Atrophic gastritis, Helicobacter pylori, and colorectal cancer risk: a case-control study

Kill Two Birds with One Stone? The Effect of Helicobacter pylori Eradication in Decreased Prevalence of Gastric Cancer and Colorectal Cancer

The connection between microbial infections and tumor formation is notably exemplified by Helicobacter pylori (H. pylori) and its association with gastric cancer (GC) and colorectal cancer (CRC). While early studies hinted at a link between H. pylori and colorectal neoplasms, comprehensive retrospective cohort studies were lacking. Recent research indicates that individuals treated for H. pylori infection experience a significant reduction in both CRC incidence and mortality, suggesting a potential role of this infection in malignancy development. Globally, H. pylori prevalence varies, with higher rates in developing countries (80-90%) compared to developed nations (20-50%). This infection is linked to chronic gastritis, peptic ulcers, and GC, highlighting the importance of understanding its epidemiology for public health interventions. H. pylori significantly increases the risk of non-cardia GC. Some meta-analyses have shown a 1.49-fold increased risk for colorectal adenomas and a 1.70-fold increase for CRC in infected individuals. Additionally, H. pylori eradication may lower the CRC risk, although the relationship is still being debated. Although eradication therapy shows promise in reducing GC incidence, concerns about antibiotic resistance pose treatment challenges. The role of H. pylori in colorectal tumors remains contentious, with some studies indicating an increased risk of colorectal adenoma, while others find minimal association. Future research should investigate the causal mechanisms between H. pylori infection and colorectal neoplasia, including factors like diabetes, to better understand its role in tumor formation and support widespread eradication efforts to prevent both gastric and colorectal cancers.

No evident causal association between Helicobacter pylori infection and colorectal cancer: a bidirectional mendelian randomization study

Observational studies have reported a correlation between Helicobacter pylori infection and colorectal cancer (CRC); however, the underlying cause has remained unclear. This research was aimed at determining whether there is a correlation between H. pylori infection and CRC by measuring the prevalence of H. pylori CagA antibodies and VacA antibodies. Using data from many genome-wide association studies (GWAS), we conducted a Mendelian randomization (MR) study with two sample GWAS. Then, we used bidirectional MR to evaluate the association between H. pylori infection and CRC for identifying causation. The most common method of analysis was the inverse variance-weighted technique. In addition, we performed supplementary analyses using the weighted median technique and MR-Egger regression. Horizontal pleiotropic outliers were identified and corrected using the MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) method. Genetically predicted anti-H. pylori IgG seropositivity was not causally associated with CRC [odds ratio (OR): 1.12; 95% confidence interval (CI): 0.98-1.27, P = 0.08] and neither were H. pylori VacA antibody levels (OR = 0.96, 95% CI: 0.90-1.02, P = 0.25) or H. pylori CagA antibody levels (OR = 1.00, 95% CI: 0.93-1.07, P = 0.92). Furthermore, reverse MR analysis did not reveal evidence for a causal effect of CRC on H. pylori infection. The weighted median, the MR-Egger method, and MR-PRESSO yielded identical results. Using genetic data, MR analysis showed there was no evidence for a causal association between seroprevalence of H. pylori infection and CRC. The relationship between H. pylori infection and CRC requires further research.

Colorectal cancer risk in East Asian patients with Helicobacter pylori infection: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis was to assess the relationship between H pylori infection and colorectal cancer risk in East Asian patients.

METHODS

Two researchers independently searched for relevant studies in the PubMed, Cochrane, and Embase databases from inception up to April 2022. A meta-analysis was then performed to calculate pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs) using a random effects model.

RESULTS

Nine studies involving 6355 patients were included. Overall, we observed that H pylori infection was associated with an increased risk of colorectal cancer in East Asian patients (OR = 1.48, 95% CI: 1.10-1.99, I2 = 70%), although significant heterogeneity was identified among studies. Subgroup analysis revealed that H pylori infection was associated with an increased risk of colorectal cancer in China (OR = 1.58, 95% CI 1.05-2.37, I2 = 81%) but not in Japan and Korea (OR = 1.26, 95% CI 0.93-1.70, I2 = 0%).

CONCLUSION

This meta-analysis identified a positive association between H pylori infection and colorectal cancer risk in East Asian patients, especially in China.

The relationship between colorectal cancer and gastric histopathology: case-control study

Aim: The aim of this study was to investigate the gastric histopathological findings (Helicobacter pylori (H. pylori), intestinal metaplasia (IM), atrophic gastritis (AG), and dysplasia) in the patients with and without colorectal cancer (CRC). Material and Method: Two hundred ninety five patients (160 CRC patients and 135 control individuals) were included in the study. Gastric histopathological findings of the patients who underwent upper gastrointestinal (GI) endoscopy were analyzed retrospectively. Results: H. pylori positivity and IM rates in the CRC patient group were significantly higher than the control group (58.8%&27.8% and 33.1%&19.5%, p<0.001 and p<0.012, respectively). In addition, AG, lymphoplasmocytic infiltration, and dysplasia rates were also higher in the CRC patients compared to the control group. But, they were not statistically significant (p=0.462, p=0.103, and p=0.195, respectively). Conclusion: In our study, the frequency of H. pylori and IM in patients with CRC was higher than in the control group. Since the prevalence of H. pylori infection is high in Turkey and H. pylori-related gastric diseases may be potential risk factors for colorectal neoplasia, it is recommended that individuals in the high-risk group to be screened for colonoscopy. Also, upper GI endoscopic examination should be performed to screen for gastric premaling lesions in patients with CRC.

Are Inflammatory Bowel Disease and Colorectal Carcinoma Associated with Helicobacter pylori? A Prospective Study and Meta-analysis

Observational studies regarding the correlation between colorectal carcinoma, inflammatory bowel disease and Helicobacter pylori infection are inconsistent. The present study aims to investigate the association between colorectal adenocarcinoma (CRA) and inflammatory bowel disease (IBD) with H. pylori status in 100 patients who have inflammatory bowel disease and colorectal carcinoma was confirmed disease by histological approach. Besides, a meta-analysis was performed of published studies, to evaluate the link between H. pylori infection and an increased risk of CRC and IBD. Among 67 cases with CRA and 33 cases with IBD, 59.7% and 51.5% were H. pylori positive; respectively. In the meta-analysis, thirty-nine articles were included, involving 13 231 cases with CRC and 2477 with IBD. The pooled odds ratio for CRC and IBD was 1.16 (95%CI = 0.73-1.82) and 0.42 (95%CI = 0.32-0.56); respectively. Our meta-analysis indicates that H. pylori is not associated with CRC.

Effects of Helicobacter pylori infection in gastrointestinal tract malignant diseases: From the oral cavity to rectum

Helicobacter pylori (H. pylori) has infected approximately fifty percent of humans for a long period of time. However, improvements in the public health environment have led to a decreased chance of H. pylori infection. However, a high infection rate is noted in populations with a high incidence rate of gastric cancer (GC). The worldwide fraction of GC attributable to H. pylori is greater than 85%, and a high H. pylori prevalence is noted in gastric mucosa-associated lymphoid tissue lymphoma patients. These results indicate that the majority of GC cases can be prevented if H. pylori infection is eliminated. Because H. pylori exhibits oral-oral or fecal-oral transmission, the relationship between this microorganism and other digestive tract malignant diseases has also attracted attention. This review article provides an overview of H. pylori and the condition of the whole gastrointestinal tract environment to further understand the correlation between the pathogen and the host, thus allowing improved realization of disease presentation.

