Prevalence of Helicobacter pylori Positive Non-cardia Gastric Adenocarcinoma Is Low and Decreasing in a US Population

Patients with Whipple's disease have a high prevalence of Helicobacter pylori infection

INTRODUCTION

Whipple's disease is a rare systemic infection due to an impaired immunological response against T. whipplei in genetically predisposed individuals. Since we previously noted development of H. pylori related complications in some patients with Whipple's disease, our aim was to study the prevalence of H. pylori infection and H. pylori related disorders in Whipple's disease.

METHODS

Whipple's disease patients diagnosed from Jan-2002 to Dec-2021 and two controls per patient, matched for age, gender, ethnicity and year of H. pylori testing were enrolled.

RESULTS

34 patients with Whipple's disease and 68 controls were enrolled. H. pylori infection (13/34 vs 8/68, p<0.01), H. pylori-related gastritis (p<0.01) and gastric atrophy (p = 0.01) were significantly more common in patients with Whipple's disease than controls. H. pylori infection and Whipple's disease were diagnosed synchronously in 6/13 patients, and during follow-up in the remaining 7. Interestingly, these last 7 patients were all on trimethoprim-sulfamethoxazole long-term therapy. Two patients developed H. pylori-related gastric malignancies during follow-up. No patients on doxycycline developed H. pylori infection.

CONCLUSIONS

H. pylori infection and related disorders are common in patients with Whipple's disease and should always be excluded both at time of diagnosis and during follow-up. These findings should be taken into account when selecting antibiotics for Whipple's disease long-term prophylaxis.

Global burden of gastric cancer: epidemiological trends, risk factors, screening and prevention

Gastric cancer remains a major cause of cancer-related mortality worldwide. The temporal trends for this malignancy, however, are dynamic, and reports from the past decade indicate important declines in some regions and demographic groups, as well as a few notable exceptions in which gastric cancer rates are either stable or increasing. Two main anatomical subtypes of gastric cancer exist, non-cardia and cardia, with different temporal trends and risk factors (such as obesity and reflux for cardia gastric cancer and Helicobacter pylori infection for non-cardia gastric cancer). Shifts in the distribution of anatomical locations have been detected in several high-incidence regions. H. pylori is an important aetiological factor for gastric cancer; importantly, the anticipated long-term findings from studies examining the effect of H. pylori eradication on the risk of (re)developing gastric cancer have emerged in the past few years. In this Review, we highlight the latest trends in incidence and mortality using an evidence-based approach. We make the best possible inferences, including clinical and public health inference, on the basis of the quality of the evidence available, and highlight burning questions as well as gaps in knowledge and public health practice that need to be addressed to reduce gastric cancer burden worldwide.

Missed Opportunities for Screening or Surveillance Among Patients with Newly Diagnosed Non-cardia Gastric Adenocarcinoma

BACKGROUND

Screening for gastric cancer is not recommended despite rising rates in certain U.S.

POPULATIONS

We determined possible missed opportunities for the detection and surveillance of preneoplastic lesions among gastric cancer patients in a VA hospital.

METHODS

This retrospective cohort study included consecutive, newly diagnosed non-cardia gastric adenocarcinoma patients from 11/2007 to 10/2018 at the Houston VA Hospital. We identified missed opportunities for screening based on risk factors (non-White race, smoking, alcohol, Helicobacter pylori infection, gastric ulcers, family history of gastric cancer). We additionally determined missed opportunities for surveillance of known high-risk lesions. Associations between receipt of prior endoscopy for screening or surveillance and cancer-related outcomes (stage, treatment, survival) were determined using logistic regression models.

RESULTS

Among 91 gastric cancer patients, 95.6% were men, 51.6% were black, 12.1% were Hispanic, with mean age of 68.0 years (standard deviation 10.8 years). The most common risk factors included non-white race (68.1%), smoking (76.9%), alcohol use (59.3%) and prior H. pylori (12.1%). Most patients had ≥ 1 risk factor for gastric cancer (92.6%), and 76.9% had ≥ 2 risk factors. Only 25 patients (27.5%) had undergone endoscopy prior to cancer diagnosis. Of 14 with known high-risk lesions (i.e., gastric intestinal metaplasia, dysplasia, ulcer), only 2 (14.3%) underwent surveillance endoscopy. Receipt of prior endoscopy was not associated with differences in cancer outcomes.

