Gastric cancer: epidemiology, biology, and prevention: a mini review

Studying the non-coding RNA expression and its role in drug resistance mechanisms of gastric cancer

Gastric cancer is the fifth most common malignancy and the fifth primary cause of death from cancer all over the world. Because of diagnosis of gastric cancer at advanced, incurable stages and limited response to treatment, the disease has an adverse prognosis and a low survival rate. Chemotherapy consisting of medications such as platinum and 5-Fluorouracil can be effective for patients with advanced stomach cancer. Nevertheless, drug resistance eventually leads to unsuccessful therapy and adverse outcomes for gastric cancer patients. Most therapy failures in gastric cancer patients undergoing chemotherapy are caused by the development of drug resistance. Several studies have shown that noncoding RNAs (ncRNAs) play important roles in the resistance of gastric cancer to chemotherapy drugs. The development of stomach cancer is greatly impacted by a number of ncRNAs, including microRNAs (e.g., miR-21, miR-27a), circular RNAs (e.g., CircPVT1), and long noncoding RNAs (e.g., HOTAIR). Because of their regulatory characteristics in certain genes implicated in the chemoresistant phenotype of gastric cancer, much evidence has demonstrated their function in the emergence and persistence of drug resistance. In the future, ncRNA-based treatment could represent a novel approach to treating drug resistance. Despite numerous studies on anticancer drug resistance mechanisms, it is still unclear how these mechanisms are regulated. In this review, we investigated the evolving function and molecular mechanisms of ncRNAs related to drug resistance, their function in controlling drug resistance in gastric cancer, and their potential to create targeted therapeutics for reducing drug resistance in gastric cancer.

Dietary polyunsaturated fatty acids and gastric cancer

Polyunsaturated fatty acids (PUFAs) are fatty acids, containing more than one double bond and have both anti-inflammatory properties and inhibit tumor progression effects as well as carcinogenic properties. There is inconclusive evidence regarding the effect of PUFA intake on gastric cancer in diverse populations. We, therefore, aimed to determine the association between PUFA intake and risk of gastric cancer in a hospital-based case-control study comprising 1182 incident cases of gastric cancer and 2965 controls in Vietnam. A semiquantitative validated food frequency questionnaire was used to derive PUFA intake. Unconditional logistic regression model was applied to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of gastric cancer in relation to PUFA intake. Overall, there was a dose-response inverse association between PUFA intake and gastric cancer risk (ORper-SD increment = 0.72, 95% CI: 0.65-0.79; Ptrend < 0.001). Compared with quintile 1 (the lowest quintile), the ORs and respective 95% CIs of gastric cancer for quintiles 2, 3, 4, and 5 of the PUFA intake were 0.65 (0.52-0.80), 0.51 (0.41-0.64), 0.47 (0.37-0.59), and 0.37 (0.28-0.48), respectively. A similar pattern was observed in both sexes and individuals aged <60 years and those aged 60 years or older. In summary, we found a risk reduction of gastric cancer in individuals with a higher intake of PUFA in the Vietnamese population, regardless of sex or age. Our findings have great implications for the prevention and control programs against gastric cancer in low-middle-income countries and similar limited-resource settings.

Modified Zuojin pill alleviates gastric precancerous lesions by inhibiting glycolysis through the HIF-1α pathway

BACKGROUND

Gastric precancerous lesions (GPL) typically originates from chronic gastritis (CG), and the changes in glycolysis mediated by the HIF-1α pathway during the progression from CG to GPL are unclear. Modified Zuojin pill (SQQT) is a traditional Chinese herbal formula used for treating GPL. However, the underlying mechanism has not been fully elucidated.

PURPOSE

To investigate the changes in glycolysis mediated by the HIF-1α pathway during the progression from CG to GPL and whether SQQT can alleviate GPL by attenuating glycolysis through the HIF-1α pathway.

