What is Barrett Esophagus (BE, metaplasia)? Is endoscopic screening and surveillance for BE necessary?
BE is the development of specialized intestinal metaplasia (SIM) of the distal tubular esophagus, which has been identified as a premalignant precursor to EAC. The incidence of EAC is currently increasing at a rate greater than that of any other cancer in the Western world. The 5-year survival rate for late-stage EAC is poor and the only hope for improved survival is early detection. Screening for BE remains controversial, however, because of a lack of randomized controlled trials documenting a decreased effect on mortality.
Which patients should undergo endoscopic screening for Barrett Esophagus?
Screening for BE in the general population is not recommended at this time but should be considered in selected male patients older than 50 with frequent heartburn (several times per week) and long-standing GERD. The primary purpose of surveillance of BE is to identify dysplasia and early EAC. Patients at increased risk for BE are typically white men older than 50 years and those with nocturnal reflux. After a negative screening examination, surveillance endoscopy is not indicated.
What techniques are used to perform endoscopic screening in Barrett Esophagus?
A complete direct visual examination (esophagogastroduodenoscopy [EGD]) of the esophagus with high-resolution and high-definition white-light endoscopy is the standard for endoscopic screening of BE.
Esophageal capsule endoscopy may provide a noninvasive assessment of suspected BE; however, studies demonstrate varying sensitivity with the device.
How is Barrett Esophagus histologically graded?
BE is histologically graded as:
• Indeterminate-grade dysplasia
• Low-grade dysplasia (LGD)
• High-grade dysplasia (HGD)
What is the rationale for endoscopic surveillance in Barrett Esophagus?
Decisions about endoscopic surveillance and treatment for BE are based on the presumption that SIM may advance to LGD, that LGD may advance to HGD, and that HGD may progress to intramucosal carcinoma. BE surveillance programs attempt to detect adenocarcinoma or HGD at an earlier, potentially curable, stage and have been shown to significantly improve 5-year survival compared with similar patients not undergoing routine endoscopic surveillance.
What techniques are used to perform endoscopic surveillance in Barrett Esophagus?
Surveillance endoscopy should only be performed after patients have their reflux aggressively controlled with a proton pump inhibitor because any inflammation may interfere with the endoscopic and microscopic identification of dysplasia. Endoscopic surveillance involves systematic four-quadrant biopsies at 1- to 2-cm intervals along the entire length of the Barrett segment. Biopsies should also specifically target any luminal irregularity in the Barrett segment (e.g., ulceration, erosion, nodule, or stricture) because there is an association of such lesions with underlying cancer. The use of jumbo biopsy forceps may improve the yield of the biopsies and should be considered, especially in patients with previous dysplasia. Newer brushing techniques (WATS, FISH etc) may provide greater sensitivity compared to biopsy for detecting high-grade lesions/dysplasia and neoplasia.
How often should patients with Barrett Esophagus undergo endoscopic surveillance?
Endoscopic surveillance intervals are determined by the presence and grade of dysplasia found in patients with BE.
2012 ASGE Guidelines Endoscopic Management Strategies for Barrett Esophagus
|Histologic Characteristics||Surveillance||Intervention options|
|Nondysplastic Barrett’s esophagus||Consider no surveillance.|
If surveillance is elected, perform EGD every 3 to 5 years with 4-quadrant biopsies every 2 cm.
|Consider endoscopic ablation in select cases.|
|Clarify presence and grade of dysplasia with expert GI pathologist.|
Increase antisecretory therapy to eliminate esophageal inflammation.
Repeat EGD and biopsy to clarify dysplasia status.
|No therapeutic intervention recommended|
|Low-grade dysplasia||Confirm with expert GI pathologist.|
Repeat EGD in 6 months to confirm LGD.
Perform surveillance EGD every year, 4-quadrant biopsies every 1 to 2 cm.
|Consider endoscopic resection or ablation.|
|High-grade dysplasia||Confirm with expert GI pathologist.|
Consider surveillance EGD every 3 months in select patients, 4-quadrant biopsies every 1 cm.
|Consider endoscopic resection or mucosal ablation.|
Consider EUS for local staging and lymphadenopathy.
Consider surgical resection.
EGD, esophagogastroduodenoscopy; EUS, endoscopic ultrasound; GI, gastrointestinal; LGD, low-grade dysplasia.
Workup once EAC is identified while performing endoscopic surveillance for Barrett Esophagus?
Once EAC is confirmed by an expert GI pathologist, staging of the cancer is performed with a computed tomography (CT) scan, preferably with integrated positron emission tomography, to evaluate for the presence of metastatic disease. Next, patients without evidence of metastatic disease by CT would undergo EUS for regional staging to provide detailed images of the esophageal masses and their relationship within the structure of the esophageal wall. EUS with fine-needle aspiration (FNA) can also be used for lymph node staging. Finally, depending on the stage of the cancer, the patient should be referred to oncology, radiation oncology, or surgery for treatment. The use of endoluminal stenting may be considered.
What other imaging modalities are available for Barrett Esophagus endoscopic screening and surveillance?
Confocal laser endomicroscopy (CLE) imaging of the GI mucosa enables endoscopists to obtain immediate real-time histologic images without biopsies as well as enhance the guidance of mucosal biopsies, leading to a higher dysplasia and neoplasia detection rate. BE and associated neoplasia can be predicted with a sensitivity of 98.1% and 92.9%, and a specificity of 94.1% and 98.4%, respectively, with CLE (overall accuracy: 96.8% and 97.4%), which may lead to decreased biopsies and lower associated cost. Narrowband imaging (NBI) is a technique that filters the illuminating white light on the endoscope into two colors (blue and green), which are avidly absorbed by blood vessels to allow for better visualization of the mucosa. In one study of patients with BE, the sensitivity of NBI detection for an irregular mucosal pattern was 100% with a specificity of 98.7%. Chromoendoscopy has also been used to stain the esophagus with agents like methylene blue, crystal violet, indigo carmine, and acetic acid that are applied to the mucosa to enhance the detection of abnormal mucosal patterns in Barrett Esophagus.