Increased prevalence of precancerous changes in relatives of gastric cancer patients: critical role of H. pylori

Asia-Pacific consensus guidelines on gastric cancer prevention

BACKGROUND AND AIM

Gastric cancer is a major health burden in the Asia-Pacific region but consensus on prevention strategies has been lacking. We aimed to critically evaluate strategies for preventing gastric cancer.

METHODS

A multidisciplinary group developed consensus statements using a Delphi approach. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded.

RESULTS

Helicobacter pylori infection is a necessary but not sufficient causal factor for non-cardia gastric adenocarcinoma. A high intake of salt is strongly associated with gastric cancer. Fresh fruits and vegetables are protective but the use of vitamins and other dietary supplements does not prevent gastric cancer. Host-bacterial interaction in H. pylori infection results in different patterns of gastritis and differences in gastric acid secretion which determine disease outcome. A positive family history of gastric cancer is an important risk factor. Low serum pepsinogens reflect gastric atrophy and may be useful as a marker to identify populations at high risk for gastric cancer. H. pylori screening and treatment is a recommended gastric cancer risk reduction strategy in high-risk populations. H. pylori screening and treatment is most effective before atrophic gastritis has developed. It does not exclude the existing practice of gastric cancer surveillance in high-risk populations. In populations at low risk for gastric cancer, H. pylori screening is not recommended. First-line treatment of H. pylori infection should be in accordance with national treatment guidelines.

CONCLUSION

A strategy of H. pylori screening and eradication in high-risk populations will probably reduce gastric cancer incidence, and based on current evidence is recommended by consensus.

Serum pepsinogen I, pepsinogen II, and gastrin 17 in relatives of gastric cancer patients: comparative study with type and severity of gastritis

BACKGROUND & AIMS

First-degree relatives of gastric cancer patients are at risk for developing precancerous conditions. The aim of this study was to investigate the potential of biomarkers pepsinogen I (PGI), pepsinogen II (PGII), their ratio (PG I:II), as well as gastrin 17 for screening of precancerous conditions and corpus predominant gastritis.

METHODS

First-degree relatives of gastric cancer patients underwent endoscopy. Three biopsy specimens from the antrum and 3 from the corpus were evaluated according to the Sydney classification. Serum was taken for the measurement of fasting PGI, PGII, and gastrin 17 by enzyme-linked immunosorbent assay kits.

RESULTS

A total of 481 patients were examined (age, 47.8 +/- 6.7 y). With the extension of gastritis, PGII was increased up to 2.5 times (6.6 +/- 2.8 microg/mL in normal mucosa, 9.5 +/- 6.7 microg/mL in antral gastritis, and 16.9 +/- 12.4 microg/mL in corpus-predominant gastritis; P < .01), PGI increased slightly (88.3 +/- 29.4 microg/mL in normal mucosa and 111.2 +/- 71.4 microg/mL in corpus-predominant gastritis), and gastrin 17 was increased substantially in corpus-predominant gastritis (15.3 +/- 19.5 pmol/mL vs 3.8 +/- 5.7 pmol/mL in normal mucosa). By using a cut-off value of 7.5 microg/mL for PGII, any type of gastritis from normal mucosa can be diagnosed with a sensitivity and specificity of 80%. The sensitivity and specificity of the PG I:II ratio (< or =3) and gastrin 17 (>17 pmol/mL) together were 9.4% and 99% for screening corpus-predominant gastritis and 14.8% and 97.8%, respectively, for screening intestinal metaplasia in the corpus.

CONCLUSIONS

PGII is a suitable marker for screening any gastritis from normal mucosa, but neither PGI, the PG I:II ratio, gastrin 17, nor their combination were able to select those with precancerous conditions and corpus-predominant gastritis among the first-degree relatives of gastric cancer patients.

Treatment of Helicobacter pylori and prevention of gastric cancer

Gastric cancer is the second commonest fatal malignancy in the world with a high incidence in China. Helicobacter pylori infection is an important factor in the pathogenesis of gastric cancer. Epidemiological studies have shown a strong causal relationship between H. pylori infection and gastric cancer. Animal studies also show that eradication of H. pylori infection, especially at the early stage, is effective in preventing H. pylori-related gastric carcinogenesis. H. pylori eradication leads to regression and prevents the progression of gastric precancerous lesions, but only in a minority of cases. H. pylori eradication appears to be the most promising approach in gastric cancer prevention. The current available data in human studies showed that H. pylori eradication can reduce the risk of developing gastric cancer and this strategy is more useful in patients without atrophic gastritis or intestinal metaplasia. A longer follow-up and additional studies are needed for better understanding this issue.

Critical role of Helicobacter pylori in the pattern of gastritis and carditis in residents of an area with high prevalence of gastric cardia cancer

We have investigated the role of Helicobacter pylori infection and of other risk factors of gastritis and carditis in residents of a high-risk area for gastric cardia cancer. During a national population-based endoscopic survey, 508 randomly-selected participants aged > or =40 were enrolled. Mucosal biopsies were obtained from six standard sites. Polymorphonuclear (PMN) and mononuclear (MN) infiltration and combined inflammatory scores (CIS) for chronic gastritis and H.pylori were assessed. Relationships of H.pylori and reflux esophagitis with these variables were calculated for cardia and non-cardia subsites. Both PMN and MN infiltrations correlated strongly with H.pylori infection. For PMN the relationship was maximum for the antrum (odds ratio (OR) = 9.4 (5.2-17.1)) and minimum for the gastric body (OR = 1.7 (1.0-2.9)). There was a significant relationship between carditis and H.pylori (OR = 2.8 (1.7-4.9)). A similar relationship was obtained for MN infiltration. In 56% of subjects the mean MN score for the corpus was equal to or greater than that for the antrum. For 59% of subjects the MN score for the cardia was greater than or equal to the antral score. Use of logistic regression revealed that was the main risk factor for gastritis and carditis in all sites. There was an inverse relationship between reflux esophagitis and carditis. H.pylori is the main risk factor for gastritis for all sites of the stomach including the cardia; but this relationship is stronger for the antrum and cardia than for the body. Continuous cardia inflammation may contribute to the high incidence of gastric cardia cancer in this region.

Higher gastric mucin secretion and lower gastric acid output in first-degree relatives of gastric cancer patients

BACKGROUND

Patients infected by Helicobacter pylori who have first-degree relatives with gastric cancer have an 8-fold increased risk of developing gastric cancer themselves. Mucins are high-molecular-weight glycoproteins that play a cardinal role in the protective mechanism of the gastric epithelium.

AIM

To study gastric acid and mucin secretion in dyspeptic patients with and without a family history of gastric cancer and H. pylori infection.

MATERIALS AND METHODS

Twenty-six dyspeptic patients underwent esophago-gastro-duodenoscopy, gastric biopsies, and acid and mucin secretory tests. The sample was divided by family history of gastric cancer and H. pylori status.

RESULTS

Patients who were infected by H. pylori had a significantly higher degree of inflammation than those who were not. H. pylori-positive patients with a positive family history had a lower basal and maximal gastric acid output than infected patients with no family history and noninfected controls, and a higher basal and maximal mucin output than infected patients with no family history. MUC5AC was the major mucin species expressed in gastric juice.

CONCLUSIONS

In patients with relatives with gastric cancer, H. pylori infection is associated with a more severe inflammatory reaction consisting of decreased gastric acid secretion and increased mucin secretion.

Comparison between serology and histology in the diagnosis of advanced gastric body atrophy: a study in a Dutch primary community

GOALS

To assess serologically diagnosed gastric body atrophy (GBA) by histology in a sample of the general population.

BACKGROUND

GBA is a precursor lesion in gastric cancer. Data on GBA in a primary health care community in the Netherlands have not been reported.

STUDY

Thirty-four subjects of 997 consecutive adults from a Dutch family practice had serologic GBA, according to hypergastrinemia (>100 ng/L), hypopepsinogenemia A (<17 microg/L), and a low pepsinogen A/C ratio (<1.6). Two years later, 25 subjects of this group, agreed in serologic retesting and gastroscopy with biopsies for histologic assessment according to the Sydney system.

