Gastric cancer and Helicobacter pylori infection

Association of Helicobacter Pylori in Carcinoma Stomach at Maharaja Krishna Chandra Gajapat Medical College: A Prospective Study

Introduction

Gastric cancer is the fourth most common type of cancer and the second leading cause of cancer-related death in the world. The etiology of gastric cancer includes Helicobacter pylori infection, diet, lifestyle, tobacco, alcohol, and genetic susceptibility. Upper gastrointestinal endoscopy (UGIE) is the most effective method for examining the upper gastrointestinal tract as compared to the other examination tools.

Objective

To study the histopathological finding of upper gastrointestinal endoscopic biopsies and its association with H. pylori in cases of carcinoma stomach.

Materials and methods

This was a hospital-based observational study carried out in the Department of Surgery, at Maharaja Krushna Chandra Gajapati Medical College, Berhampur, a tertiary care hospital in Eastern India. Study population consisted of 106 patients for a period of 2 years from July 2019 to June 2021, after due consideration of the inclusion and exclusion criteria. Endoscopic location and pathological types of the gastric lesion were noted, and all biopsy specimens were investigated to see the presence of H. pylori by rapid urease test (RUT) and histological examination in the form of Giemsa and H&E stain.

Results

In the present study of 106 cases, 62 cases (58.49%) were found to be positive for H. Pylori by RUT and 72 cases (67.92%) were positive for H. pylori by smear staining. In histopathological study, 72 cases (67.92%) were of intestinal type of carcinoma and 34 cases (32.07%) were of diffuse type of carcinoma. Smear for H. pylori was positive in 56 cases (77.78%) among the 72 cases of intestinal type of carcinoma stomach. Whereas only 16 cases (47.05%) were found to be smear-positive for H. pylori among the 34 cases of diffuse type of lesion. Irrespective of histological type, H. pylori was positive in 67.92% of patients with carcinoma stomach. This association was statistically significant (p<0.001) and indicates its role in intestinal type of gastric carcinoma.

Conclusion

There is a high frequency of H. pylori infection in cases of stomach cancer. This study confirmed the higher association of H. pylori infection with gastric cancer. Its association with the intestinal histological variety of stomach cancer is more common than diffuse type. The prevalence of H. pylori infection in distal stomach carcinoma is higher than proximal.

Time to Classify Tumours of the Stomach and the Kidneys According to Cell of Origin

Malignant tumours are traditionally classified according to their organ of origin and whether they are of epithelial (carcinomas) or mesenchymal (sarcomas) origin. By histological appearance the site of origin may often be confirmed. Using same treatment for tumours from the same organ is rational only when there is no principal heterogeneity between the tumours of that organ. Organ tumour heterogeneity is typical for the lungs with small cell and non-small cell tumours, for the kidneys where clear cell renal carcinoma (CCRCC) is the dominating type among other subgroups, and in the stomach with adenocarcinomas of intestinal and diffuse types. In addition, a separate type of neuroendocrine tumours (NETs) is found in most organs. Every cell type able to divide may develop into a tumour, and the different subtypes most often reflect different cell origin. In this article the focus is on the cells of origin in tumours arising in the stomach and kidneys and the close relationship between normal neuroendocrine cells and NETs. Furthermore, that the erythropoietin producing cell may be the cell of origin of CCRCC (a cancer with many similarities to NETs), and that gastric carcinomas of diffuse type may originate from the ECL cell, whereas the endodermal stem cell most probably gives rise to cancers of intestinal type.

Rapidly declining trend of signet ring cell cancer of the stomach may parallel the infection rate of Helicobacter pylori

Background

Studies indicate that gastric cancer (GC) incidence has decreased, whereas signet ring cell carcinoma (SRC) incidence has increased. However, recent trends in GC incidence are unclear. We used our hospital cancer registry to evaluate the changes in the incidence of GC, SRC, and non-SRC (NSRC) over time in comparison to changes in the H. pylori infection rates over time.