Helicobacter pylori infection and increased diabetes prevalence were the risks of colorectal adenoma for adults: A systematic review and meta-analysis (PRISMA-compliant article)

BACKGROUND

Helicobacter pylori infection and hyperglycemia are associated with an increased risk of colorectal neoplasm, and may have a synergistic effect in combination. However, these 2 factors that affect colorectal neoplasm remain controversial. We aimed to carry out a meta-analysis to evaluate the study population diabetes prevalence rate and H pylori infection rate with colorectal adenoma risk for adults.

METHODS

We conducted systemic research through English databases for medical reports. We also recorded the diabetes prevalence and H pylori infection prevalence in each study. We classified these studies into 4 subgroups as their background population diabetes prevalence <6% (Group 1); between 6% and 8% (Group 2); between 8% and 10% (Group 3), and more than 10% (Group 4). The random-effects model had used to calculate pooled prevalence estimates with 95% confidence interval (CI).

RESULTS

Twenty-seven studies were finally eligible for meta-analysis. The random-effects model of the meta-analysis was chosen, showing pooled odds ratio (OR) equal to 1.51 (95% CI 1.39-1.63). The subgroup meta-analyses showed in Group 1 the H pylori infection associated colorectal adenoma risk OR was 1.24 (95% CI 0.86-1.78). As the diabetes rate exceed 6%, the H pylori infection became the more significant increased risk of colorectal adenoma (Group 2: OR 2.16 (95% CI 1.61-2.91); Group 3: OR 1.40 (95% CI 1.24-1.57); and Group 4: OR 1.52 (95% CI 1.46-1.57)).

CONCLUSIONS

The results of this meta-analysis showed elevated diabetes prevalence combined H pylori infection increasing the risks of colorectal adenoma in the adult population.

Prevalence and predictors of colonoscopic findings in patients with autoimmune gastritis

The clinical spectrum of autoimmune gastritis is silent in the early stages of the disease and no specific symptom is related to this entity. Although gastroscopic findings of this entity are well defined, data regarding colonoscopic findings are limited. The aims of this study were to determine the prevalence of colonoscopic findings and to explore factors that might affect these findings. This is a retrospective chart review of patients with autoimmune gastritis (n=240). Data regarding colonoscopic findings, serum gastrin and chromogranin A (CgA) levels and gastric histopathological results were extracted and compared with 550 patients positive for Helicobacter pylori and gastric atrophy. Control subjects had colonoscopy and gastroscopy with biopsies. Colorectal lesions were observed in 64 (26.6%) of patients with autoimmune gastritis and 36 (6.6%) patients had colorectal lesions in the control group (p<0.001). Serum gastrin (OR: 8.59, 95% CI 1.72 to 25.07, p<0.001) and CgA levels (OR: 6.79, 95% CI 0.41 to 27.26, p<0.001) were found as factors affecting the presence of colorectal carcinoma. Serum gastrin and CgA levels were also found as predictors for the presence of colorectal adenomas. There is a higher prevalence of colorectal neoplastic lesions in patients with autoimmune gastritis. Serum gastrin and CgA levels were found to be determinants of colorectal neoplastic lesions observed in patients. In the workup of these patients, serum gastrin and CgA levels may guide physicians for the demonstration of colorectal neoplastic lesions.

Helicobacter pylori and colorectal neoplasms: a concise review

Helicobacter pylori is the main etiological agent of all malignant tumors caused by an infectious disease. It is a major, at times dominant, factor in the pathogenesis of a large spectrum of diseases such as acute and chronic gastritis, gastric and duodenal ulcers, gastric carcinoma, and lymphoma. Epidemiological and experimental studies suggest that H. pylori chronic infection may be related to different extragastric diseases, including colorectal neoplasms. This concise review aims to explore the association of H. pylori infection with colorectal cancer and adenoma, including the recent epidemiological findings, the diagnostic methods employed to detect H. pylori and virulent factors, and the potentially involved mechanisms. Furthermore, is attempted to establish the current data integration for causal inference using the Bradford-Hill causality criteria. The weak, although global, strength of the epidemiological positive association between H. pylori infection and colonic neoplasms associated to new mechanisms postulated to explain this interaction, including intestinal dysbiosis, should stimulate future studies. Prospective confirmatory studies to establish the role of H. pylori eradication in the process of carcinogenic transformation of the colonic epithelium may define its eventual role in the treatment and prevention of colonic neoplasms.

Helicobacter pylori infection with atrophic gastritis: An independent risk factor for colorectal adenomas

BACKGROUND

The significance of Helicobacter pylori (H. pylori) infection and atrophic gastritis (AG) in the prevalence of colorectal adenomas has been examined in a limited number of studies. However, these studies reported disputed conclusions.

AIM

To investigate whether H. pylori infection, AG, and H. pylori-related AG increase the risk of colorectal adenomas.

METHODS

This retrospective cross-sectional study included 6018 health-check individuals. The relevant data for physical examination, laboratory testing, ¹³C-urea breath testing, gastroscopy, colonoscopy and histopathological examination of gastric and colorectal biopsies were recorded. Univariate and multivariate logistic regression analyses were performed to determine the association between H. pylori-related AG and colorectal adenomas.

RESULTS

Overall, 1012 subjects (16.8%) were diagnosed with colorectal adenomas, of whom 143 (2.4%) had advanced adenomas. Among the enrolled patients, the prevalence of H. pylori infection and AG was observed as 49.5% (2981/6018) and 10.0% (602/6018), respectively. Subjects with H. pylori infection had an elevated risk of colorectal adenomas (adjusted odds ratio [OR] of 1.220, 95% confidence interval (CI): 1.053-1.413, P = 0.008) but no increased risk of advance adenomas (adjusted OR = 1.303, 95%CI: 0.922-1.842, P = 0.134). AG was significantly correlated to an increased risk of colorectal adenomas (unadjusted OR = 1.668, 95%CI: 1.352-2.059, P < 0.001; adjusted OR = 1.237, 95%CI: 0.988-1.549, P = 0.064). H. pylori infection accompanied by AG was significantly associated with an increased risk of adenomas (adjusted OR = 1.491, 95%CI: 1.103-2.015, P = 0.009) and advanced adenomas (adjusted OR = 1.910, 95%CI: 1.022-3.572, P = 0.043).

CONCLUSION

H. pylori-related AG was associated with a high risk of colorectal adenomas and advanced adenomas in Chinese individuals.

Association between Helicobacter pylori infection and the risk of colorectal cancer: A systematic review and meta-analysis

BACKGROUND

The existing evidence on the relationship between Helicobacter pylori infection and the risk of colorectal cancer is inconsistent. We conducted a systematic review with a meta-analysis to explore this relationship and to determine whether the relationship varies according to the study characteristics.

METHODS

We searched the PubMed, OVID, EMBASE database, and the reference lists of pertinent articles published up to October 2019 by 2 researchers independently. Summary odds ratios (OR) with their 95% confidence intervals (CIs) were estimated using a random-effects model.

RESULTS

Forty seven studies including 17,416 cases of colorectal cancer (CRC) and 55,811 cases of control were included. Overall, H. pylori infection was associated with an increased risk of CRC (OR = 1.70 95% CI 1.64-1.76, I = 97%), although there was significant heterogeneity among the studies. Subgroup analysis revealed that the positive correlation might vary by the design of study conducted.

