Why does Japan have a high incidence of gastric cancer? Comparison of gastritis between UK and Japanese patients

Trends in characteristics of surgically treated early gastric cancer patients after the introduction of gastric cancer treatment guidelines in Japan

BACKGROUND

The gastric cancer treatment guidelines (Guidelines) of the Japanese Gastric Cancer Association allow endoscopic treatment and a modified gastrectomy for the treatment of early gastric cancer (EGC). Endoscopic treatment is indicated for EGC with a minimal chance of nodal metastasis. Consequently, surgeons will likely treat an increasing number of EGC patients with greater chance of nodal metastasis using a reduced extent of lymphadenectomy. The aim of this study was to investigate the trends in characteristics and long-term oncological outcomes of surgically treated EGC patients after the introduction of the Guidelines.

METHODS

Between 2001 and 2003, 696 patients underwent a gastrectomy according to the Guidelines. These 696 patients (the Guidelines group) were retrospectively compared with 635 patients (the control group) who had undergone a gastrectomy between 1991 and 1995 (before the introduction of the Guidelines).

RESULTS

The incidence of nodal metastasis in mucosal cancers was higher in the Guidelines group than in the control group (6.5% vs 2.6%). The proportion of D2 or greater extended lymphadenectomy in the Guidelines group was lower than that in the control group (29.7% vs 62.5%). Nevertheless, the 5-year survival rate in the Guidelines group was similar to that in the control group (94.2% vs 92.3%).

CONCLUSION

Surgeons treated more cases of mucosal cancer with nodal metastasis after the introduction of the Guidelines. The long-term oncological outcomes for patients with EGC remained excellent. So far, the Guidelines for the treatment of EGC appear acceptable.

Sofalcone, a gastroprotective drug, promotes gastric ulcer healing following eradication therapy for Helicobacter pylori: a randomized controlled comparative trial with cimetidine, an H2-receptor antagonist

BACKGROUND AND AIMS

According to reports in Japanese patients, 1 week of Helicobacter pylori eradication therapy alone is not adequate for healing of gastric ulcers; 7-8 weeks of anti-ulcer therapy are subsequently required. We compared a gastroprotective drug, sofalcone, and an H(2)-receptor antagonist, cimetidine, in terms of promoting ulcer healing after 7 weeks of administration following 1 week of eradication therapy.

METHODS

Eradication therapy was administered to 64 patients with H. pylori-positive active gastric ulcer at least 10 mm in diameter, after which 32 patients each received 7 weeks of ulcer treatment with sofalcone (300 mg/day) or cimetidine (800 mg/day).

RESULTS

The H. pylori eradication rate was 81.3% (intention-to-treat: ITT) and 81.3% (per protocol: PP) in the sofalcone group, and 62.5% (ITT) and 64.5% (PP) in the cimetidine group. The ulcer healing rate after 8 weeks was 71.9% (ITT) and 71.9% (PP) in the sofalcone group, and 71.9% (ITT) and 71.0% (PP) in the cimetidine group. The rate of a flat pattern of scarred mucosa was 43.5% (ITT) and 43.5% (PP) in the sofalcone group, and 47.8% (ITT) and 50.0% (PP) in the cimetidine group. No significant differences were seen between the two groups in terms of H. pylori eradication rate, ulcer healing rate and flat pattern rate.

CONCLUSION

Sofalcone promoted gastric ulcer healing during 7 weeks of treatment following 1 week of eradication therapy, and the healing rate was equivalent to that of cimetidine. Symptom disappearance rates were significantly better in the sofalcone group than in the cimetidine group. This may be a useful way of using a gastroprotective drug in the H. pylori era.

Validation of diagnostic tests for Helicobacter pylori with regard to grade of atrophic gastritis and/or intestinal metaplasia

BACKGROUND AND AIMS

To evaluate the validity of the biopsy-based tests (histology, culture, and urease test) and serology in detecting current Helicobacter pylori infection against a background of atrophic gastritis (AG) or intestinal metaplasia (IM).