CONCLUSIONS

Most patients with newly diagnosed gastric cancer had ≥ 2 known risk factors for gastric cancer but never received prior screening endoscopy. Among the few with known prior preneoplastic lesions, endoscopic surveillance was not consistently performed.

The Gastric Cancer Registry: A Genomic Translational Resource for Multidisciplinary Research in Gastric Cancer

BACKGROUND

Gastric cancer is a leading cause of cancer morbidity and mortality. Developing information systems which integrate clinical and genomic data may accelerate discoveries to improve cancer prevention, detection, and treatment. To support translational research in gastric cancer, we developed the Gastric Cancer Registry (GCR), a North American repository of clinical and cancer genomics data.

METHODS

Participants self-enrolled online. Entry criteria into the GCR included the following: (i) diagnosis of gastric cancer, (ii) history of gastric cancer in a first- or second-degree relative, or (iii) known germline mutation in the gene CDH1. Participants provided demographic and clinical information through a detailed survey. Some participants provided specimens of saliva and tumor samples. Tumor samples underwent exome sequencing, whole-genome sequencing, and transcriptome sequencing.

RESULTS

From 2011 to 2021, 567 individuals registered and returned the clinical questionnaire. For this cohort 65% had a personal history of gastric cancer, 36% reported a family history of gastric cancer, and 14% had a germline CDH1 mutation. 89 patients with gastric cancer provided tumor samples. For the initial study, 41 tumors were sequenced using next-generation sequencing. The data was analyzed for cancer mutations, copy-number variations, gene expression, microbiome, neoantigens, immune infiltrates, and other features. We developed a searchable, web-based interface (the GCR Genome Explorer) to enable researchers' access to these datasets.

CONCLUSIONS

The GCR is a unique, North American gastric cancer registry which integrates clinical and genomic annotation.

IMPACT

Available for researchers through an open access, web-based explorer, the GCR Genome Explorer will accelerate collaborative gastric cancer research across the United States and world.

Prevalence of Helicobacter pylori in Non-Cardia Gastric Cancer in China: A Systematic Review and Meta-Analysis

Non-cardia gastric cancer was significantly associated with Helicobacter pylori (H. pylori) infection. Reducing H. pylori prevalence was an important prevention strategy for non-cardia gastric cancer. However, national-level data on the H. pylori prevalence in non-cardia gastric cancer were limited in China. Therefore, we conducted this study to estimate the pooled prevalence of H. pylori in non-cardia gastric cancer in China. We searched PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang, and VIP Database for Chinese Technical Periodicals for studies reporting H. pylori prevalence in non-cardia gastric cancer in China which were published before September 1, 2021. Pooled prevalence was calculated using a random-effect model. Subgroup analysis and meta-regression were used to explore the potential sources of heterogeneity. Egger’s test and funnel plot were used to assess publication bias. A total number of 55 studies with 5324 cases of non-cardia gastric cancer were included in this study. The pooled prevalence of H. pylori in non-cardia gastric cancer in China was 66.5% (95%CI: 62%-71%, I²=93.8%, P<0.0001). In subgroup analysis, a significant difference in the prevalence of H. pylori in non-cardia gastric cancer was noted when stratified by geographic region of China (P=0.0112). The highest H. pylori prevalence (78.9%, 95%CI: 69.9%-87.8%) was noted in Northwest China and the lowest (53.1%, 95%CI: 38.9%-67.3%) was in North China. In meta-regression, a significant association between H. pylori prevalence and geographic region was found, while type of sample, H. pylori testing method, diagnosis period, detection timing, type of study design, quality grade, publication year, and sample size were not associated with the prevalence of H. pylori in non-cardia gastric cancer (P>0.05). A large proportion of non-cardia gastric cancers were associated with H. pylori infection in China, emphasizing the possible benefits of H. pylori eradication for the prevention and control of non-cardia gastric cancer.

Cancer Epidemiology in Hispanic Populations: What Have We Learned and Where Do We Need to Make Progress?

