Trial Title:
Narrow Band Imaging for Gastric Neoplasia
NCT ID:
NCT02197351
Condition:
Gastric Cancer
Gastric Metaplasia
Gastric Dysplasia
Conditions: Official terms:
Stomach Neoplasms
Metaplasia
Conditions: Keywords:
stomach neoplasms
narrow band imaging
gastroscopy
Study type:
Interventional
Study phase:
N/A
Overall status:
Recruiting
Study design:
Allocation:
N/A
Intervention model:
Single Group Assignment
Primary purpose:
Diagnostic
Masking:
Single (Participant)
Intervention:
Intervention type:
Procedure
Intervention name:
White light biopsy
Description:
Endoscopy with biopsies guided by high definition white light
Arm group label:
Gastric Symptoms
Intervention type:
Procedure
Intervention name:
Protocolled
Description:
Upper Endoscopy with Protocolled Biopsy (i.e. biopsy by predetermined guideline not
influenced by white light or narrow band imaging findings)
Arm group label:
Gastric Symptoms
Intervention type:
Procedure
Intervention name:
Narrow Band Imaging Guided Biopsy
Description:
Upper Endoscopy with biopsy guided by narrow and imaging
Arm group label:
Gastric Symptoms
Summary:
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.
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.
Criteria for eligibility:
Criteria:
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
Gender:
All
Minimum age:
18 Years
Maximum age:
N/A
Healthy volunteers:
No
Locations:
Facility:
Name:
Los Angeles County Hospital
Address:
City:
Los Angeles
Zip:
90033
Country:
United States
Status:
Recruiting
Contact:
Last name:
Maria Trujillo
Phone:
323-409-6939
Email:
mit@usc.edu
Contact backup:
Last name:
James Buxbaum, MD
Phone:
323 409 5371
Email:
jbuxbaum@usc.edu
Facility:
Name:
Department of Gastroenterology Portuguese Oncology Institute of Porto
Address:
City:
Porto
Country:
Portugal
Status:
Not yet recruiting
Contact:
Last name:
Mario Dinis-Ribeiro, MD
Phone:
+351-22-5084055
Email:
mario@med.up.pt
Contact backup:
Last name:
Diogo Dias da Silva, MD
Email:
diassilva.diogo@gmail.com
Investigator:
Last name:
Mario Dinis-Ribeiro, MD
Email:
Principal Investigator
Investigator:
Last name:
Diogo Dias da Silva, MD
Email:
Sub-Investigator
Start date:
July 2014
Completion date:
December 2023
Lead sponsor:
Agency:
University of Southern California
Agency class:
Other
Collaborator:
Agency:
Universidade do Porto
Agency class:
Other
Source:
University of Southern California
Record processing date:
ClinicalTrials.gov processed this data on November 12, 2024
Source: ClinicalTrials.gov page:
https://clinicaltrials.gov/ct2/show/NCT02197351
