Impact of Helicobacter pylori Infection and Treatment on Colorectal Cancer in a Large, Nationwide Cohort

Helicobacter pylori eradication for primary prevention of gastric cancer: progresses and challenges

Gastric cancer remains a significant global health challenge, causing a substantial number of cancer-related deaths, particularly in China. While the exact causes of gastric cancer are still being investigated, Helicobacter pylori (H. pylori) infection has been identified as the primary risk factor, which triggers chronic inflammation and a multistage progression of gastric lesions that may lead to carcinogenesis over a long latency time. Since the 1990s, numerous efforts have focused on assessing the effectiveness of H. pylori eradication in preventing new cases of gastric cancer among both the general population and patients who have undergone early-stage cancer treatment. This body of work, including several community-based interventions and meta-analyses, has shown a reduction in both the incidence of and mortality from gastric cancer following H. pylori treatment, alongside a decreased risk of metachronous gastric cancer. In this review, we seek to consolidate current knowledge on the effects of H. pylori treatment on gastric cancer prevention, its systemic consequences, cost-effectiveness, and the influence of antibiotic resistance and host characteristics on treatment outcomes. We further discuss the potential for precision primary prevention of H. pylori treatment and comment on the efficient implementation of test-and-treat policies and allocation of health resources towards minimizing the burden of gastric cancer globally.

WNT and TGF-Beta Pathway Alterations in Early-Onset Colorectal Cancer Among Hispanic/Latino Populations

BACKGROUND/OBJECTIVES

One of the fastest-growing minority groups in the U.S. is the Hispanic/Latino population. Recent studies have shown how this population is being disproportionately affected by early-onset colorectal cancer (CRC). Compared to corresponding non-Hispanic White (NHW) patients, Hispanic/Latino patients have both higher incidence of disease and rates of mortality. Two well-established drivers of early-onset CRC in the general population are alterations in the WNT and TGF-Beta signaling pathways; however, the specific roles of these pathways in Hispanics/Latinos are poorly understood.

METHODS

Here, we assessed CRC mutations in the WNT and TGF-Beta pathways by conducting a bioinformatics analysis using cBioPortal. Cases of CRC were stratified both by age and ethnicity: (1) early-onset was defined as <50 years vs. late-onset as ≥50 years; (2) we compared early-onset in Hispanics/Latinos to early-onset in NHWs.

RESULTS

No significant differences were evident when we compared early-onset and late-onset CRC cases within the Hispanic/Latino cohort. These results are consistent with findings from large cohorts that do not specify ethnicity. However, we found significant differences when we compared early-onset CRC in Hispanic/Latino patients to early-onset CRC in NHW patients: specifically, alterations in the gene bone morphogenetic protein-7 (BMP7) were more frequent in early-onset CRC for the Hispanic/Latino patients. In addition to these findings, we observed that both NHW patients and Hispanic/Latino patients with early-onset disease had better clinical outcomes when there was evidence of WNT pathway alterations. Conversely, the absence of TGF-Beta pathway alterations was uniquely associated with improved outcomes exclusively in early-onset Hispanic/Latino patients.

CONCLUSIONS

In toto, these findings underscore how the WNT and TGF-Beta pathways may act differently in different ethnic groups with early-onset CRC. These findings may set a stage for developing new therapies tailored for reducing cancer health disparities.

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.

Helicobacter pylori Eradication Therapy and the Risk of Colorectal Cancer: A Population-Based Nationwide Cohort Study in Sweden

BACKGROUND

Helicobacter pylori (H. pylori) is an established gastric carcinogen, also associated with an increased risk of colorectal cancer. Therefore, we suspected that H. pylori eradication lowers the risk of colorectal cancer.

MATERIAL AND METHODS

We assessed if H. pylori eradication therapy is associated with a reduced risk of colorectal adenocarcinoma in a population-based nationwide cohort study. This study included all Swedish adults with at least one recorded H. pylori eradication episode between July 2005 and December 2012, based on the high-quality Swedish health registries. Colorectal adenocarcinoma risks were compared to the Swedish background population, presented as standardized incidence ratios (SIRs) and 95% confidence intervals (CIs), accounting for age, sex, calendar period, tumor location (left or right sided), stage, and number of eradication episodes, from 1 year after eradication and onward.

RESULTS

Among 80,381 individuals receiving H. pylori eradication therapy (average follow-up 4.1 years), 282 were diagnosed with colorectal cancer (97.2% adenocarcinoma). Overall, H. pylori eradication was associated with an elevated risk of colorectal adenocarcinoma (SIR 1.27, 95% CI: 1.12-1.43). The colorectal adenocarcinoma risk was increased 1-2 years after eradication (SIR 1.42, 95% CI: 1.17-1.72), then decreased 2-4 years (SIR 0.80, 95% CI: 0.65-0.98) and 4-6 years (SIR 0.76, 95% CI: 0.57-0.99), yet not ≥ 6 years (SIR 1.36, 95% CI: 0.78-2.21) after eradication compared to the general population. Overall, right-sided (SIR 1.47, 95% CI: 1.21-1.76) and left-sided (SIR 1.35, 95% CI: 1.09-1.67) colon adenocarcinomas risks were higher among eradicated individuals than the general population.