METHODS

A rat model of GPL was established, and the changes of glycolysis mediated by the HIF-1α pathway during the progression from CG to GPL were detected in 12th, 18th, 24th, and 30th weeks. The therapeutic efficacy of SQQT was evaluated through pathological changes. In vitro, the GPL cell model (MC cell) originated from GES-1 cells intervened by MNNG. The effects of SQQT on glycolysis and the HIF-1α pathway were detected in vivo and in vitro. In vitro, HIF-1α overexpression was used to confirmed that SQQT attenuated glycolysis by targeting the HIF-1α pathway.

RESULTS

Our study revealed that glycolysis mediated by the HIF-1α pathway exhibited dynamic changes in the progression from CG to GPL, characterized by sequential activation, deactivation, and reactivation. SQQT ameliorated gastric mucosal pathology and inflammation in GPL rats. Mechanistic studies revealed that SQQT alleviated glycolysis by targeting the HIF-1α pathway, and improved abnormal cellular proliferation and apoptosis. Importantly, HIF-1α overexpression blocked the effect of SQQT on glycolysis.

CONCLUSION

In the progression from CG to GPL, the HIF-1α pathway-mediated glycolysis was characterized by sequential activation, deactivation, and reactivation. SQQT attenuated glycolysis by targeting the HIF-1α pathway and improved abnormal cellular proliferation and apoptosis in the gastric mucosa, thereby exerting therapeutic effects on GPL.

Gastrointestinal cancer and occupational diesel exhaust exposure: a meta-analysis of cohort studies

BACKGROUND

Diesel exhaust exposure and cancer other than the lungs have been limitedly investigated.

AIMS

To conduct a systematic review and meta-analysis on the association between occupational exposure to diesel exhaust and gastrointestinal cancers.

METHODS

Two researchers performed a systematic literature review to identify all cohort studies on occupational exposure to diesel exhaust and risk of cancers other than lung. Of the 30 retained studies, 10 reported risk estimates for oesophageal, 18 on gastric, 15 on colon and 14 on rectal cancer. We performed random-effects meta-analyses to calculate summary relative risks (RRs) and 95% confidence intervals (CIs) for ever-exposure to diesel exhaust.

RESULTS

We calculated summary RR = 1.08 (95% CI 0.97-1.21, P heterogeneity = 0.06) for oesophageal, 1.06 (95% CI 0.99-1.14, P < 0.001) for gastric, 0.98 (95% CI 0.96-1.00, P = 0.453) for colon, and RR = 1.04 (95% CI 0.97-1.11, P = 0.013) for rectal cancer. Drivers showed an association with oesophageal (RR = 1.26, 95% CI 0.99-1.62), gastric (RR = 1.20, 95% CI 0.91-1.59) and rectal cancer (RR = 1.41, 95% CI 1.13-1.75); machine operators with oesophageal (RR = 1.09, 95% CI 1.00-1.20) and gastric (RR = 1.15, 95% CI 1.10-1.20) and handlers with oesophageal cancer (RR = 1.95, 95% CI 1.23-3.09). Studies from Europe revealed an association with gastric cancer while those from North America did not (P < 0.05). No difference was found by quality score except for gastric cancer, where high-quality studies but not low-quality ones showed increased risk (P heterogeneity = 0.04). There was no evidence of publication bias.

CONCLUSIONS

An increased but insignificant risk of oesophageal, gastric and rectal, but not colon cancer, was suggested in workers exposed to diesel exhaust. Residual confounding cannot be excluded.

Development and External Validation of a CT-Based Radiomics Nomogram to Predict Perineural Invasion and Survival in Gastric Cancer: A Multi-institutional Study

RATIONALE AND OBJECTIVES

To develop and validate a radiomics nomogram utilizing CT data for predicting perineural invasion (PNI) and survival in gastric cancer (GC) patients.