METHODS

Helicobacter pylori infection was diagnosed in 651 subjects, using the predefined gold standard for H. pylori tests. The sensitivity, specificity, and positive and negative predictive values of culture, CLOtest, histology (Giemsa stain), and serology were calculated with regard to the histological grade of AG and IM. The level of serum pepsinogen (PG) I and II was also measured as a marker for the presence of AG.

RESULTS

In the study population (n = 651), sensitivity and specificity, respectively, were as follows: culture, 56.2 and 100%; histology, 93.0 and 94.0%; CLOtest, 80.4 and 96.7%; serology, 96.0 and 67.5%. If the analysis is limited to those without AG or IM (n = 158) or to those younger than 40 years (n = 69), all tests, except for culture, had a sensitivity and specificity >90%. The sensitivity of CLOtest and the specificity of serology markedly decreased with progression of AG and IM, and serology was less specific in the presence of AG, as determined by a PG I/II ratio < or =4.1 (specificity, 83.7% vs 40.7% in PG I/II >4.1 and < or =4.1, respectively).

CONCLUSIONS

Any one of biopsy-based tests or serology was found to be excellent for identifying current H. pylori infection among individuals without AG or IM and/or younger patients (<40 years). However, a combination of at least two tests is necessary in the clinical setting of AG or IM.

Optimal dose of intravenous pantoprazole in patients with peptic ulcer bleeding requiring endoscopic hemostasis in Korea

BACKGROUND AND AIM

The lowest effective dose of proton pump inhibitors (PPI) for prevention of peptic ulcer rebleeding remains unclear. The objective of the present study was to evaluate whether low-dose PPI has a similar efficacy to high-dose i.v. administration for maintaining intragastric pH above 6.

METHODS

Sixty-one patients with bleeding ulcers were randomized into one of three groups after endoscopic hemostasis: pantoprazole 80 mg bolus followed by 8 mg/h; 40 mg, 4 mg/h infusion; and bolus injection of 40 mg every 24 h. Intragastric pH values and rebleeding rates were measured. In addition, pharmacokinetic parameters and association with CYP2C19 polymorphisms and H. pylori infection were assessed.

RESULTS

Mean percentage of time with intragastric pH > 6, and the proportion of patients with pH > 6 for more than 60% of the time were significantly higher in the 40 mg, 4 mg/h infusion group compared to the 40 mg bolus injection. There was no significant difference between the 80 mg, 8 mg/h and the 40 mg, 4 mg/h groups. In the H. pylori (-) group, only 40% of patients that received continuous infusion reached the target pH > 6 for more than 60% of the time; this was significantly lower than the H. pylori (+) group, 87.5% (P = 0.026).

CONCLUSIONS

A continuous infusion, regardless of high or low dose, was more effective for acid suppression than a 40 mg bolus PPI injection in Korea. H. pylori infection was an important factor for the maintenance of an intragastric pH > 6.

Could gastric histology be a useful marker for making decision on Helicobacter pylori eradication therapy in patients with dyspepsia?

CONTEXT: It still remains an open debate whether Helicobacter pylori eradication is beneficial or not for the improvement of symptoms in functional dyspepsia. Differences in geographic distribution, the worldwide H. pylori genetic variability and the fact that the outcome of infection is strongly related to the virulence of the infecting strain are factors that might be driving ongoing controversies. OBJECTIVE: To study the correlation between gastric histology and H. pylori serology status in patients with dyspepsia. METHODS: This is a cross-sectional study where 40 consecutive dyspeptic patients (28 women and 12 men, mean age 48.5 years) with endoscopically normal stomachs were selected from the endoscopy unit at a university hospital in Recife, PE, Northeast of Brazil, between March 1998 and July 1999. Patients underwent gastric mucosal biopsy and serological tests (anti-Hp and anti-CagA antibodies). Gastric biopsies were examined using H-E and Giemsa stains and gastritis was classified and graded (mild, moderate or severe) according to "the updated Sydney System - Houston, 1994". RESULTS: Among 40 patients with dyspepsia the gastric histology revealed that about ¼ had moderate (25%) or severe (2.5%) gastritis. This subgroup of patients also had a greater positive frequency of anti-Hp (100% vs 41%; P = 0.0005) and anti-CagA (91% vs 58%; P = 0.09) antibodies when compared with those with normal histology (27.5%) or mild gastritis (45%). CONCLUSION: Since upper gastrointestinal endoscopy is part of the functional dyspepsia investigation and serology for anti-CagA antibody is not available in daily clinical practice, by biopsying gastric mucosa we would only be able to selectively apply H. pylori eradication therapy for those with histology that best correlate with virulent infecting strains (moderate or severe gastritis) - around ¼ of our study patients with dyspepsia.