RESULTS

At serologic retesting, 20 of 25 subjects again fulfilled the serologic criteria of GBA. Histologic examination of the corpus biopsies showed advanced GBA in 18 subjects (75%) of 24 (1 subject had no corpus biopsies) and 17 of 19 (89%) subjects with repeated positive serology. After disclosure of serology results, reexamination of the biopsies revealed GBA also in the 2 patients with initially insufficient evidence of GBA, giving a concordance of 100% (19/19). One subject with normal serum gastrin at retesting had both antral and body atrophy giving a concordance between serologic and histologic GBA of 95% (19/20). No adenomatous polyps, tumors, or dysplastic alterations were found.

CONCLUSIONS

Identification by serology of asymptomatic patients with advanced GBA in primary care is adequately possible and useful in selecting for endoscopy.

Review article: Helicobacter pylori eradication for the prevention of gastric cancer

BACKGROUND

Gastric cancer is the fourth most common cancer and second leading cause of cancer-related death worldwide. A clear association between Helicobacter pylori infection and gastric cancer was established years ago. H. pylori eradication may be an effective approach to decrease morbidity and mortality of gastric cancer.

AIM

To discuss current evidence of H. pylori eradication for prevention of gastric cancer.

RESULTS

Recent studies have shown that the association between H. pylori and gastric cancer has probably been underestimated. This may have resulted from negative H. pylori status in subjects after loss of colonisation in the presence of atrophic gastritis and intestinal metaplasia, prior to development of gastric cancer. The recognition of the central role of H. pylori in carcinogenesis has increased expectations of gastric cancer prevention by H. pylori eradication. A primary preventive effect of eradication in subjects with H. pylori-induced gastritis has been demonstrated. However, a secondary preventive effect in patients with pre-malignant gastric lesions is still controversial, especially in patients with intestinal metaplasia and dysplasia.

CONCLUSIONS

At this moment, H. pylori eradication seems indicated at the earliest stage of gastric carcinogenesis. This treatment policy requires confirmation; results of ongoing randomised controlled trials are therefore eagerly awaited.

Assessing the severity of atrophic gastritis

Atrophic gastritis, mainly the consequence of long-standing Helicobacter pylori infection, is linked to the development of gastric cancer. In the case of atrophic gastritis, severity may be mainly related to the lifetime risk of the single patient to develop gastric cancer, mostly in relation to the degree and extension of mucosal damage. As atrophic gastritis is the result of complex multifactorial interactions, the application of artificial neural networks is promising and may be useful for the identification of those patients with atrophic gastritis at higher risk for gastric malignancies. The experience of application of artificial neural networks in atrophic gastritis is still scarce. The available data suggest that these systems may contribute to identify patients with corporal metaplastic atrophic gastritis and to optimize bioptic sampling during gastroscopy.

Epidemiology of premalignant gastric lesions: implications for the development of screening and surveillance strategies

Gastric cancer is one of the most common cancers worldwide; however, gastric cancer incidence varies greatly between different geographic areas. As gastric cancer is usually diagnosed at an advanced stage, the disease causes considerable morbidity and mortality. To detect gastric carcinomas at an early and curable stage, screening and surveillance seem necessary. Premalignant gastric lesions are well known risk factors for the development of intestinal type gastric adenocarcinomas. In a multistep cascade, chronic Helicobacter pylori-induced gastritis progresses through premalignant stages of atrophic gastritis, intestinal metaplasia and dysplasia, to eventually gastric cancer. Therefore, this cascade may provide a basis for early detection and treatment of gastric cancer. Epidemiology of gastric cancer and premalignant gastric lesions should guide the development of screening and surveillance strategies, as distinct approaches are required in countries with low and high gastric cancer incidences.

Sporadic gastric cancer; a complex interaction of genetic and environmental risk factors

Sporadic gastric cancer usually arises against a background of sequential mucosal changes. H. pylori superficial gastritis progresses to atrophy and intestinal metaplasia and then to dysplasia and cancer. A variety of environmental and host genetic factors influence this process and act at different stages in the pathway. Many different combinations of these risk factors may lead to cancer. Interactions also occur between environmental and genetic factors to increase or decrease their ability to influence the precancerous process. Sporadic gastric cancer is thus the consequence of complex combinations and interactions between many environmental and genetic factors.

Prevalence and prognosis of gastric cancer detected by screening in a large Japanese population: data from a single institute over 30 years

BACKGROUND AND AIM

In Japan, screening examination with photofluorography is widely performed to reduce the mortality due to gastric cancer. The possibility of a future decline in gastric cancer cases and changes in its characteristics is suggested. The aim of this study was to examine the usefulness of direct radiology as a general health screening technique and the historical changes of gastric cancer in Japan.

METHODS

This study involved 936 patients with gastric cancer whose carcinomas were detected by direct radiology as part of a general health screening at the Aichi Prefectural Center for Health Care from 1970 to 2000. We studied the prevalence of gastric carcinoma, its prognosis, differences between the two histological types of carcinoma and historical changes.

RESULTS

The age-adjusted cancer detection rate slightly decreased. Comparing two histological types, diffuse-type carcinoma cases relatively increased. Intestinal-type carcinomas increased in the lower portion of the stomach, whereas diffuse-type increased in the upper portion. The 5-year survival rate was 92.7% for intestinal-type carcinoma and 84.8% for diffuse-type. Diffuse-type carcinomas were further progressed than intestinal-type when detected by direct radiology; however, detection of diffuse-type improved, so the percentage of early gastric cancer of diffuse type significantly increased, and the survival rate significantly improved, from 70.4% to 90.5%.

CONCLUSION

The prevalence of gastric cancer has been decreasing, but the proportion of diffuse-type carcinoma localized in the upper portion of the stomach has been increasing in Japan.

Infection à Helicobacter pylori chez la personne âgée

PURPOSES

Helicobacter pylori (H. pylori) infection is a chronic gastric Gram-negative infection that increases with age. Acquired in childhood, H. pylori infection may induce a whole cascade of events leading to gastric pathologies such as peptic ulcer diseases, gastric precancerous lesions, and gastric lymphomas (MALT). The characteristics of the diagnosis and the treatment of this infection in geriatrics are thus particularly important to take into account.

MAIN POINTS

1) The incidence of gastric and duodenal ulcers and their bleeding complications is increasing in old-aged populations. Clinical signs such as anorexia and malnutrition are proven to be excellent indications for endoscopic explorations in the elderly. NSAID-use and H. pylori infection were shown to be independent and unrelated risk factors for peptic ulcer and gastroduodenal bleeding in elderly subjects; 2) H. pylori infection diagnosis is difficult to realize in the very old population, and the urea breath test is the test which obtain the best performances in this population.

PERSPECTIVES

Recent work showed the part played by H. pylori chronic infection in gastric aging and in appetite regulation in the elderly. Research tasks should be continued in this field in order to better understand the part played by this chronic infection in gastric aging and in other pathologies (i.e. neurological or cardiovascular diseases) in this population.

Treatment and dosing of Helicobacter pylori infection: when pharmacology meets clinic

Helicobacter pylori infection is a major cause of diseases located in the upper gastrointestinal tract. Successful eradication of the bacteria may improve H. pylori-related symptomatic complaints in functional dyspepsia, cure peptic ulcer disease and prevent gastric cancer. As vaccines are not available, the search for the optimal drug regimen has dominated the last decade. Today, most countries prefer a 7- to 10-day regimen containing a proton pump inhibitor, clarithromycin and amoxicillin as first-line treatment. An alternative (or second-line) treatment contains a proton pump inhibitor, bismuth, tetracycline and metronidazole. This review also highlights the impact of new drugs, new drug combinations, and their optimal dosing required to maximise clinical outcome.

A functional polymorphism of toll-like receptor 4 gene increases risk of gastric carcinoma and its precursors

BACKGROUND AND AIMS

TLR4 is a cell-surface signaling receptor involved in the recognition and host response to Helicobacter pylori. The TLR4+896A>G polymorphism linked with impaired reactivity to bacterial lipopolysaccharide may play a role in gastric carcinogenesis.

METHODS

We assessed associations with premalignant gastric changes in 149 relatives of gastric cancer patients, including 45 with hypochlorhydria and gastric atrophy. We also genotyped 2 independent Caucasian population-based case-control studies of upper gastrointestinal tract cancer, initially in 312 noncardia gastric carcinoma cases and 419 controls and then in 184 noncardia gastric carcinomas, 123 cardia carcinomas, 159 esophageal cancers, and 211 frequency-matched controls. Odds ratios were computed from logistic models and adjusted for potential confounding factors.