MATERIALS AND METHODS

A retrospective analysis of 408 GC patients from two institutions: 288 patients from Institution I were divided 7:3 into a training set (n = 203) and a testing set (n = 85); 120 patients from Institution II served as an external validation set. Radiomics features were extracted and screened from CT images. Independent radiomics, clinical, and combined models were constructed to predict PNI. Model discrimination, calibration, clinical utility, and prognostic significance were evaluated using area under the curve (AUC), calibration curves, decision curves analysis, and Kaplan-Meier curves, respectively.

RESULTS

15 radiomics features and three clinical factors were included in the final analysis. The AUCs of the radiomics model in the training, testing, and external validation sets were 0.843 (95% CI: 0.788-0.897), 0.831 (95% CI: 0.741-0.920), and 0.802 (95% CI: 0.722-0.882), respectively. A nomogram was developed by integrating significant clinical factors with radiomics features. The AUCs of the nomogram in the training, testing, and external validation sets were 0.872 (95% CI: 0.823-0.921), 0.862 (95% CI: 0.780-0.944), and 0.837 (95% CI: 0.767-0.908), respectively. Survival analysis revealed that the nomogram could effectively stratify patients for recurrence-free survival (Hazard Ratio: 4.329; 95% CI: 3.159-5.934; P < 0.001).

CONCLUSION

The radiomics-derived nomogram presented a promising tool for predicting PNI in GC and held significant prognostic implications.

IMPORTANT FINDINGS

The nomogram functioned as a non-invasive biomarker for determining the PNI status. The predictive performance of the nomogram surpassed that of the clinical model (P < 0.05). Furthermore, patients in the high-risk group stratified by the nomogram had a significantly shorter RFS (P < 0.05).

Development and validation of a nomogram to predict cancer-specific survival of elderly patients with unresected gastric cancer who received chemotherapy

This investigation aimed to explore the prognostic factors in elderly patients with unresected gastric cancer (GC) who have received chemotherapy and to develop a nomogram for predicting their cancer-specific survival (CSS). Elderly gastric cancer patients who have received chemotherapy but no surgery in the Surveillance, Epidemiology, and End Results Database between 2004 and 2015 were included in this study. Cox analyses were conducted to identify prognostic factors, leading to the formulation of a nomogram. The nomogram was validated using receiver operating characteristic (ROC) and calibration curves. The findings elucidated six prognostic factors encompassing grade, histology, M stage, radiotherapy, tumor size, and T stage, culminating in the development of a nomogram. The ROC curve indicated that the area under curve of the nomogram used to predict CSS for 3, 4, and 5 years in the training queue as 0.689, 0.708, and 0.731, and in the validation queue, as 0.666, 0.693, and 0.708. The calibration curve indicated a high degree of consistency between actual and predicted CSS for 3, 4, and 5 years. This nomogram created to predict the CSS of elderly patients with unresected GC who have received chemotherapy could significantly enhance treatment accuracy.

Not all carotenoids can reduce the risk of gastric cancer: a systematic review with meta-analysis

BACKGROUND

Gastric cancer is characterized by high invasiveness, heterogeneity, and late diagnosis, leading to high incidence and mortality rates. It is a significant public health concern globally. Early prevention is crucial in reducing the occurrence of gastric cancer, and dietary prevention, particularly focusing on carotenoids, has been considered a convenient and effective approach. However, the association between carotenoid intake and gastric cancer incidence remains controversial.

METHODS

A systematic search was conducted in PubMed, Ovid Embase, Web of Science, and Cochrane databases from inception to January 5, 2023. Two reviewers independently screened search results, extracted relevant data, and evaluated study quality. Statistical analysis was performed using the "metan" command in STATA 16 software. Random-effects or fixed-effects models were chosen based on the magnitude of heterogeneity among studies.

