rate (82% vs 52%, P = .03) as well as satisfaction rate (89% vs 57%, P = .02) was much higher in Stretta group than those in the PPI groupThe Stretta procedure was safe and effective in the short term for the management of NERD. The Stretta procedure resulted in higher LES pressure and achieved better improvement of symptom control and PPI cessation than did PPI in the short term.

Cryotherapy in the management of premalignant and malignant conditions of the esophagus

Endoscopic cryotherapy is a relatively new thermal ablative modality used for the treatment of neoplastic lesions of the esophagus. It relies on cycles of rapid cooling and thawing to induce tissue destruction with a cryogen (liquid nitrogen or carbon dioxide) leading to intra and extra-cellular damage. Surgical treatment was once considered the standard therapeutic intervention for neoplastic diseases of the esophagus and is associated with considerable rates of morbidity and mortality. Several trials that evaluated cryotherapy in Barrett’s esophagus (BE) associated neoplasia showed reasonable efficacy rates and safety profile. Cryotherapy has also found applications in the treatment of esophageal cancer, both for curative and palliative intent. Cryotherapy has also shown promising results as salvage therapy in cases refractory to radiofrequency ablation treatment. Cryoballoon focal ablation using liquid nitrogen is a novel mode of cryogen delivery which has been used for the treatment of BE with dysplasia and squamous cell carcinoma. Most common side effects of cryotherapy reported in the literature include mild chest discomfort, esophageal strictures and bleeding. In conclusion, cryotherapy is an effective and safe method for the treatment of esophageal neoplastic processes, ranging from early stages of low grade dysplasia to esophageal cancer.