RESULTS

TLR4+896G carriers had an 11-fold (95% confidence interval [CI], 2.5-48) increased odds ratio (OR) for hypochlorhydria; the polymorphism was unassociated with gastric acid output in the absence of H pylori infection. Carriers also had significantly more severe gastric atrophy and inflammation. Seventeen percent of gastric carcinoma patients in the initial study and 15% of the noncardia gastric carcinoma patients in the replication study had 1 or 2 TLR4 variant alleles vs 8% of both control populations (combined OR = 2.3; 95% CI = 1.6-3.4). In contrast, prevalence of TLR4+896G was not significantly increased in esophageal squamous cell (2%, OR = 0.2) or adenocarcinoma (9%, OR = 1.4) or gastric cardia carcinoma (11%, OR = 1.4).

CONCLUSIONS

Our data suggest that the TLR4+896A>G polymorphism is a risk factor for noncardia gastric carcinoma and its precursors. The findings underscore the role of the host innate immune response in outcome of H pylori infection.

[Gastric adenocarcinoma: approach to a complex biological reality]

The authors review the complex biological reality of gastric adenocarcinoma from several viewpoints. It is a neoplasm histologically expressed as a dual process (intestinal and diffuse types) with a broad cytological diversity. From an epidemiological point of view, it behaves as an entity with a deep geographical asymmetry and a changing incidence, currently decreasing. There is a multifactorial etiology with a combination of genetic, infectious (H. pylori), nutritional and environmental factors. It might have a multiphasic gestation from precancerous lesions, though not always following a lineal sequence. We only know fragmentary portions of its pathogenesis whose common denominator is a potentially mutagenic mitogenic activation of the epithelial cells implicated. A good knowledge of this complex biological reality will allow the identification of better markers for an early diagnosis as well as vulnerable etiopathogenetic points for a useful prevention and therapy.

Helicobacter pylori eradication for gastric cancer prevention

Gastric cancer is the second most common fatal malignancy in the world. Its incidence is high in East Asia. Helicobacter pylori infection is an important factor in the pathogenesis of gastric cancer. Epidemiological studies have established a strong causal relationship between H. pylori infection and gastric cancer. H. pylori eradication is therefore likely to be one of the most promising approaches to gastric cancer prevention. Animal studies have shown that eradication of H. pylori infection, especially at the early stage, is effective in preventing H. pylori-related gastric carcinogenesis. However, the available data from human studies show that H. pylori eradication does not completely prevent gastric cancer and that it might be useful only in patients without atrophic gastritis or intestinal metaplasia at baseline. Longer follow-up and additional studies are needed to clarify this issue.

Additional bedtime H2-receptor antagonist for the control of nocturnal gastric acid breakthrough: a Cochrane systematic review

OBJECTIVES

To assess the effectiveness and safety of additional bedtime H(2)-receptor antagonists (H(2)RAs) in suppressing nocturnal gastric acid breakthrough (NAB) via a systematic review.

METHODS

Eligible trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 2, 2004), MEDLINE (January 1966-June 2004), EMBASE (January 1980-June 2004) and CINAHL (January 1982-June 2004). Additional hand-searching was conducted on the proceedings of correlated conferences, eight important Chinese journals and references of all included trials. All randomized controlled trials evaluating H(2)RAs for the control of NAB were eligible for inclusion. The systematic review was conducted using methods recommended by The Cochrane Collaboration.

RESULTS

Only two randomized crossover studies, comprising 32 participants, met the inclusion criteria. Because the design, dosage and duration of the treatments were different between the studies, it was not possible to conduct meta-analysis. There were no consistent conclusions found between the two included studies in evaluating H(2)RAs for the control of NAB.

CONCLUSIONS

No implications for practice at this stage can be concluded. Appropriately designed large-scale randomized controlled trials with long-term follow up are needed to determine the effects of additional bedtime H(2)RAs in suppressing NAB.

Corpus-predominant gastritis as a risk factor for false-negative 13C-urea breath test results

BACKGROUND

Urea breath test sensitivity seems affected by increased intragastric acidity during therapy with antisecretory drugs. Intragastric pH is increased in patients with corpus gastritis with/without atrophy.

AIM

To test the hypothesis that urea breath test results may also be affected by this gastritis phenotype.

METHODS

123 untreated patients underwent gastroscopy plus biopsies and intragastric pH measurement. The study included 82 endoscopically proven Helicobacter pylori-positive patients who were offered urea breath test with an acidic meal. Histological findings, urea breath test results and intragastric pH were compared in 66 of the subjects.

RESULTS

21 of 66 (31.8%) patients had a false-negative urea breath test. In these patients corpus-predominant gastritis (85.7% vs. 37.7%; P = 0.0004) and fundic atrophy (66.6% vs. 17.7%; P = 0.0001) were more frequent than in patients with true-positive urea breath test. Intragastric pH was higher in false-negative patients (mean 6.3 vs. 4.4; P = 0.001). In a multivariate analysis, the only risk factor for a false-negative urea breath test was the presence of corpus-predominant gastritis (OR = 5.6; 95% CI: 1.1-27). There was a negative correlation between the intragastric pH and the delta over baseline values (r = -0.378; P = 0.0023).

CONCLUSIONS

Our results support the hypothesis that the pattern of gastritis can affect the sensitivity of urea breath test, and suggest that patients with corpus-predominant gastritis have a high risk of false-negative urea breath test results.

Gastroduodenal diseases of childhood

PURPOSE OF REVIEW

This paper will review new developments in the etiology and management of gastric and duodenal diseases affecting children.

RECENT FINDINGS

Despite dropping prevalence rates in developed nations, most new Helicobacter pylori infections are primarily acquired during childhood. Resistance to standard triple therapy and falling eradication rates are increasing problems for clinicians, necessitating the study of alternative treatment strategies. Eosinophilic diseases of the gastrointestinal tract are being increasingly recognized. Although population-based epidemiology and the natural history of eosinophilic diseases are not yet fully characterized, biologic therapies are in development for the treatment of these chronic, often refractory, conditions. A recent US National Institutes of Health celiac disease consensus conference suggested that infants' diet constituents and timing of solid food introduction are potential environmental influences in the development of celiac disease.

SUMMARY

New methods of diagnosis and treatment are greatly impacting care of pediatric patients with gastric and duodenal diseases. Less invasive but highly accurate tools for diagnosis are becoming better validated. Early diagnosis and effective intervention in most gastroduodenal disorders of childhood can alter natural history and improve overall quality of life.

Regional differences in the recovery of gastric acid secretion after Helicobacter pylori eradication: evaluations with Congo red chromoendoscopy

BACKGROUND

Gastric-acid secretion is reduced in Helicobacter pylori-positive fundic atrophic gastritis, but it is restored by the eradication. However, changes in the distribution of acid-secreting mucosa after the eradication remain unknown. Congo red chromoendoscopy is capable of visualizing the acid-secreting fundic mucosa.

OBJECTIVE

To evaluate the effect of H pylori eradication on the distribution of acid-secreting mucosa in the fundus by using Congo red chromoendoscopy.

DESIGN

An assessment of the distribution of acid-secreting mucosa by the visualized images of Congo red chromoendoscopy and a histologic evaluation of biopsy specimens were performed before and 1 and 7 months after the eradication. The areas of the acid-secreting mucosa in the lesser and greater curvatures of the fundus were evaluated semiquantitatively.

PATIENTS

Thirty-seven patients positive for H pylori and with fundic atrophic gastritis.

RESULTS

The area of the acid-secreting mucosa increased in 27 cases (73%) by 1 month after eradication, and in 32 cases (86%) by 7 months. This expansion of the acid-secreting mucosa coincided with the improvement of inflammatory changes rather than with that of the mucosal atrophy and was more prominent on the greater curvature than on the lesser curvature.

CONCLUSIONS

The acid-secreting mucosa in the fundus expanded in most cases with fundic atrophic gastritis after H pylori eradication, which could be responsible for the increase in acid secretion after the treatment. Regional differences in the recovery of local acid secretion may be associated with site-specific susceptibility to the development of gastric cancer after successful eradication.