CONCLUSION

This meta-analysis demonstrates a positive association between H. pylori infection and the risk of colorectal cancer.

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.

Differential Metabolic Alterations and Biomarkers Between Gastric Cancer and Colorectal Cancer: A Systematic Review and Meta-Analysis

Purpose

Numerous metabolomics studies have been conducted to detect the metabolic mechanisms and biomarkers related to gastric cancer and colorectal cancer. Because of the common metabolic features between gastric cancer and colorectal cancer, a differential diagnosis is difficult. Here, we performed a systematic review and meta-analysis to identify differential metabolic biomarkers between these two types of cancers.

Materials and Methods

PubMed, Embase, and ScienceDirect were searched to identify all metabolomics studies of gastric cancer and colorectal cancer published up to September 2018. Differential metabolites or altered pathways were extracted. The intersections and differences for these metabolites and pathways between gastric cancer and colorectal cancer were compared. Candidate biomarker sets for diagnosis were proposed from biofluid or feces by comparing them with tumor tissues.

Results

Totally, 24 and 65 studies were included in gastric cancer and colorectal cancer, and 223 and 472 differential metabolites were extracted, respectively. Eight pathways were reproducibly enriched in blood, tissue and urine in gastric cancer, while, 11 pathways were reproducibly enriched in blood, urine, feces and tissue in colorectal cancer. Candidate metabolic biomarker sets in blood, urine, or feces for these two cancers were proposed. We found 27 pathways (categorized into eight classifications) common to both cancers, five pathways involving 35 metabolites enriched only in gastric cancer, and eight pathways involving 54 metabolites enriched only in colorectal cancer.

Conclusion

The altered metabolic pathways showed signatures of abnormal metabolism in gastric cancer and colorectal cancer; the potential metabolic biomarkers proposed in this study have important implications for the prospective validation of gastric cancer and colorectal cancer.

Association of Helicobacter pylori infection with colorectal polyps and malignancy in China

BACKGROUND

Gastric Helicobacter pylori (H. pylori) infection is related to chronic gastritis, gastroduodenal ulcer, and gastric malignancies; whether this infection is related to colorectal polyps and colorectal cancer (CRC), remains debatable.

AIM

To investigate the relationship between gastric H. pylori infection and the risk of colorectal polyps and CRC.

METHODS

We retrospectively analyzed 3872 patients with colorectal polyps who underwent colonoscopy and pathological diagnosis. We also analyzed 304 patients with primary CRC. The characteristics of these patients were compared with those of the control group, which included 2362 patients with the normal intestinal mucosa. All subjects completed a ¹⁴C-urea breath test, bidirectional gastrointestinal endoscopy, and a biopsy on the same day. Data on the number, size, location, and pathology of the polyps, the location, and pathology of the CRC, the detection of H. pylori, and the incidence of H. pylori-associated atrophic gastritis or intestinal metaplasia were obtained. A logistic regression model was used to analyze the relationship between gastric infection due to H. pylori, and the incidence of colorectal polyps and CRC.

RESULTS

The prevalence of H. pylori infection was higher in the multiple polyps group than in the solitary polyp group and the control group [95% confidence interval (CI) = 1.02-1.31, P = 0.03; 95%CI: 2.12-2.74, P < 0.001]. The patients with adenomatous polyps had a higher incidence of H. pylori infection than patients with non-adenomatous polyps [59.95% vs 51.75%, adjusted odds ratio (OR) = 1.41, 95%CI: 1.24-1.60, P < 0.01]. Patients with H. pylori-associated atrophic gastritis or intestinal metaplasia were at high risk of CRC (adjusted OR = 3.46, 95%CI: 2.63-4.55, P < 0.01; adjusted OR = 4.86, 95%CI: 3.22-7.34, P < 0.01, respectively). The size and location of the polyps, the histopathological characteristics and the location of CRC were not related to H. pylori infection.

CONCLUSION

Our study demonstrates that the incidence of gastric H. pylori infection and H. pylori-associated atrophic gastritis or intestinal metaplasia elevates the risk of colorectal polyps and CRC.

Risk for Colorectal Neoplasia in Patients With Helicobacter pylori Infection: A Systematic Review and Meta-analysis

Helicobacter pylori may reportedly be associated with extragastric malignancy beyond gastric cancer. The present study aimed to evaluate the association between H. pylori infection and colorectal neoplasia through a systematic review and meta-analysis.

Helicobacter pylori infection and the risk of colorectal cancer: a nationwide population-based cohort study

BACKGROUND

The role of Helicobacter pylori (H. pylori) infection in the development of colorectal neoplasia has been a matter of scientific debate with controversial findings.

AIMS

This study examined the association between H. pylori infection and colorectal cancer (CRC) in a nationwide population-based Chinese cohort study.

METHODS

A total of approximately 3936 individuals with newly diagnosed H. pylori infection (the H. pylori-infected cohort) and 15 744 age- and sex-matched patients with diagnoses absence of H. pylori infection (the comparison cohort) from 2000 to 2005 were identified from Taiwan's National Health Insurance Research Database. The Kaplan-Meier method was used for measuring the cumulative incidence of CRC in each cohort. Cox proportional hazards models were used to compute hazard ratios (HRs) and accompanying 95% confidence intervals (CIs) for the estimation of the association between H. pylori infection and CRC.

RESULTS

The cumulative incidence of CRC was higher in H. pylori-infected cohort than that in the comparison cohort (log-rank test, P < 0.001). After adjustment for potential confounders, H. pylori infection was associated with a significantly increased risk of CRC (adjusted HR 1.87; 95% CI 1.37-2.57). In addition, the HR of CRC appeared to increase with increasing frequency of clinical visits for H. pylori infection.

CONCLUSIONS

Our study demonstrated that H. pylori infection was associated with an increased risk of CRC, which warrants confirmation and exploration of the underlying biologic mechanisms by future studies.

Helicobacter pylori infection and the risk of colorectal carcinoma: a systematic review and meta-analysis

INTRODUCTION

Helicobacter pylori is a gram-negative bacterium that is colonized in the stomach. H. pylori infection can lead to a series of stomach diseases. However, the relationship between H. pylori infection and colorectal cancer is currently controversial. Therefore, we performed this meta-analysis to further understand the relationship between H. pylori infection and colorectal cancer.

EVIDENCE ACQUISITION

We conducted a comprehensive retrieval from electronic databases, included the PubMed, Medline, China National Knowledge Infrastructure (CNKI), and China Wanfang Data Knowledge Service Platform databases (Wanfang Databases) through May 1st, 2018. We used the search terms H. pylori and colorectal cancer or colorectal carcinoma and collected all relevant studies to explore the association between H. pylori infection and colorectal cancer.

EVIDENCE SYNTHESIS

Twenty-seven studies including 14357 cases were included. H. pylori infection was associated with an increased risk of colorectal cancer. A pooled odds ratio (OR) of 1.27 with a 95% CI of 1.17-1.37 (P<0.001) was calculated by using a fixed-effects model (I2=45.5%, P=0.006). The subgroup analysis revealed that H. pylori infection was associated with an increased risk of colorectal cancer in the subgroups of Western countries (OR=1.34, 95% CI: 1.14-1.57) (P<0.001), serological testing (OR=1.20, 95% CI: 1.08-1.34) (P=0.001), multiple methods of testing (OR=2.63, 95% CI: 1.09-6.31) (P=0.031), cross-sectional studies (OR=1.92, 95% CI: 1.17-3.16) (P=0.010) and case-control studies (OR 1.26, 95% CI: 1.16-1.36) (P<0.001).

