Association of helicobacter pylori infection and chronic atrophic gastritis with risk of colonic, pancreatic and gastric cancer: A ten-year follow-up of the ESTHER cohort study

A study of the association between Helicobacter pylori infection type and pancreatic cancer risk: A systematic review and meta‑analysis

Pancreatic cancer is a highly invasive malignant tumor with a complex pathogenesis that makes early diagnosis challenging. The potential association between Helicobacter pylori infection and pancreatic cancer risk has been noted; however, the available results are still highly divergent. The aim of the present study was to systematically evaluate the association between different types of H. pylori infection and pancreatic cancer risk as well as to explore the possible causes. A systematic search was conducted using the PubMed, Embase and Cochrane Library databases up to August 2023. The literature quality was evaluated using the Newcastle-Ottawa Scale. All studies that met the criteria were included in the overall meta-analysis to calculate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs). In addition, subgroup analyses were performed based on factors such as diagnostic criteria for H. pylori infection, study region, type of study design and CagA status. The effect of publication bias on the quantitative synthesis results was assessed using the trim-and-fill analysis, and sensitivity analyses were used to verify the robustness of the quantitative synthesis results. A total of 17 studies involving 67,910 participants, including 64,372 controls and 3,538 patients with pancreatic cancer, were included in the present study. The overall analysis showed that no significant association was observed between H. pylori infection and pancreatic cancer risk (OR, 1.15; 95% CI, 0.93-1.41). Further subgroup analyses, which did not consider the effects of study quality, diagnostic criteria, geographical distribution and the type of study design, did not produce new findings that contradicted the results of the overall analysis. CagA+ H. pylori infection did not significantly affect the risk of pancreatic cancer (OR, 0.95; 95% CI, 0.78-1.16), whereas CagA- H. pylori infection may be a possible risk factor for pancreatic cancer (OR, 1.24; 95% CI, 1.004-1.541). The H. pylori infection did not significantly increase the risk of pancreatic cancer. However, it is noteworthy that CagA- H. pylori infection could be a potential factor that elevated the risk of pancreatic cancer.

Helicobacter pylori eradication following endoscopic resection might prevent metachronous gastric cancer: a systematic review and meta-analysis of studies from Japan and Korea

Objectives

A systematic review and meta-analysis was performed to evaluate the preventive effectiveness of Helicobacter pylori eradication against metachronous gastric cancer (MGC) or dysplasia following endoscopic resection (ER) for early gastric cancer (EGC) or dysplasia.

Methods

PubMed, Cochrane Library, MEDLINE, and EMBASE were searched until 31 October 2023, and randomized controlled trials or cohort studies were peer-reviewed. The incidence of metachronous gastric lesions (MGLs) including MGC or dysplasia was compared between Helicobacter pylori persistent and negative groups, eradicated and negative groups, and eradicated and persistent groups.

Results

Totally, 21 eligible studies including 82,256 observations were analyzed. Compared to those never infected, Helicobacter pylori persistent group (RR = 1.58, 95% CI = 0.98-2.53) trended to have a higher risk of MGLs and significantly in partial subgroups, while the post-ER eradicated group (RR = 0.79, 95% CI = 0.43-1.45) did not increase the risk of MGLs. Moreover, successful post-ER eradication could significantly decrease the risk of MGLs (RR = 0.54, 95% CI = 0.44-0.65) compared to those persistently infected. Sensitivity analysis obtained generally consistent results, and no significant publication bias was found.

Conclusion

The persistent Helicobacter pylori infection trends to increase the post-ER incidence of MGC or dysplasia, but post-ER eradication can decrease the risk correspondingly. Post-ER screening and eradication of Helicobacter pylori have preventive effectiveness on MGC, and the protocol should be recommended to all the post-ER patients.Systematic review registration: The PROSPERO registration identification was CRD42024512101.

Helicobacter pylori and Gastrointestinal Cancers: Recent Advances and Controversies

Helicobacter pylori (H pylori), a gastric bacterium, has been extensively studied for its association with gastritis, peptic ulcers, and gastric cancer. However, recent evidence suggests its potential implications beyond the stomach, linking it to other gastrointestinal malignancies, such as esophageal cancer, liver cancer, pancreatic cancer, gallbladder cancer, and colorectal cancer. In light of the expanding research landscape and the increasing interest in exploring H pylori broader role in gastrointestinal tumorigenesis, this comprehensive review aims to elucidate the relationship between H pylori and gastrointestinal tumors. This review encompasses recent epidemiological studies, research progress, and emerging perspectives, providing a comprehensive assessment of the relationship between H pylori and gastrointestinal tumors. The findings highlight the captivating world of H pylori and its intricate involvement in gastrointestinal malignancies.

Facilitators of and barriers to gastric cancer and precursor diagnosis among South Texas residents: Social determinants of health

BACKGROUND

Latinos/Hispanics are at higher risk for developing gastric cancer (GC) compared with non-Hispanic whites, and social determinants of health (SDoH) are thought to contribute.

AIMS/MATERIALS AND METHODS

This study addressed SDoH and their interactions contributing to disparities in the testing and treatment of Helicobacter pylori (HP) infection and diagnosis of GC and its known precursors, among Latinos/Hispanics relative to non-Latinos at two affiliated but independent health systems in San Antonio, Texas, using a mixed methods approach.

RESULTS

Secondary data abstraction and analysis showed that GCs represented 2.6% (n = 600) of our population. Men and older individuals were at higher GC risk. Individuals with military insurance were 2.7 times as likely to be diagnosed as private insurance. Latinos/Hispanics had significantly (24%) higher GC risk than Whites. Poverty and lack of insurance contributed to GC risk among the minorities classified as other (Asians, Native Americans, Multiracial; all p < 0.01). All SDoH were associated with H. pylori infection (p < 0.001). Qualitative analysis of patient and provider interviews showed providers reporting insurance as a major care barrier; patients reported appointment delays, and lack of clinic staff. Providers universally agreed treatment of H. pylori was necessary, but disagreed on its prevalence. Patients did not report discussing H. pylori or its cancer risk with providers.

DISCUSSION/CONCLUSION

These data indicate the importance of considering SDoH in diagnosis and treatment of GC and its precursors, and educating providers and patients on H. pylori risks for GC.

Colonoscopy plays an important role in detecting colorectal neoplasms in patients with gastric neoplasms

BACKGROUND

Gastric cancer (GC) and colorectal cancer (CRC) are the fifth and third most common cancer worldwide, respectively. Nowadays, GC is reported to have a potential predictive value for CRC, especially for advanced CRC.

AIM

To evaluate the necessity of colonoscopy for gastric neoplasm (GN) patients.

METHODS

Four databases, including PubMed, EMBASE, the Cochrane Library, and Ovid, were used to perform the search strategy on May 2, 2023. The prevalence of colorectal neoplasms (CRN) and baseline characteristics were compared between the neoplasm group and the control group. Continuous variables are expressed as the mean difference and standard deviation. Relationships of categorical variables in the two groups are expressed as odds ratios (OR) and 95% confidence intervals (95%CIs). Subgroup analysis according to different kinds of GNs was conducted for more in-depth analysis. The results of this study are represented by forest plots. Publication bias was evaluated by a funnel plot. All data analyses were performed by STATA SE 16.0 software.