Effects of Long-term Rofecoxib on Gastric Intestinal Metaplasia: Results of a Randomized Controlled Trial

PURPOSE

Gastric cancer and its premalignant gastric lesion, intestinal metaplasia (IM), frequently express cyclooxygenase-2 (COX-2) at high levels. We tested whether long-term use of specific COX-2 inhibitors regress gastric IM.

EXPERIMENTAL DESIGN

This is a double-blind, randomized, placebo-controlled trial. Individuals with confirmed IM and Helicobacter pylori clearance were randomized to receive rofecoxib 25 mg daily or placebo. Endoscopy was done at baseline, at the end of year 1, and at the end of year 2, with multiple biopsies taken from the antrum and corpus. The primary end point was the proportion of subjects with regression of IM. Secondary end points were the severity of other histologic variables and the proportion of subjects with complete regression of IM.

RESULTS

Two-hundred and thirteen subjects with confirmed IM were randomized. The proportion of subjects with the regression of IM did not differ significantly between rofecoxib and placebo groups (antrum, 24.5% versus 26.9%; P = 0.74; corpus, 4.3% versus 2.2%; P = 0.68). Patients on rofecoxib (19.1%) and on placebo (16.1%) had no IM detected in the stomach (P = 0.59). There was also no significant difference in the severity of IM between the two treatment groups (P >or= 0.3).

CONCLUSIONS

There was no trend to suggest that treatment with rofecoxib for 2 years resulted in the regression of gastric IM. Although our findings cast doubt on the reversibility of gastric IM by COX-2 inhibitor, further studies are needed to establish the role of COX-2 inhibitors in different stages of gastric carcinogenesis.

Risk assessment in relatives of gastric cancer patients: hyperproliferation, genetics, and Helicobacter pylori infection

Approximately 10% of cases of gastric cancer present with some kind of familial aggregation, but only 1-3% of gastric carcinomas arise as a result of clearly defined genetic syndromes that require genetic counselling and aggressive preventative measures. In the remaining families, no specific abnormalities, either genetic, biochemical or histological, responsible for the increased risk have been identified. However, several lines of evidence suggest that the increased cancer risk in first-degree relatives of gastric cancer probands is mostly dependent on Helicobacter pylori infection clustering.

Gastric epithelial cell proliferation and ras oncogene p21 expression in first-degree relatives of gastric cancer patients: a case-control study

OBJECTIVES

Individuals with a family history of gastric cancer have an increased risk of developing such neoplasia. This study aimed to assess epithelial cell proliferation and ras oncogene mutation in such individuals.

METHODS

Twenty dyspeptic, first-degree relatives of patients with gastric cancer and 20 matched controls were enrolled. Endoscopy with biopsies was performed in all cases. Gastric specimens were used to look for Helicobacter pylori infection and to assess both epithelial cell proliferation and ras oncogene expression by immunohistochemistry.

RESULTS

Cell proliferation values were not significantly different between the patient and control groups (18.1 +/- 7.1 versus 18.9 +/- 7.4; P = 0.7). Overall, ras mutation was detected in five out of 40 cases, and its distribution was similar between patients and controls (20 versus 10%; P = 0.9), as well as between H. pylori-positive and negative patients (22 versus 9%; P = 0.2). Cell proliferation values tended to be higher in cases with ras mutation than in those without (25.2 +/- 9.4 versus 16.8 +/- 5.8; P = 0.08). Cell proliferation values were significantly higher in H. pylori-positive cases compared with uninfected cases, in both patient (24.7 +/- 4.7 versus 12.5 +/- 2.4; P = 0.0003) and control (25.9 +/- 4.8 versus 13.3 +/- 2.8; P = 0.0003) groups.

CONCLUSIONS

Both gastric cell proliferation values and ras mutation prevalence did not differ between first-degree relatives of gastric cancer patients and controls. H. pylori infection similarly increased the proliferation index of gastric mucosa in both groups.

Interaction between IL1B gene promoter polymorphisms in determining susceptibility to Helicobacter pylori associated duodenal ulcer

It has been speculated that IL-1 genes play a crucial role in the genetic predisposition to duodenal ulcer upon H. pylori infection by modulating the host immune response. In the present study, 310 individuals from Eastern India were subjected to a case-control study to determine the IL1B and IL1RN risk genotypes to H. pylori mediated duodenal ulcer. An analysis of genotype frequency revealed a significantly higher frequency of IL1B -511TT (NT_022135.14:g.2302610C>T), OR=4.22 (95% CI=1.8-9.4) and -31CC (NT_022135.14:g.2302130C>T), OR=2.16 (95% CI 1.12-4.15) genotypes in H. pylori-infected individuals with duodenal ulcer compared to infected individuals with normal mucosa. Moreover, the T/C haplotype of IL1B -511 and IL1B -31 loci was present in a significantly higher frequency in H. pylori-infected duodenal ulcer patients than in infected controls (OR=2.47, CI=1.27-4.8). Quantitative analysis of the mucosal IL1B mRNA revealed that among H. pylori-infected individuals, carriers of the -31CC genotype had significantly lower IL1B transcript levels than carriers of the CT (P<0.001) and TT (P<0.001) genotypes, independently of disease status. An IL1B promoter activity assay showed that the promoter with -31T had a 10-fold increase in activity compared to the one with -31C. The IL1B promoter bearing the different combinations of both polymorphic loci showed an interaction between the -511 and -31 loci. Our results show that H. pylori-infected individuals with the -31CC genotype secrete less IL1B and are susceptible to duodenal ulcers. They also suggest that the allelic interaction between the -511 and -31 polymorphic sites determines the overall strength of the IL1B promoter.

Effect of Helicobacter pylori eradication on the outcome of reflux esophagitis and chronic gastritis in the elderly. A randomized, multicenter, eight-month study

BACKGROUND

The effect of Helicobacter pylori eradication on the clinical outcome of esophagitis in elderly patients is controversial.

AIM

To evaluate the effect of H. pylori eradication on clinical outcome of esophagitis and on chronic gastritis and its activity.

MATERIALS AND METHODS

Sixty-one symptomatic elderly patients with esophagitis and H. pylori infection were randomized into two groups. Group 1 (PPI-only, 30 patients) was treated with pantoprazole 40 mg daily for 2 months followed by pantoprazole 20 mg daily for a further 6 months; group 2 (PPI + eradication, 31 patients) was treated as group 1 plus a 1-week course of amoxicillin 1 g twice daily and clarithromycin 250 mg twice daily. Endoscopy with gastric biopsies, 13C-UBT and clinical visits were repeated after 2 and 8 months.

RESULTS

After 8 months, the intention-to-treat H. pylori eradication rates were 19.2% in group 1 vs. 80.7% in group 2 (p < 0.0001). No differences between group 1 and group 2 were observed in symptoms improvement (77 vs. 77%, p = n.s.) and healing rates of esophagitis (92.3 vs. 88.5%, p = n.s.). A significant decrease in the prevalence of moderate/severe chronic gastritis (from 52.2 to 4.7%, p = 0.002) and its activity (from 38 to 4.7%, p = 0.02) was observed in the antrum of patients of group 2, and not in patients of group 1. While a nonsignificant reduction in the chronic gastritis activity (from 28.6 to 4.7%, p = 0.09) was observed in the corpus of the eradicated patients of group 2, conversely a significant worsening of the chronic gastritis activity was found in the corpus of group 1 patients (from 25 to 60%, p = 0.05).

CONCLUSION

The eradication of H. pylori infection does not affect the clinical outcome of esophagitis, while it improves chronic gastritis and its activity in elderly patients on short- and long-term treatment with PPIs. These findings suggest that H. pylori infection should be eradicated in elderly patients with esophagitis who need maintenance treatment with PPI.

Erythrocyte Lewis (A+B-) host phenotype is a factor with familial clustering for increased risk of Helicobacter pylori-related non-cardiac gastric cancer

BACKGROUND

The purpose of the present study was to test whether host erythrocyte Lewis phenotypes correlated with the risk of gastric cancers. Because of the association of gastric cancer with familial clustering, cancer relatives were investigated as to whether they had unique distribution of Lewis phenotypes.

