Detection of Helicobacter pylori infection in early stage gastric cancer. A comparison between intestinal- and diffuse-type gastric adenocarcinomas

A population-based comparison of patients with metastatic esophagogastric carcinoma between Japan and the Netherlands

PURPOSE

Differences exist between Asian and Western patients with esophagogastric cancer, for example in terms of histological subtype and treatment strategies. This study aimed to compare characteristics and treatment between patients with metastatic esophagogastric cancer from Japan and the Netherlands using nationwide cancer registry data.

METHODS

Patients diagnosed with metastatic esophageal or gastric cancer were included from the nationwide national cancer registry of Japan (2016-2019) and the Netherlands (2015-2020). Treatment strategies were analyzed using chi-squared tests.

RESULTS

The proportion of patients with metastatic esophageal (16.0% vs 34.2%) and gastric cancer (14.9% vs 45.2%) were lower in Japan compared to the Netherlands. Japanese patients with metastatic esophageal adenocarcinoma (EAC), esophageal squamous cell carcinoma (ESCC) or gastric cancer (GC) were more often male and older compared to Dutch patients. Proportion of patients with metastatic disease who received surgical resection was higher in Japan compared to the Netherlands (EAC 9.3 vs 1.4%, p < 0.001; ESCC 10.7% vs 2.3%, p < 0.001; GC 12.0% vs 3.6% p < 0.001). Proportion of patients who received systemic therapy was also higher (EAC 44.8% vs 30.4%, p < 0.001; ESCC 26.6% vs 12.0%, p < 0.001; GC 50.7% vs 35.8% p < 0.001).

CONCLUSIONS

Japanese patients less often presented with metastatic esophagogastric cancer and more often underwent surgical resection or received systemic therapy compared to Dutch patients. Further investigation should elucidate what the deliberations are in both Japan and the Netherlands and if more patients in the Netherlands could benefit from surgical resection or systemic therapy and whether this would translate in better survival and quality of life.

FAM60A, increased by Helicobacter pylori, promotes proliferation and suppresses apoptosis of gastric cancer cells by targeting the PI3K/AKT pathway

Helicobacter pylori (H. pylori) infection can promote the development of gastric cancer (GC); however, the underlying mechanism is not clear. FAM60A has been found showing high levels in some cancer cells, including lung cancer (A549), and pancreatic cancer (Capan-2) cell lines. Data in oncomine showed that FAM60A overexpression was an critical prognostic factor in GC. In this study, we showed that knockdown of FAM60A could revert the increase of proliferation and the decrease of apoptosis caused by H.pylori infection in HGC-27 and AGS cells. Conversely, FAM60A upregulation promoted proliferation and inhibited apoptosis in HGC-27 and AGS cells. We also found that the PI3K/AKT pathway inhibitor LY294002 could revert the changes caused by FAM60A upregulation in HGC-27 and AGS cells. Thus, our study provides evidence that FAM60A act as a carcinogen and suggests that H. pylori-induced upregulation of FAM60A may contribute to the development of gastric cancer.

Helicobacter pylori CagA and VacA genotypes and gastric phenotype: a meta-analysis

BACKGROUND

CagA+ and vacuolizing cytotoxin (VacA)-specific strains of Helicobacter pylori have been associated with different risks for developing gastric lesions. We aim to summarize a possible association between these genotypes and the risk for developing different gastric phenotypes.

MATERIALS AND METHODS

A MEDLINE database (PubMed) search was performed and a meta-analysis conducted.

RESULTS

Forty-four studies were retrieved, all with either a case-control (n=13) or cross-sectional (n=31) design, including 17 374 patients. CagA positivity was associated with an increased risk for gastric cancer [odds ratio (OR) 2.09 (95% confidence interval (CI), 1.48-2.94)] compared with that in individuals without gastric lesions [OR 2.44 (95% CI 1.27-4.70)] and in those with previously identified gastritis. In addition, there was an increased risk for peptic ulcer disease [OR 1.69 (95% CI 1.12-2.55)]. Individuals harboring the H. pylori strains VacA s1 (vs. s2), m1 (vs. m2), s1m1 (vs. s1m2), and s1m1 (vs. s2m2) had an increased risk for development of cancer [OR of 5.32 (95% CI 2.76-10.26), 2.50 (95% CI 1.67-3.750), 2.58 (95% CI 1.24-5.38), and 4.36 (95% CI 2.08-9.10), respectively]. s1m1 strains (vs. s2m2) were also associated with peptic ulcer disease [OR 2.04 (1.01-4.13)].

CONCLUSION

Our results indicate that individuals infected with CagA+ H. pylori strains and those infected with VacA s1 and m1 strains have an increased risk for gastric cancer. Cohort studies are welcome to integrate this information in the management of at-risk individuals such as those with precancerous cancer conditions and/or a family history of gastric cancer.

Detection of Helicobacter pylori DNA in preliminary stage gastric cancer cells

AIMS

Helicobacter pylori (HP) DNA was assayed using a newly fabricated voltammetric handheld circuit equipped with an interfaced graphite pencil electrode (PE) sensor.