AZD6244 (ARRY-142886) enhances the therapeutic efficacy of sorafenib in mouse models of gastric cancer

Gastric cancer is a deadly disease for which current therapeutic options are extremely limited. Vascular endothelial growth factor receptors and platelet-derived growth factor receptors regulate gastric cancer cell proliferation, invasion, and tumor angiogenesis. In the present study, we report that sorafenib therapy effectively inhibited tumor growth and angiogenesis in tumor xenografts. These were associated with reduction in the phosphorylation of vascular endothelial growth factor receptor-2 Tyr951, c-Kit Tyr568/570, platelet-derived growth factor receptor-beta Tyr1021, and Akt Ser473 and Thr308, down-regulation of positive cell cycle regulators, increased apoptosis, and up-regulation of p27. Sorafenib treatment also caused up-regulation of p-c-Raf Ser338 and p-extracellular signal-regulated kinase (ERK) Thr202/Tyr204 in gastric cancer xenografts. The combination of sorafenib and MAP/ERK kinase inhibitor AZD6244 enhances the effectiveness of each compound alone. Potential effect of sorafenib/AZD6244 included increase in proapoptotic Bim. Our data show that MAP/ERK kinase inhibition enhances the antitumor activity of sorafenib in vivo, supporting a rationale for multitargeted suppression of the angiogenesis and ERK signaling network in gastric cancer therapy.

Secreted LOXL2 is a novel therapeutic target that promotes gastric cancer metastasis via the Src/FAK pathway

The purpose of this study was to investigate invasion- and metastasis-related genes in gastric cancer. To this end, we used the transwell system to select a highly invasive subcell line from minimally invasive parent cells and compared gene expression in paired cell lines with high- and low-invasive potentials. Lysyl oxidase-like 2 (LOXL2) was overexpressed in the highly invasive subcell line. Immunohistochemical analysis revealed that LOXL2 expression was markedly increased in carcinoma relative to normal epithelia, and this overexpression in primary tumor was significantly associated with depth of tumor invasion, lymph node metastasis and poorer overall survival. Moreover, LOXL2 expression was further increased in lymph node metastases compared with primary cancer tissues. RNA interference-mediated knockdown and ectopic expression of LOXL2 showed that LOXL2 promoted tumor cell invasion in vitro and increased gastric carcinoma metastasis in vivo. Subsequent mechanistic studies showed that LOXL2 could activate both the Snail/E-cadherin and Src kinase/Focal adhesion kinase (Src/FAK) pathways. However, secreted LOXL2 induced gastric tumor cell invasion and metastasis exclusively via the Src/FAK pathway. Expression correlation analysis in gastric carcinoma tissues also revealed that LOXL2 promoted invasion via the Src/FAK pathway but not the Snail/E-cadherin pathway. We then evaluated secreted LOXL2 as a target for gastric carcinoma treatment and found that an antibody against LOXL2 significantly inhibited tumor growth and metastasis. Overall, our data revealed that LOXL2 overexpression, a frequent event in gastric carcinoma progression, contributes to tumor cell invasion and metastasis, and LOXL2 may be a therapeutic target for preventing and treating metastases.

Gender difference of circulating ghrelin and leptin concentrations in chronic Helicobacter pylori infection

BACKGROUND

Both ghrelin and leptin are important appetite hormones secreted from the stomach. We examined whether demographic background, Helicobacter pylori infection, or its related gastritis severity could be associated with circulating ghrelin and leptin levels.