RESULTS

A total of 3018 patients with GNs and 3905 healthy controls (age and sex matched) were enrolled for analysis. After comparing the prevalence of CRNs between the two groups, CRNs were detected significantly more frequently in GN patients than in controls (OR = 1.69, 95%CI = 1.28 to 2.23, I2 = 85.12%, P = 0.00), especially in patients with GC (OR =1.80, 95%CI = 1.49 to 2.18, I2 = 25.55%, P < 0.1). Moreover, other risk factors including age (OR = 1.08, 95%CI = 1.00 to 1.17, I2 = 90.13%, P = 0.00) and male sex (OR = 2.31, 95%CI = 1.26 to 4.22, I2 = 87.35%, P = 0.00), were related to the prevalence of CRNs. For patients in the GN group, body mass index (BMI, OR = 0.88, 95%CI = 0.80 to 0.98, I2 = 0.00%, P = 0.92) and smoking (OR = 1.03, 95%CI = 1.01 to 1.05, I2 = 0.00%, P = 0.57) were protective and risk factors for CRNs, respectively.

CONCLUSION

Patients are recommended to undergo colonoscopy when diagnosed with GNs, especially GC patients with a low BMI and a history of smoking.

Risk factors for remnant gastric cancer after distal gastrectomy for gastric cancer: a retrospective database review

Background

The number of patients with remnant gastric cancer (RGC) following gastrectomy for gastric cancer (GC) is increasing due to the increasing number of patients undergoing function-preserving gastrectomy and improved outcomes for patients with GC. A few studies involving a small number of cases reported male sex, old age, differentiated type, tumor depth and synchronous multiple GC were associated with RGC development. However, the risk factors for RGC development had not been fully understood. This study aimed to examine the clinicopathological features, followed up patients with GC after they underwent distal gastrectomy (DG), and evaluated the potential risk factors for RGC development.

Methods

A retrospective database review of 438 patients who underwent DG for GC at a single institution, from 2006 to 2017, was conducted. We investigated the relationship of clinicopathological features, operative findings, and postoperative course with RGC development was estimated using Cox proportional hazard analysis. The cumulative incidences of RGC were calculated using the Kaplan-Meier method.

Results

We retrospectively analyzed 405 cases. The median patient age was 69 years, and the patient cohort consisted of 263 men and 142 women. The Billroth-I reconstruction method was used in 204 cases, Billroth-II method was used in 3 cases, and Roux-en Y method was used in 198 cases. RGC was diagnosed in 11 of the 405 patients. The median follow-up period was 5 years. The cumulative incidences of RGC calculated by the Kaplan-Meier method were 3.0%, 4.1%, and 10.5% at 5, 10, and 15 years after DG, respectively. During the initial surgery, differentiated type was significantly associated with RGC development [hazard ratio (HR): 4.71, 95% confidence interval (CI): 1.02-21.80, P=0.05]. Male sex (HR: 2.97, 95% CI: 0.64-13.75, P=0.16), old age (≥70 years) (HR: 2.72, 95% CI: 0.78-9.47, P=0.11), and synchronous multiple GC (HR: 1.31, 95% CI: 0.28-6.08, P=0.73) were not associated with RGC development.

Conclusions

Patients who have undergone DG for differentiated type GC were statistically significantly associated with developing RGC. Intensive endoscopic surveillance would be needed for the patients who underwent DG for differentiated type GC.

Helicobacter pylori infection prevalence declined among an urban health check-up population in Chengdu, China: a longitudinal analysis of multiple cross-sectional studies

Objectives

The efficacy of updated health policy in improving the generalization of Helicobacter pylori screening and eradication in southwest China was assessed in a longitudinal analysis of multiple cross-sectional studies from an institution.

Methods

In the periods 2009-2010, 2013-2014, and 2019-2021, 8,365, 16,914, and 18,281 urban observations from health check-ups at West China Hospital were analyzed, respectively. The 14C-urea or 13C-urea breath test was consistently used for H. pylori detection. The protocol has been reported elsewhere (PROSPERO Registration number: CRD42019120764).

Results

The overall prevalence of H. pylori dramatically decreased from 53.1% to 30.7% over the past decade (OR = 0.39, 95% CI 0.37-0.41), with a similar decline in all sex-specific and age-specific subgroups. The age-specific prevalence consistently increased before 40 years of age and always peaked at 50-59 years. Longitudinal clearance increased along with aging, and prevalence dropped to 22.6%, 25.1%, and 23.6% in the 40-49, 50-59, and 60-69 years initial age groups, respectively.

Conclusion

The generalization of H. pylori screening and eradication could greatly contribute to the control of H. pylori infection among urban health check-up populations and lower gastric cancer incidence.

Long-term effect of Helicobacter pylori eradication on colorectal cancer incidences

Background

There is evidence supporting the association between Helicobacter pylori infection and colorectal cancer (CRC), but whether H. pylori eradication reduces the risk of CRC is still unknown.

Objectives

To compare the incidence of CRC in subjects who had received H. pylori eradication therapy with general population.

Design

A population-based retrospective cohort study.

Methods

This study included all H. pylori-infected subjects who had received their first course of clarithromycin-containing triple therapy in 2003-2015 in Hong Kong. We compared the observed incidences of CRC in this H. pylori eradicated cohort with the expected incidences in the age- and sex-matched general population. The standardized incidence ratio (SIR) with 95% confidence interval (CI) was computed.

Results

Among 96,572 H. pylori-eradicated subjects with a median follow-up of 9.7 years, 1417 (1.5%) developed CRC. Primary analysis showed no significant difference in the observed and expected incidences of CRC (SIR: 1.03, 95% CI: 0.97-1.09). However, when stratified according to the follow-up period, higher incidence of CRC was only observed in the first 5 years after eradication (SIR: 1.47, 95% CI: 1.39-1.55), but it was lower (SIR: 0.85, 95% CI: 0.74-0.99) than general population after 11 years. When stratified by tumor location, the observed incidence was higher for colon (SIR: 1.20, 95% CI: 1.12-1.29) but lower for rectal cancer (SIR: 0.90, 95% CI: 0.81-0.999) among H. pylori-eradicated subjects.

Conclusions

H. pylori-infected subjects appeared to have a higher incidence of CRC initially, which declined progressively to a level lower than general population 10 years after H. pylori eradication, particularly for rectal cancer.

Is Helicobacter pylori infection associated with pancreatic cancer? A systematic review and meta-analysis of observational studies

Background and Objectives

Recent observational studies have investigated the association between Helicobacter pylori (H. pylori) infection and pancreatic cancer with conflicting data. Therefore, we conducted a systematic review and meta-analysis to assess the potential association.

Design

This is a systematic review and meta-analysis.

Methods

We searched three databases (PubMed, Embase, and Web of Science) from inception to 30 August 2022. The summary results as odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) were pooled by generic inverse variance method based on random-effects model.

Results

A total of 20 observational studies involving 67,718 participants were included in the meta-analysis. Meta-analysis of data from 12 case-control studies and 5 nested case-control studies showed that there was no significant association between H. pylori infection and the risk of pancreatic cancer (OR = 1.20, 95% CI = 0.95-1.51, p = 0.13). Similarly, we also did not find significant association between cytotoxin-associated gene A (CagA) positive strains, CagA negative strains, vacuolating cytotoxin gene A (VacA) positive strains H. pylori infection, and the risk of pancreatic cancer. Meta-analysis of data from three cohort studies showed that H. pylori infection was not significantly associated with an increased risk of incident pancreatic cancer (HR = 1.26, 95% CI = 0.65-2.42, p = 0.50).