METHODS

Under optimum analytical parameters, the square-wave (SW) stripping detection range attained was 0.1-0.7 mg/L.

RESULTS

A relative standard deviation of 1.68% (RSD, n = 5) was observed at a 3.2 mg/L HP DNA within a 90 s accumulation time. Under these conditions, the analytical detection limit approached 0.07 mg/L.

CONCLUSIONS

The developed methods can be applied to HP assays of preliminary stage gastric cancer patient tissues.

Determinação histopatológica da presença do helicobacter pylori em câncer gástrico

RACIONAL: A causa do câncer gástrico (CG) é controversa e tem vários fatores envolvidos no seu processo de carcinogênese, incluindo o Helicobacter pylori (Hp) O papel da infecção pelo Hp no CG permanece incerto, com vários estudos controversos. OBJETIVO: Correlacionar a presença da infecção pelo Hp com câncer gástrico, através de exame anatomopatológico convencional do estômago ressecado. MÉTODO: Noventa e um pacientes tratados por ressecção cirúrgica foram revistos. O exame anatomopatológico foi feito em todos os pacientes para determinar a presença de infecção por Hp, metaplasia intestinal (MI) e confirmação do tipo histológico por hematoxilina-eosina. A análise estatística foi realizada através do qui-quadrado e testes de log-rank. RESULTADOS: MI foi observada em 81 tumores (89%). Em geral, a presença de infecção pelo Hp foi observada em 46 casos (50,5%). Não houve associação entre idade e Hp. Nos grupos de pacientes com CG avançado e precoce, a infecção pelo Hp estava presente em 47,7% e 54% dos tumores. A infecção pelo Hp ocorreu em 40 tumores (49%) no grupo de pacientes com MI. Nos com tumores sem MI, Hp estava presente em cinco (50%). Tumores proximais tiveram mais infecção por Hp, quando comparados aos tumores distais. CONCLUSÕES: A taxa de infecção não teve associação significativa com o tipo histológico, sexo, MI ou estágio de desenvolvimento tumoral. Esses resultados podem indicar que a participação da infecção pelo Hp durante o desenvolvimento do CG não pode ser descartada; no entanto, provavelmente não é essencial em todas as fases e o mecanismo do CG pode ser distinto da gastrite crônica e MI. Finalmente, é possível que a associação proposta é mera coincidência e que não há nenhuma influência real das bactérias no processo de carcinogênese.

The association between Helicobacter pylori infection and early gastric cancer: a meta-analysis

OBJECTIVE

Helicobacter pylori (H. pylori) is recognized as a definite carcinogen for gastric cancer. The prevalence of H. pylori infection in patients with gastric cancer varies widely among studies and no meta-analysis on the prevalence of H. pylori infection in early gastric cancer (EGC) has been performed. We aimed to review systematically the relationship between H. pylori infection and EGC, and different types of EGC.

METHODS

Observational studies reporting raw data on the prevalence of H. pylori infection in EGC and controls, or comparing different types of EGC, conducted in adult populations, and published in the English language were identified through MEDLINE and EMBASE up to June 2006.

RESULTS

Of 87 relevant studies, 19 case-control studies met inclusion criteria. Of these, 15 studies compared EGC (N = 2,722) and non-neoplasm controls (N = 13,976) or advanced gastric cancer (AGC) (N = 1,130), 9 studies compared the intestinal-type (I-EGC) and diffuse-type (D-EGC) of EGC, and 2 studies compared the differentiated-type (DF-EGC) and undifferentiated-type (UDF-EGC) of EGC and were included in the meta-analysis. The prevalence of H. pylori infection was significantly higher in patients with EGC (87.3%) than in non-neoplasm controls (61.4%) (OR 3.38, 95% CI 2.15-5.33, P < 0.00001). However, significant heterogeneity was seen (P < 0.00001). Four large sample (N > or = 100) studies (N = 2,060) may result in the heterogeneity, but the conclusion remained unchanged when sensitivity analysis was made with the other 11 homogeneous small sample studies alone, in which the prevalence of H. pylori infection was significantly higher in EGC (N = 662) than that in controls (N = 5,898) (87.8%vs 68.6%, P < 0.00001), and the odds ratio (OR 3.28, 95% CI 2.34-4.61) was similar to the large sample studies alone (OR 3.40, 95% CI 1.14-10.12). The prevalence of H. pylori infection in EGC was significantly higher than in AGC (6 studies) (OR 2.13, 95% CI 1.75-2.59) and 16-fold higher in patients with DF-EGC than in those with UDF-EGC (OR 16.53, 95% CI 2.64-103.43). No significant difference in the prevalence of H. pylori infection was seen between the patients with I-EGC and D-EGC types (OR 0.75, 95% CI 0.26-2.18).