Methods

We identified 2532 patients with GC enrolled in our registry between January 2007 and December 2018 and statistically analyzed SRC and NSRC incidence. The H. pylori infection rate in patients with SRC was determined by serum anti-H. pylori antibody testing, urea breath test, biopsy specimen culture, and immunohistochemical analysis (IHC) of gastric tissue. Additionally, genomic detection of H. pylori was performed in SRCs by extracting DNA from formalin-fixed paraffin-embedded gastric tissue and targeting 16S ribosomal RNA of H. pylori.

Results

Overall, 211 patients had SRC (8.3%). Compared with patients with NSRC, those with SRC were younger (P <  0.001) and more likely to be female (P <  0.001). Time series analysis using an autoregressive integrated moving average model revealed a significant decrease in SRC (P <  0.001) incidence; NSRC incidence showed no decline. There was no difference in H. pylori infection prevalence between the SRC and NSRC groups. IHC and genomic methods detected H. pylori in 30 of 37 (81.1%) SRCs.

Conclusions

Reduction in H. pylori infection prevalence may be associated with the decrease in the incidence of SRC, which was higher than that of NSRC.

Infiltrative gastric adenocarcinoma in a chinchilla (Chinchilla lanigera)

A case of infiltrative gastric adenocarcinoma in a 5-year-old female chinchilla (Chinchilla lanigera) is described. The animal died after a 5-day period of lethargy and anorexia. Gross examination revealed increased gastric volume. The gastric wall was thickened and contained numerous firm, white nodules on the serosal surface. The lumen was obliterated by a firm mass and large amount of white, mucous secretion. Numerous white, irregular plaques and nodules were observed on the mesentery, visceral surface of the diaphragm, renal capsule, and uterine serosa (implantation metastases). Histopathological examination revealed an infiltrative gastric adenocarcinoma composed of neoplastic cells organized in a gland-like pattern interspersed with connective tissue. Neoplastic cells infiltrated the lamina propria, submucosa, and muscular layers, and were positive for cytokeratin. Detection of Helicobacter spp. in the gastric mucosa failed using Warthin-Starry and Steiner silver stains or immunohistochemistry, but a Helicobacter-specific nested polymerase chain reaction followed by sequencing was positive for Helicobacter pylori and showed more than 99% similarity to the 16S ribosomal RNA gene.

Prevalence of Helicobacter pylori genotypes (vacA, cagA, cagE and virB11) in gastric cancer in Brazilian's patients: an association with histopathological parameters

PURPOSE

To investigate the frequency and the association of vacA alleles, cagA, cagE and virB11 genes of Helicobacter pylori from patients with gastric cancer, considering the clinic histopathological parameters.

METHODS

One hundred and one gastric adenocarcinoma tissues were assessed by PCR to detect H. pylori and vacA alleles, cagA, cagE and virB11.

RESULTS

The distribution of cases according to the presence of the genes studied showed that the group containing vacA s1m1, cagA, cagE and virB11 H. pylori genes was significantly more frequent, followed by the group with at least one marker on the right side and left of the island. They were also present in the early stages and were the most frequent in nearly all histopathological grades.

CONCLUSIONS

This study verified that vacAs1m1 and cag-PAI genes, cagA, cagE and virB11 are important H. pylori markers for gastric cancer development. Also, this study corroborates the importance of cagE and cagA together as cag-PAI marker.

The relationship between Helicobacter pylori genes cagE and virB11 and gastric cancer

BACKGROUND

The association between Helicobacter pylori gene diversity and gastric cancer has been poorly reported, although it is one of the important ways to explain the gastric pathogenesis. The aim of this study was to investigate the frequency of cagE and virB11 genes in H. pylori isolated from patients with gastric cancer and to analyze the histology profiles.

