Differential north to south gastric cancer-duodenal ulcer gradient in China. China Ulcer Study Group

Nomogram to Predict Recurrence and Guide a Pragmatic Surveillance Strategy After Resection of Hepatoid Adenocarcinoma of the Stomach: A Retrospective Multicenter Study

BACKGROUND

An accurate recurrence risk assessment system and surveillance strategy for hepatoid adenocarcinoma of the stomach (HAS) remain poorly defined. This study aimed to develop a nomogram to predict postoperative recurrence of HAS and guide individually tailored surveillance strategies.

METHODS

The study enrolled all patients with primary HAS who had undergone curative-intent resection at 14 institutions from 2004 to 2019. Clinicopathologic variables with statistical significance in the multivariate Cox regression were incorporated into a nomogram to build a recurrence predictive model.

RESULTS

The nomogram of recurrence-free survival (RFS) based on independent prognostic factors, including age, preoperative carcinoembryonic antigen, number of examined lymph nodes, perineural invasion, and lymph node ratio, achieved a C-index of 0.723 (95% confidence interval [CI], 0.674-0.772) in the whole cohort, which was significantly higher than those of the eighth American Joint Committed on Cancer (AJCC) staging system (C-index, 0.629; 95% CI, 0.573-0.685; P < 0.001). The nomogram accurately stratified patients into low-, middle-, and high-risk groups of postoperative recurrence. The postoperative recurrence risk rates for patients in the middle- and high-risk groups were respectively 3 and 10 times higher than for the low-risk group. The patients in the middle- and high-risk groups showed more recurrence and metastasis, particularly multiple site metastasis, within 36 months after the operation than those in the low-risk group (low, 2.2%; middle, 8.6%; high, 24.0%; P = 0.003).

CONCLUSIONS

The nomogram achieved good prediction of postoperative recurrence for the patients with HAS after radical resection. For the middle- and high-risk patients, more active surveillance and targeted examination methods should be adopted within 36 months after the operation, particularly for liver and multiple metastases.

Association of gastric and duodenal ulcers with anthropometry and nutrients: Korean National Health and Nutrition Examination Survey (KNHANES II-IV) 2001-2009

Objectives

The objective of this study was to examine the association of peptic ulcer disease (PUD), including gastric ulcer and duodenal ulcer, with obesity-related indices, nutrients, and blood parameters in Korean adults.

Methods

Data were obtained from the Second-Fourth Korean National Health and Nutrition Examination Survey (KNHANES II-IV). Binary logistic regression was carried out to analyze the association between PUD and all variables in the crude analysis; in a subsequent analysis, adjustments were made for age, region, house type, number of snacks per day, and number of household members.

Results

PUD exhibited the highest association with age in both men and women among all variables used in this study. In men, only body mass index was associated with PUD in both the crude and adjusted analyses. PUD was associated with weight, height, and fat in the crude analysis, but these associations disappeared after adjustment for confounders. Vitamin B2, hemoglobin, and glucose were related to PUD, but these associations became nonsignificant in the adjusted analysis. Water, vitamin C, and potassium were not associated with PUD in the crude analysis but were associated with PUD after adjustment for confounders. In women, systolic blood pressure and height were associated with PUD. PUD was also related to waist circumference, the waist-to-height ratio, fat, and cholesterol, but these associations became nonsignificant after adjustment for confounders. Vitamin C, protein, niacin, sodium, energy, vitamin B2, vitamin B1, and aspartate aminotransferases were associated with PUD in only the crude analysis. PUD was not associated with diastolic blood pressure, water, vitamin A, or glucose, but these factors were associated with the disease in the adjusted analysis.

Conclusion

Older age was a risk factor for PUD in Korean adults, and the association of PUD with most nutrients and anthropometric indices may differ according to gender.

Different Pathophysiology of Gastritis in East and West? A Western Perspective

Background

Gastritis results from multifactorial gastric mucosal injury. Helicobacter pylori (Hp) is the main cause, and associated diseases have typical underlying patterns of gastritis. Gastric ulcer and gastric cancer (GC) develop from chronic atrophic corpus gastritis (CAG) which therefore represents the most important pattern. GC incidences in East Asia are substantially higher than elsewhere, and this should be also reflected by higher prevalences of CAG and characteristic differences in pathophysiology compared to the West.

Summary

The few available comparative studies of gastritis in Eastern and Western patients are summarized. The main pathogenic factors of gastritis are discussed together with their limitations to explain local differences in disease outcome. Emphasis was put to also include less well-established pathogenic host and environmental factors of possible impact.

Conclusions

CAG is more prevalent in East Asian areas with high GC incidences than the West. Geographic heterogeneity of associated diseases is due to differences in Hp prevalence and virulence as well as modulating host and environmental factors. The following may contribute to the higher burden of CAG in the East: ABD type of CagA with vacA s1 and babA2 alleles of Hp, host Lewis(b) expression in sej/sej nonsecretors, H. heilmannii, low parietal cell mass, high sodium and nitrate intake, preferences in vegetable and fruit consumption, cigarette smoking, air pollution, alcohol. Conversely, green tea, nonfermented soy products and rice may confer protective effects. Hp is on the decline, but also in a world cleared from this bacterium, differences in host genetics will continue to modify gastric disease outcome together with maintained customs as part of cultural diversity.

Clinical epidemiology of gastric cancer

Gastric cancer is the second leading cause of cancer-related mortality and the fourth most common cancer globally. There are, however, distinct differences in incidence rates in different geographic regions. While the incidence rate of gastric cancer has been falling, that of gastric cardia cancers is reportedly on the rise in some regions. Helicobacter pylori (H. pylori) infection is a major risk factor of non-cardia gastric cancer, and data has emerged concerning the role of H. pylori eradication for primary prevention of gastric cancer. Dietary, lifestyle and metabolic factors have also been implicated. Although addressing these other factors may contribute to health, the actual impact in terms of cancer prevention is unclear. Once irreversible histological changes have occurred, endoscopic surveillance would be necessary. A molecular classification system offers hope for molecularly tailored, personalised therapies for gastric cancer, which may improve the prognosis for patients.