CONCLUSIONS

This study indicates that H. pylori infection is strongly associated with early gastric cancer when compared with non-neoplasm controls or advanced gastric cancer. To determine more accurately the effect size of H. pylori in EGC, age-matched normal controls or adjusting for age in the analysis should be considered in H. pylori-related gastric cancer case-control studies.

Helicobacter pylori infection and early gastric cancer

BACKGROUND

Helicobacter pylori has recently been associated with an increased risk of gastric cancer. This study aimed to examine the association between H. pylori, histologic chronic gastritis, and intestinal metaplasia in early gastric cancers of different histologic types.

STUDY

Seventy-four patients who were surgically diagnosed as having early gastric cancer were included in this study. All tissue specimens were obtained from patients by endoscopic biopsy and were classified histopathologically as intestinal-type early gastric cancer in 55 patients and diffuse-type early gastric cancer in 19 patients.

RESULTS

H. pylori infection was found in 67 patients (90.5%) but not found in seven (9.5%). And the prevalence of H. pylori infection with nongastric cancer patients was also high (68.5%). There was no significant difference between the intestinal-type and the diffuse-type early gastric cancer in chronic active gastritis and atrophic chronic gastritis. Intestinal metaplasia was observed more frequently in patients with the intestinal-type than with the diffuse-type early gastric cancer (P = 0.0102).

CONCLUSIONS

Infection with H. pylori has an important relationship to both histopathologic types of early gastric cancer.

Detection of Helicobacter pylori in gastric cancer

BACKGROUND AND OBJECTIVES

Considering the high prevalence of stomach cancer in the northern region of Brazil and the recognized relationship between chronic gastric inflammation caused by Helicobacter pylori, and its carcinogenic potential, the objective we had with this study was to investigate the presence of the microorganism in macro and microscopic presentations of neoplasm in different regions of the stomach, and in non-malignant lesions concomitant to the adenocarcinoma in patients originating from the metropolitan area of Belém (State of Pará, Brazil).

METHODS

Examinations were made on 172 patients divided into two groups: group I, formed by 75 patients with gastric carcinoma, and group II, formed by 97 patients with mild enanthematic gastritis, considered control group. The diagnosis was obtained during endoscopic examination and the respective biopsy. Gastric neoplasms were classified macroscopically in accordance with Borrmann's classification, and microscopically in accordance with Laurén's classification. In group I, 54 patients were male and 21 female while in group II, 22 patients were male and 75 female. The average age in group I was 61.2 years (range 27 to 86 years), while in group II it was 37.5 years (range 16 to 69 years). Thin sections were prepared and stained using the hematoxylin-eosin method. In the Helicobacter pylori research, the modified Gram stain was utilized. Statistical analysis was done by utilizing the chi-squared (chi 2) test, Mann-Whitney test (U), and Fisher's exact test.

RESULTS

The results showed the detection of Helicobacter pylori were significantly greater in patients with mild enanthematic gastritis than in patients with gastric carcinoma. The presence of Helicobacter pylori in patients with gastric carcinoma and mild enanthematic gastritis was significantly greater in the antral region than in other gastric regions. Helicobacter pylori detection in patients with gastric carcinoma did not present a significant difference in relation to the macroscopic aspect of the tumor either intestinal or diffuse histological types.

CONCLUSIONS

These data suggest the presence of the bacteria is predominant in the antral region and it does not show relation with the macroscopic types or histological intestinal or diffuse types of gastric carcinoma.

Loss of E-cadherin expression in gastric intestinal metaplasia and later stage p53 altered expression in gastric carcinogenesis

Gastric cancers are commonly subdivided into intestinal and diffuse subtypes on a morphologic basis, supported by corollary evidence of differences at the pathogenetic and molecular levels. Chronic atrophic gastritis with intestinal metaplasia is a common precursor lesion for the intestinal type of carcinoma. To identify early molecular changes, in this study we have examined 13 surgical specimens both for the expression of E-cadherin, p53 and beta-catenin by immunohistochemistry and for methylation of the CDH1 promoter (E-cadherin) by bisulfite genomic sequencing of laser capture microdissected samples. Each specimen examined contained areas of normal (nonmetaplastic) gastric mucosa, as well as areas of intestinal metaplasia and/or carcinoma. Reduced or absent E-cadherin and partial to complete methylation of one to multiple CpG sites examined in the CDH1 promoter were observed in all of the metaplasia samples. Thus, the methylation status of the CDH1 promoter and expression of E-cadherin together provide strong evidence that loss of E-cadherin is an early event in intestinal type gastric carcinogenesis. In contrast, expression of p53, assumed to be mutant p53, was generally not detected (except for isolated cells) until the carcinoma stage in tissues from these patients. These results suggest that mutation of p53 is a late event in intestinal type gastric cancer. The level of beta-catenin expression did not appear to change between normal, metaplastic and carcinoma cells of intestinal type, and no nuclear staining was visible in any of the tissues. These results suggest that the Wnt signaling pathway is not upregulated in this type of cancer.