The Hispanic/Latino(x) population (H/L) in the United States of America is heterogeneous and fast growing. Cancer is the number one cause of death among H/Ls, accounting for 21% of deaths. Whereas for the most common cancers, incidence rates are lower in H/Ls compared with non-H/L White (NHW) individuals, H/Ls have a higher incidence of liver, stomach, cervical, penile, and gallbladder cancers. H/L patients tend to be diagnosed at more advanced stages for breast, colorectal, prostate, and lung cancers, and melanoma compared with NHW individuals. Etiologic and cancer outcomes research among H/Ls lags other populations. In this review, we provide a summary of challenges, opportunities, and research priorities related to cancer etiology, cancer outcomes, and survivorship to make progress in addressing scientific gaps. Briefly, we prioritize the need for more research on determinants of obesity, nonalcoholic fatty liver disease and its progression to liver cancer, stomach and gallbladder cancers, and pediatric acute lymphoblastic leukemia. We emphasize the need to improve cancer screening, early detection of cancer, and survivorship care. We highlight critical resources needed to make progress in cancer epidemiologic studies among H/L populations, including the importance of training the next generation of cancer epidemiologists conducting research in H/Ls.

Helicobacter pylori infection treatment in the United States: clinical consequences and costs of eradication treatment failure

INTRODUCTION

Helicobacter pylori (Hp) is causal in benign and malignant gastrointestinal diseases. Accordingly, current guidelines recommend Hp eradication in patients with active infection. Unfortunately, treatment failure is common, exposing patients to complications associated with persistent Hp infection and consequences of repeated treatment, including promotion of antibiotic resistance. In the United States (US), data regarding eradication rates with available therapies are limited. Moreover, the clinical and economic burden of eradication treatment failure have not been thoroughly described.

AREAS COVERED

We aimed to characterize Hp eradication rates and the clinical consequences and associated costs of persistent Hp infection among US adults. We conducted focused literature reviews using initial searches in Embase, MEDLINE, and Cochrane Database of Systematic Reviews via Ovid followed by manual searches to identify relevant publications.

EXPERT OPINION

Hp eradication rates were suboptimal, with most studies reporting rates ≤80% with clarithromycin-based triple therapy and bismuth quadruple therapy. There was direct evidence supporting numerous benefits of successful Hp eradication, including decreased risk of recurrent or complicated peptic disease and non-cardia gastric cancer. Cost benefits of eradication were related to mitigation of conditions associated with persistent Hp infection, (e.g. complicated peptic ulcer disease, and gastric cancer) which altogether exceed US$5.3 billion.

The Role of Gut Microbiota in Gastrointestinal Tract Cancers

Disturbances in gastrointestinal (GI) microbiota could play a significant role in the development of GI cancers, but the underlying mechanisms remain largely unclear. While some bacteria seem to facilitate carcinogenesis, others appear to be protective. So far only one bacterium (Helicobacter pylori) has been classified by the International Agency for Cancer Research as carcinogenic in humans but many other are the subject of intense research. Most studies on the role of microbiota in GI tract oncogenesis focus on pancreatic and colorectal cancers with the following three species: Helicobacter pylori, Escherichia coli, and Porphyromonas gingivalis as likely causative factors. This review summarizes the role of bacteria in GI tract oncogenesis.

Two Distinct Etiologies of Gastric Cancer: Infection and Autoimmunity

Gastric cancer is a leading cause of mortality worldwide. The risk of developing gastric adenocarcinoma, which comprises >90% of gastric cancers, is multifactorial, but most associated with Helicobacter pylori infection. Autoimmune gastritis is a chronic autoinflammatory syndrome where self-reactive immune cells are activated by gastric epithelial cell autoantigens. This cause of gastritis is more so associated with the development of neuroendocrine tumors. However, in both autoimmune and infection-induced gastritis, high risk metaplastic lesions develop within the gastric mucosa. This warrants concern for carcinogenesis in both inflammatory settings. There are many similarities and differences in disease progression between these two etiologies of chronic gastritis. Both diseases have an increased risk of gastric adenocarcinoma development, but each have their own unique comorbidities. Autoimmune gastritis is a primary cause of pernicious anemia, whereas chronic infection typically causes gastrointestinal ulceration. Both immune responses are driven by T cells, primarily CD4⁺ T cells of the IFN-γ producing, Th1 phenotype. Neutrophilic infiltrates help clear H. pylori infection, but neutrophils are not necessarily recruited in the autoimmune setting. There have also been hypotheses that infection with H. pylori initiates autoimmune gastritis, but the literature is far from definitive with evidence of infection-independent autoimmune gastric disease. Gastric cancer incidence is increasing among young women in the United States, a population at higher risk of developing autoimmune disease, and H. pylori infection rates are falling. Therefore, a better understanding of these two chronic inflammatory diseases is needed to identify their roles in initiating gastric cancer.