Geographical distribution of the incidence of gastric cancer in Bhutan

AIM: To estimate the prevalence of gastric cancer (GC) in a cohort of patients diagnosed with GC and to compare it with patients diagnosed with all other types of gastro-intestinal (GI) cancer during the same period.

METHODS: Between 2008 and 2013, five-year period, the medical records of all GI cancer patients who underwent medical care and confirm diagnosis of cancer were reviewed at the National Referral Hospital, Thimphu which is the only hospital in the country where surgical and cancer diagnosis can be made. Demographic information, type of cancer, and the year of diagnosis were collected.

RESULTS: There were a total of 767 GI related cancer records reviewed during the study period of which 354 (46%) patients were diagnosed with GC. There were 413 patients with other GI cancer including; esophagus, colon, liver, rectum, pancreas, gall bladder, cholangio-carcinoma and other GI tract cancers. The GC incidence rate is approximately 0.9/10000 per year (367 cases/5 years per 800000 people). The geographic distribution of GC was the lowest in the south region of Bhutan 0.3/10000 per year compared to the central region 1.4/10000 per year, Eastern region 1.2/10000 per year, and the Western region 1.1/10000 per year. Moreover, GC in the South part was significantly lower than the other GI cancer in the same region (8% vs 15%; OR = 1.8, 95%CI: 1.3-3.1, P = 0.05). Among GC patients, 38% were under the age of 60 years, mean age at diagnosis was 62.3 (± 12.1) years with male-to-female ratio 1:0.5. The mean age among patients with all other type GI cancer was 60 years (± 13.2) and male-to-female ratio of 1:0.7. At time of diagnosis of GC, 342 (93%) were at stage 3 and 4 of and by the year 2013; 80 (23%) GC patients died compared to 31% death among patients with the all other GI cancer (P = 0.08).

CONCLUSION: The incidence rate of GC in Bhutan is twice as high in the United States but is likely an underestimate rate because of unreported and undiagnosed cases in the villages. The high incidence of GC in Bhutan could be attributed to the high prevalence of Helicobacter pylori infection that we previously reported. The lowest incidence of GC in Southern part of the country could be due to the difference in the ethnicity as most of its population is of Indian and Nepal origin. Our current study emphasizes on the importance for developing surveillance and prevention strategies for GC in Bhutan.

North vs south differences in acute peptic ulcer hemorrhage in Croatia: hospitalization incidence trends, clinical features, and 30-day case fatality

Aim

To assess the seven-year trends of hospitalization incidence due to acute peptic ulcer hemorrhage (APUH) and associated risk factors, and examine the differences in these trends between two regions in Croatia.

Methods

The study collected sociodemographic, clinical, and endoscopic data on 2204 patients with endoscopically confirmed APUH who were admitted to the Clinical Hospital Center “Sestre Milosrdnice,” Zagreb and Clinical Hospital Center Split between January 1, 2005 and December 31, 2011. We determined hospitalization incidence rates, 30-day case fatality rate, clinical outcomes, and incidence-associated factors.

Results

No differences were observed in APUH hospitalization incidence rates between the regions. Age-standardized one-year cumulative APUH hospitalization incidence rate calculated using the European Standard Population was significantly higher in Zagreb than in Split region (43.2/100 000 vs 29.2/100,000). A significantly higher APUH hospitalization incidence rates were observed in the above 65 years age group. Overall 30-day case fatality rate was 4.9%.

Conclusion

The hospitalization incidence of APUH in two populations did not change over the observational period and it was significantly higher in the Zagreb region. The incidence of acute duodenal ulcer hemorrhage also remained unchanged, whereas the incidence of acute gastric ulcer hemorrhage increased. The results of this study allow us to monitor epidemiological indicators of APUH and compare data with other countries.

A link between cold environment and cancer

Many risk factors such as smoking and change of life style have been shown to promote genetic and adaptive epigenetic changes responsible for tumorigenesis. This study brings environmental temperature as a cancer causing factor to light. The cancer mortality rate (CMR) of a country was correlated with 17 different variables. Multivariate analysis of a total of 188 countries found that the average annual temperature (AAT) of a country might have a significant contribution to cancer death when compared with other factors such as alcohol and meat consumption. Univariate analysis found a negative correlation between AAT and CMR. All these countries were categorized into three temperature zones (zone I, -2 to 11.5 °C; number of countries, 38; zone II, 11.6 to 18.6 °C; number of countries, 32; and zone III, 18.7 to 30 °C; number of countries, 118). Out of the top-most 50 countries having the highest CMR, 26 (68.42 %), 10 (31.25 %), and 14 (11.66 %) belong to zone I, zone II, and zone III, respectively. Out of the least 50 countries having the lowest CMR, 1 (2.63 %), 4 (12.5 %), and 45 (37.5 %) belong to zone I, zone II, and zone III, respectively. CMR is low in those countries situated near to the Torrid zone (33(°) N to 23.5(°)S), but it is high for those countries situated away from these two latitudes. These data indicate that cold temperature may have a contribution in increasing tumorigenesis. High metabolic stress, which is the result of maintaining our body temperature against a cold environment, could be the possible cause for the higher cancer mortality.