MATERIALS AND METHODS

The presence of H. pylori and subtypes (cagE and virB11) was detected by PCR from the genomic DNA of 101 patients who had been diagnosed with gastric cancer. The cases were grouped according to the presence/absence of the genes studied and were analyzed in relation to histopathological parameters.

RESULTS

H. pylori infection was detected in 94 out of 101 (93.1%) gastric carcinomas. The cases were categorized into the following groups: cagE+/virB11+, cagE+/virB11-, cagE-/virB11+, and cagE-/virB11-. Frequencies were: 50% (47/94) cagE+/virB11+, 3.2% (3/94) cagE+/virB11-, 10.6% (10/94) cagE-/virB11+, and 36.2% (34/94) cagE-/virB11-. Tumors in the gastric antrum were predominant. An exception was the cagE-/virB11- group, in which tumors had a tendency to be located in the gastric cardia; the majority of the cardia tumors (56% (14/25)) were in this group. Intestinal histology type was the most frequent, but the cagE+/virB11- group only had diffuse tumors. H. pyloricagE+/virB11+ occurred most frequently (except at stage III), and was present at all gastric cancer stages.

CONCLUSIONS

This study is the first to include a relevant number of gastric cancer cases with H. pylori infection, reporting the frequency and relationship of cagE and virB11 genes and the genesis of this tumor. The presence of these cag pathogenicity island genes shows that they are important factors for the pathogenesis and malignancy of gastric cancer related to H. pylori.

H pylori (CagA) and Epstein-Barr virus infection in gastric carcinomas: Correlation with p53 mutation and c-Myc, Bcl-2 and Bax expression

AIM: To investigate the interrelationship between H pylori and Epstein-Barr virus (EBV) infection in the gastric carcinogenesis having in focus the p53 mutation and the c-Myc, Bcl-2 and Bax expression.

METHODS: seventy-one gastric carcinoma tissues were assessed by polymerase chain reaction (PCR) for H pylori and in situ hybridization for EBV. c-Myc, Bcl-2 and Bax expression were detected by immunohistochemistry and single-stranded conformational polymorphism (SSCP) for p53 mutation.

RESULTS: The positivity rates for H pylori and EBV were 94.4% and 8.45%, respectively. The majority of the cases displayed only the H pylori presence. All EBV positive cases were also H pylori positive. None infectious agent was observed in 5.55% of the cases. The intestinal type tumor was more frequent in the co-infected and non-infected groups. The female predominated in the non-infected group showing statistical significance (70.4% vs 29.6%, P = 0.039). The Bcl-2 was only detected in the group exclusively infected by H pylori. However, c-Myc and Bax were detected in the three groups but with a low frequency in the co-infected group. Mutation of p53 was present in all groups, with the highest frequencies in the H pylori positive groups.

CONCLUSION: The frequency of H pylori infection in gastric carcinomas was high. The presented data indicated that gastric carcinogenesis has different pathways depending of the presence of the two investigated infectious agents, suggesting a possible involvement of H pylori with apoptotic process. The low expression of c-Myc and Bax in the EBV-positive groups suggests that EBV may inhibit the expression of these proteins. Nevertheless, p53 mutation shows to be a relevant alteration, independent of both infectious agents.

Diet, H pylori infection and gastric cancer: evidence and controversies

Despite decreasing incidence and mortality rates, gastric cancer (GC) still remains the fourth most common cancer and the second most common cause of cancer-related deaths worldwide. Due to the limited treatment options, at present, prevention is likely to be the only effective means of controlling this disease. The success of a prevention strategy depends upon the understanding of etiological and pathogenic mechanisms underlying gastric carcinogenesis. The etiology of GC is multi-factorial, however, in the recent years, mounting evidence suggests that environmental factors play a key role. The most important environmental factors implicated in the pathogenesis of GC are diet and H pylori infection. Thus, modifications in lifestyle and dietary habit associated with eradication of H pylori infection could hypothetically represent the most promising potential targets for GC prevention. In this review we will address the evidence and the controversies on the role of these agents in non-cardia GC by focusing on retrospective and prospective observational studies and interventional trials.

