Epidemiological, clinical, and histological characteristics of intestinal metaplasia at the oesophagogastric junction compared to short segments of columnar-lined oesophagus

Intestinal metaplasia at the gastroesophageal junction is associated with gastroesophageal reflux but not with Helicobacter pylori infection

OBJECTIVE

Studies of the etiology of intestinal metaplasia (IM) at a normal appearing gastroesophageal junction (GEJ) are conflicting as associations with both H. Pylori (HP) infection and gastroesophageal reflux has been reported. The aim of this study was to investigate whether IM at the GEJ is associated with gastroesophageal reflux or HP infection.

MATERIAL AND METHODS

Fifty asymptomatic volunteers and 149 patients with reflux symptoms underwent endoscopy with biopsies obtained from the gastric antrum and the squamocolumnar junction (SCJ). All subjects underwent wireless 48 h pH monitoring with the electrode placed immediately above the SCJ and a fecal antigen test for HP infection. Clinical characteristics and the pattern of reflux were compared in subjects with and without IM.

RESULTS

Three asymptomatic volunteers and 35 patients who had clearly irregular SCJs with short extensions of columnar mucosa were excluded from the study. In the remaining 47 asymptomatic volunteers and 114 patients, variables that reached a significance level of 0.1 or less on univariate analyses were used in a binomial regression analysis to assess their relative importance for the finding of IM. IM at the GEJ was significantly associated with abnormal distal esophageal acid exposure (5.5 (1.2-24.6), p = .026), the frequency of reflux episodes/hour (1.5 (1.1-2.2), p = .031), and an endoscopic appearance of the SCJ corresponding to ZAP grade I (4.6 (1.4-15.6), p = .013). There was no association with HP infection.

CONCLUSION

The finding of IM at an endoscopically normal-appearing GEJ is associated with gastroesophageal reflux but not with HP infection.

Unraveling the mystery of the gastroesophageal junction: a pathologist's perspective

The gastroesophageal junction (GEJ), which is defined as the point where the distal esophagus joins the proximal stomach (cardia), is a short anatomic area that is commonly exposed to the injurious effects of GERD and/or Helicobacter pylori infection. These disorders often lead to inflammation and intestinal metaplasia (IM) of this anatomic region. The true gastric cardia is an extremely short segment (<0.4 mm) of mucosa that is typically composed of pure mucous glands, or mixed mucous/oxyntic glands that are histologically indistinguishable from metaplastic mucinous columnar epithelium of the distal esophagus. In patients with GERD, whether physiologic or pathologic, the length of cardia-type epithelium increases and extends proximally above the level of the anatomic GEJ into the distal esophagus. Columnar metaplasia of the distal esophagus represents a squamous to columnar metaplastic reaction that develops from an esophageal stem cell and may pass through an intermediate phase characterized by the presence of a type of epithelium that possesses a mixture of squamous and columnar features, termed multilayered epithelium. In contrast, IM of the gastric cardia represents a columnar to columnar cell metaplastic reaction that develops from a gastric stem cell located in the deep foveolar compartment of the gastric mucosa. Intestinal metaplasia, particularly the incomplete type, is widely believed to represent the precursor lesion upon which dysplasia and cancer arises. The frequency of IM is probably greater in metaplastic columnar epithelium in the esophagus secondary to GERD, than in cases of true gastric carditis secondary to H. pylori, and may be a reason why there is a higher risk of carcinoma in the former compared to the latter. A variety of clinical, endoscopic, histologic, and histochemical methods can be used to distinguish GERD-induced columnar metaplasia of the distal esophagus from H. pylori-induced inflammation of true gastric cardia, and these are outlined in this review, but further controlled studies are needed to critically evaluate these techniques. Further prospective trials are needed to adequately evaluate the different etiologic and pathogenetic mechanisms and, most importantly, the risk of malignancy in these two conditions.

Prevalence of precancerous and other metaplasia in the distal oesophagus and gastro-oesophageal junction

OBJECTIVE

The epidemiology of Barrett's oesophagus (BO) is characterized by divergent results. The aim of this study was to estimate the prevalence of BO and intestinal metaplasia (IM) at the gastro-oesophageal junction (GOJ) in a population-based series of patients referred for first-time gastroscopy.

MATERIAL AND METHODS

Consecutive patients who underwent endoscopy for the first time at endoscopy units exclusively serving defined catchment areas were invited to take part in the study. Biopsies were taken immediately below the GOJ and from the distal oesophagus, and clinical data were recorded.