Conclusion

We found insufficient evidence to support the proposed association between H. pylori infection and increased risk of pancreatic cancer. To better understand any association, future evidence from large, well-designed, high-quality prospective cohort studies that accounts for diverse ethnic populations, certain H. pylori strains, and confounding factors would be useful to settle this controversy.

Prevalence Difference of Helicobacter pylori Infection Between Tibetan and Han Ethnics in China: A Meta-analysis on Epidemiologic Studies (SIGES)

China is a multi-ethnic country, and the prevalence of Helicobacter pylori ( H pylori) infection may be diverse among ethnics. This meta-analysis was conducted to compare the prevalence of H pylori infection between Tibetans and Han ethnics. Ten studies that reported the prevalence of H pylori infection between Tibetans and Hans in China were eligible. The pooled prevalence of H pylori infection was 62.2% versus 55.3% among Tibetans and Hans, respectively. Tibetans had a higher risk of H pylori infection than Hans (odds ratio [OR] = 1.38, 95% confidence interval [CI] [1.05, 1.80]). In subgroup analysis, Tibetans with upper gastrointestinal symptoms (OR = 1.51, 95% CI [1.06-2.16]), inhabiting in Tibet (OR = 1.51, 95% CI [1.22, 1.87]), or inhabiting in Northwestern region (OR = 1.15, 95% CI [1.00, 1.31]) had significantly higher risks of H pylori infection. In addition, in the recent 10 years, Hans showed a decreased risk of H pylori infection (OR = 1.81, 95% CI [1.42, 2.30]). Heterogeneity was common, while sensitivity analyses showed partially inconsistent results against main findings. This study demonstrated higher prevalence of H pylori infection in Tibetans compared with Hans, especially in recent years, or in Tibet and northwest China, as well as symptomatic Tibetans. The results suggest tailored strategy and robustness need to be further considered for H pylori screening and eradication among Tibetans.

Association Between Helicobacter pylori Infection and the Risk of Pancreatic Cancer: A Systematic Review Based on Observational Studies

Helicobacter pylori (H. pylori) bacterial infection has long been scrutinized as one of the potential risk factors for the development of pancreatic cancer with quite inconsistent and unequivocal data. Little is known about the risk factors involved with this malignancy. In this systematic review, we aimed to examine the relationship between H. pylori infection and pancreatic cancer based on the evidence from the existing observational studies across the world. We searched major electronic databases such as PubMed, MEDLINE, Science Direct, and Cochrane Library. After a careful and thorough screening process, we selected 15 observation studies for this systematic review. Six of 15 studies found a significant association between H. pylori infection and pancreatic cancer. Additionally, four of these studies found a significant relationship between the cytotoxin-associated gene A strain of H. pylori and pancreatic cancer. Based on the evidence from the selected studies, a weak association was observed between H. pylori infection and cancer of the pancreas, especially in European and Asian populations compared to the North American population. The cross-sectional evidence from the case-control studies only suggests the existence of an association but does not provide substantial evidence of the causative relationship. Further large-scale, prospective cohort studies are warranted in the future to understand this contradictory relationship better.

Association between Helicobacter pylori antibodies determined by multiplex serology and gastric cancer risk: A meta-analysis

BACKGROUND AND AIMS

Previous studies have reported the association between limited number of Helicobacter pylori (H. pylori) antigens and gastric cancer (GC) risk. The present study evaluated the association between serum antibodies against 15 different H. pylori proteins measured by using multiplex serology assay and GC risk.

METHODS

We searched PubMed databases, Embase, Web of Science, and Cochrane Library for relevant articles. A meta-analysis was used to pool studies and to estimate odds ratios (ORs) with 95% confidence intervals (95%CIs) of different H. pylori antigens associated with GC risk. Heterogeneity was investigated using Cochran's Q test and I-squared statistic.

RESULTS

Nine studies were identified, with a total of 3209 GC cases and 6964 controls. Five H. pylori virulence factors were significantly associated with non-cardia GC risk at p-value <0.0033 including: CagA (OR = 3.22, 95%CI: 2.10-4.94), HP0305 (OR = 1.72, 95%CI: 1.32-2.25), HyuA (OR = 1.42, 95%CI: 1.13-1.79), Omp (OR = 1.83, 95%CI: 1.30-2.58), and VacA (OR = 2.05, 95%CI: 1.67-2.52). However, none of the 15 antigens was associated with cardia GC risk. In subgroup analysis by ethnicity, we identified 7 antigens associated with the risk of non-cardia GC among East Asian while only two antigens were identified in European population. Nevertheless, CagA and GroEL showed a stronger association in Caucasian (CagA OR = 5.83, 95%CI: 3.31-10.26; GroEL OR = 3.66, 95%CI: 1.58-8.50) compared with East Asian (CagA OR = 2.20, 95% CI: 1.85-2.61; GroEL OR = 1.47, 95%CI: 1.29-1.68).

CONCLUSIONS

This study determined that H. pylori infection increases the risk of non-cardia GC with differential effects by its virulence factors and with different patterns among East Asian and European populations. These results advance the understanding of the effect of H. pylori on GC.

A discussion of the gut microbiome's development, determinants, and dysbiosis in cancers of the esophagus and stomach

The microbiome refers to a population of microbes that colonize the skin, nasopharynx, oral cavity, gastrointestinal tract, and urogenital tract. The human microbiome consists of bacteria, archaea, fungi, viruses, and phages. Recent advances in genomic sequencing have catalyzed a deeper understanding of complex microbe-microbe and host-microbe interactions. Dysregulation of these interactions, or dysbiosis of the gastrointestinal tract, has been implicated in a growing list of pathologies including nonalcoholic fatty liver disease, cardiovascular disease, obesity, diabetes, depression, Parkinson's disease, autism, and various gastrointestinal cancers. Gastric and esophageal cancer, for example, continue to remain as two of the most common causes of cancer-related deaths worldwide, therefore there is an increased emphasis on investigating the role of dysbiosis on these cancers. In this review, we discuss the development and structure of the gut microbiome, its homeostatic and dysbiotic mechanisms, and the key microbes in esophageal and gastric carcinogenesis with a focus on bacterial biology. Further clarification of these pathways and discovery of diagnostic or therapeutic targets could have broad impacts on global subpopulations. It is important to understand the nature of the gastrointestinal tract microbiome and its potentional risk factors for dysbiosis in order to tailor its application to the individual patient and create an era of highly personalized, precision medicine.

Pancreatic Cancer Exposome Profile to Aid Early Detection and Inform Prevention Strategies

Pancreatic cancer (PCa) is associated with a poor prognosis and high mortality rate. The causes of PCa are not fully elucidated yet, although certain exposome factors have been identified. The exposome is defined as the sum of all environmental factors influencing the occurrence of a disease during a life span. The development of an exposome approach for PCa has the potential to discover new disease-associated factors to better understand the carcinogenesis of PCa and help with early detection strategies. Our systematic review of the literature identified several exposome factors that have been associated with PCa alone and in combination with other exposures. A potential inflammatory signature has been observed among the interaction of several exposures (i.e., smoking, alcohol consumption, diabetes mellitus, obesity, and inflammatory markers) that further increases the incidence and progression of PCa. A large number of exposures have been identified such as genetic, hormonal, microorganism infections and immune responses that warrant further investigation. Future early detection strategies should utilize this information to assess individuals' risk for PCa.

