Background: Helicobacter pylori infection has been linked with the development of gastric adenocarcinoma and its precursor lesion, intestinal metaplasia (IM). The presence of gastric IM is not associated with symptoms, which makes identification of individuals with this lesion difficult. It is not clear whether eradication of H. pylori infection leads to reversal of gastric IM or the potential decrease in the risk of cancer in these patients.
Goals: The purpose of this pilot study was to define the prevalence of gastric IM in a population at high risk for gastric cancer (Southwestern Hispanics), examine the ability of noninvasive testing to identify individuals with the lesion, and determine whether eradication of H. pylori infection reverses gastric IM in this population.
Study: Subjects from the Tucson metropolitan area were recruited, and baseline data, including the presence of upper gastrointestinal (UGI) symptoms, urinary sodium, and serum pepsinogen levels, were obtained. Upper endoscopy was performed and six gastric biopsies from specific anatomic sites were obtained, followed by methylene blue staining with targeted biopsies from blue-stained mucosa. Biopsies were evaluated for the presence of H. pylori infection and gastric IM. A subset of patients with gastric IM were treated to eradicate H. pylori infection. Follow-up exams with methylene blue staining, including biopsies for histology and rapid urease testing, were performed for up to 48 months.
Results: There were 84 subjects with a mean age of 53.0 years; 24 (29%) had gastric IM and 65 (77%) had H. pylori. There was no significant association between gastric IM and age, gender, UGI symptoms, H. pylori, or urine sodium. There was an association identified between gastric IM and a decreased pepsinogen I:II ratio (p = 0.03). Of the 11 individuals with gastric IM treated for H. pylori infection, 9 had successful therapy and underwent at least 2 follow-up examinations. The mean length of follow-up was 3.3 years. Eight of the nine (89%) had gastric IM identified histologically at the final endoscopic exam.
Conclusions: H. pylori infection and gastric IM are frequent findings in Southwestern Hispanics, a high-risk population for gastric cancer. Noninvasive testing is not clinically useful in distinguishing individuals within this group who harbor gastric IM. Although eradication of H. pylori infection may lead to a decrease in the amount of gastric IM in some individuals, the lesion may be detected in the majority of individuals after more than 3 years of follow-up. These data suggest that therapy for H. pylori may not eliminate the risk of gastric cancer once IM has developed.