Serological Immunoglobulin G antibody titers to Helicobacter pylori in Japanese Brazilian and Non-Japanese Brazilian gastric cancer patients and controls in São Paulo

Helicobacter pylori (H. pylori) infection is considered a cause of gastric cancer (GC), though evidence for this association is scarce in high-risk areas. Possible case control and/or ethnic differences were investigated as to the presence of H. pylori and its immunogloblin G antibody titer in the multi-ethnic city of São Paulo, where the incidence of GC is relatively high. We performed a cross-sectional comparison of antibody titers to H. pylori in Japanese Brazilian, and non-Japanese Brazilian GC patients and their controls. Japanese Brazilian patients were matched by age, sex and ethnicity with two controls, while non-Japanese Brazilian patients were matched as above with one control. Among Japanese Brazilians, 59 of 93 (63.4%) patients with GC and 127 of 186 (68.3%) controls were positive for H. pylori-specific antibody (odds ratio (OR) = 0.80, 95% confidence interval (CI) = 0.47 - 1.36), while among non-Japanese Brazilians, 171 of 228 patients with GC (75.7%) and 178 of 226 controls (78.8%) were positive (OR = 0.84, 95% CI = 0.54 - 1.30). The median serum antibody titer was lower in cases than in controls in both ethnic groups. A high titer (H. pylori titer > or = 50) was associated with less likelihood of GC for both ethnic groups (for Japanese Brazilians, OR = 0.39, 95% CI = 0.16 - 0.92; for non-Japanese Brazilians, OR = 0.56, 95% CI = 0.31 - 1.02). The high titer can be regarded as a sign of the necessity of eradication, and low titer is regarded as a sign of the necessity of close screening for GC in both ethnic groups, because extended atrophy may cause spontaneous disappearance of H. pylori from the stomach.

Is Helicobacter pylori infection in childhood a risk factor for gastric cancer?

Helicobacter pylori infection is associated with chronic gastritis and peptic ulcer disease. Furthermore, the World Health Organization has classified this organism as a carcinogen for gastric cancer. H pylori infection is mainly acquired in childhood. Children with H pylori infection are asymptomatic except for a very small number that develop peptic ulcer disease. However, if H pylori gastritis is associated with gastric cancer, do pediatricians need to screen children for this infection and treat those who are infected? In an attempt to determine the significance of the association between H pylori and gastric cancer, we have reviewed all of the English language literature on this topic. H pylori infection seems to be associated with an increased risk of developing gastric cancer. However, only a small number of infected individuals (~1%) will develop gastric cancer. Furthermore, there are potential cofactors other than H pylori that could be equally important. The effect of the eradication of H pylori alone on the development of gastric cancer is unknown. Based on our knowledge to date, we suggest that it is not indicated to treat all children with H pylori infection because of the risk of developing gastric cancer or to institute a screening and treatment program.

Clinicopathologic association of cyclooxygenase 1 and cyclooxygenase 2 expression in gastric adenocarcinoma

OBJECTIVE

To evaluate the association of clinicopathologic factors and prognostic value with the expression of cyclooxygenase 1 and 2 in patients with gastric adenocarcinoma.

SUMMARY BACKGROUND DATA

Epidemiologic studies have indicated that nonsteroidal antiinflammatory drugs reduce the risk of colon cancer by as much as 40% and also decrease the risk of gastric cancer. Recently, gastric cancer was found to express constitutive cyclooxygenase 1 and inducible cyclooxygenase 2 isoenzymes. Nonsteroidal antiinflammatories, which may function as cyclooxygenase inhibitors, inhibited the growth of gastric cancer cells. These two isoenzymes' expressions associated with traditional clinicopathologic factors have not been fully evaluated, and their prognostic value for determining survival in patients remains to be clarified.

METHODS

Seventy-one specimens resected from patients with gastric adenocarcinoma were investigated by immunohistochemical stain against cyclooxygenase 1 and 2. The 71 specimens were divided into stain-positive and stain-negative groups. Correlations between cyclooxygenase 1 and 2 expression, various clinicopathologic factors (including vascular invasion and Helicobacter pylori infection), and prognosis were studied.

RESULTS

The cyclooxygenase 2-positive group was significantly correlated with vascular invasion and H. pylori infection by univariate and multivariate analysis. In patients with cyclooxygenase 2-positive cancer, the prognosis was significantly poorer than in those with cyclooxygenase 2-negative cancer. However, multivariate analysis showed that vascular invasion, serosal invasion, and lymph node metastasis were independent prognostic factors for patients with gastric cancer, but cyclooxygenase 2 expression was not. There was no significant correlation between cyclooxygenase 1 expression and clinicopathologic factors and prognosis.

CONCLUSIONS

Upregulated cyclooxygenase 2 expression was associated with H. pylori infection in gastric cancer and was also strongly correlated with positive vascular invasion, which was an independent prognostic factor for poorer survival in this study. The usefulness of cyclooxygenase 2 inhibitors in the prevention or treatment of gastric cancer remains undetermined but deserves further investigation.