Role of dietary phospholipids and phytosterols in protection against peptic ulceration as shown by experiments on rats

Geographically the prevalence of duodenal ulceration is related to the staple foods in the diet in regions of developing countries where the diet is stable. It is higher in regions where the diet is based on milled rice, refined wheat or maize, yams, cassava, sweet potato, or green bananas, and is lower in regions where the staple diet is based on unrefined wheat or maize, soya, certain millets or certain pulses. Experiments on rat gastric and duodenal ulcer models showed that it was the lipid fraction in staple foods from low prevalence areas that was protective against both gastric and duodenal ulceration, including ulceration due to non-steroidal anti-inflammatory drugs (NSAIDs). It also promoted ulcer healing. The lipid from the pulse, Dolichos biflorus, horse gram which was highly protective was used to identify the fractions with protective activity in the lipid. The protective activity lay in the phospholipid, sterol and sterol ester fractions. In the phospholipid fraction phosphatidyl choline (lethicin) and phosphatidyl ethanolamine (cephalin) were predominant. In the sterol fraction the sub-fractions showing protective activity contained β-sitosterol, stigmasterol, and an unidentified isomer of β-sitosterol. The evidence from animal models shows that certain dietary phospholipids and phytosterols have a protective action against gastroduodenal ulceration, both singly and in combination. This supports the protective role of staple diets in areas of low duodenal ulcer prevalence and may prove to be of importance in the prevention and treatment of duodenal ulceration and management of recurrent ulcers. A combination of phospholipids and phytosterols could also play an important role in protection against ulceration due to NSAIDs.

Gastric ulcer patients are more susceptible to developing gastric cancer compared with concomitant gastric and duodenal ulcer patients

Intestinal metaplasia (IM) and dysplasia are precancerous lesions of gastric cancer (GC); however, the prevalence of IM and dysplasia in patients exhibiting single gastric ulcer (GU) and concomitant gastric and duodenal ulcer (CGDU) varies. In the present study consecutive patients who had undergone esophagogastroduodenal endoscopy were retrospectively screened, and those presenting with GU or CGDU were further evaluated for IM and dysplasia. Patients diagnosed with GC or lymphoma and patients with a history of anti-Helicobacter pylori, non-steroidal anti-inflammatory medicine (NSAIM), H₂-receptor antagonist or proton pump inhibitor therapy, were excluded from the present study. Of the 204,073 consecutively screened cases, 8,855 (4.3%) and 2,397 (1.2%) were diagnosed with GU and CGDU, respectively. A total of 1,722 GU and 233 CGDU patients were excluded; thus, 7,133 and 2,164 cases of GU and CGDU, respectively (n=9,297), were included in the present study. IM and dysplasia were observed in 1,348 (14.5%) and 210 (2.3%) patients, respectively. IM was more frequently identified in GU patients compared with CGDU patients (16.4 vs. 8.3%; odds ratio [OR], 2.158; 95% confidence interval [CI], 1.830–2.545; χ²=86.932; P<0.001); furthermore, GU patients exhibited significantly more frequent IM compared with CGDU patients at the gastric antrum (14.2 vs. 5.5%; OR, 2.818; 95% CI, 2.199–3.610; χ²=72.299; P<0.001), gastric incisura (24.0 vs. 14.1%; OR, 1.922; 95% CI, 1.502–2.432; χ²=30.402; P<0.001) and gastric corpus (12.6 vs. 3.3%; OR, 4.259; 95% CI, 1.030–17.609; χ²=4.736; P=0.026). Dysplasia was significantly more frequently identified in GU patients compared with CGDU patients (2.7 vs. 0.7%; OR, 4.027; 95% CI, 2.376–6.823; χ²=31.315; P<0.001), with GU patients exhibiting significantly more severe dysplasia at the gastric antrum (2.4 vs. 0.7%; OR, 3.339; 95% CI, 1.735–6.425; χ²=14.652; P<0.001) and the gastric incisura (2.9 vs. 0.7%; OR, 4.255; 95% CI, 1.694–10.689; χ²=11.229; P<0.001). Additionally, mild IM was more frequently identified in GU patients compared with CGDU patients (15.2 vs. 7.1%; OR, 2.353; 95% CI, 1.972–2.807; χ²=94.798; P<0.001) and dysplasia of a mild (1.7 vs. 0.6%; OR, 2.807; 95% CI, 1.580–4.987; χ²=13.519; P<0.001) or moderate/severe grade (1.1 vs. 0.09%; OR, 11.642; 95% CI, 2.857–47.439; χ²=18.896; P<0.001) was more frequent in GU patients compared with CGDU patients. IM and dysplasia were more frequently observed in GU compared with CGDU patients in the present study, which may be associated with an increased probability of developing GC.

Prevalence and correlation with clinical diseases of Helicobacter pylori cagA and vacA genotype among gastric patients from Northeast China

Helicobacter pylori vacA and cagA genes have significant genetic heterogenicity, resulting in different clinical outcomes. Northeast part of China has reported high prevalence of H. pylori infections and gastric cancer. Hence, we investigated the H. pylori cagA and vacA genotypes with clinical outcomes in Northeast China. Gastric tissue samples (n = 169), chronic gastritis (GIs), gastric ulcer (GU), and gastric cancer (GC) were analysed for 16S rRNA ureA, cagA, and cagA genotypes by PCR. A total of 141 (84%) cases were found positive for H. pylori by 16S rRNA and ureA. GC showed high H. pylori infection (93%) compared with GIs (72%) and GU (84%). The vacAs1am1 was highly found in GC (40%) and GU (36%), vacAs1am2 in GIs (33%), vacAs1bm1 (14%) and vacAs1bm2 (8%) in GU cases, and s2m1 in normal cases (33%), while vacAs1cm1 showed low frequency in GIs (2%) and GU (3%) and GC showed negative result. The East-Asian cagA strain was highly observed in GC (43%), as compared to GIs (41%) and GU (20%). The East-Asian cagA/vacAs1am1 was significantly higher in GC (23%) than in GU (22%) and GIs (145) patients. The East-Asian type cagA with vacAs1a and vacAm1 is the most predominant genotype in H. pylori strains of Northeast China.