RESULTS

This study included a total of 35 publications, consisting of 23 case-control studies and 12 cohort studies. Meta-analysis of case-control studies showed that alpha-carotene (OR = 0.71, 95% CI: 0.55-0.92), beta-carotene (OR = 0.62, 95% CI: 0.53-0.72), and lutein (OR = 0.82, 95% CI: 0.69-0.97) significantly reduced the risk of gastric cancer, while beta-cryptoxanthin (OR = 0.88, 95% CI: 0.75-1.04) and lycopene (OR = 0.86, 95% CI: 0.73-1.00) showed no significant correlation. Meta-analysis of cohort studies indicated no significant associations between any of the five carotenoids and gastric cancer incidence (alpha-carotene: RR = 0.81, 95% CI: 0.54-1.23; beta-carotene: RR = 0.86, 95% CI: 0.64-1.16; beta-cryptoxanthin: RR = 0.86, 95% CI: 0.64-1.16; lutein: RR = 0.94, 95% CI: 0.69-1.29; lycopene: RR = 0.89, 95% CI: 0.69-1.14).

CONCLUSIONS

The relationship between carotenoids and gastric cancer incidence may vary depending on the type of study conducted. Considering that evidence from cohort studies is generally considered stronger than evidence from case-control studies, and high-quality randomized controlled trials show no significant association between carotenoids and gastric cancer incidence, current evidence does not support the supplementation of carotenoids for gastric cancer prevention. Further targeted research is needed to explore the association between the two.

Age, period and cohort effects on gastric cancer mortality in Spain, 1980-2021

BACKGROUND

this study aimed to evaluate the effects of age, time period and cohort (A-P-C) on gastric cancer (GC) mortality in Spain from 1980 to 2021.

METHODS

an ecological trend study was performed (with aggregated data obtained from the Spanish National Statistics Institute (INE). Joinpoint regression software was used to estimate rates by sex and age group (< 35, 35-64, > 64 years) and mortality trends. The National Cancer Institute A-P-C tools were used to assess the effects of age, time of death and birth cohort.

RESULTS

GC mortality rates in Spain decreased significantly in both sexes. In the under-35 age group, rates were stable after an initial significant decline. In the 35-64 age group, the decline was more pronounced in males than in females. In the 65+ age group, rates fell significantly for both sexes, but more so for females than for males. The net drift and local drift also showed significant decreases across all age groups from 24 years onwards. GC mortality rates increased with age and decreased with calendar time and successive birth cohorts, regardless of sex. The ratio of age-specific rates between males and females increased with age, and birth cohort relative risk estimates followed a steady downward trend until the mid-1970s, after which the decline stabilized. The relative risk decreased for both sexes, with a more pronounced decrease in males.

CONCLUSION

GC mortality rates in Spain have been decreasing over time and across successive birth cohorts, with a stabilizing trend observed for those under 35 years of age.

A Mini-review on Helicobacter pylori with Gastric Cancer and Available Treatments

Helicobacter pylori (H. pylori) is the most thoroughly researched etiological component for stomach inflammation and malignancies. Even though there are conventional recommendations and treatment regimens for eradicating H. pylori, failure rates continue to climb. Antibiotic resistance contributes significantly to misdiagnoses, false positive results, and clinical failures, all of which raise the chance of infection recurrence. This review aims to explore the molecular mechanisms underlying drug resistance in H. pylori and discuss novel approaches for detecting genotypic resistance. Modulation of drug uptake/ efflux, biofilm, and coccoid development. Newer genome sequencing approaches capable of detecting H. pylori genotypic resistance are presented. Prolonged infection in the stomach causes major problems such as gastric cancer. The review discusses how H. pylori causes stomach cancer, recent biomarkers such as miRNAs, molecular pathways in the development of gastric cancer, and diagnostic methods and clinical trials for the disease. Efforts have been made to summarize the recent advancements made toward early diagnosis and novel therapeutic approaches for H. pylori-induced gastric cancer.

Germline CDH1 variants in hereditary diffuse gastric cancer syndrome with focus on younger women

PURPOSE

The objective of this study was to determine the male and female frequency of diffuse gastric cancer (DGC), the age at diagnosis, and the country of origin in a selected population with germline CDH1 variants from families with the hereditary diffuse gastric cancer (HDGC) syndrome.