Helicobacter pylori infection among Japanese children

BACKGROUND

In Japan, there are few reports describing Helicobacter pylori infection among young children. The aim of the present study was to identify risk factors associated with H. pylori in school-aged children.

METHODS

Subjects were first-grade students of three elementary schools (n = 310) and second-grade students of a junior high school (n = 300). Personal information, such as student's medical history, parent's history, family size, sibshipsize and household pets, was collected from guardians using a questionnaire. Saliva samples and personal information were collected twice (1995 and 1996). By using the saliva samples, H. pylori IgG antibody was measured using a commercial kit. To analyze the risk factors for H. pylori infection, sex- and age-adjusted odds ratios (OR) were calculated using a multiple logistic model.

RESULTS

Among the children, factors related to Helicobacter antibody in saliva included spending a longer period of time in a nursery school or kindergarten (OR = 4.0) and a maternal history of stomach disease (OR = 2.8). Birth order (OR = 2.2), sleeping situation (OR = 2.3) and sibshipsize (OR = 1.6) were not factors that were significantly related to Helicobacter antibody in the saliva. Chewing food for the infant, family size, rooms in the household, sharing a bedroom during childhood, pets, a past history and a paternal history were not related to positivity.

CONCLUSIONS

The results indicate that transmission is person-to-person, mainly through close contact with other children and intrafamilial infection. Helicobacter pylori infection seems to occur frequently early in life, probably before 6 years of age.

Histological analysis of gastritis and Helicobacter pylori infection in patients with early gastric cancer: a case-control study

BACKGROUND AND AIMS

Infection with Helicobacter pylori is associated with an increased risk of gastric adenocarcinoma. However, most patients with H. pylori infection will not develop gastric cancer. The aims of the present study were to examine which histological features, including H. pylori infection, would increase the risk of gastric cancer using a case-control study.

METHODS

Three gastric biopsy specimens were taken from 72 patients with early gastric cancer and 72 age- and sex-matched control subjects. The grade of gastritis was examined according to the updated Sydney System. The presence of H. pylori infection was determined by serology and histology. Odds ratio (OR) of developing gastric cancer was calculated for H. pylori positivity and histological features using conditional logistic regression. For patients with H. pylori infection, histological features in cancer patients and control subjects were compared.

RESULTS

The OR of the presence of mononuclear cell infiltration in the corpus and intestinal metaplasia in the angulus were significantly elevated. The grade of mononuclear cell infiltration in the corpus and antrum was significantly higher in both types of cancer patients than controls. Glandular atrophy and intestinal metaplasia were increased in patients with intestinal-type cancer in the angulus and antrum. Bacterial density in the corpus and polymorphonuclear cell infiltration in the antrum were increased in patients with diffuse-type cancer.

CONCLUSIONS

Severe chronic gastritis induced by H. pylori infection seems to be associated with diffuse-type gastric cancer. Glandular atrophy and intestinal metaplasia, which occur in gastric mucosa with chronic inflammation, are significantly associated with intestinal-type cancer.

Density of Helicobacter pylori infection evaluated semiquantitatively in gastric cancer

Helicobacter pylori infection may play a role in the development of gastric cancer; however, a quantitative evaluation of the density of H. pylori infection has not been reported previously in relation to the histologic stage and type of cancer. This study was designed to compare the density of H. pylori infection to the histologic stage and type of gastric cancer. Between March 1996 and March 1998, surgical resection of primary lesion was performed in 50 patients with gastric cancer (39 men and 11 women with a mean age of 67 years) at our institution. Using immunohistochemical stains, the density of H. pylori infection was evaluated semiquantitatively at cancer site as well as noncancerous mucosa adjacent to cancer. This density was compared with the histologic stage and the type of gastric cancer. The severity of the mucosal atrophy was evaluated using the updated Sydney System. The prevalences and density of H. pylori infection decreased in proportion to advances in the cancer stage and the mucosal atrophy. In early cancer of the intestinal- and diffuse-type, the prevalence of H. pylori in adjacent sites was almost 90% and was significantly higher (p < 0.01) than that seen in the advanced cancer lesions. In the intestinal-type early cancer, the prevalence and density of infection was higher (p < 0.05) in the adjacent mucosa than in the cancer site, whereas in the diffuse-type early cancer, H. pylori was found in all cases at the cancer site and the adjacent site. In advanced cancer, the prevalence of H. pylori was about 40% in the adjacent site and about 10% in the cancer site in both histologic types. These figures were significantly lower (p < 0.01) than in the early cancers. The prevalence and density of infection did not differ in the intestinal- and diffuse-type gastric cancers, but did decrease with more advanced cancer stages. The changes in local environment of the advanced cancer may not be conducive to the survival of H. pylori. Thus, the prevalence of H. pylori may be affected by the histologic stage rather than the histologic type of gastric cancer, and the organism may play a similar role, but through different pathways, in the pathogenesis of both types of cancer.

