Routine polypectomy for colorectal polyps and ablation for Barrett's esophagus are intellectually the same

Management of nondysplastic Barrett’s esophagus: When to survey? When to ablate?

Barrett’s esophagus (BE), a precursor for esophageal adenocarcinoma (EAC), is defined as salmon-colored mucosa extending more than 1 cm proximal to the gastroesophageal junction with histological evidence of intestinal metaplasia. The actual risk of EAC in nondysplastic Barrett’s esophagus (NDBE) is low with an annual incidence of 0.3%. The mainstay in the management of NDBE is control of gastroesophageal reflux disease (GERD) along with enrollment in surveillance programs. The current recommendation for surveillance is four-quadrant biopsies every 2 cm (or 1 cm in known or suspected dysplasia) followed by biopsy of mucosal irregularity (nodules, ulcers, or other visible lesions) performed at 3- to 5-year intervals. Challenges to surveillance include missed cancers, suboptimal adherence to surveillance guidelines, and lack of strong evidence for efficacy. There is minimal role for endoscopic eradication therapy in NDBE. The role for enhanced imaging techniques, artificial intelligence, and risk prediction models using clinical data and molecular markers is evolving.

Global burden and epidemiology of Barrett oesophagus and oesophageal cancer

Oesophageal cancer is a global health problem; in 2018 there were more than 572,000 people newly diagnosed with oesophageal cancer worldwide. There are two main histological subtypes of oesophageal cancer, oesophageal adenocarcinoma (EAC) and oesophageal squamous cell carcinoma (ESCC), and there has been a dramatic shift in its epidemiology. While the incidence of EAC and its precursor lesion, Barrett oesophagus, has increased in Western populations over the past four decades, the incidence of ESCC has declined in most parts of the world over the same period. ESCC still accounts for the vast majority of all oesophageal cancer cases diagnosed worldwide each year. Prognosis for patients with oesophageal cancer is strongly related to stage at diagnosis. As most patients are diagnosed with late-stage disease, overall 5-year survival for oesophageal cancer remains <20%. Knowledge of epidemiology and risk factors for oesophageal cancer is essential for public health and clinical decisions about risk stratification, screening and prevention. The goal of this Review is to establish the current epidemiology of oesophageal cancer, with a particular focus on the Western world and the increasing incidence of EAC and Barrett oesophagus.

Novel biomarkers for risk stratification of Barrett's oesophagus associated neoplastic progression-epithelial HMGB1 expression and stromal lymphocytic phenotype

BACKGROUND

The incidence of oesophageal adenocarcinoma is increasing globally. Barrett's oesophagus (BO) is a pre-malignant condition with no biomarker to risk stratify those at highest risk of dysplasia and malignant transformation.

METHODS

Subcellular epithelial protein (HMGB1, p53, RUNX3) expression, alongside expression of CD20, CD4, CD8 and Foxp3 to characterise stromal B lymphocyte, and helper, cytotoxic and regulatory T-lymphocyte cell infiltrate, respectively, was assessed by immunohistochemistry in 218 human tissue samples including normal oesophageal/gastric biopsies (n = 39), BO (non-dysplasia, dysplasia, non-dysplastic background from progressors to dysplasia or cancer, n = 121) and oesophageal adenocarcinoma (n = 58).

RESULTS

There is a dynamic subcellular epithelial expression of HMGB1 (loss of nuclear, emergence of cytoplasmic), associated with epithelial p53 expression and differential immune cell phenotype in oesophageal neoplastic progression. We identify a protein signature and lymphocyte infiltrate in non-dysplastic BO when progressive disease (dysplasia or adenocarcinoma) is present but not histologically represented in the biopsied field. There is a dynamic stromal lymphocytic infiltrate in oesophageal neoplastic progression.

CONCLUSIONS

This data reveals novel insights into the microenvironment of BO and progression towards cancer and identifies a novel high-risk biomarker of disease progression to aid surveillance strategies to identify early progression and impact future incidence of oesophageal cancer.

Biomarkers of Barrett's Esophagus: From the Laboratory to Clinical Practice

The currently recommended approach to managing cancer risk for patients with Barrett's esophagus is endoscopic surveillance including a biopsy protocol to sample the esophageal tissue randomly to detect dysplasia. However, there are numerous limitations in this practice that rely on the histopathological grading of dysplasia alone to make clinical decisions. The availability of in silico models demonstrating the potential cost-effectiveness of biomarker-based stratification has increased interest in finding a clinically relevant "Barrett's biomarker." The success of endoscopic eradication therapy in preventing neoplastic progression of dysplastic Barrett's esophagus has promoted the desire to stratify non-dysplastic Barrett's esophagus to those with "high risk" that may benefit from endotherapy. Furthermore, on the other end of the spectrum, there is interest in searching for a "low risk" marker that may identify those that would not likely benefit from endoscopy screening or surveillance. This review highlights recent data from the genomics (r)evolution revealing new genetic biomarkers of susceptibility to the development of Barrett's esophagus and novel pathways for its neoplastic progression, addresses the development of new modes of tissue sampling and imaging to detect early neoplasia in Barrett's esophagus, and discusses current progress in moving biomarkers from the laboratory into clinical practice in the era of precision medicine.

Columnar lined Barrett's oesophagus

Over the past few years, the definition of Barrett's oesophagus has altered with no real agreement on histological understanding. This article highlights the increasing confusion regarding Barrett's oesophagus with a focus on the all-too-frequently ignored aspect of the columnar lined oesophagus.