Different gastric mucosa and CagA status of patients in India and Japan infected with Helicobacter pylori

BACKGROUND AND AIM

Despite similar incidence of Helicobacter pylori infection, the frequency of gastric cancer is sevenfold higher in Japan than in India. The objective of this work was to define differences in H. pylori-induced gastritis and to identify the bacterial virulence factors involved.

MATERIALS AND METHODS

We prospectively enrolled 353 consecutive patients who underwent endoscopy and received three gastric biopsies in Tokyo, Japan, and Hyderabad, India. Immunohistochemistry against H. pylori and East Asian CagA and hematoxylin-eosin and Giemsa stain were used to examine gastric mucosal biopsy specimens. Histological scores were assessed in accordance with the updated Sydney System. Subjects with H. pylori infection were matched by age and sex to compare histopathology and bacterial virulence.

RESULTS

Sixty patients infected with H. pylori were prospectively selected. Median histological scores for neutrophil and mononuclear cell infiltration and for atrophy were significantly higher in Japan than in India (neutrophils 4.0 vs 3.0, p < 0.01; mononuclear cells 5.0 vs 4.5, p = 0.03; atrophy 3.0 vs 2.0, p < 0.01, respectively). Scores for H. pylori density and intestinal metaplasia were also higher in Japan, albeit without statistical significance (H. pylori 5.0 vs 3.0, p = 0.08; intestinal metaplasia 0.0 vs 0.0, p = 0.08). Prevalence of East Asian CagA-positive H. pylori was significantly higher in Japan (73.3 vs 0.0 %, p < 0.01).

CONCLUSION

The significantly higher prevalence of histologically severe gastritis and East Asian CagA in patients from Japan with H. pylori infection may be involved in the pathogenesis of gastric cancer.

Staple diets and duodenal ulcer prevalence

The prevalence of duodenal ulceration in India, Africa, China and other developing countries is high in some regions and low in others, despite a high prevalence of Helicobacter pylori infection throughout the areas. This variation is related to the staple diet of the regions involved. In regions where, because of the climate, the staple food is milled white rice, wheat or maize, or cassava, yams,sweet potato and green bananas the prevalence of duodenal ulcer is higher than in regions where the staple diet is based on unrefined wheat or maize, soya, certain millets or pulses. These differences have been reproduced in animal peptic ulcer models. Using these models it has been shown that the protective factor against ulceration lies in the lipid fraction present in staple foods from the low prevalence areas. The lipid fraction not only gave protection in the experimental models against ulceration but also promoted healing. The pulse Dolichos biflorus (horse gram) gave the greatest yield of the lipid and this was used for further investigations. It was found that the ulceroprotective activity of the lipid lay in its phospholipid and sterols fractions. The presence or absence of protective lipid in the diet would account for the regional differences in duodenal ulcer prevalence.

Is Helicobacter pylori Infection the Primary Cause of Duodenal Ulceration or a Secondary Factor? A Review of the Evidence

Helicobacter pylori (H. pylori) has a role in the multifactorial etiology of peptic ulcer disease. A link between H. pylori infection and duodenal ulcer disease is now established. Other contributing factors and their interaction with the organism may initiate the ulcerative process. The fact that eradication of H. pylori infection leads to a long-term cure in the majority of duodenal ulcer patients and the fact that the prevalence of infection is higher in ulcer patients than in the normal population are cogent arguments in favor of it being the primary cause of the ulceration. Against this concept there are issues that need explanation such as the reason why only a minority of infected persons develop duodenal ulceration when infection with H. pylori is widespread. There is evidence that H. pylori infection has been prevalent for several centuries, yet duodenal ulceration became common at the beginning of the twentieth century. The prevalence of duodenal ulceration is not higher in countries with a high prevalence of H. pylori infection. This paper debate puts forth the point of view of two groups of workers in this field whether H. pylori infection is the primary cause of duodenal ulcer disease or a secondary factor.

Dietary phosphilipids and sterols protective against peptic ulceration

The prevalence of duodenal ulceration in regions of developing countries with a stable diet is related to the staple food(s) in that diet. A higher prevalence occurs in areas where the diet is principally milled rice, refined wheat or maize, yams, cassava, sweet potato or green bananas, and a lower prevalence in areas where the staple diet is based on unrefined wheat or maize, soya, certain millets or certain pulses. Experiments using animal peptic ulcer models showed that the lipid fraction in foods from the staple diets of low prevalence areas gave protection against both gastric and duodenal ulceration, including ulceration due to non-steroidal anti-inflammatory drugs (NSAIDs), and also promoted healing of ulceration. The protective activity was found to lie in the phospholipid, sterol and sterol ester fractions of the lipid. Amongst individual phospholipids present in the phospholipid fraction, phosphatidyl ethanolamine (cephalin) and phosphatidyl choline (Lecithin) predominated. The sterol fraction showing activity contained β-sitosterol, stigmasterol and an unidentified isomer of β-sitosterol. The evidence shows that dietary phytosterols and phospholipids, both individually and in combination, have a protective effect on gastroduodenal mucosa. These findings may prove to be important in the prevention and management of duodenal and gastric ulceration including ulceration due to NSAIDs.

Observation of gastric mucosa in Bangladesh, the country with the lowest incidence of gastric cancer, and Japan, the country with the highest incidence

BACKGROUND

The prevalence of Helicobacter pylori (H. pylori) infection is high, but the incidence of gastric cancer is low in natives of Bangladesh. The gastric mucosa was observed in Bangladeshi patients to investigate the differences between Bangladeshis and Japanese.