METHODS

Relevant literature dating from 1998 to 2021 was systematically searched for data on CDH1 gene. The Wilcoxon rank sum test and the Chi-square test were used to estimate if the difference observed between patients with gastric cancer (GC) and unaffected individuals was significant.

RESULTS

We identified 80 families fulfilling the established clinical criteria for HDGC CDH1 genetic screening. There were more women than men with DGC and germline CDH1 variant (65.5%). Stratifying the age at diagnosis, we identified an association between DGC, positive CDH1 screening and young women (≤ 40 years) (p = 0.015). The mean age at diagnosis was 39.6 ys for women and 42.5 ys for men. There was an association between CDH1 carrier status and DGC (p = 0.021).

CONCLUSIONS

Young women carrying germline CDH1 variants with DGC are comparatively frequent in the HDGC syndrome, and potentially at higher risk to develop DGC particularly in low-incidence areas for GC.

Advancements and Obstacles of PARP Inhibitors in Gastric Cancer

Gastric cancer (GC) is a common and aggressive cancer of the digestive system, exhibiting high aggressiveness and significant heterogeneity. Despite advancements in improving survival rates over the past few decades, GC continues to carry a worrisome prognosis and notable mortality. As a result, there is an urgent need for novel therapeutic approaches to address GC. Recent targeted sequencing studies have revealed frequent mutations in DNA damage repair (DDR) pathway genes in many GC patients. These mutations lead to an increased reliance on poly (adenosine diphosphate-ribose) polymerase (PARP) for DNA repair, making PARP inhibitors (PARPi) a promising treatment option for GC. This article presents a comprehensive overview of the rationale and development of PARPi, highlighting its progress and challenges in both preclinical and clinical research for treating GC.

SAMD4A serves as a negative prognostic marker for gastric cancer patients

INTRODUCTION

The incidence and mortality of gastric cancer remain high in the world. We aim to explore the role of SAMD4A in gastric cancer.

METHODS

The expression of SAMD4A was up-regulated in gastric adenocarcinoma and the expression level of SAMD4A in gastric adenocarcinoma and adjacent normal tissues was verified by RT-qPCR. Immunohistochemical showed that SAMD4A was mainly located in the cytoplasm.

RESULT

The result showed that the expression of SAMD4A was positively correlated with the depth of invasion, the number of lymph node metastasis, and the clinical stage in patients with gastric adenocarcinoma. Survival analysis of GEPIA database showed that the overall survival of gastric adenocarcinoma patients with positive SAMD4A expression was lower than that of the negative group. Gastric cancer cell lines with knockdown of the SAMD4A gene were used to observe the differences in cell proliferation, invasion, and migration abilities between the knockdown group and the control group. The results showed that the proliferation, invasion, and migration abilities of the SAMD4A knockdown group were both weakened compared with the control group. This study is the first to find that the expression level of SAMD4A in gastric cancer is higher than that in the adjacent group and is associated with poor prognosis of patients. SAMD4A promotes the proliferation, invasion, and migration of gastric adenocarcinoma cells.

CONCLUSION

This indicates that SAMD4A plays an important role in the occurrence and development of gastric cancer, and is expected to be an effective indicator for the diagnosis and evaluation of the prognosis of gastric cancer.

Gastric cancer risk in the elderly is associated with omeprazole use and inversely associated with aspirin use

BACKGROUND

The association between long-term omeprazole use and gastric cancer (GC) risk is controversial. The aim of this study was to investigate the incidence of GC in elderly community-dwelling omeprazole chronic users with/without aspirin compared to non-users.

METHODS

The registry of a large health management organization was searched for all community-dwelling members aged ≥65 years from January 2002 to December 2016. Data on demographics, background parameters, and chronic omeprazole and aspirin use (>11 prescriptions/year) were retrieved. Those diagnosed with new-onset GC during the study period (from January 2003) were identified.