An Overview of Helicobacter pylori Survival Tactics in the Hostile Human Stomach Environment

Helicobacter pylori is well established as a causative agent for gastritis, peptic ulcer, and gastric cancer. Armed with various inimitable virulence factors, this Gram-negative bacterium is one of few microorganisms that is capable of circumventing the harsh environment of the stomach. The unique spiral structure, flagella, and outer membrane proteins accelerate H. pylori movement within the viscous gastric mucosal layers while facilitating its attachment to the epithelial cells. Furthermore, secretion of urease from H. pylori eases the acidic pH within the stomach, thus creating a niche for bacteria survival and replication. Upon gaining a foothold in the gastric epithelial lining, bacterial protein CagA is injected into host cells through a type IV secretion system (T4SS), which together with VacA, damage the gastric epithelial cells. H. pylori does not only establishes colonization in the stomach, but also manipulates the host immune system to permit long-term persistence. Prolonged H. pylori infection causes chronic inflammation that precedes gastric cancer. The current review provides a brief outlook on H. pylori survival tactics, bacterial-host interaction and their importance in therapeutic intervention as well as vaccine development.

Cancer Etiology and Prevention Principle: "1 + X"

Cancer was previously thought to be an inevitable aspect of human health with no effective treatments. However, the results of in-depth cancer research suggest that most types of cancer may be preventable. Therefore, a comprehensive understanding of the disparities in cancer burden caused by different risk factors is essential to inform and improve cancer prevention and control. Here, we propose the cancer etiology and prevention principle "1 + X," where 1 denotes the primary risk factor for a cancer and X represents the secondary contributing risk factors for the cancer. We elaborate upon the "1 + X" principle with respect to risk factors for several different cancer types. The "1 + X" principle can be used for precise prevention of cancer by eliminating the main cause of a cancer and minimizing the contributing factors at the same time.

Sharing With Patients the Uncertainties Regarding the Management of Dyspepsia

Background: The management of patients with dyspepsia is uncertain. Some authors advocate endoscopy for all; others restrict endoscopy only to patients at high risk of gastric cancer, namely to those above an age threshold, or with a family history, dysphagia, loss of weight, anemia, or a childhood in Asian countries. Still others recommend various combinations between test-and-treat for Helicobacter pylori, anti-secretory treatment, and/or endoscopy.

Objective: To highlight the uncertainties in the choice between the various strategies and argue that these uncertainties should be shared with the patient.

Method: An overview of reported life expectancy, patient satisfaction, gastric cancer detection rates, symptom relief, and cost effectiveness of the management strategies for dyspepsia.

Main Findings: There are no randomized controlled trials of the effect of screening by endoscopy on mortality of patients with gastric cancer. Lower grades of evidence suggest that early diagnosis reduces this mortality. Analyses, which assume a survival benefit of early diagnosis, indicate that mass screening in countries of high incidence gastric cancer (> 10 cases per 100,000) and targeted screening of high-risk persons in countries of low-intermediate incidence (<10 cases per 100,000) is cost-effective at a willingness to pay of $20,000–50,000 per QALY. Prompt endoscopy appears to be best for patient satisfaction and gastric cancer detection, and test-and-treat for H pylori—for symptom relief and avoiding endoscopies.

Conclusions: The gain in life expectancy is the main source of uncertainty in the choice between management strategies. This choice should be shared with the patients after explaining uncertainties and eliciting their preferences.

