A Case Control Study of the Seroprevalence of Helicobacter pylori Proteins and Their Association with Pancreatic Cancer Risk

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.

Exploring the Relationship Between Helicobacter pylori Infection and Biliary Diseases: A Comprehensive Analysis Using the United States National Inpatient Sample (2016-2020)

BACKGROUND

Helicobacter pylori (H. pylori) infection is widely recognized for its association with gastric diseases. Prior studies on the relationship between H. pylori infection and biliary diseases have faced constraints, including inadequate control of confounding factors and small sample sizes. This study aims to explore the association between H. pylori infection and biliary diseases using a large, population-based sample with adequate control for various covariates.

METHODS

 The National Inpatient Sample (NIS) from 2016 to 2020 was used to investigate the association between H. pylori infection and biliary diseases. We identified patients with H. pylori infection using the International Classification of Diseases, Tenth Revision (ICD-10) code (B96.81). Descriptive analysis and inferential statistics, including univariate and multivariate regression, were performed to explore the relationship between H. pylori and selected biliary diseases.  Results: Overall, 32,966,720 patients were analyzed. Among them, 736,585 patients had biliary diseases (n=1,637 with H. pylori and n=734,948 without H. pylori). The baseline characteristics revealed notable differences in demographics and healthcare variables between both groups. Univariate regression analysis demonstrated significant associations between H. pylori infection and various biliary diseases such as gallbladder stones, gallbladder cancer, cholangitis, acute cholecystitis, and biliary pancreatitis, with the highest risk for chronic cholecystitis (odds ratio: 5.21; 95% confidence interval: 4.1-6.62; p<0.0001). Multivariate regression analysis, after adjusting for various covariates, confirmed these associations, providing insights into the potential causal relationship between H. pylori and biliary diseases.

CONCLUSION

 This study strengthens the evidence suggesting a potential association between H. pylori infection and biliary diseases. The findings need to be validated in prospective clinical studies.

Helicobacter pylori Seropositivity, ABO Blood Type, and Pancreatic Cancer Risk From 5 Prospective Cohorts

BACKGROUND

Helicobacter pylori infection may be a risk factor for pancreatic cancer, particularly infection by strains without the cytotoxin-associated gene A (CagA) virulence factor. Non-O blood type is a known risk factor for pancreatic cancer, and H. pylori gastric colonization occurs largely from bacterial adhesins binding to blood group antigens on gastric mucosa.

METHODS

We included 485 pancreatic cancer cases and 1,122 matched controls from 5 U.S. prospective cohorts. Prediagnostic plasma samples were assessed for H. pylori and CagA antibody titers. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for pancreatic cancer. ABO blood type was assessed using genetic polymorphisms at the ABO gene locus or self-report.

RESULTS

Compared with H. pylori -seronegative participants, those who were seropositive did not demonstrate an increased risk of pancreatic cancer (OR 0.83, 95% CI 0.65-1.06). This lack of association was similar among CagA-seropositive (OR 0.75, 95% CI 0.53-1.04) and -seronegative (OR 0.89, 95% CI 0.65-1.20) participants. The association was also similar when stratified by time between blood collection and cancer diagnosis ( P -interaction = 0.80). Consistent with previous studies, non-O blood type was associated with increased pancreatic cancer risk, but this increase in risk was similar regardless of H. pylori seropositivity ( P -interaction = 0.51).

DISCUSSION

In this nested case-control study, history of H. pylori infection as determined by H. pylori antibody serology was not associated with pancreatic cancer risk, regardless of CagA virulence factor status. The elevated risk associated with non-O blood type was consistent in those with or without H. pylori seropositivity.

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.

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.