Narrow Band Imaging for Gastric Neoplasia

March 2, 2023 updated by: James Buxbaum, University of Southern California

Prospective Controlled Trial of Narrow Band Imaging for Detection of Gastric Cancer Precursors

It is thought that the development of cancer of the stomach follows a series of stages in which the lining becomes increasingly abnormal. Early detection of precursors of gastric cancer likely enable less invasive treatment.

The assessment of gastric mucosa using the endoscope is used to detect cancers and these precursor lesions. Narrow band imaging uses filtered light already built into modern endoscopoes to identify the early changes in the gastric lining.

The investigators' hypothesis is that narrow band imaging improves detection of precursor lesions and is a method amenable to international standardization.

The investigators will conduct a prospective trial in which standard random biopsy, white light guided biopsy, and narrow band imaging guided biopsy will be performed for each patient. The yield of the different methods for gastric cancer precursors will thus be compared.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

1 BACKGROUND

Precursor Lesions

Gastric cancer is the fourth most common cancer and second leading cause of malignant death in the world. It often presents only with vague symptoms of dyspepsia and consequently is frequently diagnosed at advanced stages.

Gastric cancer develop in a series of steps beginning with H. pylori infection. 2-4 It induces an inflammatory reaction with the surrounding gut epithelium which is theorized to drive a subsequent progression in some patients to mucosal atrophy, intestinal metaplasia, dysplasia, and finally gastric adenonocarcinoma.

Systematic biopsy protocols

In the evaluation for precancerous gastric lesions and Helicobacter pylori, experts recommend that biopsies be obtained from the antrum (3cm from pylorus), body (8cm from the pylorus), and insisura/angle. Both the greater and lesser curvature should be sampled. Additionally, recently developed staging systems including OLGIM (operative clinic on intestinal metaplasia) scores require histologic assessment (via the updated Sydney score) from two sites (antrum and corpus).

Narrow Band Imaging in endoscopy

Patients with H. pylori gastritis, gastric atrophy, intestinal metaplasia most commonly have no visible lesions on white-light endoscopy, although endoscopic findings may include antral nodularity, absent rugae, prominent gastric vessels white mucosal deposits. However, the sensitivity and specificity of these gross findings for underlying histological findings is poor. Therefore a number of image-enhancement techniques including chromoendoscopy using mucosal dyes or endoscopy-based virtual chromo-endoscopy (e.g., narrow band imaging) have been proposed. Narrow band imaging is the most widely investigated.

Narrow band imaging is an electronic, noninvasive technique in which the illuminating light from the endoscope is filtered to enable passage primarily of two narrow bands of light, 415nm and 540nm. These wavelengths correspond to the hemoglobin absorption wavelength in the capillaries and submucosal vessels respectively. This enhances evaluation of the mucosal surface patterns and vascular irregularities. NBI has been shown to be useful in the detection of dysplasia in Barrett's esophagus and characterization of small colonic adenomas.

Recently, a simple NBI classification using high-definition white light endoscopy was proposed for gastric mucosal examination.18 The NBI interpretation using this classification was compared with histological examination of mucosal biopsies, with both NBI and histology determined in blinded fashion. This classification which defines the mucosal pattern of the stomach had an accuracy exceeding 80% and excellent interobserver agreement (kappa=0.75) for normal mucosa, intestinal metaplasia, and dysplasia. However, the study was done at a referral center where 34% of patients had dysplasia and NBI was not compared with a white light assessment or standardized gastric biopsy protocol. Additionally, the results were not provided on a per patient basis, which is the most relevant endpoint in clinical practice.

2.0 OBJECTIVES AND PURPOSE Prompt detection of gastric cancer precursors enables early detection and less invasive treatment options such as endoscopic resection. Narrow band imaging is a completely noninvasive technique which uses filtered light to enhance assessment of mucosa. Our aim is to gauge whether biopsies targeted by narrow band imaging improves the detection of gastric intestinal metaplasia and gastric dysplasia relative to standard white light techniques on a per patient basis. A secondary aim will be to assess whether the technique is amenable to standardization so that it might be used more broadly to identify patients with early gastric neoplasia. While NBI is built into the vast majority of endoscopes in use few physicians are aware of its potential use.

3.0 STUDY DESIGN

The study will be a prospective tandem endoscopy trial. All EGDs will have already been planned as part of standard clinical care.

High definition white light endoscopy will initially be performed. The specific location of all mucosal findings in the stomach such as ulceration or nodularity which require biopsy will be noted by the endoscopist and research coordinator but will not be biopsied until after NBI. This is done so that blood will not distort or bias NBI assessment. Any abnormal findings in other parts of the GI tract examined using the scope (esophagus and duodenum) will be noted and biopsied.

At the completion of the white light exam, while the scope is in the stomach, the white light endoscopist will press a button on the scope which changes the view to the narrow band imaging.

At this point the NBI endoscopist who is initially blinded to the white light findings will enter the procedure room and examine the stomach using NBI. The type and location of NBI abnormalities will be noted and biopsies obtained.

At the end of the NBI exam the NBI endoscopist will switch the scope view back to white light mode. The white light endoscopist will return to the room and biopsy any sites identified and recorded during the initial white-light endoscopy. A research coordinator present for the entire procedure will verify and record that all sites identified during the initial white light exam are biopsied.

Subsequently, random biopsies will be performed by taking 2 biopsies from the lesser curvature (body and antrum), 2 biopsies from the greater curvature (body and antrum), and one from the angle.