Preference of endoscopic ablation over medical prevention of esophageal adenocarcinoma by patients with Barrett's esophagus

BACKGROUND & AIMS

Endoscopic intervention or pharmacologic inhibition of cyclooxygenase might be used to prevent progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC). We investigated whether patients with BE prefer endoscopic therapy or chemoprevention of EAC.

METHODS

Eighty-one subjects with nondysplastic BE were given a survey that described 2 scenarios. The survey explained that treatment A (ablation), endoscopy, reduced lifetime risk of EAC by 50%, with 5% risk for esophageal stricture, whereas treatment B (aspirin) reduced lifetime risk of EAC by 50% and the risk of heart attack by 30%, yet increased the risk for ulcer by 75%. Subjects indicated their willingness to undergo either treatment A and/or treatment B if endoscopic surveillance were required every 3-5 years, every 10 years, or were not required. Visual aids were included to represent risk and benefit percentages.

RESULTS

When surveillance was required every 3-5 years, more subjects were willing to undergo treatment A than treatment B (78%, 63 of 81 vs 53%, 43 of 81; P < .01). There were no differences in age, sex, education level, or history of cancer, heart disease, or ulcer between patients willing to undergo treatment A and those willing to undergo treatment B. Altering the frequency of surveillance did not affect patients' willingness to undergo either treatment.

CONCLUSIONS

In a simulated scenario, patients with BE preferred endoscopic intervention over chemoprevention for EAC. Further investigation of the shared decision-making process regarding preventive strategies for patients with BE may be warranted.

Evidence-based endoscopic management of Barrett's esophagus

Barrett’s esophagus (BE) develops as a consequence of chronic esophageal acid exposure, and is the major risk factor for esophageal adenocarcinoma (EAC). The practices of endoscopic screening for—and surveillance of—BE, while widespread, have failed to reduce the incidence of EAC. The majority of EACs are diagnosed in patients without a known history of BE, and current diagnostic tools are lacking in their ability to stratify patients with BE into those at low risk and those at high risk for progression to malignancy. Nonetheless, advances in endoscopic imaging and mucosal therapeutics have provided unprecedented opportunities for intervention for BE, and have vastly altered the approach to management of BE-associated mucosal neoplasia.

Controversies in Barrett esophagus

Barrett esophagus develops when metaplastic columnar epithelium predisposed to develop adenocarcinoma replaces esophageal squamous epithelium damaged by gastroesophageal reflux disease. Although several types of columnar metaplasia have been described in Barrett esophagus, intestinal metaplasia with goblet cells currently is required for a definitive diagnosis in the United States. Studies indicate that the risk of adenocarcinoma for patients with nondysplastic Barrett esophagus is only 0.12% to 0.38% per year, which is substantially lower than previous studies had suggested. Nevertheless, the incidence of esophageal adenocarcinoma continues to rise at an alarming rate. Regular endoscopic surveillance for dysplasia is the currently recommended cancer prevention strategy for Barrett esophagus, but a high-quality study has found no benefit of surveillance in preventing deaths from esophageal cancer. Medical societies currently recommend endoscopic screening for Barrett esophagus in patients with multiple risk factors for esophageal adenocarcinoma, including chronic gastroesophageal reflux disease, age of 50 years or older, male sex, white race, hiatal hernia, and intra-abdominal body fat distribution. However, because the goal of screening is to identify patients with Barrett esophagus who will benefit from endoscopic surveillance and because such surveillance may not be beneficial, the rationale for screening might be made on the basis of faulty assumptions. Endoscopic ablation of dysplastic Barrett metaplasia has been reported to prevent its progression to cancer, but the efficacy of endoscopic eradication of nondysplastic Barrett metaplasia as a cancer preventive procedure is highly questionable. This review discusses some of these controversies that affect the physicians and surgeons who treat patients with Barrett esophagus. Studies relevant to controversial issues in Barrett esophagus were identified using PubMed and relevant search terms, including Barrett esophagus, ablation, dysplasia, radiofrequency ablation, and endoscopic mucosal resection.

Barrett's esophagus: the American perspective

The American Gastroenterological Association (AGA) defines Barrett's esophagus as the condition in which any extent of metaplastic columnar epithelium that predisposes to cancer development replaces the squamous epithelium that normally lines the distal esophagus. Although cardiac mucosa may be metaplastic, its malignant predisposition is not clear, and the AGA still requires the demonstration of intestinal metaplasia (with goblet cells) for a diagnosis of Barrett's esophagus. The AGA generally recommends endoscopic eradication therapy for patients with high-grade dysplasia, who otherwise develop esophageal adenocarcinoma at the rate of 6% per year. Endoscopic therapy is often curative for mucosal neoplasms in Barrett's esophagus because the risk of lymph node metastases is only 1-2%. American gastroenterologists generally do not recommend endoscopic therapy for patients whose neoplasms involve any portion of the submucosa because of the high rate of lymph node metastases that has been described in these cases. The management of low-grade dysplasia is disputed because of poor agreement among pathologists on the diagnosis and because of contradictory data on the natural history, but the AGA recommends that radiofrequency ablation (RFA) should be a therapeutic option for patients with confirmed low-grade dysplasia in Barrett's esophagus. Arguments for using RFA to treat nondysplastic Barrett's metaplasia are based on the premise that RFA decreases cancer risk, but no study has established that premise. In the absence of definitive data, concerns about the frequency and importance of buried metaplastic glands and recurrent metaplasia should temper enthusiasm for treating nondysplastic Barrett's esophagus with RFA.