CONCLUSIONS

The present meta-analysis provides evidence suggests that a positive association between H. pylori infection and the risk of colorectal cancer.

Endoscopic gastric mucosal atrophy as a predictor of colorectal polyps: a large scale case-control study

Although some studies have indicated a correlation between Helicobacter pylori infection and the risk of colorectal neoplasms, these findings have not been consistent and are controversial. This case-control study aimed to investigate the association between endoscopic gastric mucosal atrophy and colorectal polyp occurrence. Records of 7,394 participants who underwent colonoscopy examinations from August 2008 to July 2018 were reviewed retrospectively. A total of 2,404 subjects were registered; 1,565 (65.1%) were in the gastric mucosal atrophy-positive group and 1,138 (47.3%) had colorectal polyps. The multivariate analysis adjusted by age, sex, smoking habits, alcohol habits, hemoglobin A1c, and systolic blood pressure indicated that patients in the gastric mucosal atrophy-positive group more frequently had colorectal polyps compared with patients in the gastric mucosal atrophy-negative group (odds ratio, 3.27; 95% confidence interval, 2.68-4.01; p<0.001). An analysis of the association between gastric mucosal atrophy degree and colorectal polyp status indicated that, compared with mild gastric mucosal atrophy, severe gastric mucosal atrophy was associated with a higher risk of proximal colon polyps (odds ratio, 1.47; 95% confidence interval, 1.05-2.07; p = 0.024) and two or more colorectal polyps (odds ratio, 1.80; 95% confidence interval, 1.30-2.49; p<0.001). In conclusion, gastric mucosal atrophy found during esophagogastroduodenoscopy may be an indication for complete colon screening.

Clinical significance of serum markers reflecting gastric function and H. pylori infection in colorectal cancer

Purpose: The study was conducted to investigate the relationship of serum pepsinogens PGI, PGII, gastrin-17, and Hp-IgG with colorectal cancer (CRC), aiming to explore the clinical significance of serum markers reflecting gastric function and H. pylori infection in CRC. Methods: A total of 569 CRC cases and 569 age and sex-matched controls were enrolled in this study between June 2012 and April 2016 from The First Hospital of China Medical University. The serum markers reflecting gastric function and H. pylori infection were detected using ELISA, including PGI, PGII, PGI/II ratio, G-17 and Hp-IgG. Information of clinicopathological parameters and tumor biomarkers was collected from the medical records of inpatients, including CEA, CA199, CA125, CA153 and AFP. Results: Serum PGII, G-17 levels and Hp-IgG were increased in CRC, while PGI and PGI/II ratio appeared no significant difference between CRC and controls. In subgroup analysis, PGII was more significant in males (P=0.014). Hp-IgG was demonstrated higher in age<60y (P=0.001). With respect to the association with serum tumor biomarkers, G-17 level was associated with the rise of CA125 (P=0.005, OR (95%CI): 4.89 (1.90-12.57)), Hp-IgG increasing was associated with the rise of CA125 (P=0.024, OR (95%CI): 4.10 (1.54-10.93)). Conclusions: Serum PGII, G-17 and Hp-IgG were associated with CRC risk. The serum levels of G-17 and Hp-IgG were associated with the rise of CA125 in patients with CRC.

Plasma cytokine levels and the presence of colorectal cancer

Background/Aims

Cancer-related activation of cytokine networks are central aspects of tumor development. The goal of the study was to examine the possibility of plasma cytokines for the screening of colorectal cancer (CRC).

Methods

We carried out a multicenter, hospital-based case-control study in 66 adult Japanese patients with CRC and 87 healthy adult Japanese. A multiplex bead array immunoassay was used to examine 27 different plasma cytokines. Their association with the presence of CRC was evaluated by logistic regression analysis after adjusting for potential confounding factors.

Results

Thirteen plasma cytokines were notably associated with the presence of CRC (p< 0.05). Receiver operating characteristic analysis revealed that the combinatorial assessment of some of these plasma cytokines showed “good” capability for discriminating between CRC patients and control subjects (area under the curve (AUC): 0.819 for the combination of IL-9, Eotaxin, G-CSF, and TNF-α; 0.832 for the combination of IL-4, IL-8, Eotaxin, IP-10, and TNF-α). Individual cytokine assessments presented lower AUCs (0.657–0.755) than the combinatorial cytokine assessments.

Conclusions

The levels of several plasma cytokines varied significantly between CRC patients and control subjects, suggesting the possibility of differentially expressed plasma cytokines as potential biomarkers for detecting the presence of CRC. Our results should be validated in other populations.

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.

Applying simple linear combination, multiple logistic and factor analysis methods for candidate fecal bacteria as novel biomarkers for early detection of adenomatous polyps and colon cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer, and presents a considerable disease burden, worldwide. Recently, the gut microbiota has been proposed as a potential risk factor for CRC, and even adenomatous polyps (AP). Here, the aim of this study was to investigate the role of selected gut bacteria as fecal bacterial biomarkers, in early detection of CRC and AP.

MATERIAL AND METHODS

Fecal samples (n = 93) were collected from Taleghani Hospital, Tehran, Iran, between 2015 and 2017, from normal controls (NC), AP cases and CRC stage I patients, who were undergoing screening for colonoscopy. Absolute quantitative real time PCR (qPCR) assays were established for the quantification of bacterial marker candidates, in all cases and control groups. In order to evaluate the diagnostic value of bacterial candidates in distinguishing CRC from a polyp, receiver operating characteristic curve (ROC) was performed. Multiple logistic regressions were used to find the best combinations of the bacterial candidates, then, combinations were analyzed based on three methods, including linear combination, multiple logistic and factor analysis models.

RESULTS

According to the logistic model, combination of Fusobacterium nucleatum, Enterococcus feacalis, Streptococcus bovis, Enterotoxigenic Bacteroides fragilis (ETBF) and Porphyromonas spp. showed improved diagnostic performance, compared to each bacterium alone, as area under the receiver operating characteristic (AUROC) increases to 0.97, with 95% confidence interval. It was found that a simple linear combination was an appropriate model for discriminating AP and CRC cases, compared to the NC, with a sensitivity of 91.4% and specificity of 93.5%.

CONCLUSION

Our results indicated that based on fecal bacterial candidates, statistical simple linear combination model and ROC curve analysis, early detection of AP and CRC might be possible.

Helicobacter pylori Infection with Atrophic Gastritis Is an Independent Risk Factor for Advanced Colonic Neoplasm

Background/Aims

Helicobacter pylori is a major risk factor for atrophic gastritis (AG) and gastric cancer. The correlation between H. pylori, AG and colorectal neoplasm (CRN) has only been examined in a limited number of studies, and findings have been inconclusive. We aimed to investigate the association between H. pylori infection status, AG and advanced CRN.

Methods

This cross-sectional study investigated the relationship between the presence of serum anti-H. pylori IgG antibodies, AG, and advanced CRN in 6,351 consecutive asymptomatic subjects who underwent a screening colonoscopy.

Results

A total of 316 participants (5.0%) had advanced CRN. H. pylori seropositivity was 61.3%. In a univariate analysis, the presence of H. pylori infection was associated with advanced CRN (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.17 to 1.91; p=0.001). H. pylori infection was associated with an increased risk of advanced CRN after adjusting for clinically relevant confounders (OR, 1.34; 95% CI, 1.04 to 1.72; p=0.023). H. pylori-related AG was significantly associated with the risk of advanced CRN (OR, 1.40; 95% CI, 1.03 to 1.91; p=0.030), whereas H. pylori infection without AG was not.