A review of lifestyle and environment risk factors for pancreatic cancer

Pancreatic cancer (PaCa) is one of the deadliest cancers known and its incidence is increasing in the developed countries. Because of the lack of biomarkers that allow early detection and the tendency of the disease to be asymptomatic, the diagnosis comes often too late for effective surgical or chemotherapy intervention. Lifestyle factors, that may cause common genetic modifications occurring in the disease, interfere with pancreatic physiology or function, and play a role in PaCa development, have been of concern recently, since a strategy to prevent this severe cancer is needed. This review identifies the latest evidences related to increased risk of developing PaCa due to dietary habits such as high alcohol, fructose and red or processed meat intake, and pathological conditions such as diabetes, obesity and infections in addition to stress and smoking behaviour. It aims to highlight the importance of intervening on modifiable risk factors: the action on these factors could prevent a considerable number of new cases of PaCa.

Cholangiocyte derived carcinomas and local microbiota

Trillions of bacteria are present in the gastrointestinal tract as part of the local microbiota. Bacteria have been associated with a wide range of gastrointestinal diseases including malignant neoplasms. The association of bacteria in gastrointestinal and biliary tract carcinogenesis is supported in the paradigm of Helicobacter pylori and intestinal-type gastric cancer. However, the association of bacterial species to a specific carcinoma, different from intestinal-type gastric cancer is unresolved. The relationship of bacteria to a specific malignant neoplasm can drive clinical interventions. We review the classic bacteria risk factors identified using cultures and PCR (polymerase chain reaction) with new research regarding a microbiota approach through 16S rRNA (16S ribosomal ribonucleic acid gene) or metagenomic analysis for selected carcinomas in the biliary tract.

Antibody Responses to Helicobacter pylori and Risk of Developing Colorectal Cancer in a European Cohort

BACKGROUND

While Helicobacter pylori (H. pylori) is the major cause of gastric cancer, it has also been suggested to be involved in colorectal cancer development. However, prospective studies addressing H. pylori and colorectal cancer are sparse and inconclusive. We assessed the association of antibody responses to H. pylori proteins with colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

METHODS

We applied H. pylori multiplex serology to measure antibody responses to 13 H. pylori proteins in prediagnostic serum samples from 485 colorectal cancer cases and 485 matched controls nested within the EPIC study. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariable conditional logistic regression to estimate the association of H. pylori overall and protein-specific seropositivity with odds of developing colorectal cancer.

RESULTS

Fifty-one percent of colorectal cancer cases were H. pylori seropositive compared with 44% of controls, resulting in an OR of 1.36 (95% CI, 1.00-1.85). Among the 13 individual H. pylori proteins, the association was driven mostly by seropositivity to Helicobacter cysteine-rich protein C (HcpC; OR: 1.66; 95% CI, 1.19-2.30) and Vacuolating cytotoxin A (VacA) (OR: 1.34; 95% CI, 0.99-1.82), the latter being nonstatistically significant only in the fully adjusted model.

CONCLUSIONS

In this prospective multicenter European study, antibody responses to H. pylori proteins, specifically HcpC and VacA, were associated with an increased risk of developing colorectal cancer.

IMPACT

Biological mechanisms for a potential causal role of H. pylori in colorectal carcinogenesis need to be elucidated, and subsequently whether H. pylori eradication may decrease colorectal cancer incidence.

Prevalence of atrophic gastritis in southwest China and predictive strength of serum gastrin-17: A cross-sectional study (SIGES)

A hospital-based cross-sectional study in SIGES project was conducted during 2016.5-2017.5 in West China Hospital. It was aimed to observe the prevalence of atrophic gastritis (AG) in southwest China, and assess the diagnostic strength of serum gastrin-17 (G-17) in predicting AG in Chinese population. Asymptomatic healthy controls from health check-up, cancer-free patients with unspecific upper gastrointestinal symptoms, and histologically proven gastric cancer patients were eligible, if serum pepsinogen-I (PG-I), PG-II, and G-17 were detected. AG status was classified by the accredited cutoffs of PG-I (<70 ug/L) and PG-I/II ratio (<3). Totally, healthy controls (n = 9,425), symptomatic patients (n = 671) and gastric cancer patients (n = 305) were simultaneously observed, in which the prevalence of AG in southwest China were estimated as 15.9/1,000, 28.3/1,000, and 55.7/1,000 persons, respectively. The age-specific prevalence of AG in healthy controls showed a significantly uphill trend (p for trend <0.001). Higher level of serum G-17 was significantly associated with increased risk of AG in healthy population (15-30 pmol/L, aOR = 20.67, 95% CI 9.17-46.55; >30 pmol/L, aOR = 314.41, 95% CI 166.10-595.12). Throughout the progression of stomach diseases, the diagnostic strength of serum G-17 for AG showed a downhill trend across more advanced situations. In despite of that, serum G-17 displayed a good performance in predicting AG in the entire cross-sectional population (AUC = 0.92, 95% CI 0.89-0.94; SEN = 85.5%; SPE = 93.2%; LR+ = 12.55; LR- = 0.11). Population in southwest China had intermediate prevalence of AG, while the prevalence was increased over age or disease progression. High level of serum G-17 might be a reliable non-invasive measurement to predict AG in southwest Chinese population.

Helicobacter pylori prevalence in the Southwest of China: A protocol for systematic review

OBJECTIVES

This epidemiological research will be aimed to evaluate the longitudinal changes of Helicobacter pylori prevalence in Southwest China during recent period through a systematic review and analysis.

METHODS

The database PubMed and China National Knowledge Infrastructure will be searched. The cross-sectional studies or cohort studies on either massive or hospital-based health checkup population will be potentially eligible. The study population was originated from one of the southwestern major cities, Chengdu (Sichuan), Chongqing, Kunming (Yunnan), Guiyang (Guizhou), or Lhasa (Tibet). Two reviewers will independently select studies, extract data, and assess the quality of studies. The prevalence of H pylori infection will be estimated. In the individual city, the longitudinal comparisons will be conducted to evaluate the trends referring to the earliest cross-sectional baseline. The risk ratio and its 95% confidence interval will be estimated. Subgroup analyses will be performed in sex-specific and age-specific subsets. Trend analysis for proportions (p for trend) will be estimated in the longitudinal evaluation. If applicable, the longitudinal clearance rate (%) will be estimated.

ETHICS AND DISSEMINATION

The ethical approval is not required due to the nature of literature-based research. The results will be disseminated through meetings and a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019120764.

Prevalence difference of Helicobacter pylori infection between Tibetan and Han ethnics: The protocol of a meta-analysis on epidemiologic studies

OBJECTIVES

Helicobacter pylori (Hp) is an identified carcinogenic pathogen of human gastric cancer. China is not only one of the countries with high incidence and mortality of gastric cancer, but also a high infection area of Hp. As a multi-ethnic country, China may have a diverse prevalence of Hp infection among ethnics. This meta-analysis tends to compare the prevalence of Hp infection between Tibetan and Han ethnics, the results may provide evidence for targeted screening and eradication of Hp in China.

