Is gastric cancer becoming a rare disease? A global assessment of predicted incidence trends to 2035

[Update on gastric cancer. New molecular classifications]

Gastric cancer (GC) is an aggressive tumor, which is usually diagnosed at an advanced stage and shows high mortality rates. Several GC classifications have been published, based on features such as tumor location, endoscopic features or microscopic architecture. However, TNM stage remains the mainstay of GC management and treatment. In the last years, technical advances have allowed us to investigate the biological heterogeneity of GC and develop new molecular classifications. This knowledge may enhance current classifications, and has the potential to refine GC management and aid in the identification of new molecular targets. In this literature review we have summarized the main findings in epidemiology, screening, classification systems and treatment of GC, focusing on the molecular alterations and new molecular classifications published in the last years.

Gastrointestinal cancers in China, the USA, and Europe

Gastrointestinal (GI) cancers, including colorectal cancer, gastric cancer, and esophageal cancer, are a major medical and economic burden worldwide and have the largest number of new cancer cases and cancer deaths each year. Esophageal and gastric cancers are most common in developing countries, while colorectal cancer forms the major GI malignancy in Western countries. However, a great shift in the predominant GI-cancer type is happening in countries under economically transitioning and, at the same time, esophageal and gastric cancers are reigniting in Western countries due to the higher exposure to certain risk factors. The development of all GI cancers is highly associated with lifestyle habits and all can be detected by identified precancerous diseases. Thus, they are all suitable for cancer screening. Here, we review the epidemiological status of GI cancers in China, the USA, and Europe; the major risk factors and their distribution in these regions; and the current screening strategies.

Recent progress in gastric cancer prevention

Gastric cancer remains a major challenge to public health on a global scale, causing the loss of 19 million disability-adjusted life years worldwide in 2017. The future burden will increase due to population growth and ageing. Considering its absolute burden and persisting disparities, in addition to the substantial prevalence of Helicobacter pylori infection worldwide that is treatable, gastric cancer is a logical target for urgent global action for prevention. In this review, we discuss recent progress in gastric cancer prevention and propose a concerted international effort to implement population-based H. pylori treatment programmes, as the best evidence-based strategy that is currently available for gastric cancer prevention, in the context of demonstration projects in selected populations, to be later scaled up. It is time for urgent action to reduce the important loss of life and productivity caused by this preventable malignancy.

The Colombian Chemoprevention Trial: 20-Year Follow-Up of a Cohort of Patients With Gastric Precancerous Lesions

BACKGROUND & AIMS

Helicobacter pylori eradication and endoscopic surveillance of gastric precancerous lesions are strategies to reduce gastric cancer (GC) risk. To our knowledge, this study is the longest prospective cohort of an H pylori eradication trial in a Hispanic population.

METHODS

A total of 800 adults with precancerous lesions were randomized to anti-H pylori treatment or placebo. Gastric biopsy samples taken at baseline and 3, 6, 12, 16, and 20 years were assessed by our Correa histopathology score. A generalized linear mixed model with a participant-level random intercept was used to estimate the effect of H pylori status on the score over time. Logistic regression models were used to estimate progression by baseline diagnosis and to estimate GC risk by intestinal metaplasia (IM) subtype and anatomic location.

RESULTS

Overall, 356 individuals completed 20 years of follow-up. Anti-H pylori therapy (intention-to-treat) reduced progression of the Correa score (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.38-0.93). H pylori-negative status had a beneficial effect on the score over time (P = .036). Among individuals with IM (including indefinite for dysplasia) at baseline, incidence rates per 100 person-years were 1.09 (95% CI, 0.85-1.33) for low-grade/high-grade dysplasia and 0.14 (95% CI, 0.06-0.22) for GC. Incomplete-type (vs complete-type) IM at baseline presented higher GC risk (OR, 13.4; 95% CI, 1.8-103.8). Individuals with corpus (vs antrum-restricted) IM showed an OR of 2.1 (95% CI, 0.7-6.6) for GC.

CONCLUSIONS

In a high-GC-risk Hispanic population, anti-H pylori therapy had a long-term beneficial effect against histologic progression. Incomplete IM is a strong predictor of GC risk.

Pancreatic Fistula after D1+/D2 Radical Gastrectomy according to the Updated International Study Group of Pancreatic Surgery Criteria: Risk Factors and Clinical Consequences. Experience of Surgeons with High Caseloads in a Single Surgical Center in Eastern Europe

PURPOSE

Incidence, risk factors, and clinical consequences of pancreatic fistula (POPF) after D1+/D2 radical gastrectomy have not been well investigated in Western patients, particularly those from Eastern Europe.

MATERIALS AND METHODS

A total of 358 D1+/D2 radical gastrectomies were performed by surgeons with high caseloads in a single surgical center from 2002 to 2017. A retrospective analysis of data that were prospectively gathered in an electronic database was performed. POPF was defined and graded according to the International Study Group for Pancreatic Surgery (ISGPS) criteria. Uni- and multivariate analyses were performed to identify potential predictors of POPF. Additionally, the impact of POPF on early complications and long-term outcomes were investigated.