Conclusions

H. pylori infection increased the risk of advanced CRN, especially when it was combined with AG. Strict colonoscopy screening and surveillance may be warranted in those with H. pylori-positive AG.

Synergistic Effect of Hyperglycemia and Helicobacterpylori Infection Status on Colorectal Adenoma Risk

CONTEXT

Both Helicobacter pylori and type 2 diabetes mellitus are possible risk factors for colon adenoma.

OBJECTIVE

The purpose of this study was to assess the interaction between H. pylori and hyperglycemia status on the risk of colon adenoma.

DESIGN, SETTING, AND PARTICIPANTS

This was a cross-sectional, retrospective study conducted at the MacKay Memorial Hospital, Taiwan. The study included 3943 subjects aged >40 years undergoing bidirectional gastrointestinal endoscopy on the same day between July 2006 and June 2015. All subjects had a gastric biopsy specimen tested for H. pylori.

MAIN OUTCOME MEASURE

Colon adenoma with and without H. pylori infection at different hemoglobin A1c (HbA1c) levels.

RESULTS

The prevalence of colorectal adenomas in patients who were H. pylori-positive and H. pylori-negative was 37.3% and 27.29%, respectively. Multivariate logistic regression analysis identified male sex, age, body mass index, H. pylori infection, and HbA1c ≥6.5% as independent risk factors for adenoma; use of hypoglycemic agents decreased this risk. The prevalence of adenoma was increased with elevated HbA1c levels regardless of H. pylori status. The odds ratio (OR) for adenoma was 1.44 (95% confidence interval [CI], 1.20 to 1.73) if H. pylori was present or 1.68 (95% CI, 1.05 to 2.70) in patients who were H. pylori-negative but had HbA1c ≥7.0%. If both conditions were present, the OR was 4.79 (95% CI, 2.92 to 7.84). A 1% increase in HbA1c was associated with an increased prevalence of adenoma by 42.4% in H. pylori-positive subjects.

CONCLUSIONS

The combination of H. pylori infection and elevated HbA1c is associated with an increased risk of colon adenoma.

Host pathogen interactions in Helicobacter pylori related gastric cancer

Helicobacter pylori (H. pylori), discovered in 1982, is a microaerophilic, spiral-shaped gram-negative bacterium that is able to colonize the human stomach. Nearly half of the world's population is infected by this pathogen. Its ability to induce gastritis, peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma has been confirmed. The susceptibility of an individual to these clinical outcomes is multifactorial and depends on H. pylori virulence, environmental factors, the genetic susceptibility of the host and the reactivity of the host immune system. Despite the host immune response, H. pylori infection can be difficult to eradicate. H. pylori is categorized as a group I carcinogen since this bacterium is responsible for the highest rate of cancer-related deaths worldwide. Early detection of cancer can be lifesaving. The 5-year survival rate for gastric cancer patients diagnosed in the early stages is nearly 90%. Gastric cancer is asymptomatic in the early stages but always progresses over time and begins to cause symptoms when untreated. In 97% of stomach cancer cases, cancer cells metastasize to other organs. H. pylori infection is responsible for nearly 60% of the intestinal-type gastric cancer cases but also influences the development of diffuse gastric cancer. The host genetic susceptibility depends on polymorphisms of genes involved in H. pylori-related inflammation and the cytokine response of gastric epithelial and immune cells. H. pylori strains differ in their ability to induce a deleterious inflammatory response. H. pylori-driven cytokines accelerate the inflammatory response and promote malignancy. Chronic H. pylori infection induces genetic instability in gastric epithelial cells and affects the DNA damage repair systems. Therefore, H. pylori infection should always be considered a pro-cancerous factor.

Bacterial Biofilms in Colorectal Cancer Initiation and Progression

Intestinal microbiota have emerged as an important factor in colorectal cancer (CRC) initiation and progression. The currently prominent view on bacterial tumorigenesis is that CRC initiation is triggered by local mucosal colonization with specific pathogens (drivers), and that subsequent changes in the peritumoral environment allow colonization by opportunistic (passenger) microbes, further facilitating disease progression. Screening for CRC 'driver-passenger' microorganisms might thus allow early CRC diagnosis or preventive intervention. Such efforts are now being revolutionized by the notion that CRC initiation and progression require organization of bacterial communities into higher-order structures termed biofilms. We explore here the concept that a polymicrobial biofilm promotes pro-carcinogenic activities that may partially underlie progression along the adenoma-CRC axis.

Helicobacter pylori and colorectal neoplasia: Is there a causal link?

Ever since Helicobacter pylori (H. pylori) was recognized as an infectious cause of gastric cancer, there has been increasing interest in examining its potential role in colorectal carcinogenesis. Data from case-control and cross-sectional studies, mostly relying on hospital-based samples, and several meta-analyses have shown a positive statistical relationship between H. pylori infection and colorectal neoplasia. However, the possibility exists that the results have been influenced by bias, including the improper selection of patients and disparities with respect to potential confounders. While the evidence falls short of a definitive causal link, it appears that infection with H. pylori/H. pylori-related gastritis is associated with an increased, although modest, risk of colorectal adenoma and cancer. The pathogenic mechanisms responsible for this association remain uncertain. H. pylori has been detected in colorectal malignant tissues; however, the possibility that H. pylori is a direct activator of colonic carcinogenesis remains purely hypothetical. On the other hand, experimental data have indicated a series of potential oncogenic interactions between these bacteria and colorectal mucosa, including induction and perpetuation of inflammatory responses, alteration of gut microflora and release of toxins and/or hormonal mediators, such as gastrin, which may contribute to tumor formation.

Association between Helicobacter pylori and extra-gastric diseases

Helicobacter pylori (H. pylori) is confirmed to be associated with many diseases such as gastric cancer, peptic ulcer, gastritis and mucosa-associated lymphoid tissue lymphoma. Recent studies found that H. pylori is associated with many extra-gastric diseases. The underlying mechanism involves autoimmunity, inflammation and oxidative stress. Here we review the association between H. pylori and extra-gastric diseases.

Helicobacter pylori infection: New pathogenetic and clinical aspects

Helicobacter pylori (H. pylori) infects more than half of the world’s human population, but only 1% to 3% of infected people consequently develop gastric adenocarcinomas. The clinical outcome of the infection is determined by host genetic predisposition, bacterial virulence factors, and environmental factors. The association between H. pylori infection and chronic active gastritis, peptic ulcer disease, gastric cell carcinoma, and B cell mucosa-associated lymphoid tissue lymphoma has been well established. With the exception of unexplained iron deficiency anemia and idiopathic thrombocytopenic purpura, H. pylori infection has no proven role in extraintestinal diseases. On the other hand, there is data showing that H. pylori infection could be beneficial for some human diseases. The unpredictability of the long-term consequences of H. pylori infection and the economic challenge in eradicating it is why identification of high-risk individuals is crucial.

Gastric Helicobacter pylori infection associates with an increased risk of colorectal polyps in African Americans

Background

Gastric Helicobacter pylori (H. pylori) infection and colorectal polyps are more prevalent in African Americans than in the general population. We aimed to investigate whether gastric H. pylori infection is associated with colorectal polyps in African Americans.