RESULTS

Of 51 405 subjects who met the inclusion criteria, 197 were diagnosed with GC during a mean follow-up period of 8.74 ± 4.16 years. This group accounted for 0.7% of PPI chronic users (72/11 008) and 0.3% (125/40 397) of nonusers (P < 0.001). GC risk was directly associated with omeprazole chronic use [hazard ratio (HR) 2.03, 95% confidence interval (CI): 1.51-2.73, P < 0.001] and inversely associated with aspirin chronic use (HR 0.55, 95% CI: 0.40-0.75, P < 0.001). Each year of omeprazole use increased GC risk by 9%, and each year of aspirin use decreased GC risk by 10% among omeprazole chronic users. The lowest rate of GC was found in omeprazole nonusers/ aspirin chronic users, and the highest, in omeprazole chronic users/aspirin nonusers.

CONCLUSION

Higher GC rate was associated with omeprazole chronic use and inversely associated with aspirin chronic use relative to omeprazole nonuse in community-dwelling elderly.

Sleep Duration and Stress Level in the Risk of Gastric Cancer: A Pooled Analysis of Case-Control Studies in the Stomach Cancer Pooling (StoP) Project

The association between sleep and stress and cancer is underinvestigated. We evaluated these factors in association with gastric cancer (GC). Five case-control studies from the Stomach Cancer Pooling (StoP) Project were included. We calculated the odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for sleep duration and stress level in association with GC through multiple logistic regression models adjusted for several lifestyle factors. The analysis included 1293 cases and 4439 controls, 215 cardia and 919 noncardia GC, and 353 diffuse and 619 intestinal types. Sleep duration of ≥9 h was associated with GC (OR =1.57, 95% CI = 1.23-2.00) compared to 8 h. This was confirmed when stratifying by subsite (noncardia OR = 1.59, 95% CI = 1.22-2.08, and cardia OR = 1.63, 95% CI = 0.97-2.72) and histological type (diffuse OR = 1.65, 95% CI = 1.14-2.40 and intestinal OR = 1.24, 95% CI = 0.91-1.67). Stress was associated with GC (OR = 1.33, 95% CI = 1.18-1.50, continuous). This relationship was selectively related to noncardia GC (OR = 1.28, 95% 1.12-1.46, continuous). The risk of diffuse (OR = 1.32, 95% CI = 1.11-1.58) and intestinal type (OR = 1.23, 95% CI = 1.07-1.42) were higher when stress was reported. Results for the association between increasing level of stress and GC were heterogeneous by smoking and socioeconomic status (p for heterogeneity = 0.02 and <0.001, respectively). In conclusion, long sleep duration (≥9 h) was associated with GC and its subtype categories. Stress linearly increased the risk of GC and was related to noncardia GC.

Association between history of cholecystectomy and risk of gastric cancer: a meta-analysis of epidemiological studies

PURPOSE

Evidence from previous studies on the association between cholecystectomy and risk of gastric cancer are still inconsistent. We aimed at conducting a meta-analysis of epidemiological studies to evaluate this association.

METHODS

Researchers searched three databases (PubMed, Embase and Web of Science) through January 2021 for eligible studies. Relative risks (RRs) and 95% CIs in each included studies were pooled by random-effects models. Patients and the public were not involved in our study.

RESULTS

Eight studies were identified. Four studies reported significantly positive association between history of cholecystectomy and risk of gastric cancer, and the remaining studies reported null association. The pooled RR of these eight studies showed that a history of cholecystectomy was associated with a 11% higher risk of gastric cancer (pooled RR=1.11, 95% CI: 1.03 to 1.20). Moderate heterogeneity across the studies was detected (p=0.117, I2=37.8%). The pooled RRs were 1.12 (95% CI: 1.01 to 1.24) for five cohort studies and 0.95 (95% CI: 0.66 to 1.38) for three case-control studies. Compared with the risk in Europe and the USA, the pooled RR was higher for two studies conducted in Asia. Six studies were assessed as high-quality studies with the pooled RR of 1.12 (95% CI: 1.02 to 1.23). The pooled results were robust by sensitivity analyses, and no indication of publication bias was detected.

