P0997 - The Type of Intestinal Metaplasia Is Strongly Related to the Underlying Condition of the Gastric Mucosa

Cristian Robiou, MD, Kevin O. Turner, DO, Anuradha Singhal, MD, Robert M. Genta, MD, FACG
Inform Diagnostics, Irving, TX

Introduction: Current evidence indicates that gastric intestinal metaplasia (IM) of the incomplete (”colonic”) type carries a greater gastric cancer risk than complete (“small intestinal”) IM. Recent AGA guidelines recommend including the IM type in pathology reports. Since the only known risk factor for gastric cancer (GC) is H. pylori infection and its sequelae (chronic and multifocal atrophic gastritis), we hypothesized that if incomplete IM is a more reliable harbinger of GC than its complete counterpart, it would be more prevalent in backgrounds of H. pylori-related gastritis than in other gastritides.

Methods: IDEA (Inform Diagnostics Electronic Archives) is a national clinicopathologic database of patients who had gastrointestinal biopsies diagnosed at Inform Diagnostics. We extracted all patients with gastric biopsies (2008-2020) and selected those with the following diagnoses: normal stomach (Normal); chronic inactive gastritis (CIG); H. pylori chronic active gastritis (Hp-CAG); multifocal atrophic gastritis without H. pylori infection (MAG); autoimmune atrophic gastritis (AIG); reactive gastropathy (RG); and gastric adenocarcinoma (GC). After extracting random samples of subjects with one of these seven gastric phenotypes and IM, we reviewed all original slides and determined location, extension, and type of IM.

Results: There were 1,673,233 subjects with gastric biopsies; 156,969 (9.4%) had IM. The prevalence of IM by gastritis type was: Normal = 2.7%; RG = 4.5%; Hp-CAG = 17.1; CIG = 27.5%; MAG = 74%; AIG= 91.6%; and GC = 17.6%. Table 1 depicts the prevalence of incomplete IM in these conditions. Not surprisingly, the greatest prevalence of incomplete IM was found in patients with GC (50.9%), followed by those with MAG (32.8%), a sequela of long-standing H. pylori gastritis and the background most likely to predispose to GC, and those with active H. pylori gastritis (19.0%). The lowest prevalence of incomplete IM (1.7%) was found in subjects with an otherwise normal stomach and in those with RG (5.2%); neither of these situations is a known risk factor for GC.

Discussion: Incomplete IM rarely occurs in the background of gastritides not associated with high risk for GC. In contrast, MAG and active H. pylori infection are fertile backgrounds for the incomplete type. These findings further support the predictive value of incomplete IM for GC risk and emphasize the importance of stating the type of IM in gastric biopsy reports, ideally adding it to the OLGA or OLGIM stage.



Disclosures:


Cristian Robiou, MD, Kevin O. Turner, DO, Anuradha Singhal, MD, Robert M. Genta, MD, FACG. P0997 - The Type of Intestinal Metaplasia Is Strongly Related to the Underlying Condition of the Gastric Mucosa, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.