The biopsies obtained by white light exam, narrow band imaging exam, and random sampling will be separately coded and submitted to pathology. Histologic analysis will be performed by expert GI pathologists blinded to the acquisition approach.

Short 10 second video clips of each site targeted for biopsy by white light narrow band imaging will be recorded. They will be matched with the final biopsy results and stored WITHOUT personal health identifiers. These short videos may be used for training and shared with collaborators to assess inter-observer variability and standardize the interpretation of NBI of the stomach.

The primary outcome measure will be yield of NBI, high definition white light endoscopy, and random biopsy for the detection of atrophic gastritis, IM and dysplasia on a per patient basis. A secondary endpoint will be the number of regions found by each method to exhibit atrophic gastritis, IM, and dysplasia (per lesion (region) yield). The yields of H. Pylori by method and the total number of biopsies guided per method will be additional outcomes.

Patients will be enrolled at the Los Angeles County Hospital of the University of Southern California as well as the Gastroenterology Unit at the University of Porto in Porto Portugal. The protocol originates from and statistical analysis will be done at the University of Southern California. No personal health identifiers will be exchanged at any point between the two institutions.

Prior to the formal initiation of the study there will be a lead in period of 10-20 patients with gastric symptoms. The initial patients will be examined using the white light, NBI, and gastric biopsy protocol. After this the images will be discussed by the investigators at the two centers to make certain that NBI interpretation of gastric premalignant changes is standardized. The LAC+USC investigators will also review the Portugese video training library on gastric NBI. Any changes in performance of the lead in versus the study will be noted to address the secondary aim of developing a standardized approach to NBI which may help this technique be used widely to identify patients with early gastric neoplasia.

4 STATISTICAL CONSIDERATIONS

The Fisher's exact chi squared test will be used for dichotomous outcomes such as the accurate detection of the highest level histology and number of biopsies. Adverse reactions will be reported in a descriptive manner.

Based on previous research which showed 74% correction detection of gastric cancer precursors with white light endoscopy versus 89% with NBI and given our anticipated gastric cancer prevalence of 20% we performed preliminary sample size estimates for a range of OR using G*Power (alpha=0.05, beta =0.20). We anticipate an N of 200 will be sufficient to show a significant difference between methods.

Study Type

Interventional

Enrollment (Anticipated)

220

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Maria Trujillo
  • Phone Number: 323 409 0939
  • Email: mit@usc.edu

Study Locations

  • Portugal
      • Porto, Portugal
        • Not yet recruiting
        • Department of Gastroenterology Portuguese Oncology Institute of Porto
        • Contact:
          • Mario Dinis-Ribeiro, MD
          • Phone Number: +351-22-5084055
          • Email: mario@med.up.pt
        • Contact:
        • Principal Investigator:
          • Mario Dinis-Ribeiro, MD
        • Sub-Investigator:
          • Diogo Dias da Silva, MD
  • United States
    • California
      • Los Angeles, California, United States, 90033
        • Recruiting
        • Los Angeles County Hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • presenting for upper endoscopy for gastric indications
  • gastric indications include upper abdominal pain dyspepsia abnormal gastric imaging iron deficiency anemia gastric ulcer management of GI blood loss without active bleeding reflux weight loss.

Exclusion Criteria:

  • Subjects who are incarcerated, younger than 18, or unable to give informed consent will be excluded.
  • Patients who have evidence of active gastrointestinal bleeding will be excluded
  • Patients taking anti-thrombotic agents including clopidogrel, ticlopidine, coumadin, heparin, enoxaparin, and direct II or Xa inhibitors
  • Patients with INR >1.5, platelet count <75,000

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Gastric Symptoms
Patients with gastric symptoms including dyspepsia undergoing upper endoscopy will undergo white light biopsy narrow band imaging guided biopsy protocolled biopsy
Procedure: White light biopsy
Endoscopy with biopsies guided by high definition white light
Procedure: Protocolled
Upper Endoscopy with Protocolled Biopsy (i.e. biopsy by predetermined guideline not influenced by white light or narrow band imaging findings)
Procedure: Narrow Band Imaging Guided Biopsy
Upper Endoscopy with biopsy guided by narrow and imaging

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Detection of Intestinal Metaplasia or Dysplasia
Time Frame: One Year
Confirmation of intestinal metaplasia in stomach per patient by each method-NBI versus white light-versus random
One Year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Regions with Intestinal Metaplasia
Time Frame: 1 year
Number of Region with Intestinal Metaplasia detected in the stomach (total not per patient) detected by each method-NBI versus white light-versus random
1 year
Number of regions with dysplasia
Time Frame: one year
Number of regions with dysplasia detected in the stomach (total not per patient) detected by each method-NBI versus white light-versus random
one year
Biopsies driven by method
Time Frame: One year
Number of biopsies driven by each method. Number driven by each method-NBI versus white light-versus random will be compared.
One year
Helicobacter pyrlori detection
Time Frame: One year
Detection ofHelicobacter pylori by method
One year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Southern California

Collaborators

Universidade do Porto

Investigators

  • Principal Investigator: James Buxbaum, MD, University of Southern California

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2014

Primary Completion (Anticipated)

December 1, 2023

Study Completion (Anticipated)

December 1, 2023

Study Registration Dates

First Submitted

July 18, 2014

First Submitted That Met QC Criteria

July 21, 2014

First Posted (Estimate)

July 22, 2014

Study Record Updates

Last Update Posted (Estimate)

March 6, 2023

Last Update Submitted That Met QC Criteria

March 2, 2023

Last Verified

March 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HS-14-00418

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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