METHODS

The study prospectively enrolled 74 Helicobacter pylori-positive gastric cancer patients and 100 H. pylori-positive duodenal ulcer patients to serve as non-cancer controls after panendoscopy. In addition, 433 family members from the 74 index cancer and 100 non-cancer control patients were enrolled. All enrolled cases were checked for their H. pylori status and erythrocyte Lewis phenotypes, defined as Le(a-b-), Le(a-b+), Le(a+b-), and Le(a+b+) subtypes by the anti-Le(a) and anti-Le(b) monoclonal antibodies.

RESULTS

These H. pylori-infected patients with gastric cancer had a higher rate of Le(a+b-) phenotype and a lower rate of Le(a-b+) phenotype than the non-cancer duodenal ulcer controls (20.3% vs 9%; 51.4% vs 72%, P < 0.05). Among these H. pylori-infected patients, the risk of the patients with Le(a+b-) phenotype having gastric cancer was 3.15-fold higher as compared with those with the Le(a-b+) phenotype (P = 0.02, 95% confidence interval: 1.26-7.87). The offspring and cousins of the cancer patients had a higher rate of Le(a+b-) phenotype as compared to either that of the spouses of cancer index patients or to that of the family members of the non-cancer control (P < 0.05).

CONCLUSION

Le(a+b-) phenotype of the H. pylori-infected host could be a risk factor (with familial clustering) for gastric carcinogenesis.

Cellular and molecular aspects of gastric cancer

Gastric cancer remains a global killer with a shifting burden from the developed to the developing world. The cancer develops along a multistage process that is defined by distinct histological and pathophysiological phases. Several genetic and epigenetic alterations mediate the transition from one stage to another and these include mutations in oncogenes, tumour suppressor genes and cell cycle and mismatch repair genes. The most significant advance in the fight against gastric caner came with the recognition of the role of Helicobacter pylori (H pylori) as the most important acquired aetiological agent for this cancer. Recent work has focussed on elucidating the complex host/microbial interactions that underlie the neoplastic process. There is now considerable insight into the pathogenesis of this cancer and the prospect of preventing and eradicating the disease has become a reality. Perhaps more importantly, the study of H pylori-induced gastric carcinogenesis offers a paradigm for understanding more complex human cancers. In this review, we examine the molecular and cellular events that underlie H pylori-induced gastric cancer.

Gastric histology, serological markers and age as predictors of gastric acid secretion in patients infected with Helicobacter pylori

BACKGROUND

Acid secretion is intimately associated with most upper gastrointestinal diseases. Helicobacter pylori infection is a major environmental factor modifying acid secretion.

AIM

To study the association between the pattern of H pylori gastritis and gastric secretory function in a large number of subjects without specific upper gastrointestinal disease.

METHODS AND MATERIALS

Maximal acid output (MAO) was measured in 255 patients with dyspepsia showing normal endoscopy. Activity and severity of gastritis, atrophy and H pylori infection were assessed in body and antral biopsies. The correlations of histological parameters as well as age, sex, height, weight, smoking, serum gastrin, pepsinogen I and II, and their ratio with MAO were determined. Multiple linear regression was used to show the best possible predictors of MAO.

RESULTS

Negative relationships: Body atrophy and body-combined (active and chronic) inflammatory scores showed a potent inverse correlation with MAO (correlation coefficients (CC) 0.59 and 0.50, respectively). Body:antral chronic gastritis ratio and body:antral combined inflammation ratio (both with CC = 0.49) and age (CC = 0.44) were also inversely correlated with MAO. Intestinal metaplasia at both antral and body sites had negative relationships with acid output with CC = 0.23 and 0.20, respectively. Positive relationships: Serum pepsinogen I, body H pylori density:combined inflammation ratio and pepsinogen I:II ratio with CC of 0.38, 0.38 and 0.30, respectively, correlated with MAO. The H pylori density: combined inflammation of both antrum and body positively correlated with MAO (CC = 0.29 and 0.38, respectively). Male sex and patient height also positively correlated with acid output. Modelling showed that body combined inflammatory score, body atrophy, age and serum pepsinogen I are independent predictors of acid output (R(2) = 0.62).

CONCLUSION

Combination of body gastritis, body atrophy, age and serum pepsinogen I can be used as predictors of acid-secretory state in populations infected with H pylori.

The effects of genetic polymorphisms of IL-1 and TNF-A on Helicobacter pylori-induced gastroduodenal diseases in Korea

OBJECTIVE

To evaluate whether or not genetic polymorphism of IL-1B, IL-1RN, and TNF-Alpha is an important factor in the different expression of gastroduodenal diseases after Helicobacter pylori infection.

METHODS

This study consisted of 1360 subjects: control, gastric cancer (GC, intestinal type, and diffuse type), benign gastric ulcer (BGU), duodenal ulcer, and first-degree gastric cancer relative (GCR). IL-1Beta-511 and TNF-A-308 biallelic polymorphism were genotyped by 5' nuclease polymerase chain reaction (PCR) assays, and PCR-restriction fragment length polymorphism (PCR-RFLP). IL-1RN penta-allelic variable number of tandem repeats was genotyped by PCR.

RESULTS

There was no difference in the genetic polymorphism of IL-1Beta-511, IL-1RN and TNF-A in the patients with gastric cancer regardless of H. pylori positivity compared with control. However, the frequencies of IL-1B-511 C/T (OR: 0.5, 95% CI: 0.3-0.7) and T carrier (OR: 0.6, 95% CI: 0.4-0.8) were lower in the H. pylori-positive BGU patients. The IL-1RN 2/2 was higher (OR: 5.5, 95% CI: 1.1-28.5) in the H. pylori-positive GCR. There was no significance in the polymorphism of TNF-Alpha-308 regardless of H. pylori-induced gastroduodenal diseases.

CONCLUSIONS

The IL-1Beta-511 T-carrier polymorphism has a negative effect on the development of H. pylori-positive BGU, and high frequency of IL-1RN 2/2 was found in the H. pylori-positive relatives of GC patients, which suggest that this genetic polymorphism could play some role in the H. pylori-induced gastroduodenal diseases in Korea.

Causal role of Helicobacter pylori infection in gastric cancer: An Asian enigma

Helicobacter pylori (H pylori) has been etiologically linked to gastric cancer. H pylori infection is more frequent in less developed Asian countries like India, Bangladesh, Pakistan, and Thailand and is acquired at early age than in more developed Asian countries like Japan and China. Frequency of gastric cancer, however, is very low in India, Bangladesh, Pakistan and Thailand compared to that in Japan and China. Similar enigma has been reported from Africa as compared to the West. Seroprevalence of H pylori infection in adult populations of India, Bangladesh, Pakistan and Thailand varies from 55% to 92%. In contrast, seroprevalence of H pylori in Chinese and Japanese adults is 44% and 55%, respectively. Annual incidence rate of gastric cancer in India, Bangladesh, and Thailand is 10.6, 1.3, 7.1 per 100 000 populations, respectively; in contrast, that in China and Japan is 32-59 and 80-115 per 100 000 populations, respectively. Several studies from India failed to show higher frequency of H pylori infection in patients with gastric cancer than controls. Available evidences did not support difference in H pylori strains as an explanation for this enigma. Despite established etiological role of H pylori, situation is somewhat enigmatic in Asian countries because in countries with higher frequency of infection, there is lower rate of gastric cancer. Host’s genetic make-up and dietary and environmental factors might explain this enigma. Studies are urgently needed to solve this issue.

Risk factors associated with the development of intestinal metaplasia in first-degree relatives of gastric cancer patients

Family relatives of gastric cancer patients have a higher risk of gastric cancer and premalignant gastric lesions. We sought to determine the risk factors associated with the presence of intestinal metaplasia in a large cohort of gastric cancer relatives. First-degree relatives of gastric cancer patients were invited for screening gastroscopy. Endoscopic gastric biopsies were obtained from the antrum and corpus. Gastric biopsies were analyzed for Helicobacter pylori infection, severity of inflammation, and presence of intestinal metaplasia. Stepwise logistic regressions were used to identify for risk factors associated with presence of intestinal metaplasia in cancer relatives. Two hundred seventy cancer relatives underwent screening endoscopy (median age, 42; 47% male and 48% siblings). Among them, 161 (59.6%) were H. pylori positive and 81 (30%) had confirmed intestinal metaplasia. The following factors were found to be associated with the presence of intestinal metaplasia: age, male sex, H. pylori infection, birth order, alcohol use, siblings with stomach cancer, childhood living conditions, and water supply. Individuals with intestinal metaplasia had more severe acute and chronic inflammation in the antrum and corpus (P < 0.003). With multiple logistic regression, H. pylori infection [odds ratio (OR), 3.23], male gender (OR, 2.09), age (OR, 1.07), and a history of gastric cancer in siblings (OR, 1.91) were independent factors associated with the development of intestinal metaplasia in cancer relatives. In conclusion, we have identified risk factors associated with gastric intestinal metaplasia in stomach cancer relatives, which may be useful in the understanding of gastric carcinogenesis in these high-risk individuals.