MATERIALS AND METHODS

The study involved 418 Bangladeshi and 2356 Japanese patients with abdominal complaints who underwent endoscopy examinations and had no history of H. pylori eradication. The prevalence of H. pylori infection and the gastric mucosa in H. pylori-positive patients were compared between age-, gender-, and endoscopic diagnosis-matched Bangladeshi and Japanese subjects.

RESULTS

The prevalence of H. pylori infection was higher in Bangladeshi than in Japanese subjects (60.2 and 45.1%, respectively). All the scores for chronic inflammation, neutrophil activity, glandular atrophy, and intestinal metaplasia were significantly lower in H. pylori-positive Bangladeshis than in H. pylori-positive Japanese. The ratio of the corpus gastritis score (C) to the antrum gastritis score (A) (C/A ratio) was <1 (antrum-predominant gastritis) in all age groups of Bangladeshi subjects, whereas the C/A ratio changed from <1 to more than 1 (corpus-predominant gastritis) with aging in Japanese subjects.

CONCLUSIONS

The scores for glandular atrophy and intestinal metaplasia in H. pylori-positive Bangladeshis were significantly lower than those in Japanese. All age groups of Bangladeshis had antrum-predominant gastritis, whereas corpus-predominant gastritis was more common than antrum-predominant gastritis in older Japanese age groups. These results may explain the low incidence of gastric cancer in Bangladeshis and the high incidence in Japanese.

Dietary Phytosterols Protective Against Peptic Ulceration

BACKGROUND

In developing countries the prevalence of duodenal ulceration is related to the staple diet and not to the prevalence of Helicobacter pylori. Experiments using animal peptic ulcer models show that the lipid fraction in foods from the staple diets of low prevalence areas gives protection against ulceration, including ulceration due to non-steroidal anti-inflammatory drugs (NSAIDs), and also promotes healing of ulceration. The lipid from the pulse Dolichos biflorus (Horse gram) was highly active and used for further investigations. Further experiments showed the phospholipids, sterol esters and sterols present in Horse gram lipid were gastroprotective. Dietary phospholipids are known to be protective, but the nature of protective sterols in staple diets is not known. The present research investigates the nature of the protective phytosterols.

METHODS

Sterol fractions were extracted from the lipid in Dolichos biflorus and tested for gastroprotection using the rat ethanol model. The fractions showing protective activity were isolated and identification of the components was investigated by Gas Chromatography-Mass Spectrometry (GC-MS).

RESULTS

The protective phytosterol fraction was shown to consist of stigmasterol, β-sitosterol and a third as yet unidentified sterol, isomeric with β-sitosterol.

CONCLUSIONS

Dietary changes, affecting the intake of protective phospholipids and phytosterols, may reduce the prevalence of duodenal ulceration in areas of high prevalence and may reduce the incidence of recurrent duodenal ulceration after healing and elimination of Helicobacter pylori infection. A combination of phospholipids and phytosterols, such as found in the lipid fraction of ulceroprotecive foods, may be of value in giving protection against the ulcerogenic effect of NSAIDs.

Differences in peptic ulcer between the East and the West

PUD affects both the East and the West. The magnitude of the problem, however, varies within these regions. The study of peptic ulcer epidemiology is impeded by the paucity of general population-based data, invasiveness of diagnostic tests, and variable access to testing facilities. As such, direct comparisons of PUD epidemiology between the East and the West are difficult. The prevalence rates of H pylori are highly variable and depend greatly on the local sanitation conditions. The use of NSAIDs and aspirin is ubiquitous and increasing especially for the antiplatelet activity of aspirin in the prophylaxis of cardiovascular events. There is evidence that pharmacogenetics play a role in susceptibility to the ulcerogenic properties of NSAIDs. The prevalence of PUD parallels the risk factors, but emerging in both the East and the West is idiopathic PUD, now a substantial proportion of ulcers in areas of declining H pylori infection. Genetic polymorphisms affect the efficacy of treatment using PPIs. Local H pylori resistance rates also influence the eradication success rates.

Controversies in the Helicobacter pylori/duodenal ulcer story

In patients with Helicobacter pylori-positive duodenal ulcer (DU), the organism must be eradicated to achieve rapid, stable healing. However, evidence is against much else that is commonly accepted. (1) Does H. pylori cause the ulcer? Evidence against includes archaeopathology, geographical prevalence, temporal relationships and H. pylori-negative DU patients. DU can recur after eradication of H. pylori infection, and DUs may remain healed after reduction of acid secretion despite persistent infection. The faster healing of ulcers when H. pylori has been eradicated is due to the organism's interference with neoangiogenesis and the healing of wounded epithelial cells. (2) Does H. pylori infection persist until pharmacologically eradicated? Studies based on current infection show that H. pylori infection is a labile state that can change in 3 months. High rates of gastric acid secretion result in spontaneous cure, whereas low rates permit re-infection. Hydrochloric acid, necessary for producing a DU, is strongly associated with the likelihood of an ulcer. At the start, patients owe their ulcer to gastric hypersecretion of hydrochloric acid; approximately 60% may be H. pylori-negative. If acid is suppressed, the less acid milieu encourages invasion by H. pylori, especially if the strain is virulent.