Methods

Medical records of African Americans, 40 years and older (n = 1256) who underwent bidirectional gastrointestinal endoscopy on the same day were reviewed. H. pylori status was assessed by immunohistochemistry on gastric specimens. Colorectal polyps were confirmed by histological examination of colorectal biopsies. A subset of serum samples from healthy and polyp-bearing patients (n = 163) were analyzed by ELISA for anti-H. pylori and anti-CagA antibodies. The crude and adjusted effect of H. pylori on the risk of colorectal adenoma and polyp were computed by logistic regression models.

Results

The prevalence of colorectal polyps and adenomas were 456 (36%) and 300 (24%) respectively. Colorectal polyps were more prevalent in gastric H. pylori infected than non-infected subjects [43% vs. 34%; Odds Ratio (OR) (95% CI): 1.5 (1.2-1.9), P = 0.001]. Patients with H. pylori-associated chronic active gastritis were at high risk to have adenomas [Unadjusted OR (95% CI): 1.3 (1.0-1.8); P = 0.04]. There was no difference in histopathology, size, or location of polyps with respect to H. pylori status. Gastric H. pylori infection, age, male gender and high risk clinical presentations were independent risk factors for colorectal polyps. Serological testing also revealed a higher prevalence of H. pylori and its toxin Cag-A in polyp patients vs. non polyp patients’ sera, although in a non-statistically significant manner.

Conclusions

This study showed that current gastric H. pylori infection is associated with an increased risk of colorectal polyps in African Americans. Patients with H. pylori induced gastritis may benefit from early screening colonoscopy as a preventative measure for colorectal cancer.

Helicobacter pylori infection and normal colorectal mucosa-adenomatous polyp-adenocarcinoma sequence: a meta-analysis of 27 case-control studies

AIM

The study aimed to determine whether Helicobacter pylori infection is associated with colorectal adenocarcinoma and to quantify the extent of the risk.

METHOD

A literature search was performed to identify studies published between 1995 and 2012 for relevant risk estimates. Fixed and random effect meta-analytical techniques were conducted for colorectal adenocarcinoma and adenomatous polyp.

RESULTS

Twenty-seven case-controlled studies involving 3450 adenocarcinoma patients, 1304 adenomatous polyp patients and more than 4000 controls were included. Helicobacter pylori was associated with an increased risk of colorectal adenocarcinoma and adenomatous polyp [odds ratio (OR) 1.24, 95% CI 1.12-1.37, P = 0.66; OR 1.87, 95% CI 1.53-2.28, P = 0.81]. There was a significant association between the CagA-positive strain and adenocarcinoma risk (OR 1.22, 95% CI 1.08-1.37, P = 0.05). In addition, there was an increased risk of tubular adenoma and villous adenoma formation (OR 3.06, 95% CI 1.98-4.73, P = 0.14; OR 2.05, 95% CI 0.84-4.97, P = 0.86).

CONCLUSION

The meta-analysis suggests a promoting effect of Helicobacter pylori on the risk of adenocarcinoma. It also suggests that Helicobacter infection might have its influence at the start of the adenomatous polyp disease sequence.

Clinical effects of Helicobacter pylori outside the stomach

The discovery of Helicobacter pylori infection in the stomach could be considered as one of the most important events of modern gastroenterology. Understanding of the natural history of many disorders of the upper gastrointestinal tract, including chronic gastritis, peptic ulcer disease, gastric cancer and MALT lymphoma, was altered by this discovery. Interestingly, epidemiological studies have also revealed a correlation between H. pylori infection and some diseases localized outside the stomach, especially those characterized by persistent and low-grade systemic inflammation. Of note, H. pylori has an important role in iron deficiency anaemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency. Moreover, the association of this bacterial pathogen with many other diseases, including hepatobiliary, pancreatic, cardiovascular and neurodegenerative disorders is currently under investigation. In this Review, we summarize the results of the most important studies performed to date surrounding the association of H. pylori infection with extragastric diseases, as well as the strength of the evidence. We also provide information concerning bacterial-host interactions and the mechanisms implicated in the pathogenesis of each of these extragastric diseases.

Helicobacter pylori-related chronic gastritis as a risk factor for colonic neoplasms

To summarize the current views and insights on associations between Helicobacter pylori (H. pylori)-related chronic gastritis and colorectal neoplasm, we reviewed recent studies to clarify whether H. pylori infection/H. pylori-related chronic gastritis is associated with an elevated risk of colorectal neoplasm. Recent studies based on large databases with careful control for confounding variables have clearly demonstrated an increased risk of colorectal neoplasm associated with H. pylori infection. The correlation between H. pylori-related chronic atrophic gastritis (CAG) and colorectal neoplasm has only been examined in a limited number of studies. A recent large study using a national histopathological database, and our study based on the stage of H. pylori-related chronic gastritis as determined by serum levels of H. pylori antibody titer and pepsinogen, indicated that H. pylori-related CAG confers an increased risk of colorectal neoplasm, and more extensive atrophic gastritis will probably be associated with even higher risk of neoplasm. In addition, our study suggested that the activity of H. pylori-related chronic gastritis is correlated with colorectal neoplasm risk. H. pylori-related chronic gastritis could be involved in an increased risk of colorectal neoplasm that appears to be enhanced by the progression of gastric atrophy and the presence of active inflammation.

Helicobacter pylori and gastrointestinal symptoms in diagnostics and adjuvant chemotherapy of colorectal cancer

5-Fluorouracil (5-FU)-based chemotherapy is the mainstay of adjuvant treatment for colorectal cancer (CRC). Few studies have explored Helicobacter pylori (H. pylori)-associated gastrointestinal symptoms in the diagnosis of CRC, and the association between H. pylori infection and gastrointestinal toxicity during adjuvant chemotherapy in CRC. Seventy-nine CRC patients were randomised in a prospective clinical trial to receive 5-FU and leucovorin administered as bolus injection (Mayo regimen) or continuous infusion (simplified de Gramont regimen). H. pylori antibodies were analysed at baseline, twice monthly during treatment and after treatment up to 12 months. Thirty-seven patients (47%) were H. pylori-seronegative at baseline. There was no significant association between baseline H. pylori seropositivity (n=42; 53%) and oro-gastrointestinal toxicity during chemotherapy. The median time from symptom onset of CRC to surgery was significantly longer in patients with H. pylori infection (median time, 6 vs. 5 months; P=0.012). Functional dyspeptic symptoms at presentation significantly delayed diagnosis (median time, 7.5 vs. 5 months; P=0.035), whereas anaemia, bowel symptoms, occlusion, blood in the stool, infection and hypolactasia did not. We conclude that there is no association between H. pylori status and gastrointestinal toxicity in CRC patients during chemotherapy. Dyspeptic symptoms and presence of H. pylori may delay the diagnosis of CRC. (www.controlled-trials.com/ISRCTN98405441).

Helicobacter pylori seropositivity is positively associated with colorectal neoplasms

BACKGROUND/AIMS

Helicobacter pylori is a well known precursor to gastric cancer and gastric mucosa-associated lymphoid tissue lymphoma. This study was to determine whether H. pylori was associated with colorectal neoplasms in Korean subjects undergoing routine checkup.

METHODS

A total of 10,082 subjects underwent routine checkups from January 2004 to April 2005. A H. pylori IgG test and stool occult blood test were included in the routine checkup program. Colonoscopy was performed if the stool occult blood test was positive or under subject request. Patients who underwent colonoscopy and had histologically confirmed cases of colorectal neoplasms were designanted as the subject group and those without as the control group.