Association of Helicobacter pylori-dependent gastritis with gastric carcinomas in young Japanese patients: histopathological comparison of diffuse and intestinal type cancer cases

AIMS

The causal relationship of H. pylori gastric colonization with gastric cancer development has not as yet been fully elucidated. The prevalence of H. pylori infection increases with age in the asymptomatic population in Japan, and reaches a high plateau in those older than 40 years. The objective of this study was to assess the link between H. pylori and gastric carcinomas in patients younger than 40 years.

METHODS AND RESULTS

Detection of H. pylori and assessment of background mucosa based on the Sydney system was performed histopathologically for 40 Japanese gastric cancer cases younger than 40 years and compared with 40 age- and sex-matched controls. H. pylori infection in gastric mucosa was detected significantly more frequently (P < 0.001) in patients with cancer (29/40; 72.5%) than in controls (11/40; 27.5%). Additionally, by histopathological comparison between intestinal (18 cases) and diffuse (70 cases) types of young gastric cancer patients, mucosal atrophy and intestinal metaplasia were found to coexist with acute and chronic inflammation in the background mucosa of both intestinal and diffuse types, being significantly more prevalent than in young controls.

CONCLUSIONS

As well as the high prevalence of H. pylori in young subjects with gastric cancer, it is clear that persistent infection induces mucosal damage, resulting in atrophy and intestinal metaplasia. Thus, acute/chronic gastritis could play an essential role in the early development of neoplasia in the stomach.

Effect of Helicobacter pylori eradication on malignant transformation of gastric adenoma

BACKGROUND

A nonrandomized trial of Helicobacter pylori eradication was conducted in patients with endoscopically diagnosed gastric adenoma to determine the long-term effect of antimicrobial treatment on progression of the adenoma.

METHODS

Of 64 patients with an endoscopically diagnosed gastric adenoma and H pylori infection, 32 were treated with omeprazole and antibiotics to eradicate the infection, and 32 were not.

RESULTS

During 2 years of follow-up, 4 (12.5%) of the 32 patients in the untreated group developed an early stage, intestinal-type gastric cancer, whereas no gastric cancer was found in the 32 patients in the treated group.

CONCLUSION

H Pylori eradication may inhibit progression of gastric adenoma to carcinoma.

Helicobacter pylori infection induces gastric cancer in mongolian gerbils

BACKGROUND & AIMS

Although epidemiological studies have indicated that Helicobacter pylori infection plays a crucial role in gastric carcinogenesis in humans, there is no direct proof that H. pylori is actually associated with gastric carcinogenesis. The purpose of this study was to elucidate the relationship between H. pylori infection and gastric carcinogenesis using an animal model of long-term H. pylori infection.

METHODS

Mongolian gerbils were orally inoculated with H. pylori, and the sequential morphological changes in the stomach were examined for up to 62 weeks.

RESULTS

H. pylori was constantly detected in all infected animals throughout the study. At the 26th week, severe active chronic gastritis, ulcers, and intestinal metaplasia could be observed in infected animals. By the end of the study, adenocarcinoma had developed in the pyloric region of 37% of the infected animals. All tumors consisted of well-differentiated intestinal-type epithelium, and their development seemed to be closely related to intestinal metaplasia.

CONCLUSIONS

We have successfully demonstrated that long-term infection with H. pylori induces adenocarcinoma in Mongolian gerbils. The observations are thus highly suggestive of the involvement of H. pylori infection in gastric carcinogenesis in humans.

Meta-analysis of the relationship between Helicobacter pylori seropositivity and gastric cancer

BACKGROUND & AIMS

Reports in the literature regarding the relationship of Helicobacter pylori infection to gastric cancer are conflicting. The aim of this study was to identify the source of heterogeneity between studies.

METHODS

Meta-analysis of cohort or case-control studies with age- and/or sex-matched controls, providing raw data on H. pylori infection detected by serology, was used.

RESULTS

A fully recursive literature search identified 19 qualified studies with 2491 patients and 3959 controls. Test for homogeneity found a significant difference in odds ratio between patients with early and advanced gastric cancer (6.35 vs. 2.13; P = 0.01), patients with cardiac and noncardiac gastric cancer (1.23 vs. 3.08; P = 0.003), and population- and hospital-based controls (2.11 vs. 1.49; P < 0.001). The summary odds ratio for gastric cancer in H. pylori-infected patients is 1.92 (95% confidence interval [CI], 1.32-2.78), 2.24 (95% CI, 1.15-4.4), and 1.81 (95% CI, 1.16-2.84) for all studies, cohort, and case-control studies, respectively. H. pylori-infected younger patients have a higher relative risk for gastric cancer than older patients with odds ratios decreasing from 9.29 at age < or = 29 years to 1.05 at age > or = 70 years. H. pylori infection is equally associated with the intestinal or diffuse type of gastric cancer.

CONCLUSIONS

H. pylori infection is a risk factor for gastric cancer. The heterogeneity of reported results is caused by differences in the selection of controls, patient age, and the site and stage of gastric cancer.

