Helicobacter pylori Treatment and Gastric Cancer Risk After Endoscopic Resection of Dysplasia: A Nationwide Cohort Study

Current Understanding of Optimal Prevention of Helicobacter pylori-Induced Cancer

Gastric cancer is the fifth most common cancer and the fifth most common cause of cancer-related death globally. The key to improving outcomes lies in effective prevention and early detection, which are critical for successful curative interventions. Helicobacter pylori is the strongest known risk factor for gastric cancer, and eradication of this pathogen is critical for reducing cancer risk. By synthesizing current evidence and exploring the advanced therapeutic approaches, this review provides a comprehensive overview of best practices for mitigating gastric cancer through targeted bacterial intervention.

Gastric Cancer Screening in the United States: A Review of Current Evidence, Challenges, and Future Perspectives

Gastric cancer remains a leading cause of cancer-related mortality worldwide. In the United States, gastric cancer incidence and mortality are substantially higher among non-White racial and ethnic groups and new immigrants from high-incidence countries. This is in large part related to the higher prevalence of Helicobacter pylori -associated gastric premalignant changes in these populations. Apart from primary prevention, early detection of gastric cancer is the principal strategy to reduce gastric cancer mortality and improve survival. Extensive evidence in Asian countries has demonstrated the benefits of endoscopic screening in detecting early-stage gastric cancer and reducing gastric cancer-related mortality. By contrast, direct, high-quality US-based data, such as from large clinical trials or observational studies, on important outcomes of gastric cancer screening are still lacking. In this review, we evaluate and summarize the latest global evidence on the epidemiology and predisposing factors of gastric cancer as well as the efficacy, benefits vs. risks, and cost-effectiveness of gastric cancer screening. We further discuss the critical knowledge gaps and challenges in promoting gastric cancer screening in the United States. Dedicated research is urgently needed to enrich the US-based data on gastric cancer primary and secondary prevention to inform clinical practice and reduce gastric cancer-related morbidity and mortality in a cost and resource efficient manner.

Integrative analysis of single-cell and bulk RNA sequencing reveals the oncogenic role of ANXA5 in gastric cancer and its association with drug resistance

Background

Gastric cancer (GC) remains a leading cause of cancer-related mortality, with over one million new cases and 769,000 deaths reported in 2020. Despite advancements in chemotherapy, surgery, and targeted therapies, delayed diagnosis due to overlooked early symptoms leads to poor prognosis.

Methods

We integrated bulk RNA sequencing and single-cell RNA sequencing datasets from TCGA, GEO, and OMIX001073, employing normalization, batch effect correction, and dimensionality reduction methods to identify key cell populations associated with GC invasion and epithelial-mesenchymal transition (EMT), as well as analyze the tumor immune microenvironment.

Results

Our analysis identified the MUC5AC+ malignant epithelial cell cluster as a significant player in GC invasion and EMT. Cluster 1, representing this cell population, exhibited higher invasion and EMT scores compared to other clusters. Survival analysis showed that high abundance in cluster 0 correlated with improved survival rates (P=0.012), whereas cluster 1 was associated with poorer outcomes (P=0.045). A prognostic model highlighted ANXA5 and GABARAPL2 as two critical genes upregulated in GC tumors. High-risk patients demonstrated increased immune cell infiltration and worse prognosic. Analysis of tumor mutation burden (TMB) indicated that patients with low TMB in the high-risk group had the worst prognosis. Wet-lab validation experiments confirmed the oncogenic role of ANXA5, showing its facilitation of cell proliferation, invasion, and migration while suppressing apoptosis.

Conclusion

This study offers novel insights into the subpopulations of malignant epithelial cells in GC and their roles in tumor progression. It provides a prognostic model and potential therapeutic targets to combat GC, contributing crucial understanding to the fundamental mechanisms of drug resistance in gastrointestinal cancers.

Helicobacter pylori Eradication Is Associated With a Reduced Risk of Metachronous Gastric Neoplasia by Restoring Immune Function in the Gastric Mucosa

BACKGROUND

Helicobacter pylori infection is a significant contributing factor of gastric cancer. Metachronous neoplasms also pose a risk. The mechanism underlying the impact of H. pylori eradication on preventing metachronous gastric cancer is unclear. This study aimed to investigate immunity changes in gastric mucosa after H. pylori eradication and to identify mechanisms preventing metachronous recurrence.

MATERIALS AND METHODS

Patients diagnosed with gastric neoplasm and H. pylori infection, who underwent endoscopic resection, were included. Thirty-six cases of metachronous neoplasms occurring after eradication (metachronous group) were compared to 36 controls matched for age, sex, atrophy, and metaplasia (control group). Histological features and immunohistochemical staining for T-cell (CD3, CD4, and CD8) and immune exhaustion (forkhead/winged helix transcription factor and programmed cell death-ligand 1) markers in the non-tumor-bearing mucosa were evaluated.

RESULTS

In histologic features, glandular atrophy and intestinal metaplasia in the gastric mucosa significantly improved following H. pylori eradication in the control group (p < 0.001, 0.008), whereas they did not improve in the metachronous group (p = 0.449, 0.609). CD8 and CD8/CD3 ratios increased in the control group (p < 0.001, 0.04), but did not show differences in the metachronous group (p = 0.057, 0.245). The CD4/CD3 ratio and programmed cell death-ligand 1/CD4 expression significantly decreased after H. pylori eradication in the control group (p = 0.003, 0.042), but not in the metachronous group (p = 0.54, 0.55).