METHODS

The following databases will be searched: PubMed, Web of Science, Technology Periodical Database (VIP), China National Knowledge infrastructure (CNKI), and WanFang databases. Studies which reported the prevalence of Hp infection between Tibetans and Hans in China are eligible. Two reviewers will independently screen studies, extract data and assess the risk of bias of included studies. The prevalence of Hp infection between Tibetan and Han ethnics will be compared by meta-analysis. Heterogeneity tests and meta-analyses will be conducted using RevMan 5.3 and Stata 12.0 softwares. Meanwhile, subgroup analysis, publication bias and sensitivity analysis evaluation will be performed where applicable.

RESULTS

This study will be reported in compliance with the PRISMA statement.This systematic review will not be submitted for any ethical approval since no privacy health information will be included. The findings will be published through peer-reviewed publications or conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42019121192.

CONCLUSIONS

Our study will provide us evidence for tailored strategy and robustness of Hp screening and eradication among Tibetans.

Screening high-risk populations for esophageal and gastric cancer

Cancers of the esophagus and stomach remain important causes of mortality worldwide, in large part because they are most often diagnosed at advanced stages. Thus, it is imperative that we identify and treat these cancers in earlier stages. Due to significant heterogeneity in incidence and risk factors for these cancers, it has been challenging to develop standardized screening recommendations. This review summarizes the current recommendations for screening populations at high risk of developing esophagogastric cancers.

Associations between gastric cancer risk and virus infection other than Epstein-Barr virus: The protocol of a systematic review and meta-analysis based on epidemiological studies

BACKGROUND

Gastric cancer is one of the infection associated malignancies. In addition to Helicobacter pylori and Epstein-Barr virus (EBV), other oncoviruses might play potential roles in the development of gastric cancer. Associations of oncoviruses other than EBV with gastric cancer risk are aimed to be comprehensively reviewed and assessed in this systematic review and meta-analysis, to identify any potentially causative oncovirus. It might be informative to identify or deny certain oncoviruses which are candidates of risk factor for gastric cancer. To our knowledge, there is no comprehensive review on oncoviruses other than EBV associated with gastric cancer risk. Positive findings might be helpful to suggest further mechanism investigation and high-risk subpopulation recommendation.

METHODS

PubMed database will be searched up to Dec 31, 2018. The studies, compared the positivity of any oncovirus other than EBV between cases with histologically proven gastric cancer and healthy or nonmalignant controls, are eligible. The detection of oncovirus either in tissue or blood is acceptable. Selection, quality assessment (Newcastle-Ottawa Scale), and data extraction of eligible studies will be performed by 2 independent reviewers. Pooled prevalence of any oncovirus will be combined by meta-analysis for rate. Pooled odds ratio between gastric cancer cases and controls will be estimated by meta-analysis. Heterogeneity and publication bias will be tested. In sensitivity analysis, the leave-one-out method and exclusion of low power studies will be applied where applicable.

RESULTS

This review was not submitted for any ethical approval due to the literature-based nature. The results will be published in a journal and presented at conferences for academic purposes.Registration number was CRD42015029703 in the PROSPERO International Prospective Register of Systematic Reviews.

CONCLUSIONS

To our knowledge, there is no comprehensive review on oncoviruses other than EBV associated with gastric cancer risk. Positive findings might be helpful to suggest further mechanism investigation and high-risk subpopulation recommendation.

Body site-dependent variations of microbiota in pancreatic cancer pathophysiology

Lack of specific symptoms and reliable biomarkers, along with aggressive nature and resistance to therapies makes pancreatic cancer (PC) one of the leading causes of death from cancer worldwide. The search for new diagnostic, prognostic, predictive, and therapeutic tools that could improve clinical outcomes of patients has led, in recent years, to the investigation of potential roles for the microbiota in the pathogenesis of this disease. The human microbiota encompasses trillions of microorganisms residing within several body tissues and organs, where they provide beneficial functions for host homeostasis and health. Derangements of the microbial ecology in different anatomic districts have been described in PC, as in many other diseases, both in patients and in animal models. In detail, infection from the gastric pathogen Helicobacter pylori and changes in composition and diversity of oral, intestinal, and pancreatic microbiota have been found to associate with PC. Future research should assess how to potentially exploit such differences in microbiota composition as diagnostic, prognostic, or predictive biomarkers, and as targets for therapeutic interventions, in the hope of improving the dismal prognosis of this insidious cancer.

Exploring the microbiota to better understand gastrointestinal cancers physiology

Gastrointestinal cancers account for around 40% of cancer-related deaths worldwide, representing a global health burden. There is a growing body of evidence highlighting the link between microbiota and gastrointestinal tumorigenesis and/or resistance to therapy. In the present manuscript, we reviewed the published studies on the relationship between the microbiota and the different gastrointestinal tumors, namely, gastric, colorectal and esophageal, including also the cancer of accessory organs such as liver and pancreas. There is an emergent interest in the manipulation of gastrointestinal microflora in order to understand the gastrointestinal tumorigenesis' processes and the establishment of chemoresistance mechanisms.

Syk: a new target for attenuation of Helicobacter pylori-induced gastric mucosal inflammatory responses

The magnitude of gastric mucosal inflammatory response to H. pylori relies primarily on the extent of its key endotoxin, LPS, engagement of Toll-like receptor-4 (TLR4) and the initiation of signal transduction events converging on mitogen-activated protein kinase (MAPK) and IκB complex (IKK) cascades. These cascades, in turn, exert their control over the assembly of transcription factors, NFκB and AP1, implicated in the induction of the expression of iNOS and COX-2 proinflammatory genes. The LPS-induced TLR4 activation and the ensuing phosphorylation of its intracellular tyrosine domain by Src-family kinases not only leads to recruitment to the cytoplasmic domain of TLR4 of adaptor molecules directly involved in propagation of the signaling cascades converging on MAPK and IKK, but also provides a propitious docking site for a non-receptor tyrosine kinase, spleen tyrosine kinase (Syk), the activation of which apparently leads to upregulation in the expression of proinflammatory genes. Here, we review the pathways engaged by H. pylori in the recruitment and interaction of Syk with TLR4 in gastric mucosa, and discuss the cascades involved in Syk-mediated amplification in proinflammatory signaling. We focus, moreover, on the potential role of drugs targeting Syk and TLR4 in the treatment of H. pylori-related gastric disease.

