Intestinal metaplasia is the probable common precursor of adenocarcinoma in barrett esophagus and adenocarcinoma of the gastric cardia

Risk factors for Barrett’s oesophagus and oesophageal adenocarcinoma: Results from the FINBAR study

AIM: To investigate risk factors associated with Barrett’s oesophagus and oesophageal adenocarcinoma.

METHODS: This all-Ireland population-based case-control study recruited 224 Barrett’s oesophagus patients, 227 oesophageal adenocarcinoma patients and 260 controls. All participants underwent a structured interview with information obtained about potential lifestyle and environmental risk factors.

RESULTS: Gastro-oesophageal reflux was associated with Barrett’s [OR 12.0 (95% CI 7.64-18.7)] and oesophageal adenocarcinoma [OR 3.48 (95% CI 2.25-5.41)]. Oesophageal adenocarcinoma patients were more likely than controls to be ex- or current smokers [OR 1.72 (95% CI 1.06-2.81) and OR 4.84 (95% CI 2.72-8.61) respectively] and to have a high body mass index [OR 2.69 (95% CI 1.62-4.46)]. No significant associations were observed between these risk factors and Barrett's oesophagus. Fruit but not vegetables were negatively associated with oesophageal adenocarcinoma [OR 0.50 (95% CI 0.30-0.86)].

CONCLUSION: A high body mass index, a diet low in fruit and cigarette smoking may be involved in the progression from Barrett’s oesophagus to oesophageal adenocarcinoma.

Gastric carditis: Is it a histological response to high concentrations of luminal nitric oxide?

During the last decade, inflammation (carditis) and intestinal metaplasia localized to immediately below the human gastro-oesophageal junction have received much attention in relation to the rising incidence of cancer at this site. Since these histological findings are frequently observed even among those who are H pylori-negative, the causative factors for such histologic events at the human gastro-oesophageal junction remain obscure. A series of recent studies have demonstrated that a high level of salivary nitrite is sustained over several hours after the ingestion of a high nitrate meal, and that the nitrite in swallowed saliva is rapidly converted to nitric oxide by an acid catalyzed chemical reaction at the gastro-oesophageal junction. Eventually, a substantial amount of nitric oxide diffuses from the lumen into the adjacent tissue. Therefore, the human gastro-oesophageal junction is likely to be a region of high nitrosative stress. Considering the life-time exposure of the gastro-oesophageal junction to cytotoxic levels of nitric oxide, this may account for the high prevalence of inflammation, intestinal metaplasia, and subsequent development of neoplasia at this site. Although gastric acid, pepsin, and bile acid have been intensively investigated as a cause of adenocarcinoma at the gastro-oesophageal junction and the distal esophagus, nitric oxide and the related nitrosative stress should also be examined.

N/A

N/A

Distinction between short-segment Barrett’s esophageal and cardiac intestinal metaplasia

AIM: To investigate the roles of mucin histochemistry, cytokeratin 7/20 (CK7/20) immunoreactivity, clinical characteristics and endoscopy to distinguish short-segment Barrett’s esophageal (SSBE) from cardiac intestinal metaplasia (CIM).

METHODS: High iron diamine/Alcian blue (HID/AB) mucin-histochemical staining and immunohistochemical staining were used to classify intestinal metaplasia (IM) and to determine CK7/20 immunoreactivity pattern in SSBE and CIM, respectively, and these results were compared with endoscopical diagnosis and the positive rate of gastroesophageal reflux disease (GERD) symptoms and H pylori infection. Long-segment Barrett’s esophageal and IM of gastric antrum were designed as control.

RESULTS: The prevalence of type III IM was significantly higher in SSBE than in CIM (63.33% vs 23.08%, P<0.005). The CK7/20 immunoreactivity in SSBE showed mainly Barrett’s pattern (76.66%), and the GERD symptoms in most cases which showed Barrett’s pattern were positive, whereas H pylori infection was negative. However, the CK7/20 immunoreactivity in CIM was gastric pattern preponderantly (61.54%), but there were 23.08% cases that showed Barrett’s pattern. H pylori infection in all cases which showed gastric pattern was significantly higher than those which showed Barrett’s pattern (63.83% vs 19.30%, P<0.005), whereas the GERD symptoms in gastric pattern were significantly lower than that in Barrett’s pattern (21.28% vs 85.96%, P<0.005).

CONCLUSION: Distinction of SSBE from CIM should not be based on a single method; however, the combination of clinical characteristics, histology, mucin histochemistry, CK7/20 immunoreactivity, and endoscopic biopsy should be applied. Type III IM, presence of GERD symptoms, and Barrett’s CK7/20 immunoreactivity pattern may support the diagnosis of SSBE, whereas non-type III IM, positive H pylori infection, and gastric CK7/20 immunoreactivity pattern may imply CIM.