RESULTS

POPF was observed in 20 patients (5.6%), according to the updated ISGPS grading system. Cardiovascular comorbidities emerged as the single independent predictor of POPF formation (risk ratio, 3.051; 95% confidence interval, 1.161-8.019; P=0.024). POPF occurrence was associated with statistically significant increased rates of postoperative hemorrhage requiring re-laparotomy (P=0.029), anastomotic leak (P=0.002), 90-day mortality (P=0.036), and prolonged hospital stay (P<0.001). The long-term survival of patients with gastric adenocarcinoma was not affected by POPF (P=0.661).

CONCLUSIONS

In this large series of Eastern European patients, the clinically relevant rate of POPF after D1+/D2 radical gastrectomy was low. The presence of co-existing cardiovascular disease favored the occurrence of POPF and was associated with an increased risk of postoperative bleeding, anastomotic leak, 90-day mortality, and prolonged hospital stay. POPF was not found to affect the long-term survival of patients with gastric adenocarcinoma.

Helicobacter pylori induced gastric carcinogenesis - The best molecular model we have?

Gastric carcinogenesis can be described as a consequence of multilevel molecular alterations that is triggered by a cascade of events. Historically, diet and environmental factors have been identified to substantially contribute to carcinogenesis before the discovery of Helicobacter pylori (H. pylori). But H. pylori infection has revolutionized the understanding of gastric carcinogenesis. Although the model of H. pylori-driven carcinogenesis remains valid, there is a continuous effort to precisely delineate the molecular pathways involved and to understand the interplay with additional risk factors including recent relevant knowledge on the stomach microbiota. In this review, we provide an updated view on the models of gastric carcinogenesis. This includes historically appreciated H. pylori-induced models and expands these taking recent molecular data into consideration. Based on the data provided, we conclude that indeed H. pylori-carcinogenesis remains one of the best-established models at least for a subset of gastric cancers. Implementation of the recently identified molecular subtypes in novel genetic animal models is required to expand our knowledge on H. pylori-independent carcinogenesis.

Targeted and immunotherapy in the era of personalised gastric cancer treatment

Gastric cancer is a major cause of cancer-related morbidity and mortality worldwide. Advances in targeted medical treatment were scarce in the past and challenged by the marked spatial and temporal biological heterogeneity of gastric cancer. Recent molecular profiling studies have increased our understanding of genetic and epigenetic drivers, leading to better patient selection for drug development. Beyond that, immune-related biomarkers were identified, paving the way for future effective immunotherapy. We systematically reviewed articles from PubMed of the past 10 years, and abstracts from annual meetings of ESMO, ASCO and AACR to summarise the current knowledge about targeted and immunotherapy and outline pathways to future personalised therapy of gastric cancer.

Epidemiology, Diagnosis, Staging and Multimodal Therapy of Esophageal and Gastric Tumors

Gastric and esophageal tumors are diverse neoplasms that involve mucosal and submucosal tissue layers and include squamous cell carcinomas, adenocarcinomas, spindle cell neoplasms, neuroendocrine tumors, marginal B cell lymphomas, along with less common tumors. The worldwide burden of esophageal and gastric malignancies is significant, with esophageal and gastric cancer representing the ninth and fifth most common cancers, respectively. The approach to diagnosis and staging of these lesions is multimodal and includes a combination of gastrointestinal endoscopy, endoscopic ultrasound, and cross-sectional imaging. Likewise, therapy is multidisciplinary and combines therapeutic endoscopy, surgery, radiotherapy, and systemic chemotherapeutic tools. Future directions for diagnosis of esophageal and gastric malignancies are evolving rapidly and will involve advances in endoscopic and endosonographic techniques including tethered capsules, optical coherence tomography, along with targeted cytologic and serological analyses.

Premedication with simethicone and N-acetylcysteine for improving mucosal visibility during upper gastrointestinal endoscopy in a Western population

Background and study aim  Pre-endoscopic use of a preparation with tensioactive and mucolytic agents improved gastric mucosa visualization in Eastern studies. Data on Western population are scanty. Patients and methods  This prospective, endoscopist-blinded, randomized study enrolled patients who underwent esophagogastroduodenoscopy in a single center. Before endoscopy patients, were randomized to receive or not receive an oral preparation with simethicone and N-acetylcysteine in water. A pretested score (Crema Stomach Cleaning Score [CSCS]) for gastric mucosa cleaning evaluation was used. In detail, the stomach was divided into the antrum, body, and fundus and a score of 1 to 3 was assigned to each part (the higher the score, the better the preparation), and a total value ≤ 5 was considered as insufficient. Time between endoscope insertion and clean achievement (mouth to clean time) or the end of examination (mouth to mouth time) was recorded. Results  A total of 197 patients were enrolled. The mean overall CSCS value and mucosal cleaning in all parts was better in treated patients than in controls. Prevalence total score ≤ 5 was significantly lower in patients treated before endoscopy. Need for water flush occurred less frequently in treated patients ( P  < 0.0001). The mouth to clean time was lower in the treated than in the control group (2.3 ± 1.6 vs 3.8 ± 1.6 min; P  < 0.001), whereas no significant difference in mouth to mouth time emerged. Conclusions  Data from this study show that premedication with simethicone and N-acetylcysteine results in significantly better endoscopic visualization of gastric mucosa, and the proposed CSCS could be useful for standardizing this evaluation.