[Helicobacter pylori and gastric cancer: relationship with histological subtype and tumor location]

INTRODUCTION

Helicobacter pylori (HP) has been implicated in the pathogenesis of gastric adenocarcinoma. Published data on HP infection and its association with both histological subtype and tumor localization are contradictory and few data are available on this topic in Spain. The aim of the present study was to evaluate the association of HP infection with histological subtype and tumor localization in a series of patients with gastric adenocarcinoma.

MATERIAL AND METHOD

We retrospectively reviewed all the patients diagnosed with gastric neoplasms in Hospital del Mar in Barcelona between 1995 and 2001. The histological subtype was established using Lauren's classification. Tissue samples were obtained from the surgical specimen or from endoscopic biopsies. HP infection was histologically determined through hematoxylin-eosin, Masson's trichromic, and Giemsa staining.

RESULTS

During the study period, 304 gastric neoplasms, 275 (90.4%) adenocarcinomas, 22 (7.2%) lymphomas, 3 (1.0%) leiomyosarcomas, 2 (0.7%) degenerated gastrointestinal stromal tumors (GIST) and 2 (0.7%) Kaposi's sarcomas were diagnosed. In patients with adenocarcinoma, the mean age at diagnosis was 69 years and most patients were male (62%). A total of 48.1% of the neoplasms were located in the gastric antrum, 23.7% in the body and 19.1% in the fundus (13.6% in the period 1994-1997 and 25.4% in the period 1998-2001, p = 0.018). Intestinal-type gastric carcinoma was observed in 56% of the patients, diffuse-type in 28% and indeterminate-type in 16%. HP infection was confirmed in 69% of the patients (68% in intestinal subtype, 69% in diffuse subtype, and 69% in indeterminate subtype, p = 0.84), and was significantly associated with distal adenocarcinomas vs. proximal adenocarcinomas (73.6% vs 48.6%, p < 0.05).

CONCLUSIONS

No differences were observed between the histological type of adenocarcinoma and HP infection. In the last few years, the incidence of fundic adenocarcinomas has increased. These tumors show a lower association with HP infection.

Does eradication of Helicobacter pylori reduce the risk of carcinogenesis in the residual stomach after gastrectomy for early gastric cancer?

BACKGROUND AND AIMS

After partial gastrectomy, the mucosa of the residual stomach usually undergoes severe changes, and these lesions are known to be pre-cancerous. Recently, Helicobacter pylori has been highlighted as an agent that induces such mucosal alterations. In the present study, we evaluated whether eradication of H. pylori reduced the risk of carcinogenesis.

PATIENTS AND METHODS

The subjects were 12 patients who underwent distal gastrectomy with Billroth I anastomosis for early gastric cancer and were positive for H. pylori. We performed endoscopy and biopsy both before and after H. pylori eradication therapy to assess changes in the gastric mucosa.

RESULTS

After eradication therapy, no mucosal edema or erythema was detected. On histological examination, mononuclear cell infiltration had decreased and there was complete absence of neutrophil infiltration. The Ki-67 labeling index and the tissue IL-8 level had also decreased significantly, compared with before eradication.

CONCLUSION

Before H. pylori eradication, the mucosa of the residual stomach may be at high risk of carcinogenesis due to induction of mucosal damage and active gastritis by H. pylori. Such changes were almost completely normalized by eradication therapy, so the eradication of H. pylori may reduce the risk of H. pylori-associated carcinogenesis in patients who have undergone gastrectomy for early gastric cancer.