CONCLUSION

H. pylori eradication was not associated with a clear and consistent reduction of colorectal cancer in our Swedish cohort.

Development of a High-Resolution Melting Method for the Detection of Clarithromycin-Resistant Helicobacter pylori in the Gastric Microbiome

Background: The issue of Helicobacter pylori (H. pylori) resistance to clarithromycin (CLR) has consistently posed challenges for clinical treatment. Hence, a rapid susceptibility testing (AST) method urgently needs to be developed. Methods: In the present study, 35 isolates of H. pylori were isolated from 203 gastritis patients of the Guangzhou cohort, and the antimicrobial resistance phenotypes were associated with their genomes to analyze the relevant mutations. Based on these mutations, a rapid detection system utilizing high-resolution melting (HRM) curve analysis was designed and verified by the Shenzhen cohort, which consisted of 38 H. pylori strains. Results: Genomic analysis identified the mutation of the 2143 allele from A to G (A2143G) of 23S rRNA as the most relevant mutation with CLR resistance (p < 0.01). In the HRM system, the wild-type H. pylori showed a melting temperature (Tm) of 79.28 ± 0.01 °C, while the mutant type exhibited a Tm of 79.96 ± 0.01 °C. These differences enabled a rapid distinction between two types of H. pylori (p < 0.01). Verification examinations showed that this system could detect target DNA as low as 0.005 ng/μL in samples without being affected by other gastric microorganisms. The method also showed a good performance in the Shenzhen validation cohort, with 81.58% accuracy, and 100% specificity. Conclusions: We have developed an HRM system that can accurately and quickly detect CLR resistance in H. pylori. This method can be directly used for the detection of gastric microbiota samples and provides a new benchmark for the simple detection of H. pylori resistance.

Association of Antibody Responses to Helicobacter pylori Proteins with Colorectal Adenoma and Colorectal Cancer

Helicobacter pylori (H. pylori) has been implicated in colorectal carcinogenesis. Here, the association of immune responses to bacterial exposure with advancing stages of colorectal neoplasia was assessed by multiplex serology. Immunoglobulin (Ig) A and G antibody responses to thirteen proteins of H. pylori were measured by a Luminex-based multiplex assay in plasma from patients with colorectal cancer (CRC, n = 25), advanced adenoma (n = 82), or small polyps (n = 85) and controls (n = 100). Multivariable logistic regression was used to assess the association of bacterial seropositivity with colorectal neoplasia. The threshold for overall seropositivity required subjects to be positive for at least 4 out of the 13 tested antigens. In a cohort subset with matched data (n = 34), H. pylori seropositivity was correlated with bacterial abundance in both neoplastic and matched normal tissue. While no association was found between H. pylori seropositivity and the presence of CRC, IgA seropositivity to CagA was associated with a decreased risk of advanced adenoma (odds ratio, OR = 0.48, 95% confidence intervals, CIs: 0.24-0.96). Regarding IgG, higher antibody responses to HpaA was associated with advanced adenoma occurrence (OR = 2.46, 95% CI: 1.00-6.01), while responses to HP0395, CagA and Catalase were associated with polyp development (OR = 2.65, 95%, CI: 1.31-5.36, OR = 1.83, 95% CI: 1.01-3.32, and OR = 2.16, CI: 1.09-4.29, respectively). Positive correlations were found between H. pylori abundance in the normal mucosa and levels of both the IgA and IgG antibody response to Catalase and VacA antigens (r = 0.48, p < 0.01; r = 0.37, p = 0.04; r = 0.51, p < 0.01; and r = 0.71, p = 0.04, respectively). Conversely, H. pylori abundance was negatively correlated with levels of IgA antibody response to HpaA and with IgG antibody response to HP0231 in the diseased tissue (r = -0.34, p = 0.04 and r = -0.41, p = 0.01, respectively). The association between levels of H. pylori antigens and colorectal neoplasia risk gradually decreased with the adenoma progression, implicating the early activation of the immune response at the polyp stage. Thus, the evaluation of antibody response to certain bacterial antigens may indicate the presence of early-stage colorectal neoplasia. Further studies are needed to clarify the role H. pylori or the immune response to its antigens may have in colorectal carcinogenesis stages.

Exploring the Role of the Gut Microbiota in Colorectal Cancer Development

Colorectal cancer is currently a public health concern due to its high incidence, morbidity, and mortality rates. Researchers have identified the intestinal microbiome as a crucial factor in the development of this disease. Currently, specialized literature data support the role of the microbiota in both the development of colorectal cancer and resistance to oncological therapies. Therefore, studying the composition of the gut microbiome can aid in creating risk assessment tools to identify specific populations that would benefit from tailored screening approaches. Also, manipulation of the intestinal microbiome can be useful in improving the response to chemotherapy or immunotherapy. Identifying the pathogenic mechanisms responsible for this causal link can aid in the discovery of novel treatment targets. This article will provide the latest information regarding the influence of the intestinal microbiota on the development and progression of colorectal cancer.