RESULTS

Of the 10,082 subjects, 597 had full colonoscopy. The results identified 9 colorectal carcinomas and 118 adenomas. H. pylori seropositivity was identified in 6 (66%) subjects with colorectal carcinoma, 81 (68.6%) with colorectal adenoma and 248 (52.8%) controls. Subjects having colorectal neoplasms had a significantly higher H. pylori seropositivity rate compared with the controls (OR 1.94, 95% CI 1.28-2.95). This remained significant after adjusting for age, sex, body mass index, HbA1c and total cholesterol (OR 1.90, 95% CI 1.23-2.93). Patients with distal neoplasms also had a significantly higher H. pylori seroposivity rate (OR 1.88, 95% CI 1.17-3.01) which persisted after multivariate adjustment (OR 1.79, 95% CI 1.10-2.94).

CONCLUSIONS

Subjects with colorectal neoplasms present an increased H. pylori seroprevalence compared with controls.

Association between Helicobacter pylori infection and the risk of colorectal neoplasia: a systematic review and meta-analysis

AIM

The existing evidence on the relationship between Helicobacter pylori infection and the risk of colorectal neoplasia is inconsistent. We conducted a systematic review with a meta-analysis to explore this relationship and to determine whether the relationship varies according to the study characteristics.

METHOD

We searched the PubMed database and the reference lists of pertinent articles published up to July 2012. Summary odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated using a random-effects model.

RESULTS

Twenty-seven studies including 3792 cases of colorectal adenoma (CRA) and 3488 cases of colorectal cancer (CRC) were identified. Overall, H. pylori infection was associated with an increased risk of CRA (OR = 1.66, 95% CI 1.39-1.97, I(2)  = 54.3%) and CRC (OR = 1.39, 95% CI 1.18-1.64, I(2)  = 35.8%), although there was significant heterogeneity among the studies. Subgroup analysis revealed that the positive correlation did not differ by sex, geographic variation or subsite of neoplasia, but might vary by the method of detection of H. pylori. The study was underpowered to determine the risk of colorectal neoplasia associated with cytotoxin-associated gene A-positive H. pylori.

CONCLUSION

This meta-analysis demonstrates a positive association between H. pylori infection and the risk of colorectal neoplasia.

Helicobacter pylori is a risk factor for colonic neoplasms

OBJECTIVES

It has been suggested that Helicobacter pylori (H. pylori) constitutes a risk for the development of adenomatous polyps and adenocarcinoma of the colon. Our aim was to study the association between H. pylori-positive gastritis and the occurrence of any colonic neoplasm.

METHODS

From a computerized database of surgical pathology reports, we selected 156,000 subjects who underwent colonoscopy and esophago-gastro-duodenoscopy with biopsy results from both procedures.

RESULTS

Compared with normal gastric mucosa, H. pylori gastritis occurred more frequently among patients with hyperplastic polyps (OR=1.24, 95% CI: 1.18-1.30), adenomatous polyps (1.52, 1.46-1.57), advanced adenomas (1.80, 1.69-1.92), villous adenomas or adenomas with high-grade dysplasia (1.97, 1.82-2.14), and adenocarcinomas (2.35, 1.98-2.80). Similarly, the strength of the association between H. pylori-positive gastritis and colonic neoplasm increased with size and number of the adenomas. The association between H. pylori gastritis and the occurrence of colonic neoplasm was similar for different locations of the large bowel. Other gastric conditions etiologically associated with H. pylori, such as intestinal metaplasia, adenoma, lymphoma, and adenocarcinoma, were also significantly associated with an increased risk of colonic neoplasm.

CONCLUSIONS

Various forms of gastritis related to H. pylori infection confer an increased risk for colonic neoplasm. In the past, when H. pylori infection was more prevalent, its attributable risk to the occurrence of colorectal neoplasm may have been quite substantial.

Elevated risk of recurrent colorectal neoplasia with Helicobacter pylori-associated chronic atrophic gastritis: A follow-up study of patients with endoscopically resected colorectal neoplasia

In a previous population-based case-control study, we demonstrated an elevated risk of colorectal neoplasia with Helicobacter pylori (H. pylori) infection. The present study investigated the effects of H. pylori-associated chronic gastritis on the development of colorectal neoplasia by analyzing the recurrence of colorectal neoplasia subsequent to endoscopic resection. Ninety-nine patients who had undergone endoscopic resection of colorectal neoplasia were monitored under colonoscopy, and the recurrence of colorectal neoplasia was prospectively investigated. The stage of H. pylori-associated chronic gastritis in each subject was evaluated using a combination of two serum tests: H. pylori antibody and pepsinogen. In the present cohort, colorectal neoplasia recurred at a rate of 15,296/100,000 person-years during the study period. After adjusting for the confounding factors, chronic atrophic gastritis (CAG) was identified as an independent risk factor [adjusted hazard ratio (HR), 2.72; 95% confidence interval, 1.33-5.57], while H. pylori-infected non-atrophic gastritis was not identified as an independent risk factor for recurrent colorectal neoplasia. Colorectal neoplasia recurred earlier and was significantly more frequent in patients with CAG (22,573/100,000 person-years) compared to patients without CAG (11,089/100,000 person-years; P=0.029, log-rank test). Patients with more extensive CAG showed a higher risk of recurrence. These results demonstrated a significant elevation of the risk of recurrent colorectal neoplasia with the establishment and progression of CAG, indicating the involvement of H. pylori infection in the development of colorectal neoplasia. The two serum tests were useful clinical markers for noninvasively evaluating the risk of each individual for recurrent colorectal neoplasia subsequent to endoscopic resection.

No higher risk for colorectal cancer in atrophic gastritis-related hypergastrinemia

BACKGROUND

Atrophic gastritis of the corporal mucosa is a frequent cause of hypergastrinemia. Hypergastrinemia is implicated in colorectal cancer development.

AIM

To assess whether hypergastrinemic atrophic gastritis is associated with a higher risk of neoplastic colorectal lesions.

METHODS

Among 441 hypergastrinemic atrophic gastritis patients, 160 who were aged >40 and underwent colonoscopy for anaemia, diarrhoea or colorectal cancer-screening were retrospectively selected. Each patient was age- and gender-matched with a normogastrinemic control with healthy stomach. Controls had colonoscopy, gastroscopy with biopsies and gastrin assessment.

RESULTS

160 hypergastrinemic atrophic gastritis patients and 160 controls were included. 28 atrophic gastritis patients and 36 controls had neoplastic colorectal lesions (p=0.33). Patients and controls did not differ for frequency of colorectal adenomas (10.6% vs. 13.1%, p=0.60) or cancer (6.9% vs. 9.4%, p=0.54). Hypergastrinemic atrophic gastritis was not associated with a higher probability of developing colorectal cancer (OR 1.03, 95% CI 0.34-3.16). Age >50 years (OR 3.86) but not hypergastrinemia (OR 0.61) was associated with colorectal cancer.

CONCLUSIONS

Hypergastrinemic atrophic gastritis is not associated with higher risk for colorectal cancer. Atrophic gastritis-related hypergastrinemia is not associated with an increased risk of neoplastic colorectal lesions. Closer surveillance of colonic neoplasia in atrophic gastritis patients seems not appropriate.

Association of helicobacter pylori infection and colon cancer

BACKGROUND

Gastrin has been shown to exert carcinogenic effect to the epithelium of the colon. This study examines whether hypergastrinemia and H. pylori infection -especially infection by the CagA+ strain- are statistically associated with colorectal cancer and examine possible correlations with the colorectal cancer stage and lymph node metastasis.