Gastric carcinoma with lymphoid stroma: incidence of EBV and Helicobacter pylori infection

Lymphoepithelioma-like carcinoma (LELC) of the stomach is reported to be associated with Epstein-Barr virus (EBV) and to have a better prognosis than typical adenocarcinoma. However, the incidence of EBV and its association with Helicobacter pylori is controversial. In our series, 9 of 370 (2.4%) cases of gastric adenocarcinoma were LELC. Formalin-fixed, paraffin-embedded LELC tissue was immunostained with monoclonal antibodies against CD3, CD20, and Ki-67. Warthin-Starry stain for H. pylori and in situ hybridization for EBV were performed. As a control, 21 cases of adenocarcinoma with prominent lymphoid stroma were compared with LELC. The most common location of LELC was the body of the stomach (five cases), followed by the cardia (two cases), whereas the antrum was the most common site for the control group. There were no significant differences in age, sex, or lymph node metastasis between the LELC and control groups. The mean Ki-67 index was similar (38.2% in LELC versus 35.3% in control). H. pylori was found in 2 LELC cases (22%) and 6 controls (28.5%). EBV was positive in 7 LELC cases (77.8%) and 4 controls (19.0%). All patients with LELC are alive and well, whereas three patients have died of their disease in the control group. Although EBV appeared to be a contributing factor, H. pylori had a minor role in LELC. There were no clinicopathologic differences between LELC and the control group, except for the location of the tumor in the body of the stomach and the tendency toward a better prognosis in LELC.

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 infection with gastric carcinoma: a meta-analysis

OBJECTIVE

As conflicting studies have recently been published, we aimed to determine if Helicobacter pylori (H. pylori) infection is associated with gastric adenocarcinoma.

METHODS

This was a meta-analysis of observational epidemiological studies.

RESULTS

A total of 42 studies met the selection criteria and were categorized by the type of study design: eight cohort and 34 case-control studies. The pooled odds ratio for H. pylori in relation to gastric carcinoma was 2.04 (95% CI: 1.69-2.45). Both patient age (OR 0.77, 95% CI: 0.68-0.89) and intestinal type cancers (OR 1.14, 95% CI: 1.05-1.25) were independent effect modifiers. Analysis of other effect modifiers showed no relationship with female gender (OR 0.76, 95% CI: 0.64-0.89), stage of cancer (advanced %) (OR 1.12, 95% CI: 0.88-1.43), anatomical location (cardia %) (OR 1.54, 95% CI: 0.32-7.39) or cohort (nested case-control) studies (OR 1.72, 95% CI: 0.32-9.17). There was significant heterogeneity among the studies (tau2 = 149; p < 0.001). The quality of the studies varied considerably, with the majority of excellent studies producing positive results and the very poor to moderate studies producing mixed results.

CONCLUSIONS

H. pylori infection is associated with a 2-fold increased risk of developing gastric adenocarcinoma.

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.

Distinct clinicopathologic characteristics of diffuse- and intestinal-type gastric cancer in Taiwan

The clinicopathologic features of 221 patients with intestinal-type (IT) gastric cancer were compared retrospectively with those of 290 diffuse type (DT). Intestinal type was characterized by an older mean age (65.0 +/- 10.8 years vs. 56.2 +/- 13 years), a higher male-female ratio (2.56 vs. 1.06), predominance of blood group O (46.2% vs. 31.1%), and frequent habitual smoking (50.7% vs. 31.4%) and drinking (28.5% vs. 17.6%) than did DT. In contrast, DT had a higher frequency of positive history of parent or sibling with gastric cancer (9.3% vs. 4.1%) and blood group A (40.3% vs. 27.6%) than did IT. The distinguishing histologic features of DT included more Borrmann type IV (13.1% vs. 1.3%) but less Borrmann type I (1% vs. 7.2%), more frequent involvement of middle third (26.9% vs. 15.9%) and whole stomach (4.1% vs. 0%), and more peritoneal seeding (15.5% vs. 9%), lymph node metastasis (67.2% vs. 51%), and nerve permeation (34.1% vs. 24.4%), but less Helicobacter pylori infection (55.9% vs. 69.2%) when compared with those of IT. There was no difference in depth of tumor invasion, venous permeation, duodenal involvement, and postoperative survival between IT and DT. These distinct clinicopathologic features between IT and DT in Taiwan suggest the presence of a different pathogenic process for these two histologic subtypes of gastric cancer.