Gene expression in rats with Barrett’s esophagus and esophageal adenocarcinoma induced by gastroduodenoesophageal reflux

AIM: To study the different gene expression profiles in rats with Barrett’s esophagus (BE) and esophageal adenocarcinoma (EA) induced by gastro-duodeno-esophageal reflux.

METHODS: Esophagoduodenostomy was performed in 8-wk old Sprague-Dawley rats to induce gastro-duodeno-esophageal reflux, and a group of rats that received sham operation served as control. Esophageal epithelial pathological tissues were dissected and frozen in liquid nitrogen immediately. The expression profiles of 4 096 genes in EA and BE tissues were compared to normal esophagus epithelium in normal control (NC) by cDNA microarray.

RESULTS: Four hundred and forty-eight genes in BE were more than three times different from those in NC, including 312 upregulated and 136 downregulated genes. Three hundred and seventy-seven genes in EA were more than three times different from those in NC, including 255 upregulated and 142 downregulated genes. Compared to BE, there were 122 upregulated and 156 downregulated genes in EA. In the present study, the interested genes were those involved in carcinogenesis. Among them, the upregulated genes included cathepsin C, aminopeptidase M, arachidonic acid epoxygenase, tryptophan-2,3-dioxygenase, ubiquitin-conjugating enzyme, cyclic GMP-stimulated phosphodiesterase, tissue inhibitor of metalloproteinase-1, betaine-homocysteine methyltra-nsferase, lysozyme, complement 4b binding protein, complement 9 protein, insulin-like growth factor binding protein, UDP-glucuronosyltransferase, tissue inhibitor of metalloproteinase-3, aldolase B, retinoid X receptor gamma, carboxylesterase and testicular cell adhesion molecule 1. The downregulated genes included glutathione synthetase, lecithin-cholesterol acyltransferase, p55CDC, heart fatty acid binding protein, cell adhesion regulator and endothelial cell selectin ligand.

CONCLUSION: Esophageal epithelium exposed excessively to harmful ingredients of duodenal and gastric reflux may develop into BE and even EA gradually. The gene expression level is different between EA and BE, and may be related to the occurrence and progression of EA.

Microsatellite instability in gastric cancer and pre-cancerous lesions

AIM: To investigate the microsatellite instability (MSI) in cancer and pre-cancerous lesions of the stomach and its mechanisms underlying the development of gastric cancer.

METHODS: Thirty-six gastric cancer samples were obtained from patients undergoing surgery. Forty-one gastric mucosa samples with dysplasia and 51 with intestinal metaplasia (IM) were obtained from patients with chronic gastritis undergoing gastro-endoscopy. Genomic DNA was extracted from the samples. Silver staining single strand conformation polymorphis-polymerize chain reaction (SSCP-PCR) was used to screen MSI markers at 5 loci (Bat-25, Bat-26, D5S346, D17S250, and D2S123) in fresh tissues and formalin-fixed, paraffin-embedded samples and their corresponding normal gastric mucosa.

RESULTS: The abnormal shifting of the single-strand DNA (MSI) was identified in 21 out of 36 (58.3%) gastric cancers. Seven cases showed high-level MSI (two or more loci altered) and 14 showed low-level MSI (one locus altered). Gastric cancer with MSI had a tendency to be located in the distal stomach. MSI was also detected in 11 out of 41 (26.8%) dysplasia samples and in 9 of 51 (17.6%) IM samples respectively. Three cases of dysplasia and one case of IM showed high-level MSI. Eight cases of dysplasia and 8 cases of IM displayed low-level MSI. MIS in IM was found only in moderate or severe-grade IM. No association was detected between MSI and dysplasia grade.

CONCLUSION: Accumulation of MSI in dysplasia and intestinal metaplasia of gastric mucosa may be an early molecular event during gastric carcinogenesis and may contribute to the acquisition of transformed cell phenotype and the development of gastric cancer.

Histochemical studies on intestinal metaplasia adjacent to gastric cardia adenocarcinoma in subjects at high-incidence area in Henan, north China

AIM: To characterize the histochemical type and pattern of intestinal metaplasia (IM) adjacent to gastric cardia adenocarcinoma (GCA) and distal gastric cancer (GC) in Linzhou, Henan Province, China.

METHODS: Alcian-blue-periodic acid Schiff and high iron diamine-Alcian blue histochemical methods were performed on 142 cases of IM, including 49 cases of GCA and 93 cases of GC. All the patients were from Linzhou, Henan Province, China, the highest incidence area for both GCA and squamous cell carcinoma. Radio- or chemotherapy was not applied to these patients before surgery.