Precise role of H pylori in duodenal ulceration

The facts that H pylori infection is commoner in duodenal ulcer (DU) patients than in the normal population, and that eradication results in most cases being cured, have led to the belief that it causes DU. However, early cases of DU are less likely than established ones to be infected. H pylori-negative cases are usually ascribed to specific associated factors such as non-steroidal anti-inflammatory drugs (NSAIDs), Crohn’s disease, and hypergastrinaemia, but even after excluding these, several H pylori-negative cases remain and are particularly common in areas of low prevalence of H pylori infection. Moreover, this incidence of H pylori negative DU is not associated with a fall in overall DU prevalence when compared with countries with a higher H pylori prevalence. In countries with a high H pylori prevalence there are regional differences in DU prevalence, but no evidence of an overall higher prevalence of DU than in countries with a low H pylori prevalence. There is no evidence that virulence factors are predictive of clinical outcome. After healing following eradication of H pylori infection DU can still recur. Medical or surgical measures to reduce acid output can lead to long-term healing despite persistence of H pylori infection. Up to half of cases of acute DU perforation are H pylori negative. These findings lead to the conclusion that H pylori infection does not itself cause DU, but leads to resistance to healing, i.e., chronicity. This conclusion is shown not to be incompatible with the universally high prevalence of DU compared with controls.

Elevated risk for gastric adenocarcinoma can be predicted from histomorphology

The number of patients with gastric cancer has more than doubled since 1985 in developing countries. Thus, the questions of whether it can be predicted from gastritis morphology, who is at risk and who has a lower risk of developing gastric carcinoma are raised. H pylori-infection leads to erosions, ulcerations, carcinoma, mucosa associated lymphoid tissue (MALT)-lymphoma and extragastric diseases only in some individuals. The frequency of ulcerations among H pylori-infected individuals is estimated to be 13%, gastric cancer about 1% and MALT lymphoma around 0.1%. In the literature a multistep model from chronic active H pylori-infection through multifocal atrophy, intestinal metaplasia, dysplasia (intraepithelial neoplasia) and carcinoma has been described. But this model cannot be applied to all routine cases. Since risk factors such as metaplasia and atrophy are paracancerous rather than precancerous conditions, this raises the question whether there is a better morphological marker. Differences in topography, grade and activity of Helicobacter gastritis in the antrum and corpus might be good markers for identifying those who are at risk of developing gastric cancer. It is known that the so-called corpus dominant

H pylori gastritis is found more frequently among individuals with early and advanced gastric cancer and within high risk populations. This is valid both for first-degree relatives of gastric cancer patients and for patients with gastric adenoma and hyperplastic polyps. In conclusion, corpus-dominant H pylori gastritis is significantly more common in patients with advanced and early gastric cancer, first-degree relatives of patients with gastric cancer, patients with gastric adenoma and gastric hyperplastic polyps. Therefore, all these patients are at risk of developing gastric cancer. Next, the question of who is at risk of developing corpus-dominant gastritis is raised. It appears that patients with a low acid output more frequently develop gastric cancer. Eradication therapy is never performed too early but probably sometimes too late after the patients pass a “point of no return”. Large prospective long term studies are necessary to prove this and identify new reliable markers for gastric cancer development.

H pylori receptor MHC class II contributes to the dynamic gastric epithelial apoptotic response

AIM: To investigate the role of MHC class II in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.

METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC class II and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively.

RESULTS: Pretreatment of N87 cells with the anti-MHC class II IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class II resulted in a marked reduced caspase activation, while simple ligation of MHC class II did not. Crosslinking of MHC class II also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class II IgM blocked the recruitment of FADD to the cell surface.

CONCLUSION: The results presented here demonstrate that the ability of MHC class II to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. Furthermore, while previous research has demonstrated that MHC class II signaling can be pro-apoptotic during extended ligation, we have shown that the crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC class II to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.

H pylori receptor MHC class II contributes to the dynamic gastric epithelial apoptotic response

AIM: To investigate the role of MHC class II in the modulation of gastric epithelial cell apoptosis induced by H pylori infection.

METHODS: After stimulating a human gastric epithelial cell line with bacteria or agonist antibodies specific for MHC class II and CD95, the quantitation of apoptotic and anti-apoptotic events, including caspase activation, BCL-2 activation, and FADD recruitment, was performed with a fluorometric assay, a cytometric bead array, and confocal microscopy, respectively.

RESULTS: Pretreatment of N87 cells with the anti-MHC class II IgM antibody RFD1 resulted in a reduction in global caspase activation at 24 h of H pylori infection. When caspase 3 activation was specifically measured, crosslinking of MHC class II resulted in markedly reduced caspase activation, while simple ligation of MHC class II did not. Crosslinking of MHC class II also resulted in an increased activation of the anti-apoptosis molecule BCL-2 compared to simple ligation. Confocal microscope analysis demonstrated that the pretreatment of gastric epithelial cells with a crosslinking anti-MHC class II IgM blocked the recruitment of FADD to the cell surface.

CONCLUSION: The ability of MHC class II to modulate gastric epithelial apoptosis is at least partially dependent on its crosslinking. The crosslinking of this molecule has anti-apoptotic effects during the earlier time points of H pylori infection. This effect is possibly mediated by the ability of MHC class II to modulate the activation of the pro-apoptotic receptor Fas by blocking the recruitment of the accessory molecule FADD, and this delay in apoptosis induction could allow for prolonged cytokine secretion by H pylori-infected gastric epithelial cells.