Epidemiology of Pancreatic Cancer: Global Trends, Etiology and Risk Factors

Pancreatic cancer is the seventh leading cause of cancer-related deaths worldwide. However, its toll is higher in more developed countries. Reasons for vast differences in mortality rates of pancreatic cancer are not completely clear yet, but it may be due to lack of appropriate diagnosis, treatment and cataloging of cancer cases. Because patients seldom exhibit symptoms until an advanced stage of the disease, pancreatic cancer remains one of the most lethal malignant neoplasms that caused 432,242 new deaths in 2018 (GLOBOCAN 2018 estimates). Globally, 458,918 new cases of pancreatic cancer have been reported in 2018, and 355,317 new cases are estimated to occur until 2040. Despite advancements in the detection and management of pancreatic cancer, the 5-year survival rate still stands at 9% only. To date, the causes of pancreatic carcinoma are still insufficiently known, although certain risk factors have been identified, such as tobacco smoking, diabetes mellitus, obesity, dietary factors, alcohol abuse, age, ethnicity, family history and genetic factors, Helicobacter pylori infection, non-O blood group and chronic pancreatitis. In general population, screening of large groups is not considered useful to detect the disease at its early stage, although newer techniques and the screening of tightly targeted groups (especially of those with family history), are being evaluated. Primary prevention is considered of utmost importance. Up-to-date statistics on pancreatic cancer occurrence and outcome along with a better understanding of the etiology and identifying the causative risk factors are essential for the primary prevention of this disease.

Role of screening colonoscopy for colorectal tumors in Helicobacter pylori-related chronic gastritis with MDM2 SNP309 G/G homozygous: A prospective cross-sectional study in Thailand

BACKGROUND/AIMS

Helicobacter pylori infection is a risk factor for gastric cancer and colorectal cancer (CRC). MDM2 SNP309 G/G homozygosity is known to be the genetic background that influences the severity of inflammation in the gastric mucosa, and it corresponds to CRC development. We examined the role of screening colonoscopy in H. pylori-related chronic gastritis and the association of patients who have MDM2 SNP309 G/G homozygosity and advanced colorectal neoplasia (CRN) susceptibility.

MATERIALS AND METHODS

A prospective cross-sectional study was used to investigate H. pylori-related gastritis in 331 consecutive asymptomatic patients who had MDM2 SNP309 G/G homozygosity and who were enrolled from November 2014 to July 2017. The MDM2 SNP309 polymorphism was genotyped by real-time PCR hybridization probe assay.

RESULTS

Totally, there were 331 patients with H. pylori-related gastritis, of whom 39 (8.76%) had advanced CRN. The H. pylori-positive group comprised 180 patients (54.36%). H. pylori infection was associated with advanced CRN (OR: 2.09, 95% CI: 1.56-2.80; p=0.01) and had an increased risk of advanced CRN (OR: 4.24, 95% CI: 1.76-5.21; p=0.01) after adjusting for confounding factors. Patients with H. pylori infection had a significantly increased risk of high-grade dysplasia or invasive adenocarcinoma (OR: 2.96, 95% CI: 1.48-4.17; p=0.03).

CONCLUSION

Chronic gastritis patients infected with H. pylori and who had MDM2 SNP309 G/G homozygosity had an increased risk of advanced CRN, particularly high-grade dysplasia including invasive adenocarcinoma. Screening colonoscopy in these patients might benefit colorectal polyp diagnosis and prevention and early CRC treatment in the Thai population.

The Microbiome and Pancreatic Cancer: An Evidence-based Association?

Many risk factors for pancreatic cancer are related with microbiome alteration. In the past few years, the human microbiome and its relation with the immune system have been linked with carcinogenesis of different organs distant from the gut, including the pancreas. Patterns of oral microbiome associated with periodontitis are associated with an increased risk of pancreatic cancer, possibly because of the increased systemic inflammatory response, or to the capacity of some specific bacteria to alter the host immune response, making it more favorable to cancer cells. Helicobacter pylori infection when affecting the gastric body mucosa with subsequent hypochlorhydria also seems associated with an increased risk of pancreatic cancer. The composition of the intestinal microbiome is different in animal models and in humans with pancreatic cancer who have a distinct microbiome population compared with controls. Some specific bacteria can migrate from the intestine to the pancreas, and their ablation restores the immune system activity through its reprogramming with a switch toward a Th1 response and displays a protective effect toward tumor growth. More research in this area might lead to progress in terms of pancreatic cancer prevention and treatment, possibly in association with immunotherapy.

The association between Helicobacter pylori infection and the risk of advanced colorectal neoplasia may differ according to age and cigarette smoking

BACKGROUND

The association between Helicobacter pylori infection and advanced colorectal neoplasia (ACN) remains controversial. This study aimed to clarify the association between H. pylori infection and ACN according to age groups.

METHODS

We retrospectively analyzed the association between H. pylori infection and ACN in patients aged <50 and ≥50 years receiving a health checkup that included colonoscopy. Helicobacter pylori positivity was determined by the results of serum anti-H. pylori immunoglobulin G or rapid urease test, if the anti-H. pylori immunoglobulin G was in the borderline range.

RESULTS

Among the 19 337 patients who were included, 56.2% and 3.4% were positive for H. pylori and ACN, respectively. Helicobacter pylori infection independently increased the risk of ACN in patients aged <50 years (odds ratio [OR], 1.602; 95% confidence intervals [CI], 1.194-2.150) but not in patients aged ≥50 years (OR, 1.046; 95% CI, 0.863-1.268). The positive association between H. pylori infection and ACN was affected by smoking history. When stratified by age and smoking history, H. pylori infection conferred an increased risk of ACN in patients aged <50 years with a history of smoking (OR, 1.926; 95% CI, 1.336-2.775) but not in the other 3 groups (3-way interaction test P = .023). Among patients aged <50 years with ACN, ACN in the left colon was found more frequently in patients with H. pylori infection and a history of smoking than in those without (69.3% vs 54.4%, respectively; P = .031).

CONCLUSIONS

Helicobacter pylori infection confers an increased risk of ACN, but the association may differ according to age and smoking history.

Correlation between serum vitamin B12 level and peripheral neuropathy in atrophic gastritis

AIM

To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis (CAG).

METHODS

A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination from September 2013 to September 2016 were selected for this study. The age of these patients ranged within 18- to 75-years-old. Blood pressure, height and weight were measured in each patient, and the body mass index value was calculated. Furthermore, gastric acid, serum gastrin, serum vitamin and serum creatinine tests were performed, and peripheral nerve conduction velocity and Helicobacter pylori (H. pylori) were detected. In addition, the type of gastritis was determined by gastroscopy. The above factors were used as independent variables to analyze chronic gastritis with peripheral neuropathy and vitamin B12 deficiency risk factors, and to analyze the relationship between vitamin B12 levels and peripheral nerve conduction velocity. In addition, in the treatment of CAG on the basis of vitamin B12, patients with peripheral neuropathy were observed.

RESULTS

Age, H. pylori infection, CAG, vitamin B9 and vitamin B12 were risk factors for the occurrence of peripheral nerve degeneration. Furthermore, CAG and H. pylori infection were risk factors for chronic gastritis associated with vitamin B12 deficiency. Serum vitamin B12 level was positively correlated with sensory nerve conduction velocity in the tibial nerve (R = 0.463). After vitamin B12 supplementation, patients with peripheral neuropathy improved.

CONCLUSION

Serum vitamin B12 levels in patients with chronic gastritis significantly decreased, and the occurrence of peripheral neuropathy had a certain correlation. CAG and H. pylori infection are risk factors for vitamin B12 deficiency and peripheral neuropathy. When treating CAG, vitamin B12 supplementation can significantly reduce peripheral nervous system lesions. Therefore, the occurrence of peripheral neuropathy associated with vitamin B12 deficiency may be considered in patients with CAG. Furthermore, the timely supplementation of vitamin B12 during the clinical treatment of CAG can reduce or prevent peripheral nervous system lesions.