Mass eradication of Helicobacter pylori to reduce gastric cancer incidence and mortality: a long-term cohort study on Matsu Islands

OBJECTIVE

Although mass eradication of Helicobacter pylori has been proposed as a means to eliminate gastric cancer, its long-term effects remain unclear.

DESIGN

Mass eradication of H. pylori infection was launched in 2004 and continued until 2018 for a high-risk Taiwanese population aged 30 years or older dwelling on Matsu Islands with prevalent H. pylori infection. Test positives for the ¹³C-urea breath test underwent eradication therapy. We evaluated the effectiveness of the mass eradication in reducing two main outcomes, incidence and mortality rates of gastric cancer, until the end of 2016 and 2018, respectively.

RESULTS

After six rounds of mass screening and eradication, the coverage rate reached 85.5% (6512/7616). The referral rate for treatment was 93.5% (4286/4584). The prevalence rates of H. pylori fell from 64.2% to 15.0% with reinfection rates of less than 1% per person-year. The presence and severity of atrophic gastritis and intestinal metaplasia also decreased with time. Compared with the historical control period from 1995 to 2003, the effectiveness in reducing gastric cancer incidence and mortality during the chemoprevention period was 53% (95% CI 30% to 69%, p<0.001) and 25% (95% CI -14% to 51%, p=0.18), respectively. No significant changes were noted in the incidence rates of other digestive tract cancers or the antibiotic resistance rate of H. pylori.

CONCLUSION

Population-based eradication of H. pylori has significantly reduced gastric cancer incidence with no increase in the likelihood of adverse consequences. A significant reduction in mortality is likely to be achieved with a longer follow-up period.

TRIAL REGISTRATION NUMBER

NCT00155389.

Role of Long Non-Coding RNAs in the Chemoresistance of Gastric Cancer: A Systematic Review

PURPOSE

Accumulating evidence demonstrates that long non-coding RNAs (lncRNAs) play a vital role in the chemoresistance of gastric cancer (GC). The present systematic review summarises the emerging role, potential targets or pathways and regulatory mechanisms of lncRNAs involved in chemoresistance and proposes a number of clinical implications of lncRNAs as novel therapeutic targets for GC.

METHODS

Studies on lncRNAs involved in the chemoresistance of GC published until July 2020 in the PubMed and Web of Science databases were systematically reviewed and the expression form, role in chemoresistance, targets or pathways, corresponding drugs and potential mechanisms of relevant lncRNAs were summarised in detail.

RESULTS

A total of 48 studies were included in this systematic review. Amongst these studies, 32 involved single drug resistance and 16 involved in multidrug resistance (MDR). The 48 studies collected described 38 lncRNAs in the drug-resistant cells of GC, including 33 upregulated and 5 downregulated lncRNAs. Cisplatin (DDP) was the most studied drug and lncRNA MALAT1 was the most studied lncRNA related to the chemoresistance of GC. The potential mechanisms of chemoresistance for lncRNAs in GC mainly included, amongst others, reduction of apoptosis, induction of autophagy, repair of DNA damage, promotion of epithelial-mesenchymal transition (EMT) and regulation of the related signalling pathways.

CONCLUSION

LncRNAs play a vital role in the chemoresistance of GC and are novel therapeutic targets for the disease. Detailed chemoresistance mechanisms, translational studies and clinical trials on lncRNAs in GC are urgently needed.

Bibliometric Evaluation of Publications (2000-2020) on the Prognosis of Gastric Cancer

Background: Gastric cancer remains a global malignancy. The role of bibliometric analysis is increasingly valued. It is feasible and necessary to perform a bibliometric analysis to regurgitate studies in the prognosis of gastric cancer. Materials and methods: Web of Science was selected for the dataset resource. Articles published between 2000 and 2020 within the database of Web of Science Core Collection were included with predefined search terms. CiteSpace version 5.7.R1 and R software program version 4.0.3 were used for bibliometric analysis with parameters extrapolated from included studies. Results: A total of 1721 articles were included from 2000 to 2020 with remarkably increasing trends. China (n=1183), Japan (n=218), and South Korea (n=119) showed the most publications. SUN YAT SEN University, FUDAN University, and NANJING MED University were the top institutions with most publications. Keywords with strongest citation bursts between 2000 and 2020 were characterized. Particularly, “statistics”, “resistance”, “mortality”, “lncrna”, “diagnosis”, “outcome”, “migration”, “promote,” and “regulatory t cell” were the latest rising keywords since 2017, indicating possible study trends ahead. Several articles showed strongest citation bursts, including Jemal A. CA-CANCER J CLIN, Van Cutsem E. LANCET, and Japanese Gastric Cancer Association GASTRIC CANCER. Conclusion: This bibliometric analysis provides a thought-provoking, insightful result concerning the trajectory of research development in prognosis of gastric cancer with a future perspective.