METHODS

This study prospectively enrolled 341 dyspeptic patients (196 females, 145 males), who had received endoscopy to provide the gastric specimens over both antrum and corpus for histology reviewed by the updated Sydney's system. The fasting blood sample of each patient was obtained for total ghrelin and leptin analysis.

RESULTS

Without H. pylori infection, there were similar ghrelin levels between female and male patients. In the H. pylori-infected patients, the males had lower plasma ghrelin levels than females (1053 vs. 1419 pg/mL, p < .001). Only in males, not in females, the H. pylori infection and its related acute and chronic inflammation scores were significantly associated with a lower ghrelin level (p < or = .04). The multivariate regression disclosed that only the chronic inflammation score independently related to a lower ghrelin level. Only in males, the ghrelin levels ranked in a downward trend for the gastritis feature as with limited-gastritis, with antrum-predominant gastritis, and with corpus-gastritis (1236, 1101, and 977 pg/mL). Leptin level was not related to H. pylori-related gastritis, but positively related to body mass index.

CONCLUSION

There should be a gender difference to circulating total ghrelin levels, but not leptin levels, in response to H. pylori infection and its related chronic gastritis.

Influence of Helicobacter pylori eradication on reflux esophagitis in Japanese patients

The relationship between Helicobacter pylori eradication and reflux esophagitis is controversial. We analyzed the development of reflux esophagitis and the change in the grade of pre-existing reflux esophagitis after eradication. Enrolled were 559 Japanese patients who received eradication therapy for H. pylori. The grade of reflux esophagitis by endoscopy before and after therapy was evaluated retrospectively. No esophagitis was present before eradication in 526 patients. H. pylori was and was not eradicated in 429 and 97, respectively. Reflux esophagitis developed in 40 of the eradication group and in three of the treatment failure group, with prevalence higher with successful eradication (P = 0.04). Successful eradication and hiatus hernia were significant risk factors for reflux esophagitis development. Twenty-seven of 33 patients with pre-existing reflux esophagitis had successful eradication and six treatment failure. The reflux esophagitis grade worsened in two (Los Angeles classification from A to B) and improved in 14 patients after eradication. With treatment failure, reflux esophagitis worsened in none and improved in three patients. There showed no significant change in the grade of pre-existing reflux esophagitis after H. pylori eradication but the sample size was too small to evaluate the difference. In conclusion, the eradication of H. pylori increases the prevalence of reflux esophagitis, and hiatus hernia was a significant risk factor for the development of reflux esophagitis.

Effect of Low-dose, Enteric Coated Aspirin on Gastrointestinal Bleeding in Patients with Coronary Artery Disease

BACKGROUND/AIMS

This study was performed to determine whether low-dose aspirin and/or clopidogrel can induce gastrointestinal bleeding and gastroduodenal mucosal injury.

METHODS

A total of 387 patients who underwent coronary angiography at Seoul National University Bundang Hospital were assigned to one of three antiplatelet treatment groups: (1) control, (2) 100-mg enteric coated aspirin, and (3) 100-mg enteric coated aspirin plus clopidogrel. The incidences of gastroduodenal mucosal injury and gastrointestinal bleeding were prospectively evaluated, and risk factors for gastrointestinal bleeding were analyzed.

RESULTS

for gastrointestinal bleeding were analyzed.

RESULTS

The rate of gastroduodenal mucosal injury was higher in the aspirin-plus-clopidogrel group than in the aspirin group (p=0.012), and higher in the aspirin group than in the control group (p=0.049). The rate of gastrointestinal bleeding was significantly higher in the aspirin-plus-clopidogrel group (9.4%) than in the control group (2.4%, p=0.048). The risk factors for gastrointestinal bleeding were older age (>/=60 years) and the presence of at least two comorbid disorders.

CONCLUSIONS

Low-dose enteric coated aspirin was found to be safe in patients with coronary artery disease, but the addition of clopidogrel increased the rate of gastrointestinal bleeding. Combined clopidogrel and aspirin should be used with caution in older patients having at least two comorbid conditions.