RESULTS

A total of 769 patients (mean age 53 years, 43% M) were examined. Overall IM prevalence was 14%. BO was noted in 4%. Overall, the prevalence of IM increased by 8% (95% CI 6-10%) per year of age. BO patients were predominately women (69%). Presence of cardia-type mucosa in the cardia increased with age from 25% among the youngest to 59% among the oldest patients. Pancreatic acinar metaplasia (PAM) was found in 18%.

CONCLUSIONS

While BO is not common among Swedish gastroscopy patients, IM and PAM are found in every 7th and 6th patient, respectively. Age-dependent increments in prevalence suggest that not only BO and IM, but also cardia-type mucosa are acquired and/or progressive lesions.

Colonization with cagA-positive Helicobacter pylori strains in intestinal metaplasia of the esophagus and the esophagogastric junction

OBJECTIVES

Recent studies indicate that colonization with cagA-positive Helicobacter pylori (H. pylori) strains may protect against gastroesophageal reflux disease (GERD) and its complications, but the role of cagA in the etiology of Barrett's esophagus has so far been poorly investigated. The pathogenesis of intestinal metaplasia (IM) at an endoscopically normal esophagogastric junction (EGJ) is still unclear, and the role of the H. pylori virulence factor cagA in it has not been investigated. The aim of our study was to assess the relationship between H. pylori and cagA-positive H. pylori in particular and IM at an endoscopically normal EGJ and Barrett's esophagus.

METHODS

Serum samples were obtained from 62 patients without IM, 43 patients with IM at an endoscopically normal junction, and 51 patients with Barrett's esophagus. IM was defined as presence of goblet cells with positive staining with Alcian blue. The prevalence of H. pylori and cagA was investigated by assessment of IgG antibody levels as determined by ELISA.

RESULTS

The overall H. pylori prevalence was 59% (92/156), and the cagA prevalence was 29% (46/156). Although 63% (39/62) of IM negative subjects and 74% (32/43) of those with IM at the junction were H. pylori positive, only 41% (21/51) of Barrett's patients tested positive. The differences between the IM negative and the Barrett's group (p = 0.02) and between IM at the junction and Barrett's were significant (p = 0.002). The relative cagA prevalence (percentage with cagA positivity and H. pylori positivity) was 56% (22/39) in patients who were IM negative, 59% (19/32) in those with IM at the junction, and 24% (5/21) in those with Barrett's. The prevalence of anti-CagA was significantly lower in patients with Barrett's esophagus compared with patients who were IM negative (p = 0.002) and those who had IM at the junction (p < 0.001). No difference in cagA prevalence was seen between the latter groups.

CONCLUSIONS

These findings are in line with the concept that H. pylori and cagA-positive strains in particular protect against the development of Barrett's esophagus. In contrast, our findings do not support the theory that IM at an endoscopically normal esophagogastric junction is associated with H. pylori or cagA-positive strains. IM at the junction and Barrett's esophagus seem to have different etiologies.

Prevalence of Barrett's esophagus in asymptomatic individuals

BACKGROUND & AIMS

The incidence of esophageal adenocarcinoma in the western world has been linked to chronic heartburn, regurgitation, and the development of the premalignant epithelium of Barrett's esophagus (BE). However, up to 40% of esophageal adenocarcinomas occur in patients without prior reflux symptoms. We prospectively screened for the presence of BE in asymptomatic subjects older than 50 years of age undergoing screening sigmoidoscopy for colorectal cancer.

METHODS

Subjects undergoing sigmoidoscopy for colorectal cancer (CRC) screening were invited to undergo upper endoscopy. Exclusion criteria included symptoms of gastroesophageal reflux disease (GERD) more than once a month, use of medications for GERD, or previous endoscopy. BE was classified as long-segment BE (LSBE), short-segment BE (SSBE), and microscopic specialized intestinal metaplasia of the esophagogastric junction (SIM-EGJ).

RESULTS

Of 408 potential study candidates, 110 subjects were screened; 9 were women. The mean (+/-SD) age was 61 +/- 9.3 (range, 50-80) years, most of them (73%) Caucasian. Intestinal metaplasia (IM) extending above the EGJ was detected in 27 (25%) subjects; 8 (7%) had LSBE, and 19 (17%) had SSBE. Patients with BE were no more likely to be obese, consumers of tobacco or alcohol, report a family history of GERD, show association with toxic exposure, or use antacids more than once a month, compared with those without BE.

CONCLUSIONS

BE was detected in 25% of asymptomatic male veterans older than 50 years of age undergoing screening sigmoidoscopy for CRC.