Laparoscopic surgery for gastric cancer: Current status and future direction

Gastric cancer is still a major cause of death worldwide. While laparoscopic gastrectomy (LG) has gained evidence as a standard treatment for early gastric cancer in the distal stomach, there are still concerns regarding its application for gastric cancer in the upper stomach and advanced gastric cancer. Nevertheless, LG has shown to have faster recovery, shorter hospital stay, less pain, and less blood loss in many retrospective and prospective studies. The application of LG has now extended from conventional radical gastrectomy to novel approaches such as function-preserving gastrectomy and sentinel-node navigated surgery. Studies on the use of laparoscopy in treatment for stage IV gastric cancer are rare, but show that there may be some roles of LG in selected cases. With the development of new laparoscopic tools that augment human ability, the future of LG should move on from proving non-inferiority to demonstrating superiority compared to the traditional open gastrectomy.

A clinical model to predict distant metastasis in patients with superficial gastric cancer with negative lymph node metastasis and a survival analysis for patients with metastasis

BACKGROUND

Distant metastasis (DM) is relatively rare in superficial gastric cancer (SGC), especially in patients without lymph node metastasis. This study aimed to explore the main clinical risk factors for DM in patients with superficial gastric cancer-no lymph node metastasis (SGC-NLNM) and the prognostic factors for patients with DM.

METHODS

Records of patients with SGC-NLNM between 2004 and 2015 were collected from the public Surveillance, Epidemiology, and End Results (SEER) database. Both univariate and multivariate logistic regressions were performed to analyze the clinical risk factors for DM. The Kaplan-Meier method and Cox regression model were used to identify prognostic factors for patients with DM. A nomogram was built based on multivariate logistic regression and evaluated by the C-index, the calibration, and the area under the receiver operating characteristic curve (AUC).

RESULTS

We developed and validated a nomogram to predict DM in patients with SGC-NLNM, showing that race, age, primary site, depth, size, and grade were independent risk factors. The built nomogram had a good discriminatory performance, with a C-index of 0.836 (95% confidence interval [CI]: 0.813-0.859). Calibration plots showed that the predicted DM probability was identical to the actual observations in both the training and validation sets. AUC was 0.846 (95% CI: 0.820-0.871) and 0.801 (95% CI: 0.751-0.850) in the training and validation sets, respectively. The results of the survival analysis revealed that surgery (hazard ratio [HR] = 0.249; 95% CI, 0.125-0.495), chemotherapy (HR = 0.473; 95% CI, 0.353-0.633), and grade (HR = 1.374; 95% CI, 1.018-1.854) were independent prognostic factors associated with cancer-specific survival (CSS), but radiotherapy was not (log-rank test, p = 0.676).

CONCLUSIONS

We constructed a sensitive and discriminative nomogram to identify high-risk patients with SGC-NLNM who may harbor dissemination at initial diagnosis. The tumor size and primary site were the largest contributors to DM prediction. Compared with radiotherapy, aggressive surgery, and chemotherapy may be better options for patients with DM.

BTEB2-Activated lncRNA TSPEAR-AS2 Drives GC Progression through Suppressing GJA1 Expression and Upregulating CLDN4 Expression

Long non-coding RNAs (lncRNAs) are characterized as key layers of the genome in various cancers. TSPEAR-AS2 was highlighted to be a candidate lncRNA potentially involved in gastric cancer (GC) progression. However, the clinical significance and mechanism of TSPEAR-AS2 in GC required clarification. The clinical significance of TSPEAR-AS2 was elucidated through Kaplan-Meier Plotter. The mechanism of TSPEAR-AS2 in GC was clarified in vitro and in vivo using luciferase reporter, chromatin immunoprecipitation, RNA immunoprecipitation assays, and animal models. TSPEAR-AS2 elevation was closely correlated with overall survival of GC patients. A basic transcription element-binding protein 2 (BTEB2)-activated TSPEAR-AS2 model was first explored in this study. TSPEAR-AS2 silencing substantially reduced tumorigenic capacities of GC cells, while TSPEAR-AS2 elevation had the opposite effect. Mechanistically, TSPEAR-AS2 bound with both polycomb repressive complex 2 (PRC2) and argonaute 2 (Ago2). TSPEAR-AS2 knockdown significantly decreased H3K27me3 levels at promoter regions of gap junction protein alpha 1 (GJA1). Ago2 was recruited by TSPEAR-AS2, which was defined to sponge miR-1207-5p, contributing to the repression of claudin 4 (CLDN4) translation. The axis of EZH2/GJA1 and miR-1207-5p/CLDN4 mediated by BTEB2-activated-TSPEAR-AS2 plays an important role in GC progression, suggesting a new therapeutic direction in GC treatment.