Helicobacter pylori virulence factors in duodenal ulceration: A primary cause or a secondary infection causing chronicity

Reports from countries with a high prevalence of Helicobacter pylori (H pylori) infection do not show a proportionately high prevalence of duodenal ulceration, suggesting the possibility that H pylori cannot be a primary cause of duodenal ulceration. It has been mooted that this discrepancy might be explained by variations in the prevalence of virulence factors in different populations. The aim of this paper is to determine whether the published literature gives support to this possibility. The relevant literature was reviewed and analyzed separately for countries with a high and low prevalence of H pylori infection and virulence factors. Although virulent strains of H pylori were significantly more often present in patients with duodenal ulcer than without the disease in countries with a low prevalence of H pylori infection in the population, there was no difference in the prevalence of virulence factors between duodenal ulcer, non - ulcer dyspepsia or normal subjects in many countries, where the prevalence of both H pylori infection and of virulence factors was high. In these countries, the presence of virulence factors was not predictive the clinical outcome. To explain the association between virulence factors and duodenal ulcer in countries where H pylori prevalence is low, only two papers were found that give little support to the usual model proposed, namely that organisms with the virulence factors are more likely than those without them to initiate a duodenal ulcer. We offer an alternative hypothesis that suggests virulence factors are more likely to interfere with the healing of a previously produced ulcer. The presence of virulence factors only correlates with the prevalence of duodenal ulcer in countries where the prevalence of H pylori is low. There is very little evidence that virulence factors initiate duodenal ulceration, but they may be related to failure of the ulcer to heal.

Clinical and endoscopic characteristics of non-Helicobacter pylori, non-NSAID duodenal ulcers: a long-term prospective study

BACKGROUND

The proportion of duodenal ulcers not associated with Helicobacter pylori infection or the use of non-steroidal anti-inflammatory drugs (NSAIDs) is increasing.

AIM

To identify the clinical and endoscopic characteristics of non-H. pylori, non-NSAID duodenal ulcers.

METHODS

Clinical and endoscopic data and H. pylori status were prospectively collected from consecutive patients who underwent upper endoscopy from 1997 to 1999. Patients with duodenal ulcers were identified, and those with non-H. pylori, non-NSAID duodenal ulcers were analysed further.

RESULTS

A total of 11 717 upper endoscopies were performed in 8344 patients. Of these, 1153 (14%) had duodenal ulcers. Of 599 patients with active ulcers and known H. pylori status, 104 (17%) had ulcers not associated with H. pylori or the use of NSAIDs, 393 (66%) had ulcers associated with H. pylori alone, 51 (8.5%) had ulcers associated with the use of NSAIDs alone and 51 (8.5%) had ulcers associated with both. Multivariate logistic regression analysis revealed that the presence of concomitant diseases (odds ratio=15.0; 95% confidence interval, 8.64-25.9; P < 0.001) and the absence of epigastric pain/discomfort (odds ratio=0.52; 95% confidence interval, 0.29-0.91; P=0.022) were independent predictors for non-H. pylori, non-NSAID duodenal ulcers.

CONCLUSIONS

Non-H. pylori, non-NSAID duodenal ulcers exhibit certain distinct clinical and endoscopic characteristics. The presence of concomitant diseases is an important predictive factor.

High prevalence of mixed infections by Helicobacter pylori in Hong Kong: metronidazole sensitivity and overall genotype

BACKGROUND

Diversity in metronidazole susceptibility and genotypes of Helicobacter pylori have been reported with varying results in different areas.

AIMS

To investigate the prevalence of multiple strain infection in a symptomatic Chinese population and to determine the metronidazole susceptibility pattern and genotypic characteristics of these infecting strains.

METHODS

Gastric biopsies from antrum, body and cardia were taken during upper endoscopy in symptomatic patients referred to our department. Pooled cultures and single colony isolates were obtained and tested for metronidazole susceptibility and random amplified polymorphic DNA (RAPD) fingerprint patterns.

RESULTS

A total of 461 isolates were successfully cultured from 46 patients. Fifty-seven per cent of subjects had metronidazole-resistant strains. Among them, 77% carried a mixture of sensitive and resistant strains, non-uniformly distributed in the gastric mucosa. Mixed genotypes were found by RAPD typing in 24% of subjects. These did not correlate with the metronidazole susceptibility/resistance pattern.

CONCLUSION

H. pylori infections with mixed metronidazole sensitive/resistant strains and mixed genotypes are common in Hong Kong. This makes it prudent to use bacterial strains from several biopsy sites when testing for traits such as drug resistance or virulence in relation to disease.

(13)C-urea breath test without a test meal is highly accurate for the detection of Helicobacter pylori infection in Chinese

BACKGROUND

Conventional (13)C-urea breath testing ((13)C-UBT) includes a test meal to delay gastric emptying, which, theoretically, improves the accuracy of the test. Citric acid has been proposed as the best test meal. However, recent studies have suggested that a test meal may not be necessary.

AIM

To investigate a new (13)C-UBT protocol without a test meal in a Chinese population.

METHODS

Consecutive dyspeptic patients referred for upper endoscopy were recruited. (13)C-UBT was performed on two separate days with or without a test meal (2.4 Gm citric acid) and compared with the 'gold standard' (CLO test and histology).

RESULTS

Two hundred and two patients were tested. Using receiver operating characteristics (ROC) analysis, the optimal delta-value and optimal measurement interval for UBT were 5% and 30 min, respectively, both with or without a test meal. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of (13)C-UBT with citric acid (96.5%, 97.7%, 98.2%, 95.6%, 97.0%) were similar to (13)C-UBT without a test meal (94.7%, 97.7%, 98.2%, 93.5%, 96.0%).

CONCLUSION

This simplified (13)C-UBT protocol without a test meal produced highly accurate and reliable results in the Chinese population.