Association of interleukin-1beta gene polymorphisms with precancerous gastric lesions in African Americans and Caucasians

OBJECTIVE

Interleukin-1beta plays an important role in inflammation and gastric physiology. Polymorphisms of the IL1B gene have been associated with gastric atrophy and increased cancer risk, especially in Helicobacter pylori-infected subjects. The aim of this study was to evaluate the relationship between IL1B and IL1 receptor antagonist gene polymorphisms and the risk of multifocal atrophic gastritis in African Americans and Caucasians.

METHODS

Genomic DNA was extracted from gastric biopsies of 269 adult outpatients (172 African Americans and 97 Caucasians) undergoing diagnostic upper gastrointestinal endoscopy. Histological diagnosis was evaluated according to the updated Sydney System and H. pylori status was assessed by Steiner silver stain. Polymorphisms of the IL1B gene (-511, -31, and +3954) and the IL1 receptor antagonist were investigated by PCR-RFLP. Logistic regression models were used to identify variables associated with multifocal atrophic gastritis in terms of odds ratios and 95% confidence intervals.

RESULTS

Considering subjects with normal histology and nonatrophic gastritis as controls, a significant association was found between IL1B+3954T carrier and multiatrophic gastritis (OR 2.23, 95% CI 1.28, 3.88). Analyses stratified by ethnic group demonstrated similar associations in both African Americans (OR 2.23, 95% CI 1.14, 4.37) and Caucasians (OR 2.04, 95% CI 0.74, 5.65). A positive but not significant association was found between the allele 2 of the IL1RN and the presence of multifocal atrophic gastritis. The remaining proinflammatory polymorphisms were not associated with this precancerous lesion.

CONCLUSIONS

Our results suggest that the presence of IL1B+3954T allele is a risk marker for multifocal atrophic gastritis in the population studied.

Of microbe and man: determinants ofHelicobacter pylori-related diseases

The human gastric pathogen Helicobacterpylori infects the human gastric mucus layer of approximately half of the world's population. Colonization with this bacterium results in superficial gastritis without clinical symptoms, but can progress into gastric or duodenal ulcers, gastric malignancies and mucosa-associated lymphoid tissue-lymphomas. Disease outcome is affected by a complex interplay between host, environmental and bacterial factors. Irrespective of disease outcome, the majority of H. pylori infected individuals remain colonized for life. Changing conditions in the human gastric mucosa may alter gene expression and/or result in the outgrowth of more fit H. pylori variants. As such, H. pylori is a highly flexible organism that is optimally adapted to its host. the heterogeneity in H. pylori populations make predictions on H. pylori-related pathogenesis difficult. In this review, we discuss host, environmental and bacterial factors that are important in disease progression. Moreover, H. pylori adaptive mechanisms, which allow its life-long survival and growth in the gastric mucosa are considered.

Recovery of gastric function after Helicobacter pylori eradication in subjects with body atrophic gastritis: prospective 4-year study

BACKGROUND

The relationship between Helicobacter pylori (H. pylori) eradication and atrophic changes in the gastric mucosa has not yet been fully defined. Although studies report a partial restoration of serum pepsinogen I (sPGI) levels after eradication, it is not clear if this finding reflects gastric mucosal healing on a morphological level.

AIM

To assess alterations in gastric function after H. pylori eradication on moderate/severe body atrophic gastritis by determination of sPGI levels.

METHODS

Twenty-three dyspeptic patients, selected from 284 consecutive H. pylori positive patients, with histological features of moderate/severe body atrophic gastritis and sPGI < 25 microg/L (11 men, mean age: 51.8 years, range: 29-79 years), underwent an upper gastrointestinal endoscopy with gastric biopsies and sPGI determination at baseline. All patients underwent eradication therapy. Serum pepsinogen I was measured again after 6 months, and at 1, 2, 3 and 4 years after eradication therapy.

RESULTS

Mean sPGI levels prior to eradication were 11.9 microg/L (range: 4-23 microg/L). Six months after eradication therapy, mean sPGI levels significantly increased to 17.4 microg/L (P = 0.04). At the completion of the study, 4 years after eradication, sPGI levels increased from 17.4 to 32.7 microg/L (P = 0.01). A significant progressive increase in sPGI levels was observed from 6 months to 1 year (17.4 to 23.9 microg/L) and from 1 to 2 years (23.9 to 26.0 microg/L, P = 0.01). Serum pepsinogen I levels higher than the cut-off value of 25 microg/L were observed at various time-points: 6.3% of patients at 6 months (1/16), 33.3% (5/15) at 1 year, 50% (7/14) at 24 months, 66.7% (6/9) at 36 months and 87.5% (7/8) at 4 years.

CONCLUSION

After H. pylori eradication, subjects with body atrophic gastritis showed long-term improvement of physiological gastric function, reflected by significantly and continually increasing sPGI levels over a 4-year period.

Racial differences in Helicobacter pylori, serum pepsinogen and gastric cancer incidence in an urban Asian population

BACKGROUND

In Singapore, the highest incidence of gastric cancer occurs in the Chinese (C), with lower rates among Malay (M) and Indian (I) subjects. The purpose of the present paper was to examine whether racial differences in the prevalence of Helicobacter pylori and serum pepsinogen (PG) could account for this difference.

METHODS

A randomized community health survey involving 7000 asymptomatic healthy individuals was conducted. Among the Chinese, Malay and Indian respondents, subjects were matched for age, gender and race and a total of 595 sera were obtained. The H. pylori seropositivity and serum PG levels were determined by ELISA. The dependency of the cumulative gastric incidence rate on H. pylori seroprevalence was evaluated by linear regression. The racial difference in the seroprevalence of H. pylori and low serum PG was determined.

RESULTS

The H. pylori seroprevalence was similar between Chinese and Indian subjects, but significantly lower among Malay subjects (C, 46.3%; M, 27.9%; I, 48.1%). The gastric cancer incidence rates correlated with H. pylori seropositivity for the Chinese and Malay subjects, but not for the Indian subjects. The prevalence of low PG was highest in Indian subjects (PG I low: C, 2.1%; M, 5.4%; I, 14.2%; P < 0.0001; PG I:II ratio low: C, 5.3%; M, 5.9%; I, 12.6%; P = 0.012), even when adjusted for gender and the presence of H. pylori.

CONCLUSIONS

The difference in gastric cancer incidence correlated with H. pylori seroprevalence for Chinese and Malay subjects. The lower incidence of gastric cancer among Indian subjects cannot be explained by differences in H. pylori or serum PG. Other modifying factors such as host and environmental factors may be important.

Long-term follow-up in atrophic body gastritis patients: atrophy and intestinal metaplasia are persistent lesions irrespective of Helicobacter pylori infection

BACKGROUND

Long-term outcome of atrophic body gastritis has not yet been defined.

AIM

To investigate at long-term follow-up the behaviour of atrophy and intestinal metaplasia and the occurrence of neoplastic lesions in atrophic body gastritis patients.

METHODS

Overall 106 atrophic body gastritis patients with > or = 4-year follow-up were studied; 38 were Helicobacter pylori-positive at histology + serology and cured of infection (group A), 36 were positive at serology and not treated (group B) and 32 were H. pylori-negative (group C). Patients underwent gastroscopy with antral (n = 3) and body (n = 3) biopsies for histology according to the Sydney System.

RESULTS

At 6.7-year follow-up body atrophy and intestinal metaplasia remained unchanged in all 106 patients irrespective of H. pylori status. Antral atrophy was significantly increased at follow-up only in group C, whereas antral intestinal metaplasia was unchanged in all three groups. During follow-up eight (8%) patients developed neoplastic lesions (one adenocarcinoma, one adenoma with low-grade dysplasia and six low-grade dysplasia without endoscopic lesions). Antral atrophic gastritis was present at baseline in all but one (88%) of the eight patients with neoplastic lesions, but only in 15 (15%) of the 98 patients without (P < 0.0001, RR = 26.7).