Prevalence and risk factors of atrophic gastritis and intestinal metaplasia in a Korean population without significant gastroduodenal disease

BACKGROUND AND AIM

The prevalence of gastric cancer and Helicobacter pylori infection is unacceptably high in Korea. This study was performed to evaluate the prevalence of atrophic gastritis (AG) and intestinal metaplasia (IM) and to identify their risk factors with respect to H. pylori virulence factors, and environmental and host factors, in Korean population without significant gastroduodenal disease.

METHODS

The study cohort consisted of 389 subjects (> or = 16 years). AG and IM were scored histologically using the Sydney classification in the antrum and body, respectively. Prevalences and bacterial factors (i.e. cagA, vacA m1, and oipA), environmental factors (i.e. smoking and alcohol), and host factors (i.e. genetic polymorphisms of IL-1B-511, IL-1RN, TNF-A-308, IL-10-592, IL-10-819, IL-10-1082, IL-8-251, IL-6-572, GSTP1, p53 codon 72, and ALDH2) were evaluated.

RESULTS

Prevalences of AG in the antrum and body were 42.5% and 20.1%, and those of IM were 28.6% and 21.2%, respectively. The presences of AG and IM were significantly higher in H. pylori-positive than in the H. pylori-negative subjects. Multivariate analysis showed that the risk factors for AG were H. pylori infection, age > or = 61 years, and cagA and vacA m1 positivity. For IM the risk factors were H. pylori infection, age > or = 61 years, a smoking history (rather than current smoking), strong spicy food, occupation (unemployed or nonprofessional vs. professional), and the presence of IL10-592 C/A as opposed to A/A. In addition, IL6-572 G carrier was found to have a protective effect against IM development as compared with C/C.

CONCLUSION

H. pylori infection was most important risk factor of AG and IM. Bacterial factors were found to be important risk factor for AG but environmental and host factors were more important for IM.

Natural history of Helicobacter pylori infection

This report describes the modalities of chronic gastritis induced by Helicobacter pylori infection in different populations. The full gamut of lesions representing the precancerous cascade is very prevalent in populations of low socioeconomic background experiencing very high gastric cancer risk, as seen in the Latin American Andes Mountains. In populations of high socioeconomic standards and high cancer risk, such as Japan and Korea, the precancerous cascade predominates and "early" cancers are also diagnosed frequently. Some reports describe frequent corpus atrophy, not prominent in the former group. The so-called African enigma is seen in populations of low socioeconomic standards, usually living at low altitudes, with high prevalence of infection but low frequency of cancer and precancerous lesions. In populations in transition from high to low cancer risk, duodenal ulcer and antral non-atrophic gastritis are frequently seen. In affluent societies at low risk of cancer, such as Western Europe, Australia and North America, mild non-atrophic gastritis associated with low virulence Helicobacter pylori genotypes predominate. The varied phenotypes of gastritis may reflect secular changes in the ecology of our species.

Helicobacter pylori infection and the pathogenesis of gastric cancer: a paradigm for host-bacterial interactions

Helicobacter pylori infection is the most important acquired risk factor for gastric cancer. The infection initiates a chronic inflammatory process that eventually alters the physiology of the gastric environment and leads to achlorohydria. Gastric atrophy may be part of this process but cancer can arise without this precursor. The net effect of decades of inflammation is the establishment of a milieu awash with pro-inflammatory cytokines and characterized by the activation of signalling pathways that cross-talk between inflammation and carcinogenesis. Many of the factors involved in chronic inflammation play a dual role in the process-promoting neoplastic progression but also facilitating cancer prevention. H. pylori bacterial virulence factors as well as host genetic factors play a major role in orchestrating the increased risk of cancer. The study of such host-bacterial interaction is key to uncovering the molecular and cellular pathways involved and will ultimately lead to developing preventive and therapeutic strategies against this global killer.

Assessment of atrophic gastritis using the OLGA system

BACKGROUND

An international group of gastroenterologists and pathologists (Operative Link for Gastritis Assessment (OLGA)) proposed the staging system of atrophy. The aim of this study was to assess the severity of atrophic gastritis using the OLGA system.