Helicobacter pylori eradication therapy to prevent gastric cancer: systematic review and meta-analysis

OBJECTIVES

Gastric cancer is strongly associated with Helicobacter pylori (H. pylori). We conducted a previous systematic review and meta-analysis that suggested eradication therapy reduced future incidence of gastric cancer, but effect size was uncertain, and there was no reduction in gastric cancer-related mortality. We updated this meta-analysis, as more data has accumulated. We also evaluated impact of eradication therapy on future risk of gastric cancer in patients having endoscopic mucosal resection for gastric neoplasia.

DESIGN

We searched the medical literature through February 2020 to identify randomised controlled trials (RCTs) examining effect of eradication therapy on subsequent occurrence of gastric cancer in healthy H. pylori-positive adults, and in H. pylori-positive patients with gastric neoplasia undergoing endoscopic mucosal resection. The control arm received placebo or no treatment. Follow-up was for ≥2 years. We estimated the relative risk (RR) number needed to treat (NNT), and evaluated the disability-adjusted life-years (DALYs) gained from screening from the meta-analysis.

RESULTS

We identified 10 RCTs, seven recruited 8323 healthy individuals, and three randomised 1841 patients with gastric neoplasia. In healthy individuals, eradication therapy reduced incidence of gastric cancer (RR=0.54; 95% CI 0.40 to 0.72, NNT=72), and reduced mortality from gastric cancer (RR=0.61; 95% CI 0.40 to 0.92, NNT=135), but did not affect all-cause mortality. These data suggest that 8 743 815 DALYs (95% CI 5 646 173 to 11 847 456) would be gained if population screening and treatment was implemented globally. In patients with gastric neoplasia, eradication therapy also reduced incidence of future gastric cancer (RR=0.49; 95% CI 0.34 to 0.70, NNT=21). Adverse events were incompletely reported.

CONCLUSION

There is moderate evidence to suggest that H. pylori eradication therapy reduces the incidence of gastric cancer in healthy individuals and patients with gastric neoplasia in East Asian countries. There also appears to be a reduction in gastric cancer-related mortality.

Could Periodontal Disease through Periopathogen Fusobacterium Nucleatum be an Aggravating Factor for Gastric Cancer?

Periodontal disease affects the supporting tissues of the teeth, being a chronic inflammatory disease caused by specific microorganisms from subgingival biofilm. Fusobacterium nucleatum is a Gram-negative anaerobic bacterium that acts as a periodontal pathogen, being an important factor in linking Gram-positive and Gram-negative bacteria in the periodontal biofilm, but its involvement in systemic diseases has also been found. Several studies regarding the implication of Fusobacterium nucleatum in gastro-enterological cancers have been conducted. The present review aims to update and systematize the latest information about Fusobacterium nucleatum in order to evaluate the possibility of an association between periodontal disease and the evolution of gastroenterological cancers through the action of Fusobacterium nucleatum, highlighting gastric cancer. This would motivate future research on the negative influence of periodontal pathology on the evolution of gastric cancer in patients suffering from both pathologies.

The Spectrum of Helicobacter-Mediated Diseases

Helicobacter pylori is the leading cause of peptic ulcer disease. The infection has been implicated in more than 75% of duodenal ulcer cases and 17% of gastric ulcer cases. H. pylori has been classified as a human carcinogen, since it is the main cause of distal gastric adenocarcinoma and B cell mucosa-associated lymphoid tissue lymphoma. Evidence also links H. pylori with extragastric conditions including iron deficiency anemia, idiopathic thrombocytopenic purpura, and vitamin B₁₂ deficiency. Studies indicate that H. pylori may be protective against other conditions of the gastrointestinal tract (e.g., reflux esophagitis and related pathologies) and elsewhere in the body (e.g., asthma). The infection is asymptomatic in the vast majority of cases; more serious outcomes occur in only 10-15% of infected individuals. Despite extensive research over the past 3 decades, there is no effective vaccine, and the circumstances leading to disease development remain unclear. In addition, there is now a growing prevalence of antimicrobial resistance in H. pylori. This review discusses these important issues.

Cancer burden in China: trends, risk factors and prevention

As the most populous country in the world, China has made strides in health promotion in the past few decades. With the aging population, the burden of cancer in China continues to grow. Changes in risk factors for cancer, especially diet, obesity, diabetes, and air pollution, continue to fuel the shift of cancer transition in China. The burden of upper gastrointestinal cancer in China is decreasing, but still heavy. The rising burden of colorectal, prostate, and breast cancers is also significant. Lung cancer became the top cause of cancer-related deaths, together with smoking as the most important contributor to cancer deaths. The Chinese government has taken several approaches to control cancer and cancer-related risk factors. Many achievements have been made, but some challenges remain. Health China 2030 is ambitious and depicts a bright vision of the future for cancer control in China. The decrease in the cancer burden in China will require cross-sector collaboration and coordinated efforts on primary and secondary preventions by governments, public health organizations, and individuals. In this review, we describe the trends of cancer burden and discuss cancer-related risk factors in China, identifying strategies to reduce the burden of cancer in China.