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.

Relation between histologic subtypes and location of gastric cancer and Helicobacter pylori

BACKGROUND

Epidemiologic studies have consistently shown an association between Helicobacter pylori infection and gastric cancer, and it is now widely accepted that this organism plays a role in the pathogenesis of this tumor. Nevertheless, there are discrepant results on its relationship with the histologic type and location of gastric cancer within the stomach. The aim of this study was to determine the seroprevalence of H. pylori in a group of gastric cancer patients and the association between H. pylori and specific histologic types of gastric cancer and tumor location within the stomach.

METHODS

Systemic IgG antibodies against H. pylori were assayed using an enzyme-linked immunosorbent assay technique in 48 patients (male to female ratio, 31:17; age range, 39-88 years; mean, 69 years) with histologically confirmed gastric cancer and 50 controls (male to female ratio, 33:17; age range, 40-77 years, mean, 64 years).

RESULTS

Thirty-one cases of gastric cancer were of the intestinal type, and 12 of the diffuse type; the remaining 5 were unclassified. Thirteen gastric cancers were located in the distal stomach (antrum/pylorus), 12 in the body, and 5 in the proximal stomach (cardia/fundus); the remaining 17 were unclassified because the tumor extended towards more than one location. The overall seroprevalence of H. pylori in patients with gastric cancer and controls was 85.4% and 66%, respectively (P < 0.05). The seroprevalence increased with increasing age in cancer patients, but the difference was not significant. H. pylori seroprevalence among patients with the intestinal type of gastric cancer was higher than in those with the diffuse type (P < 0.05). The prevalence of H. pylori infection was higher among patients with the cancer located distally than in those with the cancer located proximally (P < 0.05).

CONCLUSIONS

H. pylori seroprevalence was higher in gastric cancer patients than in controls. The prevalence of H. pylori infection in intestinal-type gastric cancer was clearly higher than in the diffuse type and in the control group. An association was found between H. pylori infection and tumors located distally (antrum/pylorus).

Helicobacter pylori infection in young patients with gastric carcinoma

BACKGROUND

Helicobacter pylori infection has been linked with chronic atrophic gastritis and gastric cancer. This case-control study was performed to investigate a possible relationship between H. pylori infection and gastric cancer in young age groups.

METHODS

Gastrectomy and/or biopsy samples were collected from 50 consecutive patients 45 years old or younger treated between 1980 and 1994 for noncardiac gastric cancer. The control group consisted of age- and sex-matched dyspeptic patients. The presence of H. pylori infection was assessed by modified Giemsa staining and immunostaining, using antibody against H. pylori.

RESULTS

H. pylori was found in 36 (72%; 95% confidence interval 60-84%) cancer patients and in 22 (43%; 30-58%) control patients (p = 0.0023, chi-square test). The odds ratio was 3.27 (1.42-7.52). Nonatrophic (superficial) gastritis was present in 30 (60%) cancer patients and in 19 (38%) (p = 0.028, chi-square test) control cases.

CONCLUSIONS

The results of the present study support the hypothesis that H. pylori is a risk factor for gastric cancer also in young age groups and in patients with a diffuse type of gastric cancer.

Prevalence of gastric cancer in a large group of healthcare workers routinely exposed to Helicobacter pylori

Secondary data analysis of the Society of Gastroenterology Nurses and Associates Endoscopic Disinfectant Survey was undertaken to answer the question, "What was the prevalence of gastric cancer among endoscopy personnel who were routinely exposed to Helicobacter pylori (HP) in their work environment?" This large sample of healthcare personnel (4,001) was occupationally exposed to both endoscopic disinfectants and HP. There is a known positive relationship between the prevalence of HP infection, gastritis, and gastric cancer. Results indicated that zero respondents reported gastric cancer in this sample.