Serum pepsinogen 1 and anti-Helicobacter pylori IgG antibodies as predictors of gastric cancer risk in Finnish males

BACKGROUND

Serum pepsinogen 1 (SPG1) and anti-Helicobacter pylori serology have been used for gastric risk stratification in Asia.

AIM

To assess utility of these markers in a Western population.

METHODS

SPG1 measurements were available for 21 895 Finnish male smokers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. We used Cox proportional hazards models adjusted for potential confounders to estimate gastric cancer hazard ratios (HR) and 95% confidence intervals (95% CI) for low SPG1 (<25 μg/L). In a subset (n = 3555) with anti-H. pylori serology, these markers jointly defined the following: Group A (H. pylori[-], SPG1[normal]; reference group), Group B (H. pylori[+], SPG1[normal]), Group C (H. pylori[+], SPG1[low]) and Group D (H. pylori[-], SPG1[low]). Odds ratios (ORs) and 95% CI were calculated using multivariate logistic regression.

RESULTS

There were 329 gastric cancers diagnosed an average of 13.9 years after baseline. Pre-diagnostic low SPG1 was significantly associated with increased gastric cancer risk (HR 2.68, 95% CI 1.99-3.61). Among subjects with both SPG1 and H. pylori serology, groups B, C and D had increased gastric cancer ORs (95% CI) of 1.79 (1.21-2.64), 3.85 (2.36-6.28) and 6.35 (2.20-18.34), respectively. CagA seropositives had significantly higher ORs than CagA seronegatives within group B (P_{heterogeneity}  = 0.01). For groups B and C, repeat SPG1 level at 3 years did not further stratify gastric cancer risk.

CONCLUSIONS

Low SPG1 was associated with increased gastric cancer risk in our large Finnish cohort. A single measurement of SPG1 along with H. pylori whole cell and CagA serology provides potentially useful prediction of gastric cancer risk.

Helicobacter pylori LPS-induced gastric mucosal spleen tyrosine kinase (Syk) recruitment to TLR4 and activation occurs with the involvement of protein kinase Cδ

Spleen tyrosine kinase (Syk) has emerged recently as a major effector of proinflammatory genes expression induced by LPS-elicited TLR4 activation, and manifested by the up-amplification in the production of inflammatory mediators, including PGE2 and NO. Here, we investigated the nature of factors involved in the recruitment and interaction of Syk with TLR4 in gastric mucosa in response to H. pylori LPS. We show that stimulation of gastric mucosal cells with the LPS leads to localization of Syk with the membrane-associated TLR4 complex and its activation through phosphorylation on Tyr. Furthermore, we reveal that the membrane translocation of Syk upon the LPS stimulation occurs with the involvement of protein kinase Cδ (PKCδ)-mediated phosphorylation of Syk on Ser. Thus, our findings demonstrate that H. pylori LPS-induced up-regulation in Syk activity proceeds through the stage of PKCδ-mediated Syk phosphorylation on Ser, required for its recruitment to the membrane-anchored TLR4, followed by the kinase activation through phosphorylation on Tyr. Hence, the phase of PKCδ-mediated Syk phosphorylation on Ser affects the extent of amplification in gastric mucosal inflammatory response to H. pylori.

Associations of Helicobacter pylori infection and chronic atrophic gastritis with accelerated epigenetic ageing in older adults

Background:

Helicobacter pylori (HP) infection and chronic atrophic gastritis (CAG) have shown strong associations with the development of gastric cancer. This study aimed to examine whether both risk factors are associated with accelerated epigenetic ageing, as determined by the ‘DNA methylation age’, in a population-based study of older adults (n=1477).

Methods:

Serological measurements of HP antibodies and pepsinogen I and II for CAG definition were obtained by ELISA kits. Whole blood DNA methylation profiles were measured by Illumina Human Methylation450K Beadchip. DNA methylation ages were calculated by two algorithms proposed by Horvath and Hannum et al.

Results:

After adjusting for potential covariates in linear regression models, we found that HP infection, infection with virulent HP strains (CagA+) and severe CAG were significantly associated with an increase in DNA methylation age by ∼0.4, 0.6 and 1 year (all P-values <0.05), respectively.

Conclusions:

Our study indicates that both CagA+ HP infection and CAG go along with accelerated epigenetic ageing.

Microbiota dysbiosis in select human cancers: Evidence of association and causality

The human microbiota is a complex ecosystem of diverse microorganisms consisting of bacteria, viruses, and fungi residing predominantly in epidermal and mucosal habitats across the body, such as skin, oral cavity, lung, intestine and vagina. These symbiotic communities in health, or dysbiotic communities in disease, display tremendous interaction with the local environment and systemic responses, playing a critical role in the host's nutrition, immunity, metabolism and diseases including cancers. While the profiling of normal microbiota in healthy populations is useful and necessary, more recent studies have focused on the microbiota associated with disease, particularly cancers. In this paper, we review current evidence on the role of the human microbiota in four cancer types (colorectal cancer, head and neck cancer, pancreatic cancer, and lung cancer) proposed as affected by both the oral and gut microbiota, and provide a perspective on current gaps in the knowledge of the microbiota and cancer.

Helicobacter pylori infection, atrophic gastritis, and pancreatic cancer risk: A meta-analysis of prospective epidemiologic studies

BACKGROUND

To investigate the associations of Helicobacter pylori (Hp) infection and atrophic gastritis (AG) with pancreatic cancer risk.

METHODS

A literature search in PubMed was performed up to July 2017. Only prospective cohort and nested case-control studies enrolling cancer-free participants were eligible. Incident pancreatic cancer cases were ascertained during the follow-up. The risks of pancreatic cancer were compared between persons infected and noninfected with Hp, or between those with and without AG status at baseline. Odds ratios (ORs) or hazard ratios were combined. Subgroup and sensitivity analyses were performed, and publication bias was estimated.

RESULTS

Three cohort studies and 6 nested case-control studies, including 65,155 observations, were analyzed. The meta-analyses did not confirm the association between pancreatic cancer risk and Hp infection (OR = 1.09, 95% confidence interval [CI] = 0.81-1.47) or AG status (OR = 1.18, 95% CI = 0.80-1.72). However, particular subpopulations potentially had increased risks of pancreatic cancer. Cytotoxin-associated gene A (CagA)-negative strains of Hp might be a causative factor of pancreatic cancer (OR = 1.30, 95% CI = 1.05-1.62), but a sensitivity analysis by leave-one-out method did not fully warrant it (OR = 1.20, 95% CI = 0.93-1.56). In 1 nested case-control study, AG at stomach corpus in Hp-negative subpopulation might have increased risk of pancreatic cancer, but with a poor test power = 0.56. Publication biases were nonsignificant in the present meta-analysis.

CONCLUSION

Based on current prospective epidemiologic studies, the linkage of pancreatic cancer to Hp infection or AG status was not warranted on the whole. Nevertheless, prospective studies only focusing on those specific subpopulations are further required to obtain better power.