METHODS

In this prospective case-control study, fasting serum samples from 93 consecutive patients with colorectal cancer treated in a university surgical clinic were preoperatively collected and serum levels of gastrin were measured. A group of 20 age matched hernia patients were used as controls. The pathology report of the specimens was documented and statistical analysis of the data where performed with the spss 17 statistical suite.

RESULTS

H. pylori IgG antibodies was reported in 66/93 (71%) in the colorectal cancer group and 13/20 patients in the control group (65%), the difference having non-statistical significance (P = n.s). The prevalence of cagA protein expression in the anti- H. pylori IgG+ patients were higher in the colorectal cancer group (56% positivity), when compared to the control group (38,4% positivity) but the difference was not of statistical significance (P = n.s). The mean levels of serum gastrin levels in the two groups did not significantly differ (Ca group 51.1 ± 36.6 pg/mL vs Control 49.8 ± 17.6 P = n.s.). Patients with lymph node metastasis had higher serum gastrin levels than patients without metastasis and this difference was statistically significant. (53.6 vs 41.06 pg/mL P = 0.025).

CONCLUSIONS

Although the serum gastrin levels were not statistically different between the TNM stages of our patient cohort, our data found that serum gastrin levels were significantly higher in patients with lymph node metastasis. Whether gastrin is implicated in the ability of cancer cells to metastasize to the lymph nodes merits further research.

Helicobacter pylori infection and colorectal cancer risk: evidence from a large population-based case-control study in Germany

Evidence concerning the role of Helicobacter pylori infection in the development of colorectal cancer remains controversial. The authors assessed the association of H. pylori seroprevalence with risk of colorectal cancer in a large population-based case-control study from Germany in 2003-2007. Serum antibodies to H. pylori in general and the cytotoxin-associated gene A protein (CagA) were measured in 1,712 incident colorectal cancer cases and 1,669 controls. The association between H. pylori seroprevalence and colorectal cancer risk was estimated by logistic regression, with adjustment for potential confounders and stratification by age group, sex, anatomic subsites, and cancer stage. Overall, H. pylori seroprevalence was higher in cases (46.1%) than in controls (40.1%), resulting in an age- and sex-adjusted odds ratio of 1.30 (95% confidence interval (CI): 1.14, 1.50). Adjustment for established colorectal cancer risk factors decreased the odds ratio to 1.26 (95% CI: 1.09, 1.47), with a further reduction to 1.18 (95% CI: 1.01, 1.38) after additional adjustment for previous colorectal endoscopy. Stratified analyses showed risk elevation to be essentially confined to left-sided colorectal cancer, with an odds ratio of 1.22 (95% CI: 1.02, 1.45), suggesting that H. pylori infection may be associated with a small yet relevant risk increase in the left colorectum.

Elevated risk of colorectal adenoma with Helicobacter pylori-related chronic gastritis: a population-based case-control study

This study investigated correlations between Helicobacter pylori infection or chronic atrophic gastritis (CAG) and risk of colorectal adenoma in a population-based case-control study. Subjects comprised asymptomatic, middle-aged, male Japanese factory workers who participated in an annual health check-up program, including cancer screening with colonoscopy. We selected 239 colorectal adenoma cases based on histological evaluation and 239 age-matched adenoma-free controls, and evaluated colorectal adenoma risk according to stage of H. pylori-related chronic gastritis as determined by serum tests for H. pylori antibody titer and pepsinogen. Subjects with colorectal adenoma were more likely to be smokers and have hypercholesterolemia. H. pylori infection was a risk factor for adenoma as a whole (crude odds ratio [OR]: 2.26, 95% confidence interval [CI]: 1.44-3.55). Analysis of distal adenoma cases showed that adenoma risk was significantly increased in the presence of H. pylori infection, but there was no further increase in risk with CAG. In contrast, proximal adenoma risk increased stepwise with the presence and progression of H. pylori-related chronic gastritis and showed a maximal and significant increase with CAG (crude OR: 4.51, 95% CI: 1.43-14.2). Subjects with more extensive and severe gastritis showed still higher risk not only for proximal but also for distal adenoma. H. pylori-related chronic gastritis is likely to be involved in the development of colorectal neoplasms, and its progression appears to increase the risk, particularly for proximal adenomas. Knowing the H. pylori-related chronic gastritis stage will probably be useful for evaluation of risk for colorectal neoplasia.

Infectious causes of colorectal cancer

Colorectal cancer is a major cause of cancer-related morbidity and mortality in the United States and many other regions of the world. Our understanding of the pathogenesis of colorectal cancer, from the precursor adenomatous polyp to adenocarcinoma, has evolved rapidly. Colorectal carcinogenesis is a sequential process characterized by the accumulation of multiple genetic and molecular alterations in colonic epithelial cells. However, the development of colorectal cancer involves more then just a genetic predisposition. External or environmental factors presumably play a significant role, and inflammatory bowel diseases, obesity, alcohol consumption, and a diet high in fat and low in fiber have all been implicated as risk factors for the development of either colonic adenomas or carcinomas. We are becoming increasingly aware of microbes as causes of malignancies. This article reviews the various microbes that have been associated with the development of colorectal carcinomas.

Atrophic gastritis and the risk of incident colorectal cancer

Previous studies evaluating whether risk factors for gastric cancer are also associated with colorectal cancer (CRC) have shown inconsistent results. We prospectively examined the association of atrophic gastritis, a pre-malignant condition for gastric cancer and long-term sequelae common to many exposure factors, and the risk of incident CRC.

METHODS

A total of 20,928 Finnish male smokers, aged 50-69, who were participants in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC) had serum pepsinogen I (SPGI) levels measured. Participants with low SPGI levels (< 25 microg/l; n = 1,665) were invited for gastroscopy. Of these, 1,059 (63.6%) participants underwent gastroscopy and atrophic gastritis was histologically confirmed in 1,006 (95.0%) participants. We used Cox proportional hazards regression to evaluate the risk of incident CRC.

RESULTS

During a mean follow-up of 11.3 years (236,258 person-years), 425 incident CRCs were diagnosed. The incidence rates were 1.82, 1.48, and 1.82 per 1,000 person-years of follow-up for participants with normal SPGI (> or =25 microg/l), low SPGI, and histologically confirmed atrophic gastritis, respectively. Compared to subjects with normal SPGI, there was no increased risk of CRC among subjects with low SPGI (Adjusted Hazard Ratio (HR) = 0.71; 95% CI: 0.47-1.05) and among those with histologically confirmed atrophic gastritis (Adjusted HR = 0.86; 95% CI: 0.55-1.34).

CONCLUSION

Atrophic gastritis is not associated with an increased risk of colorectal cancer among male smokers.

Infectious agents and colorectal cancer: a review of Helicobacter pylori, Streptococcus bovis, JC virus, and human papillomavirus

Based on the high volume of bacteria and viruses that the intestine is exposed to and the importance of infectious agents in some gastrointestinal and anogenital cancers, it is not surprising the many studies have evaluated the association between colorectal cancer and infectious agents. This review highlights investigations of four agents in relation to colorectal cancer. Helicobacter pylori, Streptococcus bovis, JC virus, and human papillomavirus have all been evaluated as possible etiologic agents for colorectal cancer. For each of these agents, a review of possible mechanisms for carcinogenesis and epidemiologic evidence is discussed, and future directions for research are proposed.