Review article: Helicobacter pylori and gastric cancer--the clinicians'point of view

Although the incidence of gastric cancer has declined dramatically in Western countries, the most recent data from the International Agency for Research on Cancer show that it remains the second most common cancer worldwide and caused 628 000 deaths in 1990. The incidence and prevalence of gastric cancer are projected to increase over the next few decades in less developed countries as a result of the increased longevity of H. pylori-infected populations and improved therapies. Gastric carcinogenesis is a multistep and multifactorial process beginning with H. pylori-associated gastritis in most cases. H. pylori infection, together with other environmental factors and individual susceptibility, determine the final risk for the development of gastric cancer. The magnitude of H. pylori infection as a risk factor for gastric cancer in the published H. pylori and gastric cancer epidemiology studies may have been underestimated due to the inclusion of improperly selected controls. Eradication of the infection has been shown to prevent the occurrence of metachronous gastric cancer following endoscopic resection of early gastric cancer in a Japanese study. However, the generalization of this study to other populations is difficult because of the vast differences in the definition of gastric atrophy and early gastric cancer between Japanese and Western pathologists. Until an international consensus on the pathological diagnosis of gastric atrophy and early gastric cancer is reached, interpretation of studies performed in different countries remains difficult. Clinicians rely on the correct pathological diagnosis to guide the management of H. pylori infection-associated gastrointestinal diseases.

Diet and duodenal ulcer

BACKGROUND

Despite the fact that the main cause of duodenal ulcer incidence and recurrence is the Helicobacter pylori bacterium, more than 80% of Helicobacter pylori-infected people never develop an ulcer. Diet may be one of the most important environmental factors contributing to duodenal ulcer.

AIMS

To explore the role of diet in causation, treatment and prevention of duodenal ulcer recurrence.

METHODS

All research papers published in English from 1966 to October 1999 present in Medline, involving human subjects, and having duodenal ulcer as outcome, entered the review.

RESULTS AND CONCLUSIONS

Soluble fibre from fruit and vegetables seem to be protective against duodenal ulcer and refined sugars a risk factor. The role of fibre in the treatment and prevention of recurrence of duodenal ulcer is uncertain, as is that of essential fatty acids. However, none of the epidemiological studies on the relationship between diet and duodenal ulcer disease controlled for Helicobacter pylori.

Differences in peptic ulcer between East and West

In general, peptic ulcer occurs at equal rates in the East and the West but with marked regional differences in both, even within the same country. In the West, the incidence of peptic ulcer, particularly duodenal ulcer, rose sharply at the turn of the century and has shown a rapid decline in the past three decades. In the East, the rise was equally impressive, but the decline appears to have been delayed, only starting in the past decade. Asians present their ulcer symptoms a decade earlier than Caucasians, and it has been suggested that this early presentation may be attributable to Helicobacter pylori (H. pylori) infection at a younger age. Interestingly, the male-to-female ratio is much higher in the East than in the West, and the duodenal-to-gastric ulcer ratio manifests a much wider variation in Asians than in Caucasians. As in Western countries, peptic ulcer occurrence in the East shows a cyclical trend, with a peak frequency in the winter months. In the West, the placebo healing rate varies widely up to 78%, whereas in the East it is rather consistent at around one-third. These variations in geographical distribution, time trends, sex and ulcer ratios, seasonal rates and behavioral response to placebo treatment indicate that while H. pylori is a major cause of peptic ulceration, other environmental and genetic factors contribute to ulcer formation. The parietal cell mass and acid secretory capacity of Asian patients with duodenal ulcer are only slightly more than half of those of Caucasian patients, which may explain why Asian patients respond equally well to half the standard dose of anti-secretory agents used in Caucasians. H. pylori infection is generally more prevalent in the East than in the West and is more resistant to metronidazole. The response to standard triple therapies for eradication, however, appears to be as effective in the East as in the West.

Is Helicobacter pylori the primary cause of duodenal ulceration?

Helicobacter pylori infection may not be the primary cause of duodenal ulceration in cases not associated with non-steroidal anti-inflammatory drugs, but may be a secondary complication. In developing countries with a uniformly high prevalence of H. pylori infection there are marked regional differences in the prevalence of duodenal ulcer (DU). In some countries, especially those with a low prevalence of H. pylori, 30-40% or more patients with DU may be H. pylori negative. The absence of H. pylori infection in early cases of DU is also reported. In DU patients with antral H. pylori infection, duodenal colonization by H. pylori may often be absent. After complete H. pylori eradication, recurrence of DU within 6 months in some reports is as high as 20%. The evidence suggests that high acidity and reduced duodenal mucosal resistance remain the primary causes of DU and that H. pylori infection, when present, results in chronicity. Reduced mucosal resistance results in duodenal gastric metaplasia which permits colonization of the duodenum with H. pylori from the antrum. Therefore, whatever causes reduced mucosal resistance may be the primary factor and evidence suggests that this cause may be diet related. This would explain the enigma of regional variations in DU prevalence unrelated to H. pylori prevalence.

Helicobacter Pylori

All infected patients with a peptic ulcer should be treated for H. pylori. The role of treating H. pylori in patients with undiagnosed dyspepsia or non-ulcer dyspepsia, those taking nonsteroidal anti-inflammatory medications, or with a family history of gastric cancer remains controversial. Triple therapies consisting of a proton pump inhibitor or ranitidine bismuth citrate and two antibiotics are the current standard of therapy for H. pylori. In general, dual therapies should no longer be used to treat H. pylori. Bismuth triple therapy consisting of bismuth, tetracycline, and metronidazole is a less expensive alternative to proton pump inhibitor-or ranitidine bismuth citrate-based triple therapies. However, bismuth triple therapy is hampered by frequent side effects and the need for qid dosing. In Europe, a 7-day course of therapy appears to be adequate. In the United States, 10-14 days of therapy are currently recommended. Metronidazole resistance in H. pylori strains varies geographically, and negatively influences the effectiveness of therapies containing this antibiotic. Clarithromycin resistance is relatively infrequent at the current time but may be rising in countries where this antibiotic is in use. If a patient remains infected after a course of therapy for H. pylori, the second treatment should avoid the antibiotics used initially.