Hypergastrinemia is associated with an increased risk of gastric adenocarcinoma with proximal location: A prospective population-based nested case-control study

The incidence of proximal gastric adenocarcinoma is increasing among younger adults. Rodent models have shown that hypergastrinemia causes carcinogenesis in the proximal stomach. The aim of our study was therefore to assess if hypergastrinemia was associated with an increased risk of developing gastric adenocarcinoma also in humans. A prospective population‐based nested case‐control study within the Nord‐Trøndelag Health Study (HUNT) cohort, Norway, was used to assess this association. Serum was collected from 78 962 participants in 1995 to 1997 and 2006 to 2008. In the cohort, 181 incident gastric adenocarcinoma cases were identified from the Norwegian Cancer and Patient Registries through 2015 and matched with 359 controls. The risk of gastric adenocarcinoma was compared between participants with prediagnostic hypergastrinemia (>60 pmol/L) and normal serum gastrin (≤60 pmol/L). Logistic regression provided odds ratios (ORs) with 95% confidence intervals (CIs), adjusted for body mass index, tobacco smoking and comorbidity. Hypergastrinemia was associated with increased risk of gastric adenocarcinoma overall (OR 2.2, 95% CI 1.4‐3.4) and in particular for gastric adenocarcinoma with proximal location (OR 6.1, 95% CI 2.7‐13.8), but not with gastric adenocarcinoma with distal location (OR 1.7, 95% CI 0.9‐3.4). Moreover, hypergastrinemia was associated with an increased risk of gastric adenocarcinoma of intestinal histological type (OR 3.8, 95% CI 1.8‐7.9), but not for diffuse histological type (OR 1.6, 95% CI 0.7‐3.7). In conclusion, hypergastrinemia was associated with an increased risk of proximal and intestinal type gastric adenocarcinoma.

What's new?

The incidence of proximal gastric adenocarcinoma has been reported to increase among younger adults in Western countries. Rodent models have shown that serum gastrin levels above the normal range cause carcinogenesis in the proximal stomach. In this first prospective population‐based study on the association between hypergastrinemia and gastric adenocarcinoma, the risk of gastric adenocarcinoma in the proximal stomach, but not in the distal stomach, was markedly increased in hypergastrinemic individuals. The finding supports the hypothesis that hypergastrinemia mediates the development of gastric adenocarcinoma in the proximal stomach, where mucosal proliferation is stimulated by gastrin.

Population-Based Analysis of Differences in Gastric Cancer Incidence Among Races and Ethnicities in Individuals Age 50 Years and Older

BACKGROUND & AIMS

There are racial and ethnic differences in the incidence of gastric adenocarcinoma worldwide and in the US. Based on a decision analysis, screening for noncardia gastric adenocarcinoma might be cost-effective for non-White individuals 50 years or older. However, a lack of precise, contemporary information on gastric adenocarcinoma incidence in specific anatomic sites for this age group has impeded prevention and early detection programs in the US. We aimed to estimate the differences in gastric adenocarcinoma incidence in specific anatomic sites among races and ethnicities in individuals 50 years or older.

METHODS

We analyzed California Cancer Registry data from 2011 through 2015 to estimate incidences of gastric adenocarcinoma in specific anatomic sites for non-Hispanic White (NHW), non-Hispanic Black, Hispanic, and the 7 largest Asian American populations. We calculated the differential incidence between non-White groups and NHW using incidence rate ratios and 95% confidence intervals (CIs).

RESULTS

Compared with NHW subjects, all non-White groups had significantly higher incidences of noncardia gastric adenocarcinoma; the incidence was highest among Korean American men 50 years and older (70 cases per 100,000). Compared with NHW subjects 50 years and older, the risk of noncardia gastric adenocarcinoma was 1.8-fold (95% CI, 1.37-2.31) to 7.3-fold (95% CI, 5.73-9.19) higher in most non-White groups and 12.0-fold (95% CI, 9.96-14.6) to 14.5-fold (95% CI, 12.5-16.9) higher among Korean American men and women 50 years and older, respectively. Compared with NHW men 50 years and older, all non-White men, except Japanese and Korean American men, had a significantly lower risk of cardia gastric adenocarcinoma.

CONCLUSIONS

We identified several-fold differences in incidences of gastric adenocarcinoma in specific anatomic sites among racial and ethnic groups, with significant age and sex differences. These findings can be used to develop targeted risk reduction programs for gastric adenocarcinoma.

Predictors for development of complete and incomplete intestinal metaplasia (IM) associated with H. pylori infection: A large-scale study from low prevalence area of gastric cancer (IM-HP trial)

Background

Gastric intestinal metaplasia (IM) is precancerous lesion of gastric cancer related to H. pylori infection. There has been limited data about IM and associated risk factors. This study aimed to determine risk factors related to development of IM to guide proper management.

Methods

1,370 patients undergoing UGI endoscopy at Thammasat University Hospital, Thailand were included between January 2018-August 2019. Patients’ data including baseline characteristics, laboratory results, and histopathology from medical database were extensively reviewed. Immunohistochemical staining for p53 expression from gastric biopsies was also performed.

