Endoscopic Management of Barrett’s Esophagus

Introduction

Barrett’s esophagus (BE) is characterized by the replacement of squamous epithelium by columnar metaplasia of the distal esophagus (>1 cm length). It is a precancerous condition, with 3%-5% of patients with BE developing esophageal adenocarcinoma (EAC) in their lifetime. EAC is one of the cancers with high morbidity and mortality (5-year survival < 20%), and its incidence has been on the rise. Studies examining the natural history of BE have demonstrated that the progression happens through a metaplasia-dysplasia-neoplasia sequence. Therefore, early detection of BE and timely management to prevent progression to EAC is crucial.

Grades of Dysplasia

The current gold standard for the diagnosis of BE neoplasia includes a high-quality endoscopic evaluation and biopsies. Biopsies should be obtained from any visible lesions (nodules, ulcers) followed by a random 4-quadrant fashion (Seattle protocol) interval of the entire length of the BE segment. It is essential to pay attention to the results of the biopsy that have been obtained since it will not only determine the surveillance interval but is crucial in planning any necessary endoscopic therapy. The possible results of the biopsy and its implications are:

• No intestinal metaplasia (IM): This would rule out Barrett’s esophagus and no further surveillance would be necessary. A recent population-based study of over 1 million patients showed a 55% and 61% reduced risk of upper gastrointestinal (UGI) cancer and deaths respectively after a negative endoscopy.¹
• Intestinal metaplasia with no dysplasia (non-dysplastic BE): Biopsies confirm presence of intestinal metaplasia in the biopsies without any evidence of dysplasia. While the rate of progression to EAC is low (0.07%-0.25%), it is not absent and thus surveillance would be indicated. Current guidelines suggest repeating an endoscopy with biopsy in 5 years if the length of BE is < 3 cm or 3 years if length of BE ≥ 3 cm.²
• Indeterminate for dysplasia (BE-IND): Biopsies confirm IM but are not able to definitively rule out dysplasia. This can be seen in about 4%-8% of the biopsies obtained. The progression rates to EAC are reported to be comparable or lower to low-grade dysplasia (LGD), so the current recommendation is to intensify acid reduction therapy and repeat endoscopy in 6 months. If repeat endoscopy downgrades to non-dysplastic, then can follow surveillance according to NDBE protocol; otherwise recommend continuing surveillance every 12 months.
• Low-grade dysplasia (BE-LGD): Biopsies confirm IM but also show tightly packed overlapping basal nuclei with hyperchromasia and irregular contours, basal stratification of nuclei, and diminished goblet and columnar cell mucus. There is significant inter-observer variability reported,³ and thus the slides must be reviewed by a second pathologist with experience in BE to confirm the findings. Once confirmed, based on risk factors such as presence of multifocal LGD, persistence of LGD, presence of visible lesions, etc., the patient can be offered Barrett’s endoscopic therapy (BET) or undergo continued surveillance. The decision of pursuing one or the other would be dependent on patient preference and shared decision-making between the patient and the provider.
• High-grade dysplasia (BE-HGD): Biopsies confirm IM with cells showing greater degree of cytologic and architectural alterations of dysplasia than LGD but without overt neoplastic features. Over 40% of the patients would progress to EAC and thus the current recommendations would be to recommend BET in these patients.⁴
• Esophageal adenocarcinoma (EAC): Biopsies demonstrate neoplasia. If the neoplastic changes are limited to the mucosa (T1a) on endoscopic ultrasound or cross-sectional imaging, then BET is suggested. If there is involvement of submucosa, then depending on the depth of invasion, absence of high-risk features (poor differentiation, lymphovascular invasion), BET can be considered as an alternative to esophagectomy.