Gastritis: The clinico-pathological spectrum

The inflammatory spectrum of gastric diseases includes different clinico-pathological entities, the etiology of which was recently established in the international Kyoto classification. A diagnosis of gastritis combines the information resulting form the gross examination (endoscopy) and histology (microscopy). It is important to consider the anatomical/functional heterogeneity of the gastric mucosa when obtaining representative mucosal biopsy samples. Gastritis includes self-limiting and non-self-limiting (long-standing) inflammatory diseases, and the latter are epidemiologically, biologically and clinically linked to the onset of gastric cancer (i.e. "inflammation-associated cancer"). Different biological models of inflammation-associated gastric oncogenesis have been proposed. Helicobacter pylori (H. pylori) gastritis is the most prevalent worldwide, and H. pylori is classified as a first-class carcinogen. On these bases, eradicating H. pylori is mandatory for the primary prevention of gastric cancer. Non-self-limiting gastritis may also be triggered by the immune-mediated destruction of gastric parietal cells, resulting in autoimmune gastritis. In both H. pylori-related and autoimmune gastritis, the non-self-limiting inflammation results in atrophy of the gastric mucosa, which is the main factor promoting gastric cancer. Long-term follow-up studies consistently demonstrate the prognostic impact of the histological staging of gastritis in gastric cancer secondary prevention strategies.

Clinicopathological characteristics of gastric intraepithelial neoplasia: Analysis of 653 cases

BACKGROUND

The high mortality rate of gastric carcinoma (GC) is becoming a serious public concern around the world. Gastric intraepithelial neoplasia (GIN) is believed to be the pre-invasive lesions of GC. Therefore, this study aimed to investigate the clinicopathological characteristics of GIN and explore the risk factors for gastric precancerous lesions.

AIM

To analyze the clinical and pathological characteristics of GIN and identify its risk factors, so as to better guide the clinical diagnosis and treatment of GIN.

METHODS

A total of 653 Chinese patients undergoing diagnostic gastroscopy at a single center from June 2010 to October 2020 were included. The demographic, endoscopic, and pathological characteristics were collected to identify the risk factors associated with GIN.

RESULTS

There were 536 cases with low-grade gastric intraepithelial neoplasia (LGIN) (82.08%) and 117 cases with high-grade gastric intraepithelial neoplasia (HGIN) (17.92%). The gastric antrum was the most common location for GIN lesions (58.35%). The incidence of GIN lesions > 2 cm in the HGIN group (27/117, 23.08%) was twice as high as that of the LGIN group (56/536, 10.45%). The positive rate of atrophy and intestinal metaplasia improved as the age increased among patients 50-80 years old and > 60 years old, respectively. In addition, no statistical difference was observed in Helicobacter pylori infection rate between the LGIN and HGIN groups (P = 0.162).

CONCLUSION

Advanced age, lesion located at the antrum, lesion size > 1 cm, and presence of atrophy or intestinal metaplasia in the gastric mucosa are risk factors for HGIN. LGIN patients with these risk factors are more likely to develop into HGIN. H. pylori infection has no statistical correlations with LGIN and HGIN.

Effect of Ranitidine Intake on the Risk of Gastric Cancer Development

Gastric cancer is one of the most prevalent cancers globally, with high mortality, particularly in East Asia. Certain ranitidine products contain potentially carcinogenic N-nitrosodimethylamine. We investigated the potential association between gastric cancer risk and ranitidine intake using a nationwide cohort, extracted from the Korean National Health Insurance Service. In this longitudinal study, we employed a 1:1 propensity score matching according to sociodemographic factors. A total of 40,887 subjects were enrolled, of which 906 developed gastric cancer during the follow-up period. We investigated gastric cancer events during the follow-up period using the survival analysis, log-rank test, and Cox proportional hazards regression models to estimate incidence, survival rate, and hazard ratio. The incidence of gastric cancer was 67,422; 67,470; and 67,444 person-years in the control, other histamine-2 blockers, and ranitidine groups, respectively. Because the adjusted hazard ratio of gastric cancer was 0.98 and 1.01 in the other histamine-2 blockers and ranitidine groups, respectively, we could not calculate the likelihood of gastric cancer development in the ranitidine group. Ranitidine intake did not significantly increase the incidence of gastric cancer. Therefore, the relative risk of gastric cancer may be low in patients taking ranitidine products in South Korea.

A standardized protocol improves testing rates for Helicobacter Pylori among inpatients with peptic ulcer disease

BACKGROUND

Despite a strong link between Helicobacter Pylori infection and peptic ulcer disease (PUD), rates of testing for H. Pylori in hospitalized patients with PUD remain largely unexplored. We aimed to determine H. Pylori testing practices at our institution among inpatients with PUD, and to implement a protocol to improve testing rates.