RESULTS: The detection rate of IM in tissues adjacent to GCA tissues was 44.9%, which was significantly lower than that in GC tissues (80.64%, P < 0.01). The rates of both incomplete small intestinal and colonic IM types identified by histochemistry in GCA tissues (31.82% and 63.64%, respectively) were significantly higher than those in GC (5.33% and 21.33%, respectively, P < 0.01).

CONCLUSION: IM in GCA and GC should be considered as a separate entity. Further research is needed to evaluate whether neoplastic progression of IM is related to its mucin profile in GCA.

Gene expression in Barrett’s esophagus and reflux esophagitis induced by gastroduodenoesophageal reflux in rats

AIM: To investigate the difference of gene expression profiles between Barrett’s esophagus and reflux eso-phagitis induced by gastroduodenoesophageal reflux in rats.

METHODS: Eight-week-old Sprague-Dawley rats were treated esophagoduodenostomy to produce gastroduode-noesophageal reflux, and another group received sham operation as control. Esophageal epithelial tissues were dissected and frozen in liquid nitrogen immediately for pathology 40 wk after surgery. The expression profiles of 4096 genes in reflux esophagitis and Barrett’s esophagus tissues were compared with normal esophageal epithelium by cDNA microarray.

RESULTS: Four hundred and forty-eight genes in Barrett’s esophagus were more than three times different from those in normal esophageal epithelium, including 312 up-regulated and 136 down-regulated genes. Two hundred and thirty-two genes in RE were more than three times different from those in normal esophageal epithelium, 90 up-regulated and 142 down-regulated genes. Compared to reflux esophagitis, there were 214 up-regulated and 142 down-regulated genes in Barrett’s esophagus.

CONCLUSION: Esophageal epithelium exposed excessively to harmful ingredients of duodenal and gastric reflux can develop esophagitis and Barrett’s esophagus gradually. The gene expression level is different between reflux esophagitis and Barrett’s esophagus and the differentially expressed genes might be related to the occurrence and development of Barrett’s esophagus and the promotion or progression in adenocarcinoma.

Gene expression profiling in Barrett’s esophagus and cardia intestinal metaplasia: A comparative analysis using cDNA microarray

AIM: To study the difference of gene expression profile changes in Barrett’s esophagus (BE) and cardia intestinal metaplasia (CIM) and to screen the novel genes in the early stage by cDNA microarray.

METHODS: cDNA retrotranscribed from an equal amount of mRNA from BE and CIM epithelial tissues was labeled with Cy3 and Cy5 fluorescence as probes. The mixed probe was hybridized with three pieces of BiostarH-40 s double dot human whole gene chip. The chips were scanned with a ScanArray 4000. The acquired images were analyzed using GenePix Pro 3.0 software.

RESULTS: A total of 141 genes were screened out that exhibited different expression in all three chips. There were 74 upregulated and 67 downregulated genes in gene expression profiles of BE which were two times of that in CIM.

CONCLUSION: There is a difference in gene expression level between BE and CIM epithelia. These 141 genes probably relate to the occurrence and development of BE and the progression to adenocarcinoma.

Barrett’s esophagus and its correlation with gastroesophageal reflux in Chinese

AIM: To study the prevalence of Barrett’s esophagus in Chinese and its correlation with gastroesophageal reflux.

METHODS: This study was carried out in a large prospective series of 391 patients who had undergone upper endoscopy. The patients were divided into 3 groups according to the position of squamocolumnar junction (SCJ). Reflux esophagitis (RE) and its degree were recorded. Intestinal metaplasia (IM) in biopsy specimen was typed according to histochemistry and HE and alcian blue (pH2.5) staining separately. Results correlating with clinical, endoscopic, and pathological data were analysed.

RESULTS: The prevalence of IM endoscopically appearing Long-segment Barrett’s Esophagus (LSBE) was 26.53%, Short-segment Barrett’s Esophagus (SSBE) was 33.85% and gastroesophageal junction (GEJ) was 34.00%. IM increased with age of above 40 years old and no difference was found between male and female. Twelve were diagnosed as dysplasia (7 low -grade, 5 high-grade), 16 were diagnosed as cardiac adenocarcinoma and 1 as esophageal adenocarcinoma. The more far away the SCJ moved upward above GEJ, the higher the prevalence and the more severe the RE were.

CONCLUSION: There was no difference of the prevalence of IM in different places of SCJ, and IM increased with age of above 40 years old. It is important to pay attention to dysplasia in the distal esophagus and gastro-esophageal junction, and adenocarcinoma is more common in cardia than in esophagus. BE is a consequence of gastroesophageal reflux disease.

Relationship of gastric Helicobacter pylori infection to Barrett’s esophagus and gastro-esophageal reflux disease in Chinese

AIM: To evaluate the relationship of Helicobacter pylori infection to reflux esophagitis (RE), Barrett’s esophagus (BE) and gastric intestinal metaplasia (IM).