Co-existing gastric cancer and duodenal ulcer disease: role of Helicobacter pylori infection

BACKGROUND

The association of gastric cancer and chronic duodenal ulcer disease is considered rare. In fact duodenal ulcer disease is believed to somehow "protect" against the development of gastric cancer. Helicobacter pylori infection is an important factor in the development of gastric cancer. No detailed investigation on the prevalence of H. pylori in coexistence of gastric cancer and duodenal ulcer disease has been performed. We evaluated the frequency of H. pylori infection in the patients with co-existence of gastric cancer and duodenal ulcer disease.

MATERIALS AND METHODS

During the period March 1994 to February 1995, we collected data from 3,652 patients in whom esophagogastroduodenoscopy was done. During this period, when the cancerous or ulcerative lesions in stomach or duodenum were found, rapid urease tests were performed.

RESULTS

Six patients had concurrent gastric carcinoma and duodenal ulcer disease. Three of the cases had early gastric carcinoma; 2 had active duodenal ulcers and one had a duodenal ulcer scar; all 3 had positive rapid urease tests. The patients with early gastric cancer were younger than the individuals with advanced gastric cancer.

CONCLUSIONS

The co-existence of both diseases may be higher than reported from Western countries or from Peru which may either reflect the high prevalence of circulation of H. pylori ulcer and cancer strains in Korea and the co-infection with both types of organism in some individuals.

Vitamin C inhibits the growth of a bacterial risk factor for gastric carcinoma: Helicobacter pylori

BACKGROUND

Helicobacter pylori infection is a risk factor for gastric carcinogenesis. High dietary vitamin C intake appears to protect against gastric carcinoma. It has been suggested that vitamin C exerts the protective effect by scavenging free radicals that may be enhanced by H. pylori. However, vitamin C has not been investigated in relation to the direct action on H. pylori. In this study, the authors attempted to clarify this possibility both in vitro and in vivo.

METHODS

Susceptibility testing of H. pylori (64 strains) was performed by the agar dilution method. Bactericidal actions were determined by a broth cultivation technique. The effect of vitamin C on in vivo H. pylori colonization was evaluated by using the Mongolian gerbil model.

RESULTS

At concentrations of 2048, 512, and 128 microg/mL (minimum inhibitory concentrations [MICs]), vitamin C could inhibit the growth of 90% of the bacterial stains incubated at pH values of 7.4, 6.0, and 5.5, respectively. The broth cultures exposed to the MICs of vitamin C displayed a 1.57 approximately 2.5-log decrease in the number of viable bacteria, and the loss of viability was observed in 24 hours at concentrations 8-fold higher than the MICs. In an in vivo experiment, H. pylori colonies decreased significantly in animals treated with vitamin C after oral administration of vitamin C (10 mg/head/day) for 7 days.

CONCLUSIONS

High doses of vitamin C inhibit the growth of H. pylori in vitro as well as in vivo.

The histopathology of human gastric mucosa inhabited by Helicobacter heilmannii-like (Gastrospirillum hominis) organisms, including the first culturable case

The aim was to determine the prevalence of Helicobacter heilmannii-like organisms in human gastric biopsies and the associated histology compared with that of Helicobacter pylori-bearing gastric biopsies. Furthermore, the feasibility of culturing H. heilmannii was examined. A consecutive series of 727 gastric biopsies from 650 patients were prospectively scrutinized for H. heilmannii. Their distribution pattern was recorded as well as the affiliated morphology of the gastric mucosa. Additional biopsies from some of the patients were examined microbiologically. Four cases (0.6%)(95% confidence intervals: 0.01-1.2%) of the examined material harboured H. heilmannii. The bacterial burden was graded as sparse in three cases, moderate in one case. The distribution pattern was patchy; thus, in no case did all biopsies from one endoscopy comprise H. heilmannii. Adhesion to epithelial cells was infrequent. A mild gastritis, active in three cases, characterized all biopsies. Lymphoid aggregates occurred in biopsies from three patients. Micropapillary tufting of the epithelial layer and intestinal metaplasia were not apparent. Culture studies proved successful in the one of the four cases assayed. In conclusion the morphology of H. heilmannii-bearing mucosa deviates from that of H. pylori-associated mucosa by the absence of epithelial damage in the former. This observation can in part be explained by the predominant location of H. heilmannii at a distance from the epithelium in contrast to the conspicuous H. pylori adhesion to epithelial cells, coupled with a usually low bacterial burden and patchy occurrence of H. heilmannii as opposed to the generally more heavy infestation with H. pylori.

Helicobacter pylori in areas of intestinal metaplasia in gastric antral mucosa

Colonization of areas of intestinal metaplasia by Helicobacter pylori is rare and there is only one report in the literature of this organism colonizing areas of intestinal metaplasia in the antral mucosa. We report two more cases where H. pylori were seen in the gastric pits with intestinal metaplastic changes in the antral biopsy specimens.