Results

Overall H. pylori prevalence was 43.8%. Mean age was 60.7 years and 45% of whom were males. Chronic gastritis was observed in 1,064(77.7%) patients, while 223(16.3%) had IM. Of 223 patients with IM, 194(87%) patients had complete IM, while 29 (13%) had incomplete IM. In groups of complete and incomplete IM, current H. pylori infection rates were 66.5% and 58.6%, respectively. The BMI of incomplete IM group(27.4) was significantly higher than BMI of complete IM group (23.6). Overweight and obese patients (BMI ≥23 kg/m²) were significantly associated with higher risk for the development of incomplete IM (OR 3.25; 95%CI 1.14–9.27, p = 0.027). Males, age >50 years, and current H. pylori infection were significantly higher in IM than chronic gastritis group with OR 1.43 (95%CI 1.01–2.03, p = 0.048), OR 1.67 (95% CI 1.08–2.57, p = 0.021), and OR 3.14 (95% CI 2.29–4.30, p<0.001), respectively. During 20 months of study, there were 15 patients (1.1%) diagnosed with gastric cancer and 1-year survival rate was only 60%.

Conclusions

Males, age >50 years, and current H. pylori infection are significant predictors for the presence of intestinal metaplasia. BMI might be beneficial for using as a predictive risk factor to reduce the development of incomplete intestinal metaplasia. H. pylori eradication could be an effective way to prevent the development of gastric precancerous lesions.

Global burden of oesophageal and gastric cancer by histology and subsite in 2018

OBJECTIVES

To provide updated estimates of the global burden of oesophageal and gastric cancer by subsite and type.

METHODS

Using data from population-based cancer registries, proportions of oesophageal adenocarcinoma (OAC) and squamous cell carcinoma (OSCC) out of all oesophageal as well as cardia gastric cancer (CGC) and non-CGC (NCGC) out of all gastric cancer cases were computed by country, sex and age group. Proportions were subsequently applied to the estimated numbers of oesophageal and gastric cancer cases from GLOBOCAN 2018. Age-standardised incidence rates (ASR) were calculated.

RESULTS

In 2018, there were an estimated 572 000 new cases of oesophageal cancer worldwide, 85 000 OACs (ASR 0.9 per 100 000, both sexes combined) and 482 000 OSCCs (ASR 5.3). Out of 1.03 million gastric cancers, there were an estimated 181 000 cases of CGC (ASR 2.0) and 853 000 cases of NCGC (ASR 9.2). While the highest incidence rates of OSCC, CGC and NCGC were observed in Eastern Asia (ASRs 11.1, 4.4 and 17.9, respectively), rates of OAC were highest in Northern Europe (ASR 3.5). While globally OSCC and NCGC remain the most common types of oesophageal and gastric cancer, respectively, rates of OAC exceed those of OSCC in an increasing number of high-income countries.

CONCLUSIONS

These updated estimates of the global burden of oesophageal and gastric cancer by subtype and site suggest an ongoing transition in epidemiological patterns. This work will serve as a cornerstone for policy-making and will aid in developing appropriate cancer control strategies.

Review: Prevention and management of gastric cancer

Gastric cancer (GC) is still the fifth most frequently diagnosed cancer and the third leading cause of cancer deaths in both sexes worldwide. Although the incidence of GC is predicted to continue declining in a growing number of countries in the future, on a global scale the number of newly diagnosed GC cases will remain high, or increase even further, due to changes in population size and increasing risks observed in younger generations. In a retrospective cohort study, collecting data from the Veterans Health Administration, treatment of Helicobacter pylori infection decreased GC risk only if eradication was successful. In a German case-control study, among GC patients with autoimmune gastritis, pernicious anemia was associated with earlier detection of GC, which translated into a significantly better 5-year survival. In an updated meta-analysis, H. pylori eradication therapy in healthy individuals significantly reduced both GC incidence and mortality from GC with a number needed to treat of 72 and 135, respectively. In Korea, successful H. pylori eradication substantially reduced GC incidence in first-degree relatives of GC patients as well. A meta-analysis of four trials including 1,556 patients with resectable GC reported that the patient subgroup tumors with high microsatellite instability undergoing surgery did not benefit from perioperative or adjuvant chemotherapy.

Gastric cancer

Gastric cancer is the fifth most common cancer and the third most common cause of cancer death globally. Risk factors for the condition include Helicobacter pylori infection, age, high salt intake, and diets low in fruit and vegetables. Gastric cancer is diagnosed histologically after endoscopic biopsy and staged using CT, endoscopic ultrasound, PET, and laparoscopy. It is a molecularly and phenotypically highly heterogeneous disease. The main treatment for early gastric cancer is endoscopic resection. Non-early operable gastric cancer is treated with surgery, which should include D2 lymphadenectomy (including lymph node stations in the perigastric mesentery and along the celiac arterial branches). Perioperative or adjuvant chemotherapy improves survival in patients with stage 1B or higher cancers. Advanced gastric cancer is treated with sequential lines of chemotherapy, starting with a platinum and fluoropyrimidine doublet in the first line; median survival is less than 1 year. Targeted therapies licensed to treat gastric cancer include trastuzumab (HER2-positive patients first line), ramucirumab (anti-angiogenic second line), and nivolumab or pembrolizumab (anti-PD-1 third line).