MATERIALS AND METHODS

The subjects comprised 163 H. pylori-positive patients: 18 with early gastric cancers of the intestinal type (GC), 55 with atrophic gastritis (AG), 49 with gastric ulcers or scars (GU), and 41 with duodenal ulcers or scars (DU). Biopsies were taken from the lesser and greater curvatures of the antrum and middle body. The OLGA gastritis stage (0-IV) (the severity and topography of atrophy) was obtained by combining antral with body atrophy scores. The gastritis grade (the severity and topography of inflammation) was obtained by combining antral and body inflammation scores.

RESULTS

Most (84%) of patients with GC showed stage III or IV. Gastritis stages were significantly higher in patients with GC than in those with AG, GU, and DU. Gastritis stage became higher with age. Gastritis grades were slightly higher in patients with AG than in others.

CONCLUSIONS

Our results indicate that higher stages are found in patients with GC using the OLGA staging system and that the high risk of GC can be recognized. It is simple to use and useful for the assessment of the severity of atrophic gastritis.

Environmental factors in the etiology of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is currently one of the most common health problems in the Western world, affecting up to 20% of the adult population weekly and 50% monthly. It generates substantial suffering among patients as well as significant costs to both patients and society in general. GERD can further result in serious complications such as esophageal strictures, Barrett's esophagus and esophageal adenocarcinoma. This review discusses the current knowledge on risk factors and potential protective factors in the development of GERD.

Host-bacterial interactions in Helicobacter pylori infection

Helicobacter pylori are spiral-shaped gram-negative bacteria with polar flagella that live near the surface of the human gastric mucosa. They have evolved intricate mechanisms to avoid the bactericidal acid in the gastric lumen and to survive near, to attach to, and to communicate with the human gastric epithelium and host immune system. This interaction sometimes results in severe gastric pathology. H pylori infection is the strongest known risk factor for the development of gastroduodenal ulcers, with infection being present in 60%-80% of gastric and 95% of duodenal ulcers.(1)H pylori is also the first bacterium to be classified as a definite carcinogen by the World Health Organization's International Agency for Research on Cancer because of its epidemiologic relationship to gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue lymphoma.(2) In the last 25 years, since H pylori was first described and cultured, a complete paradigm shift has occurred in our clinical approach to these gastric diseases, and more than 20,000 scientific publications have appeared on the subject. From the medical point of view, H pylori is a formidable pathogen responsible for much morbidity and mortality worldwide. However, H pylori infection occurs in approximately half of the world population, with disease being an exception rather than the rule. Understanding how this organism interacts with its host is essential for formulating an intelligent strategy for dealing with its most important clinical consequences. This review offers an insight into H pylori host-bacterial interactions.

Geographical conservation of short inserts in the signal and middle regions of the Helicobacter pylori vacuolating cytotoxin gene

Short nucleotide sequence inserts within the signal (s) and mid (m) regions of the vacuolating cytotoxin gene (vacA) of Helicobacter pylori provide the basis for defining the allelic forms widely used for strain typing and as markers for toxin functionality and severity of interactions with host gastric epithelial cells. Here 484 signal region and 411 mid-region sequences (new and from public databases) from 32 countries were analysed to determine the effect of geographical location on insert diversity, which is currently undefined. Short (27 bp) inserts of 52 mol% G+C from 201 sequences (98 %) of the s2 allelic family encoded a highly conserved nine amino acid sequence irrespective of geographical origin. The longer (75 bp) mid-region insert of 38 mol% G+C in 255 sequences of the m2 allelic family was more diverse and represented by 23 peptide variants, with one predominant sequence (MRI type 4) representing 62 % of inserts. Mid-region inserts were widespread throughout European/North American (Western) sequences in the dataset whereas a lower insert frequency was a geographical feature of East Asian sequences. Each insert was preceded by an associated conserved motif that provided a marker of the insertion sites within vacA, and facilitated identification of the Chinese m2b genotype. It is concluded that the observed sequence conservation supports the continued global use of vacA genotyping, and that inserts could have a functional significance in the mature protein, particularly the s2 form of the toxin, as the same combination of signal and mid-region insert type and preinsert motif was highly conserved.