CONCLUSIONS

Atrophy and intestinal metaplasia persist at 6.7-year follow-up and atrophic body gastritis patients with panatrophic gastritis are at increased risk of developing neoplastic lesions.

Gastric achlorhydria in H/K-ATPase-deficient (Atp4a(-/-)) mice causes severe hyperplasia, mucocystic metaplasia and upregulation of growth factors

BACKGROUND

Gastric neoplasia is common in humans, yet controversy remains over contributions of chronic achlorhydria, gastrinemia and hyperplasia, to cancer risk. To study this, mice lacking the gastric H/K-ATPase (Atp4a(-/-) mice) were used to determine whether chronic loss of acid secretion, with attendant hypergastrinemia, predisposes to cancer phenotype.

METHODS

Atp4a(-/-) and Atp4a(+/+) mice, paired for age and gender, were examined at 3, 8, 12 and 20 months for histopathology, and for expression of the trefoil factor family (TFF)1-3, Reg IIIbeta, gamma and delta, osteopontin, CD44, chromogranin A, Crp-ductin, and galectin, all of which are important in cell growth.

RESULTS

By 8 months, the glandular stomach of the Atp4a(-/-) mice doubled in weight and thickness, and several modulators of growth were increased. Female Atp4a(-/-) mice were more hyperplastic than Atp4a(-/-) males at 12 and 20 months. By 1 year, severe mucocystic hyperplasia, incomplete intestinal metaplasia, ciliated metaplasia, a shift in mucins from neutral to acidic, and inflammation were widespread. Cells in the mucus pit zone developed a pyloric-type appearance, containing large hyaline-like, periodic acid-Schiff (PAS)-negative/alcian blue-negative inclusions. But critical characteristics of gastric neoplasia, such as nuclear atypia, invasion into the muscularis mucosa, and metastases were absent. In Atp4a(-/-) mice, chromogranin A and histidine decarboxylase, RegIIIgamma and delta, TFF3, osteopontin and CD44 were upregulated while Reg IIIbeta, and TFF1 were reduced.

CONCLUSIONS

Chronic achlorhydria and hypergastrinemia in aged Atp4a(-/-) mice produced progressive hyperplasia, mucocystic and incomplete intestinal metaplasia, and the upregulation of growth factors without histological evidence of neoplasia.

Gastric cancer: new genetic developments

Gastric cancer's (GC) incidence shows large geographic differences worldwide with the lowest rates occurring in most Western industrialized countries including the United States and the United Kingdom; in contrast, relatively high rates of GC occur in Japan, Korea, China, and South America, particularly Chile. The Laurén classification system classifies GC under two major histopathological variants: 1) an intestinal type and 2) a diffuse type. The intestinal type is more common in the general population, more likely to be sporadic and related to environmental factors such as diet, particularly salted fish and meat as well as smoked foods, cigarette smoking, and alcohol use. It exhibits components of glandular, solid, or intestinal architecture, as well as tubular structures. On the other hand, the diffuse type is more likely to have a primary genetic etiology, a subset of which, known as hereditary diffuse gastric cancer (HDGC), is due to the E-cadherin (CDH1) germline mutation. The diffuse type pathology is characterized by poorly cohesive clusters of cells which infiltrate the gastric wall, leading to its widespread thickening and rigidity of the gastric wall, known as linitis plastica. Helicobacter pylori infection is associated with risk for both the intestinal and diffuse varieties of gastric cancer. Germline truncating mutations of the CDH1 gene, which codes for the E-cadherin protein, were initially identified in three Maori families from New Zealand that were predisposed to diffuse GC. Since then, similar mutations have been described in more than 40 additional HDGC families of diverse ethnic backgrounds. It is noteworthy that two-thirds of HDGC families reported to date have proved negative for the CDH1 germline mutation. A number of candidate genes have been identified through analysis of the molecular biology of E-cadherin. Patients with evidence of the CDH1 germline mutation in the context of a family history of HDGC must be considered as candidates for prophylactic gastrectomy, given the extreme difficulty in its early diagnosis and its exceedingly poor prognosis when there is regional or distant spread. Specifically, the E-cadherin cytoplasmic tail interacts with catenins, assembling the cell-adhesion complex involved with E-cadherin mediated cell:cell adhesion. Beta-catenin and gamma-catenin compete for the same binding site on the E-cadherin cytoplasmic tail, directly linking the adhesion complex to the cytoskeleton through alpha-catenin. Beta-catenin gene (CTNNB1) mutations have been described predominantly in intestinal-type gastric cancers and CTNNB1 gene amplification and overexpression have recently been described in a mixed-type gastric cancer. This paper reviews the genetics of both intestinal and diffuse types of gastric carcinoma, their differential diagnosis, molecular genetics, pathology, and, when known, their mode of genetic transmission within families.

Simple method for determination of the number of Helicobacter pylori CagA variable-region EPIYA tyrosine phosphorylation motifs by PCR

Helicobacter pylori strains possessing the cag pathogenicity island are associated with the development of gastric cancer. The CagA protein is translocated into epithelial cells and becomes phosphorylated on tyrosine residues within EPIYA motifs, which may be repeated within the variable region of the protein. Strains possessing CagA with greater numbers of these repeats have been more closely associated with gastric carcinogenesis. Phosphorylated CagA leads to epithelial cell elongation, which is dependent on the number of variable-region EPIYA motifs. Thus, determination of the degree of CagA phosphorylation and the number of EPIYA motifs appears to be more important than detection of cagA alone. Determination of the number of EPIYA motifs by nucleotide sequencing, however, is a laborious and expensive process. We describe here a novel and rapid PCR method for determination of the pattern of repeats containing the EPIYA motif. This will aid in the identification of those strains that may be more likely to cause disease.

Prediction of malignant potential in reflux disease: are cytokine polymorphisms important?

OBJECTIVES

Esophageal reflux is common in the Western world and can lead to a number of diseases, such as esophagitis, Barrett's esophagus, and adenocarcinoma. Barrett's predisposes to adenocarcinoma and endoscopic surveillance may lead to earlier detection of adenocarcinoma. However, clinical methods only identify one patient in 15 with Barrett's esophagus. The aim of this study was to find factors that may help identify patients with Barrett's earlier.

METHODS

Blood samples and detailed histories were taken from 456 patients with gastroesophageal reflux who were recruited into three study groups: esophagitis, Barrett's esophagus without dysplasia, and Barrett's with dysplasia or adenocarcinoma. PCR was used to determine the frequency of five functional cytokine polymorphisms: interleukin-1 receptor antagonist position +2018 (IL-1 Ra +2018), interleukin-1 beta position -511 (IL-1 beta-511), tumor necrosis factor-alpha position -238 (TNF-alpha-238), interleukin-10 position +1082 (IL-10 +1082), and interleukin-4 receptor position -1902 (IL-4R -1902).

RESULTS

IL-1 Ra +2018 genotype 2/2 was associated with Barrett's more commonly than esophagitis (OR-3.7, p= 0.0345). The IL-10 +1082 genotype 2/2 was more strongly associated with Barrett's and adenocarcinoma than esophagitis (OR-1.76, p= 0.056 and OR 1.96, p= 0.025, respectively). There were no differences for the IL-1 beta-511, IL-4R -1902, and TNF-alpha-238 polymorphisms.

CONCLUSIONS

Cytokine polymorphisms are more commonly found in patients with Barrett's or adenocarcinoma than those with esophagitis. Together with demographic data, this may help identify those patients with Barrett's who would benefit from surveillance.

A pilot study of Helicobacter pylori infection and risk of laryngopharyngeal cancer

BACKGROUND

Squamous cell carcinoma of the laryngopharynx has been linked to laryngopharyngeal reflux disease. Helicobacter pylori corpus gastritis decreases gastric acid secretion and provides some protection against complications of gastroesophageal reflux, including adenocarcinoma of the distal esophagus. The aim of this study was to investigate whether H. pylori infection also protects against laryngopharyngeal carcinoma.