Helicobacter pylori Antibody Reactivities and Colorectal Cancer Risk in a Case-control Study in Spain

Background: Several studies have suggested that Helicobacter pylori (H. pylori) infection is a risk factor for colorectal cancer (CRC), while others have not confirmed this hypothesis. This work aimed to assess the relation of CRC with H. pylori seropositivity and with seropositivity to 16 H. pylori proteins, in the MultiCase-Control study, MCC-Spain.

Methods: MCC-Spain is a multicase-control study carried out in Spain from 2008 to 2013. In total, 2,140 histologically-confirmed incident CRC cases and 4,098 population-based controls were recruited. Controls were frequency-matched by sex, age, and province. Epidemiological data were collected through a questionnaire fulfilled by face-to-face interviews and a self-administered food-frequency questionnaire. Seroreactivities against 16 H. pylori proteins were determined in 1,488 cases and 2,495 controls using H. pylori multiplex serology. H. pylori seropositivity was defined as positivity to ≥4 proteins. Multivariable logistic regression mixed models were used to estimate odds ratios (OR) and 95% confidence intervals (CI).

Results:H. pylori seropositivity was not associated with increased CRC risk (OR = 0.91; 95% CI: 0.71–1.16). Among H. pylori seropositive subjects, seropositivity to Cagδ showed a lower CRC risk, and risk decreased with increasing number of proteins seropositive. Seropositivity to the most recognized virulence factors, CagA and VacA, was not associated with a higher CRC risk. No statistically significant heterogeneity was identified among tumor sites, although inverse relations were stronger for left colon cancer. An interaction with age and sex was found: H. pylori seropositivity was associated with a lower CRC risk in men younger than 65 and with a higher risk in older women.

Conclusions: Our results suggest that neither H. pylori seropositivity, nor seropositivity to the virulence factor CagA are associated with a higher CRC risk. A possible effect modification by age and sex was identified.

Role of LPS-elicited signaling in triggering gastric mucosal inflammatory responses to H. pylori: modulatory effect of ghrelin

Infection with Helicobacter pylori is a primary culprit in the etiology of gastric disease, and its cell-wall lipopolysaccharide (LPS) is recognized as a potent endotoxin responsible for triggering a pattern of the mucosal inflammatory responses. The engagement by the LPS of gastric mucosal Toll-like receptor 4 (TLR4) leads to initiation of signal transduction events characterized by the activation of mitogen-activated protein kinase (MAPK) cascade, induction of phosphoinositide-specific phospholipase C (PLC)/protein kinase C (PKC)/phosphatidylinositol 3-kinase (PI3K) pathway, and up-regulation in Src/Akt. These signaling events in turn exert their influence over H. pylori-elicited excessive generation of NO and PGE2 caused by the disturbances in nitric oxide synthase and cyclooxygenase isozyme systems, increase in epidermal growth factor receptor transactivation, and the induction in matrix metalloproteinase-9 (MMP-9) release. Interestingly, the extent of gastric mucosal inflammatory response to H. pylori is influenced by a peptide hormone, ghrelin, the action of which relays on the growth hormone secretagogue receptor type 1a (GHS-R1a)-mediated mobilization of G-protein dependent transduction pathways. Yet, the signals triggered by TLR-4 activation as well as those arising through GHS-R1a stimulation converge at MAPK and PLC/PKC/PI3K pathways that form a key integration node for proinflammatory signals generated by H. pylori LPS as well as for those involved in modulation of inflammation by ghrelin. Hence, therapeutic targeting these signals' convergence and integration node could provide a novel and attractive opportunities for developing more effective treatments of H. pylori-related gastric disease.

Genetic variations of TLR5 gene interacted with Helicobacter pylori infection among carcinogenesis of gastric cancer

Gastric cancer (GC) ranks the second prevalent cancer type and the second cancer-related death in China. However, the precise mechanisms of GC development remain poorly understood. Chronic infection with Helicobacter pylori is the strongest identified risk factor for GC. Toll-like receptor (TLR) genes, which play critical roles in Helicobacter pylori induced chronic inflammation, may also be implicated in GC susceptibility. TLR5 signaling deficiency could deregulate a cascade of inflammatory events. In current study, we systematically evaluated genetic variations of TLR5, and their interaction with Helicobacter pylori infection among carcinogenesis of gastric cancer, using a large case-controls study among Chinese population. Minor alleles of three SNPS, including rs5744174 (P = 0.001), rs1640827 (P = 0.005), and rs17163737 (P = 0.004), were significantly associated with increased GC risk (OR ranged from 1.20-1.24). Significant interactions with Helicobacter pylori infection were also identified for rs1640827 (P for interaction = 0.009) and rs17163737 (P for interaction = 0.006). These findings suggest that genetic variants in TLR5 may modify the role of Helicobacter pylori infection in the process of causing GC.

The Gastric Microbiome and Its Influence on Gastric Carcinogenesis: Current Knowledge and Ongoing Research

Gastric malignancies are a leading cause of cancer-related death worldwide. At least 2 microbial species are currently linked to carcinogenesis and the development of cancer within the human stomach. These include the bacterium Helicobacter pylori and the Epstein-Barr virus. In recent years, there has been increasing evidence that within the human gastrointestinal tract it is not only pathogenic microbes that impact human health but also the corresponding autochthonous microbial communities. This article reviews the gastrointestinal microbiome as it relates primarily to mechanisms of disease and carcinogenesis within the upper gastrointestinal tract.

Factors associated with gastric adenocarcinoma and dysplasia in patients with chronic gastritis: a population-based study

OBJECTIVE

Gastric cancer (GC) is one of the leading causes of death in China and other Asian countries. Recently, gastric endoscopy has become the main approach for GC screening, but the identification of high-risk individuals remains a challenge in GC screening programs.

METHODS

There were 7,302 patients with chronic gastritis involved in this study. Endoscopic examinations were performed, and their demographic characteristics and lifestyle data were collected. Each possible associated factor of GC/premalignant and precursor lesions was evaluated by univariate and multivariate logistic regressions. Nomograms were used for visualization of those models, and receiver operating characteristic (ROC) curve analysis was used to present the predictive accuracy.

RESULTS

We detected 8 (0.11%) gastric adenocarcinomas, 17 (0.23%) dysplasia cases, 14 (0.19%) hyperplasia cases, 52 (0.71%) intestinal metaplasia cases, 217 (2.97%) inflammatory lesions, 141 (1.93%) gastric ulcers, 10 (0.14%) atrophic gastritis cases, 1,365 (18.69%) erosive gastritis cases, and 5,957 (81.58%) superficial gastritis cases in 7,302 patients. The age (P<0.001), gender (P=0.086), labor intensity (P=0.018) and leek food intake (P=0.143) were identified as independent predictive factors of GC/premalignant lesions possibility. The corresponding nomogram exhibited an area under the curve (AUC) [95% confidence interval (95% CI)] of 0.82 (0.74-0.89) for the modeling group and 0.80 (0.75-0.85) for the validation group. The age (P=0.002), gender (P=0.024), smoking (P=0.002) and leek food intake (P=0.039) were independent predictive factors of precursor lesions possibility. The corresponding nomogram exhibited an AUC (95% CI) of 0.62 (0.60-0.65) for the modeling group and 0.61 (0.59-0.63) for the validation group.

CONCLUSIONS

We identified several potential associated factors and provided a preclinical nomogram with the potential to predict the possibility of GC/premalignant and precursor lesions.