CONCLUSIONS

This observational study suggests that H. pylori eradication may prevent the recurrence of gastric neoplasia by improving histological inflammation and overcoming immune exhaustion.

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.

Development and validation of a nomogram for obesity and related factors to detect gastric precancerous lesions in the Chinese population: a retrospective cohort study

Objectives

The purpose of this study was to construct a nomogram to identify patients at high risk of gastric precancerous lesions (GPLs). This identification will facilitate early diagnosis and treatment and ultimately reduce the incidence and mortality of gastric cancer.

Methods

In this single-center retrospective cohort study, 563 participants were divided into a gastric precancerous lesion (GPL) group (n=322) and a non-atrophic gastritis (NAG) group (n=241) based on gastroscopy and pathology results. Laboratory data and demographic data were collected. A derivation cohort (n=395) was used to identify the factors associated with GPLs to develop a predictive model. Then, internal validation was performed (n=168). We used the area under the receiver operating characteristic curve (AUC) to determine the discriminative ability of the predictive model; we constructed a calibration plot to evaluate the accuracy of the predictive model; and we performed decision curve analysis (DCA) to assess the clinical practicability predictive model.

Results

Four -predictors (i.e., age, body mass index, smoking status, and -triglycerides) were included in the predictive model. The AUC values of this predictive model were 0.715 (95% CI: 0.665-0.765) and 0.717 (95% CI: 0.640-0.795) in the derivation and internal validation cohorts, respectively. These values indicated that the predictive model had good discrimination ability. The calibration plots and DCA suggested that the predictive model had good accuracy and clinical net benefit. The Hosmer-Lemeshow test results in the derivation and validation cohorts for this predictive model were 0.774 and 0.468, respectively.

Conclusion

The nomogram constructed herein demonstrated good performance in terms of predicting the risk of GPLs. This nomogram can be beneficial for the early detection of patients at high risk of GPLs, thus facilitating early treatment and ultimately reducing the incidence and mortality of gastric cancer.

Endoscopic Submucosal Dissection of Gastric High-Grade Foveolar Dysplasia With Normal Background Mucosa

Most gastric neoplastic lesions appear in patients with gastric premalignant conditions. Here, we present the case of a 75-year-old woman with no prior history of Helicobacter pylori infection, with a big gastric adenoma resected by endoscopic submucosal dissection. Histopathological examination revealed high-grade foveolar dysplasia. Interestingly, surrounding mucosa was normal, without signs of H. pylori infection or gastric preneoplastic conditions. The presented case emphasizes that high-risk gastric lesions may be present within a normal stomach without endoscopic signs of H. pylori infection or premalignant conditions. This underscores the importance of careful examination in regular practice of esophagogastroduodenoscopy, even in low-risk patients.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

The cGAS/STING Pathway-A New Potential Biotherapeutic Target for Gastric Cancer?

Gastric cancer ranks among the top five deadliest tumors worldwide, both in terms of prevalence and mortality rates. Despite mainstream treatments, the efficacy in treating gastric cancer remains suboptimal, underscoring the urgency for novel therapeutic approaches. The elucidation of tumor immunosuppressive microenvironments has shifted focus towards cancer biotherapeutics, which leverage the patient's immune system or biologics to target tumor cells. Biotherapy has emerged as a promising alternative for tumors resistant to traditional chemotherapy, radiation, and immunotherapy. Central to this paradigm is the cGAS-STING pathway, a pivotal component of the innate immune system. This pathway recognizes aberrant DNA, such as that from viral infections or tumor cells, and triggers an immune response, thereby reshaping the immunosuppressive tumor microenvironment into an immune-stimulating milieu. In the context of gastric cancer, harnessing the cGAS-STING pathway holds significant potential for biotherapeutic interventions. This review provides a comprehensive overview of the latest research on cGAS-STING in gastric cancer, including insights from clinical trials involving STING agonists. Furthermore, it assesses the prospects of targeting the cGAS-STING pathway as a novel biotherapeutic strategy for gastric cancer.

Risk Factors for Developing Metachronous Superficial Gastric Epithelial Neoplasms after Endoscopic Submucosal Dissection

Background: Although endoscopic submucosal dissection (ESD) provides a high rate of curative resection, the remaining gastric mucosa after ESD is at risk for metachronous superficial gastric epithelial neoplasms (MSGENs). It leaves room for risk factors for developing MSGENs after ESD. This study aimed to identify clinicopathological risk factors for the occurrence of MSGENs, and to evaluate the association of Helicobacter pylori (H. pylori) with the MSGENs. Methods: We conducted a retrospective cohort study including 369 patients with 382 lesions that underwent ESD for adenoma/early gastric cancer. Results: Twenty-seven MSGENs occurred. The subjects were divided into MSGEN and not-MSGEN groups. There was a significantly higher frequency of histological intestinal metaplasia (HIM) and initial neoplasm location in the upper or middle parts (INUM) in the MSGEN group. The HIM and INUM groups had a significantly higher cumulative incidence of MSGENs. We compared 27 patients from the MSGEN group and 27 patients from the not-MSGEN group that were matched to the MSGEN group for variables including HIM and INUM. There was a significantly higher frequency of the spontaneous disappearance of H. pylori in the MSGEN group. Conclusions: HIM, INUM, and the spontaneous disappearance of H. pylori may be clinicopathological risk factors for developing MSGENs after ESD.