Helicobacter Pylori Infection in Patients with Gastric Adenocarcinoma

We examined the biologic tumor behavior in Helicobacter pylori-seropositive patients with gastric adenocarcinoma. A total of 214 consecutive patients with pathologically confirmed adenocarcinoma of the stomach who underwent gastric resection were studied. The stored serum samples were tested for serum antibody to H. pylori by using a highly sensitive and specific IgG enzyme-linked immunosorbent assay. The difference in H. pylori-seropositive and seronegative patients with gastric adenocarcinoma was evaluated in terms of various clinicopathologic parameters. A multivariate logistic regression analysis was used to adjust for potential confounding variables. Antibodies to H. pylori were detected in 65.9% of patients with gastric adenocarcinoma. H. pylori-seropositive patients were younger than seronegative patients and had infiltrative tumor according to Ming's criteria. When adjusted for age, infiltrative tumor come out stronger. These findings suggest that H. pylori infection may be related to infiltrative type gastric adenocarcinoma; further study is necessary.

Prevalence of Helicobacter pylori infection in subtypes of gastric cancer

BACKGROUND & AIMS

Although Helicobacter pylori has already been declared a human carcinogen, the exact nature of the association with gastric cancer remains to be explored. The aim of this study was to determine if the association is confined to specific types of gastric cancer.

METHODS

The prevalence of H. pylori immunoglobulin G antibodies (HM-CAP immunoassay; Enteric Products Inc., Westbury, NY) was determined in prospectively collected sera from 279 patients with gastric cancer.

RESULTS

The overall prevalence of H. pylori seropositivity was 77%. The prevalence of H. pylori infection was significantly lower among patients with tumors of the gastric cardia compared with those with other gastric locations. Age-adjusted H. pylori seroprevalence among patients with the intestinal type of gastric cancer tended to be higher than among those with the diffuse type according to Laurén (P > 0.05). In both histological types, the seroprevalence decreased with increasing age. Multivariate logistic regression analysis showed that high age and proximal tumor location were independent predictors of absence of H. pylori.

CONCLUSIONS

The association with H. pylori infection is similar regardless of the histological features of the tumor, whereas it is stronger for noncardiac gastric cancer than for cardiac cancer. The apparent loss of H. pylori seropositivity among patients with gastric cancer is determined by age rather than tumor stage.

Helicobacter pylori associated with a high prevalence of duodenal ulcer disease and a low prevalence of gastric cancer in a developing nation

This study examines the relationship between Helicobacter pylori infection and peptic ulcer disease and gastric cancer--in particular, the presence or absence of bacteria, the grading of gastritis, and the degree of inflammation in the antral and oxyntic mucosae. The grading of gastritis and the detection of H pylori were determined by histology using the Sydney system. Of the 1006 patients examined, 34.5% had duodenal ulcer disease, 3.5% gastric ulcer disease, and 2% with coexistent ulceration. Most patients (50.2%) were classified as having non-ulcer dyspepsia. Altogether 2.4% of patients had gastric cancer and two further patients had carcinoma in the gastric stump. Of the ulcer disease patients, 87.2% had histological evidence of H pylori infection. After patients who had taken antibiotics or bismuth compounds in the preceding four weeks were excluded, 98.9% of the duodenal ulcer disease, 100% of the gastric ulcer disease, and 100% of the coexistent ulcer disease patients had evidence of H pylori infection. In patients with gastric cancer who had not taken antimicrobial agents in the four weeks before endoscopy, 83.3% had evidence of H pylori infection. Thus, there was a high rate of duodenal ulcer disease and a low rate of gastric ulcer disease in southern China, an area of low gastric cancer mortality. There was a specific topographical relationship between H pylori, the histological response, and gastroduodenal disease. Our data suggest that the status of a nation as either 'developed' or 'developing' can not be used to predict the upper gastrointestinal disease profile of its population.