Helicobacter pylori gastritis, the unifying concept for gastric diseases

Helicobacter pylori infection causes a broad spectrum of clinical diseases and the clinical manifestations of the infection depend on host, environmental, and bacterial factors. These factors have an impact on the pattern and severity of gastritis and ultimately determine the clinical outcome of H. pylori infection. Better staging of gastritis may help to identify patients at risk of gastric cancer. In this article we will examine the complex interaction between host, environmental, and bacterial factors in the pathogenesis of H. pylori infection.

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.

Helicobacter and gastric malignancies

Over the past year Helicobacter pylori has been confirmed as the most important risk factor for non-cardia gastric adenocarcinomas and gastric mucosa-associated lymphoid tissue (MALT) lymphomas. Eradication therapy has been proven to be beneficial when given prior to the development of intestinal metaplasia, but is less efficacious when administered later. However, the best data from clinical trials indicate that H. pylori eradication alone will have only a moderate effect on gastric cancer incidence worldwide. The mechanisms responsible for H. pylori-associated gastric carcinogenesis continue to be dissected. Accumulating evidence suggests that some H. pylori may be able to invade through the gastric epithelial barrier, though pro-carcinogenic effects may also be related to the complex and evolving pathways of altering signal transduction pathways within gastric epithelial cells that are stimulated by adherence and translocation of H. pylori products through its type IV secretory system. Determinants of the host response to H. pylori infection continue to focus on polymorphisms in genes related to the innate and acquired immune responses, including NOD2, COX-2, and TLR-4. H. pylori eradication is indicated for low-grade gastric B-cell MALT lymphoma and may even provide "cure" in some apparently H. pylori-negative cases. How and why does H. pylori promote lymphomagenesis? Some evidence from human and murine models points to specific chromosomal translocations and host genetic polymorphisms as relating to the outcome of infection. Finally, Helicobacter hepaticus infection has been linked to both intestinal and breast tumorigenesis in susceptible strains of female mice - a provocative and novel finding warranting further investigation.

Histopathological profile of gastritis in adult patients seen at a referral hospital in Kenya

AIM

To conduct a detailed histological study of gastritis in adult patients attending an endoscopy clinic at a Kenyan teaching and referral hospital.

METHODS

Biopsy specimens from consecutive patients were examined and graded according to the Updated Sydney System for H pylori infection, chronic inflammation, neutrophil activity, glandular atrophy and intestinal metaplasia. Also documented were gastric tissue eosinophil counts and presence of lymphoid follicles.

RESULTS

The rate of the graded variables, in the antrum and corpus respectively, were as follows: H pylori infection (91%, 86%), chronic inflammation (98%, 93%), neutrophil activity (91%, 86%), glandular atrophy (57%, 15%) and intestinal metaplasia (11%, 2%). Lymphoid follicles were noted in 11% of cases. Duodenal and gastric ulcers were documented in 32% and 2% respectively. The mean eosinophil count was 5.9 +/- 0.74 eosinophils/HPF and 9.58 +/- 0.93 eosinophils/HPF in the corpus and antrum respectively. Significant association was found between the degree of H pylori colonisation with chronic inflammation, neutrophil activity and antral glandular atrophy. Biopsies from the antrum and corpus showed significant histopathological discordance for all the graded variables. H pylori negative cases were associated with recent antibiotic use.

CONCLUSION

The study reaffirms that H pylori is the chief cause of gastritis in this environment. The majority of patients show a moderate to high degree of inflammation but a low degree of glandular atrophy and intestinal metaplasia. The study shows that inter-relationships between the histological variables in this African population are similar to those found in other populations worldwide including non-African populations.

Helicobacter pylori and oesophageal cancer--not always protective

The mechanism of the positive association between atrophic gastritis and oesophageal squamous cell carcinoma