Increased prevalence of Helicobacter pylori infection among patients affected with intestinal-type gastric cancer at non-cardiac locations

Previous data on the association of Helicobacter pylori infection with gastric cancer by demographic or histological features are inconsistent due to a univariate analysis of limited case numbers. The aim of the present study was to determine such an association by the use of a large series of patients and multiple variables analysis. The serum IgG antibodies against H. pylori were measured in 397 patients with histologically verified gastric cancer. A multiple logistic regression analysis was used to define the association between seropositivity and demographic or tumour characteristics of gastric cancer. The overall seropositivity of H. pylori was 63%. In univariate analysis, the prevalence was significantly lower among patients with cardia (50%) or diffuse-type (56.6%) cancers than those with non-cardia (64.8%) or intestinal-type (70.3%) cancer (P < 0.05 and P < 0.01, respectively). There was no statistical difference between H. pylori infection rate and gender, age or tumour stage. A multiple logistic regression analysis showed tumour location and histology remained significant factors associated with seropositivity of H. pylori with an odds ratio of approximately 2.0. Analysis of combined histology and location revealed that patients with intestinal-type cancer at non-cardia locations had the highest odds ratio of 3.93 (95% confidence interval (CI): 1.55-10.0) compared with the lowest odds ratio of 0.69 (95% CI: 0.30-1.62) in diffuse cardia cancer (P < 0.005). Our data indicate H. pylori infection in gastric cancer is independently affected by the histological subtype and by tumour location.

Detection of Helicobacter pylori in biopsy of patients with gastric carcinoma

Superficial chronic gastritis caused by Helicobacter pylori may lead potentially to the development of atrophic gastritis, a precursor of gastric carcinoma. Based on histological studies, the prevalence of Helicobacter pylori infection in gastric cancer patients, has been reported to vary widely from 38% to 100%. This positivity rate tends to be higher in patients with gastric cancer in early stage than in those with advanced malignant disease, probably, due to the relative mild atrophic and intestinal metaplastic changes of the surrounding gastric mucosa that occur in the former group. The prevalence of Helicobacter pylori infection is not related to the anatomical localization of cancer in the stomach. The inclusion of cases in advanced stages of disease and the examination of a few small-sized number of gastric specimens may explain the discrepant findings reported so far regarding the prevalence of Helicobacter pylori infection in patients with gastric cancer. We found a strong association between Helicobacter pylori infection and the occurrence of gastric carcinoma. Therefore, Helicobacter pylori may be an important carcinogenetic factor for the occurrence of malignant disease in the stomach. Cure of Helicobacter pylori infection may potentially reduce the incidence of gastric cancer.

Cell surface glycosaminoglycans are not involved in the adherence of Helicobacter pylori to cultured Hs 198.St human gastric cells, Hs 746T human gastric adenocarcinoma cells, or HeLa cells

Hs 198.St cells (a line derived from normal human gastric tissue), Hs 746T cells (a line derived from human gastric adenocarcinoma), and HeLa cells were used together with 3H-labelled Helicobacter pylori, strain NCTC 11637 to determine if cell surface glycosaminoglycans could act as initial receptors for adherence of the bacteria. Although as much as 40% of the 3H-labelled bacteria adhered to monolayers of the cultured cells, removal of glycosaminoglycans by prior treatment of the cells with heparitinase, heparinase, or chondroitin ABC lyase had no effect in modifying the adherence. Prior addition of heparan sulfate, heparin, or chondroitin/dermatan sulfate to bacteria had no effect on adherence, nor were bacteria released when these same glycosaminoglycans or these same enzymes were added to cultures already containing adherent bacteria. These results indicated that neither heparan sulfate nor chondroitin/dermatan sulfate are involved as receptors in the initial adherence step of H. pylori to these cultured cells.

Helicobacter pylori serology in chronic gastritis with antral atrophy and negative histology for Helicobacter-like organisms

It has been suggested that there may be a correlation between Helicobacter pylori (Hp) infection and precancerous lesions of the stomach. However, histological evaluation of bacterial colonization in chronic atrophic gastritis shows a relatively low prevalence of the microorganism, which does not support the hypothesis. The aim of our study was to investigate the Hp serology in 95 patients with chronic gastritis with antral atrophy, with (27 cases) and without (68 cases) intestinal metaplasia, and without Helicobacter-like organisms in antral and corpus biopsy specimens. For all subjects, serum anti-Hp immunoglobulin IgG was identified by a fluorescent immunoenzymatic method (Helori-test; Eurospital), and mucosal atrophy and activity were graded histologically (Sydney System score). The serum Hp-antibody status documented the presence of current bacterial infections in 64 of 95 (67.4%) patients and previous infections in another 17 subjects. In only 14.7% of cases was there no evidence of current or previous infection. These subjects had less severe mucosal atrophy and lower inflammatory scores. In addition, there were no cases of intestinal metaplasia in such subjects. The high prevalence of Hp infection confirms the primary role of the microorganism in the pathogenesis of chronic gastritis with antral atrophy, although the bacterium is no longer present in the advanced stages of such disease. The histological evaluation of Hp colonization following the criteria of the Sydney System appears from our study to underestimate the true prevalence of the infection in the stomach when there is mucosal atrophy.