METHODS

This was a case-control study comparing patients with histologically confirmed, previously untreated laryngeal or pharyngeal squamous cell carcinomas with cancer-free controls selected from a pool of hospital-based cancer-free controls identified during a similar time period. Each subject completed a self-administered questionnaire that elicited information on age, sex, ethnicity, and tobacco and alcohol consumption. The 120 case subjects were frequency matched to 120 control subjects on age (+/- 5 years), sex, tobacco use, and alcohol use; all subjects were non-Hispanic whites. H. pylori and human papillomavirus type 16 (HPV-16) seropositivity was determined by use of an enzyme-linked immunosorbent assay.

RESULTS

The serologic assay was unsuccessful in one case subject and nine control subjects; therefore, 119 case subjects and 111 control subjects were included in the analysis. The proportion of subjects with anti-H. pylori immunoglobulin G was similar between the two groups (32.8% among cases vs 27.0% among controls; p = .342). Although seropositivity was more common in the patients with laryngeal cancer (39.1%) than in the patients with pharyngeal cancer (28.8%), this difference was neither significant (p = .241) nor associated with a significant risk of laryngeal cancer (adjusted odds ratio, 1.53; 95% confidence interval, 0.69-3.41). H. pylori seropositivity was more common among patients who were HPV-16 seronegative (38.2% vs 22.9%, p = .081), and this was particularly true among patients with laryngeal cancer (47.1% vs 18.2%; p = .089).

CONCLUSIONS

These results do not show that H. pylori infection either protects against or promotes laryngopharyngeal carcinoma. However, segregation analyses suggested that H. pylori may play a role in laryngeal cancers not associated with HPV-16 infection, and further study in this group is warranted.

Overexpression of glycine-extended gastrin inhibits parietal cell loss and atrophy in the mouse stomach

Recently we have reported synergistic effects between glycine-extended gastrin (G-gly) and amidated gastrin-17 on acid secretion in short-term infusion studies. In the present study, we examined the long-term effect of G-gly on the atrophy-promoting effects of amidated gastrin in the mouse stomach with or without Helicobacter infection. Transgenic mice overexpressing amidated gastrin (INS-GAS mice), G-gly (MTI/G-gly mice), and both peptides (INS-GAS/G-gly mice) were used for assessment of acid secretion and ulcer susceptibility and histologic examination and scoring of preneoplastic lesions in response to the 3 and 6 months Helicobacter felis (H. felis) infection. We found that MTI/G-gly mice had normal gastric histology and acid secretion. Double transgenic (INS-GAS/G-gly) mice showed 2-fold increases in acid secretion compared with INS-GAS mice. Acute peptic ulcers after pyloric ligation were noted in 50% of the INS-GAS/G-gly mice but in none of the INS-GAS mice at 6 months of age. Whereas male INS-GAS mice had a >50% decrease in the numbers of parietal cell and enterochromaffin-like cell at 6 months of age, the male double transgenic mice had no such decrease. Overexpression of G-gly reduced the scores of preneoplasia in the stomach; however, it did not prevent the development of amidated gastrin-dependent gastric cancer in both H. felis-infected mice and uninfected mice. We conclude that G-gly synergizes with amidated gastrin to stimulate acid secretion and inhibits parietal cell loss in INS-GAS/G-gly mice. The overexpression of G-gly seems to increase the susceptibility to peptic ulcer disease and delay the development of Helicobacter-mediated gastric preneoplasia in this model.

Will eradication of Helicobacter pylori infection influence the risk of gastric cancer?

Gastric adenocarcinoma is a disease of high mortality and poor prognosis that is second only to lung cancer as a leading cause of cancer-related deaths worldwide. Although gastric cancer has a multifactorial etiology, infection with Helicobacter pylori is highly associated with its development. New information on bacterial and host genetics and results of epidemiologic studies suggest that better identification of individuals at high risk for gastric malignancy may be possible. Studies suggest that cure of H pylori infection may be associated with retardation of glandular atrophy and intestinal metaplasia but not reversal of dysplasia. Theoretically, it is attractive to believe that eradication of H pylori infection might prevent gastric cancer; however, studies supporting this hypothesis are not yet available. Public policy strategies for the identification of patients at risk for H pylori-related gastric malignancy are likely to be complex, but testing and treating for the infection earlier rather than later in life is anticipated to be the more beneficial approach.

Gastric acid secretion of normal Japanese subjects in relation to Helicobacter pylori infection, aging, and gender

BACKGROUND

In Japan, where the incidence of gastric cancer is high, Helicobacter pylori infection could affect gastric acid secretion differently from that in Western countries. The aim of this study was to investigate the relationship between H. pylori infection, acid secretion, aging, and gender in normal Japanese subjects.

METHODS

The study comprised 193 Japanese subjects who had undergone routine endoscopy. Gastrin-stimulated acid output was performed during the routine endoscopic examination using the endoscopic method of gastric acid secretory testing (EGT: endoscopic gastrin test), which has been reported previously. H. pylori status was determined by histology, rapid urease test, and serology.

RESULTS

Mean EGT values were 3.9 +/- 1.5 mEq/10 min in H. pylori-negative men, 1.6 +/- 2.5 in H. pylori-positive men, 2.2 +/- 0.9 in H. pylori-negative women, and 1.5 +/- 1.2 in H. pylori-positive women. Although acid secretion was lower in H. pylori-positive subjects compared with H. pylori-negative subjects in both men and women, the decrease was more marked in men with H. pylori infection. Multiple linear regression analysis showed that aging is positively associated with gastric acid secretion in the H. pylori-negative subjects, whereas a negative association was found between them in the H. pylori-positive subjects.

CONCLUSIONS

In Japanese subjects, aging affects gastric acid secretion differently depending on the status of H. pylori infection. H. pylori infection showed a stronger inhibitory effect on the acid secretion in men than in women. This gender-related difference in the susceptibility of acid secretion to H. pylori infection may explain the higher rates of gastric cancer in men in Japan.

Long-term effect of Helicobacter pylori eradication on the reversibility of acid secretion in profound hypochlorhydria

BACKGROUND

Although profound hypochlorhydria is considered to be an important risk factor for development of gastric cancer, long-term effect of Helicobacter pylori eradication on its reversibility remains uncertain.

AIM

To clarify the change in acid secretion after eradication in a long-term follow-up over 5 years in patients with profound hypochlorhydria.

METHODS

Twenty-three H. pylori-positive patients with hypochlorhydria (<0.6 mmol/10 min) were enrolled prospectively. Assessment of gastrin-stimulated acid output and histologic evaluation of biopsy specimens were performed prior to, and 1, 7 months after eradication. Subsequently, gastric acid secretion was assessed for long-term period over 5 years after eradication in 12 patients.

RESULTS

Gastric acid secretion was reversed to normal range in nine of 23 patients (39%) at 7 months after eradication. In the long-term follow-up, gradual and significant recovery in gastric acid secretion was observed up to 2 years post-therapy. However, there was no additional increase during the last 3 years of 5-year follow-up period, leaving the acid secretory levels subnormal in the majority of the patients.

CONCLUSIONS

This long-term follow-up study suggests that the pathologic process has already progressed to an irreversible stage in the majority of H. pylori-positive patients with marked body atrophy and profound hypochlorhydria.

Genetic screening for familial gastric cancer

Approximately 10% of gastric cancer cases show familial clustering but only 1-3% of gastric carcinomas arise as a result of inherited gastric cancer predisposition syndromes. Direct proof that Hereditary Gastric Cancer a genetic disease with a germline gene defect has come from the demonstration of co-segregation of germline E-cadherin (CDH1) mutations with early onset diffuse gastric cancer in families with an autosomal dominant pattern of inheritance (HDGC). E-cadherin is a transmembrane calcium-dependent cell-adhesion molecule involved in cell-junction formation and the maintenance of epithelial integrity. In this review, we describe frequency and type of CDH1 mutations in sporadic and familial gastric cancer. Further we demonstrate the functional significance of some CDH1 germline missense mutations found in HDGC. We also discuss the CDH1 polymorphisms that have been associated to gastric cancer. We report other types of malignancies associated to HDGC, besides diffuse gastric cancer. Moreover, we review the data available on putative alternative candidate genes screened in familial gastric cancer. Finally, we briefly discuss the role of low-penetrance genes and Helicobacter pylori in gastric cancer. This knowledge is a fundamental step towards accurate genetic counselling, in which a highly specialised pre-symptomatic therapeutic intervention should be offered.