MATERIALS AND METHODS

In this quality improvement initiative, baseline H. Pylori testing practices were determined by analysis of historical data on 100 subsequent inpatients with PUD from January 2016 to June 2017 at a tertiary care hospital undergoing esophagogastroduodenoscopy (EGD). Subsequently, a division-wide testing protocol was implemented, and data were analyzed from 43 consecutive inpatients with PUD from October 2019-March 2020 to determine the protocol's effects.

RESULTS

The analysis of baseline testing practices showed a 57% testing rate for H. Pylori. Gastric biopsies were less likely to be performed during EGDs done outside the endoscopy unit (5.9% vs 32.7%, P = 0.001), outside of usual business hours (6.7% vs 24.3%, P = 0.04), and in cases where endoscopic therapy was administered (6% vs 32%, P = 0.02). After implementation of the new division-wide testing protocol, testing rates increased to 93% (P < 0.001).

CONCLUSIONS

Low baseline inpatient testing for H. Pylori represents a missed opportunity to test a substantial number of high-risk patients with PUD. Implementation of a conceptually simple protocol aimed at increasing rates of gastric biopsy significantly improved testing rates in a prospective follow-up. Widespread standardization of H. Pylori testing for inpatients with PUD may improve important patient outcomes related to complicated PUD.

Associations of the MTHFR rs1801133 polymorphism with gastric cancer risk in the Chinese Han population

In recent years, increasing evidence has implicated the importance of mutations in the MTHFR gene in the risk of gastric cancer risk. A single nucleotide polymorphism (SNP) in the MTHFR gene (rs1801133) may serve a critical role in gastric cancer. A hospital-based case-controlled study was performed to assess the risk of the rs1801133 polymorphism on gastric cancer. A total of 307 patients with gastric cancer and 560 patients in the control group were recruited. Genomic DNA was extracted from peripheral blood and genotyped for rs1801133 using the ligase detection reaction. The relationship between rs1801133 and gastric cancer risk was evaluated by unconditional logistical regression analysis. The rs1801133-TT genotype was associated with a borderline significantly decreased risk of gastric cancer [(TT vs. CC, adjusted odds ratio (OR)=0.54, 95% confidence intervals (CI)=0.35-0.83; P=0.006; CT vs. CC, adjusted OR=0.59, 95% CI=0.44-0.79, P<0.001; and TT/CT vs. CC, adjusted OR=0.61, 95% CI=0.44-0.83, P=0.001), and further analysis showed the relationship was evident amongst older patients and patients who never drank alcohol. The C>T mutation at rs1801133 of the MTHFR gene was associated with a decreased risk of gastric cancer in older individuals and those who never drink.

A Predictive Nomogram for Early Mortality in Stage IV Gastric Cancer

Background

The study was intended to establish predictive nomogram models for predicting total early mortality (the probability of surviving less than or equal to 3 months) and cancer-specific early mortality in patients with stage IV gastric cancer. This was the first study to establish prognostic survival in patients with stage IV gastric cancer.

Material/Methods

Patients from the SEER database were identified using inclusion and exclusion criteria. Their clinical characteristics were statistically analyzed. The Kaplan-Meier method and the log-rank test were used to compare the influences of different factors on survival time. Logistic regression models were conducted to explore the correlative factors of early mortality. A nomogram was established based on factors significant in the logistic regression model and an internal validation was performed.

Results

Of the 11,036 eligible patients included in the study, 4932 (44.7%) patients resulted in total early death (42.6% died of the cancer and 2.1% died of other reasons). Larger tumor size, poor differentiation, and liver metastasis were positively related to cancer-specific early mortality. Surgery was negatively related to total early mortality and cancer-specific early mortality, while cardia was only negatively associated with total early death. Predictive nomogram models for total early mortality and cancer-specific early mortality have been validated internally. The areas under the receiver operating characteristics curve were 73.5%, and 68.0%, respectively, and the decision curve analysis also proved the value of the models.

Conclusions

The nomogram models proved to be a suitable tool for predicting the early mortality in stage IV gastric cancer.