Transcript Intestinal Type

Intestinal Metaplasia
of the Stomach
A Review
Kent Humble MD
Assistant Professor of Family Medicine
LSU School of Medicine
Objectives
Discuss relationship between gastric IM and gastric cancer
Review pathophysiology and epidemiology of gastric IM
Review guidelines concerning endoscopic surveillance
Gastric Cancer
Gastric Cancer in US
US Incidence by
Ethnic Background
2008
Int J Cancer 2010;127(12):2893
Highest incidence in
East Asia, Eastern
Europe, and
Western South
America
Worldwide Incidence Rates
Intestinal Type
Diffuse Type
Gastric Cancer
Intestinal Type
Diffuse Type
70-80% of cases
20-30% of cases
Predominantly in high risk
areas
Uniform across countries
Older age (mean 69)
Younger age (mean 38)
Develops from precursors
No identified precursors
Male to Female 2:1
Male to Female 1:1
Environmental factors
Genetic factors
What is Gastric IM?
Correa
Progression
Gastritis
Atrophic
Gastritis
Intestinal
Metaplasia
Dysplasia
Cancer
Gastric IM is likely the 'breaking point' between chronic gastritis and
dysplasia
Am J Physiol Gastrointest Liver Physiol 291: G999 –G1004, 2006
What is Gastric IM?
• Foci appear at junction of Antrum & Body, often at
Angularis
• Enlarge, coalesce, extending to Antrum & Body
• Small foci of dysplasia may appear in areas of IM,
subject to sampling error
• Severity & tempo of progression may be influenced by
virulence of H Pylori (?cagA), environmental, host
genetic factors
Epidemiology of Gastric
IM
EPIDEMIOLOGY
OF IM
Found in up to 25% US Adults
13% of Caucasians
50% of Blacks/Hispanics
H. pylori infection significantly raises IM prevalence
Increases with patient age
Higher in first degree relatives with gastric cancer
Cancer Epidemiol Biomarkers Prev 1992;1:293–296.
EPIDEMIOLOGY
OF IM
•
Systematic review:
Patients with IM
Gastric cancer incidence varied 0-10%
Am J Surg Pathol 2000; 24: 167-176
• Dutch study:
Histology based
• 61,707 pts with IM
• 874 developed gastric CA over 10 years
• 0.18%yearly
Gastroenterology 2008; 134: 945-952
ARE ALL PATIENTS WITH
IM AT EQUAL RISK OF
GASTRIC CANCER?
ARE ALL PATIENTS WITH IM AT
EQUAL RISK OF GASTRIC
CANCER?
The presence of incomplete-type IM is associated with a higher
gastric cancer risk compared to complete-type IM.
Spain study:
Mean follow-up 12.8 years
• Incomplete IM: 16 of 88 pts (18.2%) developed gastric CA
• Complete IM: 1 of 104 pts (0.96%) developed gastric CA
Int J Cancer 2010; 127: 2654-2660
ARE ALL PATIENTS WITH IM AT
EQUAL RISK OF GASTRIC
CANCER?
Gastric cancer risk is associated with IM topography.
Columbia study:
Compared to antral predominate (focal)
• Extension through angularis- risk 5.7 fold
• Antrum plus body (diffuse)- risk 12.2 fold
Incomplete IM presents as diffuse more commonly than focal
Am J Gastroenterol 2000; 95: 1431-1438
ARE ALL PATIENTS WITH IM AT
EQUAL RISK OF GASTRIC
CANCER?
Extensive IM increases the risk of progression to
dysplasia.
Italian Study
• The rate of gastric cancer appeared to increase with increasing
IM extension
Hum Pathol 2006; 37 1489-1497
IM may be considered extensive when it involves at least two locations or when it is moderate
or marked in more than one biopsy specimen
IS IM
REVERSIBLE?
IS IM REVERSIBLE?