METHODS: RE, BE and gastric IM were determined by upper endoscopy. Patients were divided into 2 groups; those with squamocolumnar junction (SCJ) beyond gastroesophageal junction (GEJ) ≥ 3 cm (group A), and those with SCJ beyond GEJ < 3 cm (group B). Biopsy specimens were obtained endoscopically from just below the SCJ, gastric antrum along the greater and lesser curvature. Pathological changes and H pylori infection were determined by HE staining, Alcian blue staining and Giemsa staining.

RESULTS: The prevalence of H pylori infection was 46.93%. There was no difference in the prevalence between males and females. The prevalence of H pylori infection decreased stepwise significantly from RE grade I to III. There was no difference in the prevalence between the two groups, and between long-segment and short-segment BE. In distal stomach, prevalence of H pylori infection was significantly higher in patients with IM than those without IM.

CONCLUSION: There is a protective role of H pylori infection to GERD. There may be no relationship between H pylori infection of stomach and BE. H pylori infection is associated with the development of IM in the distal stomach.

Differences in proximal (cardia) versus distal (antral) gastric carcinogenesis via retinoblastoma pathway

AIM: Disruption of cell cycle regulation is a critical event in carcinogenesis, and alteration of the retinoblastoma (pRb) tumour suppressor pathway is frequent. The aim of this study was to compare alterations in this pathway in proximal and distal gastric carcinogenesis in an effort to explain the observed striking epidemiological differences.

METHODS: Immunohistochemistry was performed to investigate expression of p16 and pRb in the following groups of both proximal (cardia) and distal (antral) tissue samples: (a) biopsies showing normal mucosa, (b) biopsies showing intestinal metaplasia and, (c) gastric cancer resection specimens including uninvolved mucosa and tumour.

RESULTS: In the antrum there were highly significant trends for increased p16 expression with concomitant (and in the group of carcinomas inversely proportional) decreased pRb expression from normal mucosa to intestinal metaplasia to uninvolved mucosa (from cancer resections) to carcinoma. In the cardia, there were no differences in p16 expression between the various types of tissue samples whereas pRb expression was higher in normal mucosa compared with intestinal metaplasia and tissue from cancer resections.

CONCLUSION: Alterations in the pRb pathway appear to play a more significant role in distal gastric carcinogenesis. It may be an early event in the former location since the trend towards p16 overexpression with concomitant pRb underexpression was seen as early as between normal mucosa and intestinal metaplasia. Importantly, the marked differences in expression of pRb and p16 between the cardia and antrum strongly support the hypothesis that tumours of the two locations are genetically different which may account for some of the observed epidemiological differences.

Proliferation/apoptosis and expression of P53 and Bcl-2 in gastric carcinoma

AIM

To study proliferation and apoptosis in gastric carcinoma (GC) and precancerous lesions and expression of their regulating genes.

METHODS

Total 24 cases of GC, 14 dysplasia (DP), 24 chronic gastritis (10 superfical gastritis, SG, 14 atrophic gastritis, AG) and 32 intestinal metaplasia (IM) were studied by histopathological, immunohistochemical techniques with Ki67, P53 and Bcl-2 antibodies, and by TUNEL for apoptosis. Proliferation index (PI), apoptosis index (AI), apoptosis/ proliferation ratio, apoptosis degree and positive percent of P53 and Bcl-2 were counted.

RESULTS

The PI of GC, DP, IM, AG were 12.4±6.8%, 6.4±4.2%, 6.6±3.4%, 3.8±2.9% respectively. There was a significant difference between SG and GC, DP, IM, and AG (P<0.01). The AI of GC, DP, IM, and AG was 2.4±1.4%, 2.6±1.6%, 3.1±1.2% and 3.8±2.0% respectively. The apoptosis degree of AG was the highest, and significantly higher than that of GC, DP, and IM (P<0.01). There was no significantly different among GC, moderate and severe DP (P>0.05). Mucosa in AG showed excessive apoptosis, however the apoptosis degree in severe DP and early gastric carcinoma was about 1/3 of SG, and in advanced GC was its 1/5. The positive percentages of P53 in GC, DP, IM and AG were 25.0%, 14.3%, 3.1% and 0% respectively. The positive rate of Bcl-2 was 58.3%, 42.8%, 9.4% and 7.1% respectively. There was a significant correlation beween P53 and Bcl-2.

CONCLUSION

Mutated P53 gene and Bcl-2 apoptosis regulating gene not only express in GC, also partly express in DP, IM, and in those precancerous lesions in which gastric carcinogenesis may have been initialized. The imbalance between proliferation and apoptosis is manifestation of the gene mutations on the cytodynamics. The DP and IM may be the different stages in gastric carcinogenesis.