Treatment of Gastric Cancer Patients During COVID-19 Pandemic: The West is More Vulnerable

The outbreak of the COVID-19 is currently the biggest international concern. Treatment of gastric cancer (GC) patients in the pandemic era with high hospital burden and under severe oncological/surgical resource constraints should implicate a need for resource re-allocation with a new "pandemic" GC treatment algorithm. The neoadjuvant/perioperative (radio-)chemotherapy is applied in the majority of advanced GC cases with poor postoperative therapy compliance. In the East, radical surgery is frequently used in the first instance, with adjuvant chemotherapy reserved for patients with a high risk of recurrence. Moreover, the elderly population might be effectively treated by surgery alone, thus saving oncological resources for younger people who need a more aggressive approach. In this framework, prioritization is a key concept based on the severity of symptoms and the need for urgent (surgical) intervention. High-risk and marginally effective surgery should be replaced with definitive radio- and/or chemotherapy. The pandemic framework to provide optimal care for GC patients must be based on multidisciplinary decision-making and include all anti-cancer treatment options: surgery, systemic therapy, and radiotherapy. The priority and staffing dictate adherence to the new algorithm. We believe that these priorities may improve the delivery of care to all, including elderly GC patients.

Non‑coding RNAs that regulate the Wnt/β‑catenin signaling pathway in gastric cancer: Good cop, bad cop? (Review)

Gastric cancer (GC) is one of the most common causes of cancer‑related mortality worldwide. Despite remarkable progress in the diagnosis and treatment of GC, a large number of cases are diagnosed as advanced GC, and treatment failure occurs. Emerging evidence has shown that non‑coding RNAs (ncRNAs), especially microRNAs (miRNAs) and long non‑coding RNAs (lncRNAs), play a vital role in the tumorigenesis and development of GC. Moreover, the pathogenesis of GC is closely related to aberrant activation of the Wnt (Wingless‑type MMTV integration site family) signaling pathway. ncRNAs serve as potential novel biomarkers in the clinical examination, prognosis and therapeutic targeting of GC. Furthermore, dysregulation of ncRNAs has been demonstrated to affect tumor initiation, epithelial‑mesenchymal transition (EMT), angiogenesis, tumor development, invasion, metastasis and resistance to therapy via the Wnt/β‑catenin signaling pathway. This review focuses on the role of ncRNAs in modulating the Wnt/β‑catenin signaling pathway in the pathogenesis of GC, which may provide a reference for the clinical diagnosis and treatment of GC.

Recent Guidelines on the Management of Patients with Gastric Atrophy: Common Points and Controversies

Patients with gastric precancerous lesions (atrophic gastritis and intestinal metaplasia) have increased risk of developing gastric cancer, and adequate management and surveillance of these patients should allow to reduce gastric cancer-related mortality. The guidelines on the management of these patients have been recently published by the European Societies (MAPS II guidelines) and by the American Gastroenterological Association (AGA). The aim of this commentary is to compare these two guidelines by highlighting the common points and differences between them. Both guidelines recommend a systematic detection and eradication of Helicobacter pylori in all patients with gastric atrophy. However, there is a major difference in the recommendations for surveillance: while the MAPS II guidelines recommend systematic endoscopic surveillance in all patients with severe gastric atrophy (with or without intestinal metaplasia), the AGA guidelines focus only on intestinal metaplasia and plead against systematic surveillance, leaving the possibility of surveillance in individual patients based on shared decision between clinicians and patients. The difference between two guidelines comes essentially from the different arguments used by two authorities (randomized control studies by AGA and observational cohort studies by the European Societies), and may be, at least in part, related to the difference between the European and American health care systems and potential economic burden.

Peritoneal carcinomatosis, unilateral malignant pleural effusion with bilateral hydronephrosis post-radical gastrectomy in a signet-ring gastric cancer patient: a case report

Gastric cancer is the fifth most common cancer in the world and the third leading cause of cancer-related deaths. Signet-ring cell type is the most malicious subtype. We report a case of advanced stage gastric adenocarcinoma case post-radical gastrectomy who presented with nausea, vomiting, and diarrhea. Though there were no signs of bowel obstruction on abdominal CT and PET imagine studies, and the cytology of body fluid was initially negative, the patient had unilateral malignant pleural effusion, a moderate amount of ascites and bilateral hydronephrosis. After laparoscopic surgery, the patient was diagnosed with local cancer relapse causing jejunojejunal anastomosis obstruction and peritoneal carcinomatosis causing hydronephrosis. We urge broadening the indication of EGD in the evaluation of advanced stage gastric carcinoma to include mechanic bowel obstruction.