H. pylori eradication may slow IM progression.
Hong Kong Study
• 537 pts with IM and H. Pylori randomized to
treatment or placebo
• H Pylori eradication prevented IM progression
• Odds ratio 0.48 (95% CI: 0.32-0.74)
Gut 2004; 53: 1244-1249
IS IM REVERSIBLE?
IM does not appear to regress following H. pylori eradication.
Meta-analysis of 7 studies
• Unlike atrophy, no significant IM regression occurred
following H. Pylori eradication
Helicobacter 2007; 12 Suppl 2: 32-38
Meta-analysis of 12 studies
• Atrophy improved in the body but not antrum
• IM did not improve after eradication
Digestion 2011; 83: 253-260
IS IM REVERSIBLE?
Italian Study
• 6 months of ascorbic acid qOD following H. Pylori eradication
helped reduce IM
Aliment Pharma- col Ther 2000; 14: 1303-1309
Taiwan Study
• IM regressed in 24% of 33 pts following 8 wks of treatment with
celecoxib 200 mg/d after H. Pylori eradication
J Gastroenterology Hepatol 2010; 25: 48-53
What About Surveillance?
What About Surveillance?
Dutch study: Can extension be predicted?
88 patients with previous IM on gastric biopsy
Repeat EGD & blood tests done
Most important predictors of extensive IM:
Family history of gastric cancer
Alcohol use 10ml per day
Marked IM of index biopsy
Pepsinogen I/II ratio < 3.0
Gastrointestinal Endoscopy Vol 70, No.1:2009
PG
II
PG I & II
PG
II
What do Guidelines say?
2006 ASGE Guideline
• Endoscopic surveillance for gastric intestinal
metaplasia has not been extensively studied in the U.S.
and therefore cannot be uniformly recommended
• Patients at increased risk for gastric cancer due to
ethnic background or family history may benefit from
surveillance
• Endoscopic surveillance should incorporate topographic mapping of the entire stomach
Gastrointestinal Endoscopy Volume 63, No. 4 : 2006
2012 European Guideline
• Conventional white light endoscopy cannot
accurately differentiate between benign and
precancerous gastric conditions/lesions
• Magnification chromoendoscopy (MCE) or
narrow-band imaging (NBI) endoscopy with or
without magnification may be offered in these
cases as it improves diagnosis of such lesions
• At least four non-targeted biopsies of the proximal
and distal stomach, on the lesser and greater
curvatures, are needed for adequate assessment of
premalignant gastric conditions
Virchows Arch. 2012 Jan;460(1):19-46. Epub 2011 Dec 22.
2012 European Guideline
• Patients with extensive atrophy and/or extensive IM
should be offered endoscopic surveillance every 3 years
• Further studies are needed however, to accurately estimate the
cost–effectiveness of such an approach
• Patients with mild to moderate atrophy/IM only in
Antrum do not need follow-up
• Sub-typing of IM is not recommended for clinical
practice
Virchows Arch. 2012 Jan;460(1):19-46. Epub 2011 Dec 22.
2012 European Guideline
• COX-2 inhibitors, or the use of dietary supplementation
with antioxidants (ascorbic acid and beta-carotene) are
not endorsed as approaches to decrease the risk of
progression of gastric precancerous lesions
• Neither age, gender, H. pylori virulence factors, or host
genetic variations change these clinical
recommendations
Virchows Arch. 2012 Jan;460(1):19-46. Epub 2011 Dec 22.
2012 European Guideline
Virchows Arch. 2012 Jan;460(1):19-46. Epub 2011 Dec 22.
IM may be considered extensive when it involves at least two locations or when it is moderate
or marked in more than one biopsy specimen
What's new?
OLGA
Operative Link for Gastritis Assessment
OLGIM
Operative link on Gastric Intestinal Metaplasia Assessment.
Gastritis staging systems that arrange histological phenotypes of gastritis
along a scale of progressively increasing gastric cancer risk, from the lowest
(stage 0) to the highest (stage IV).
Thank You
[email protected]