Evolving screening and surveillance techniques for Barrett's esophagus

Table 1 Current guidelines for screening Barrett's esophagus from major gastroenterology societies[3]

Society (year published)	Target populations
American College of Gastroenterology (2016)	Primary: Male patients with either > 5 years of GERD or with more than weekly GERD symptoms and at least two other risk factors including: (1) Age > 50; (2) central obesity; (3) smoking history; (4) Caucasian; (5) first degree relative with BE or EAC
American Society for Gastrointestinal Endoscopy (2012)	Patients with multiple risk factors including male sex, older than 50, Caucasian, family history of BE, increased duration of reflux symptoms, smoking and obesity
American Gastroenterological Association (2011)	Patients with multiple risk factors including male sex, older than 50, Caucasian, chronic GERD, hiatal hernia and obesity
British Society of Gastroenterology (2014)	Primary: Patients with GERD and at least three risk factors including male, older than 50, Caucasian, and obesity unless there is a family history of BE or EAC which would lower threshold

GERD: Gastroesophageal reflux disease; BE: Barrett's esophagus; EAC: Esophageal adenocarcinoma.

Table 2 Univariate analyses for each risk factors progression to high grade dysplasia or esophageal adenocarcinoma[4]

Variable	Adjusted P value and hazard ratios (95%CI)
Males	P = 0.0023, HR = 3.01 (1.48-6.11)
Smoking	P = 0.0029, HR = 1.83 (1.23-2.71)
Age + 10 yr	P = 0.3055, HR = 0.96 (0.89-1.04)
Caucasian	P = 0.8429, HR = 1.06 (0.61-1.82)
Hiatal hernia present	P = 0.5928, HR = 1.12 (0.73-1.72)
Visible lesion at baseline	P = 0.9254, HR = 1.04 (0.49-2.2)
Aspirin use	P = 0.2807, HR = 0.81 (0.56-1.18)
Non-steroidal anti-inflammatory drug	P = 0.5602, HR = 0.9 (0.64-1.28)
Proton pump inhibitor	P = 0.8197, HR = 0.9 (0.37-2.21)
Low grade dysplasia	P ≤ 0.0001, HR = 3.68 (2.56-5.31)
BE length + 1 cm increase in length	P ≤ 0.0001, HR = 1.12 (1.08-1.18)

BE: Barrett's esophagus; HGD: High grade dysplasia; EAC: Esophageal adenocarcinoma; HR: Hazard ratio; CI: Confidence interval.

Table 3 Progression in Barrett's esophagus point system based on risk variables[4]

Variable	Points
BE length in centimeters
< 1	0
1 to < 2	1
2 to < 3	2
3 to < 4	3
4 to < 5	4
5 to < 6	5
6 to < 7	6
7 to < 8	7
8 to < 9	8
9 to < 10	9
10 +	10
Males	9
Smokers	5
Baseline confirmed LGD	11

BE: Barrett's esophagus; LGD: Low grade dysplasia.

Table 4 Barrett's international narrow band imaging group classification for Barrett's esophagus with narrow band imaging[8]

Mucosal pattern
Circular, ridged/villous, or tubular	Regular
Absent or irregular	Irregular
Vascular pattern
Blood vessels situated regularly along or between mucosal ridges and/or showing normal long branching patterns	Regular
Focally or diffusely distributed vessels not following normal architecture of the mucosa	Irregular

Table 5 Miami criteria for classifying Barrett's esophagus using confocal laser endoscopy[12]

Histology	Confocal characteristics
1 Normal Squamous Epithelium	Flat Cells with bright intrapapillary capillary loops
2 Non-dysplastic Barrett's Esophagus	Uniformed villiform architecture with dark goblet cells
3 Barrett's esophagus with high-grade dysplasia	Villiform structures with dark, irregular and thick borders
4 Adenocarcinoma	Disorganized villiform architecture and dilated irregular vessels

Table 6 Screening techniques for Barrett's esophagus[7]

	Advantage	Disadvantage
Standard definition white light endoscopy	Provides wide-field imaging and is widely available	Decreased sensitivity when compared to high definition
High definition white light endoscopy	Provides wide-field imaging and is widely available with improved image quality	Cost of procedure, sedation and in some cases updating entire endoscopy system. Some concerns over missed rates of dysplastic lesions
Dye-based chromoendoscopy	Provides wide-field imaging with benefit of mucosal enhancement	Additional steps in procedure are time consuming and some concerns over harm of contrast
Narrow band imaging	Provides wide-field imaging and is widely available with improved sensitivity and without need for contrast. Relatively cheap.	Still requires white light endoscopy as an adjunct with unclear evidence on its benefits when compared to white light endoscopy alone
Flexible intelligent chromoendoscopy and i-SCAN	Provides wide field imaging without the need for contrast	Not widely available and not enough research to determine benefits compared to standard of car
Blue light imaging	Helpful in defining subtle changes in elevation and depression of the mucosa	Beneficial as an adjunct to WLE only and hence requires similar costs. Not widely available.
Auto flourescence imaging	Provides wide field imaging with improved sensitivity and without the need for contrast	Poor specificity with high false positive rate.
Confocal laser endomicroscopy	Provides in vivo information, has a validated scoring classification, and can be used with any endoscope	Does not provide wide-field imaging, requires fluorescein prolonging procedure time, requires expert interpretation and expensive
Endocytoscopy	Increases ability to identify dysplastic and neoplastic lesions	Does not provide wide-field imaging and requires giving contrast agent
Optical coherence tomography	Provides in vivo information without need for contrast or fluorescein. Ability to evaluate subsurface	Does not provide wide-field imaging and research has varied and is ongoing
Volumetric laser endomicroscopy	Similar to OCT but provides high resolution, high speed images over wider surface area	Expensive and studies are still working to obtain interobserver agreement and correlating images with histology
Tethered capsule endomicroscopy	Utilizes same technology used for OCT and is safe, well tolerated by patients	Early in stages of research
Spectroscopy	Early studies have shown good success in real time detection of BE and neoplasia	Early in stages of research
wide area transepithelial sampling	Provides wide area sampling of tissue with high sensitivity and specificity and easy to use	Not yet widely available? Regarding cost and more research needed
Cytosponge	Generally safe and well tolerated with low cost	Still requires endoscopy for treatment if abnormality is identified
Transnasal Endoscopy	Generally safe and well tolerated with relatively lower cost than endoscopy without the need for general sedation. Can be used in clinic as well as hospital	While early studies have shown equivocal ability to diagnosis BE compared to conventional endoscopy, more research required
Biomarker panels	Early studies have shown ability to predict progression of BE from non-dysplastic to neoplasia	A single, ideal biomarker has not been delineated and more research is required.
Breath testing with an electronic nose device	Safe and well tolerated and easy to use with overall cost-effectiveness	Sensitivity and specificity are good but not great compared to some other methods and research at this point is limited

WLE: White light endoscopy; OCT: Optical coherence tomography; BE: Barrett's esophagus.