CONCLUSION

This meta-analysis suggests that a history of cholecystectomy may be associated with an increased risk of gastric cancer.

18β-glycyrrhetinic acid promotes gastric cancer cell autophagy and inhibits proliferation by regulating miR-328-3p/signal transducer and activator of transcription 3

BACKGROUND

Gastric cancer (GC) is one of the most common cancer types worldwide, and its prevention and treatment methods have garnered much attention. As the active ingredient of licorice, 18β-glycyrrhetinic acid (18β-GRA) has a variety of pharmacological effects. The aim of this study was to explore the effective target of 18β-GRA in the treatment of GC, in order to provide effective ideas for the clinical prevention and treatment of GC.

AIM

To investigate the mechanism of 18β-GRA in inhibiting cell proliferation and promoting autophagy flux in GC cells.

METHODS

Whole transcriptomic analyses were used to analyze and screen differentially expressed microRNAs (miRNAs) in GC cells after 18β-GRA intervention. Lentivirus-transfected GC cells and the Cell Counting Kit-8 were used to detect cell proliferation ability, cell colony formation ability was detected by the clone formation assay, and flow cytometry was used to detect the cell cycle and apoptosis. A nude mouse transplantation tumor model of GC cells was constructed to verify the effect of miR-328-3p overexpression on the tumorigenicity of GC cells. Tumor tissue morphology was observed by hematoxylin and eosin staining, and microtubule-associated protein light chain 3 (LC3) expression was detected by immunohistochemistry. TransmiR, STRING, and miRWalk databases were used to predict the relationship between miR-328-3p and signal transducer and activator of transcription 3 (STAT3)-related information. Expression of STAT3 mRNA and miR-328-3p was detected by quantitative polymerase chain reaction (qPCR) and the expression levels of STAT3, phosphorylated STAT3 (p-STAT3), and LC3 were detected by western blot analysis. The targeted relationship between miR-328-3p and STAT3 was detected using the dual-luciferase reporter gene system. AGS cells were infected with monomeric red fluorescent protein-green fluorescent protein-LC3 adenovirus double label. LC3 was labeled and autophagy flow was observed under a confocal laser microscope.

RESULTS

The expression of miR-328-3p was significantly upregulated after 18β-GRA intervention in AGS cells (P = 4.51E-06). Overexpression of miR-328-3p inhibited GC cell proliferation and colony formation ability, arrested the cell cycle in the G0/G1 phase, promoted cell apoptosis, and inhibited the growth of subcutaneous tumors in BALB/c nude mice (P < 0.01). No obvious necrosis was observed in the tumor tissue in the negative control group (no drug intervention or lentivirus transfection) and vector group (the blank vector for lentivirus transfection), and more cells were loose and necrotic in the miR-328-3p group. Bioinformatics tools predicted that miR-328-3p has a targeting relationship with STAT3, and STAT3 was closely related to autophagy markers such as p62. After overexpressing miR-328-3p, the expression level of STAT3 mRNA was significantly decreased (P < 0.01) and p-STAT3 was downregulated (P < 0.05). The dual-luciferase reporter gene assay showed that the luciferase activity of miR-328-3p and STAT3 3' untranslated regions of the wild-type reporter vector group was significantly decreased (P < 0.001). Overexpressed miR-328-3p combined with bafilomycin A1 (Baf A1) was used to detect the expression of LC3 II. Compared with the vector group, the expression level of LC3 II in the overexpressed miR-328-3p group was downregulated (P < 0.05), and compared with the Baf A1 group, the expression level of LC3 II in the overexpressed miR-328-3p + Baf A1 group was upregulated (P < 0.01). The expression of LC3 II was detected after intervention of 18β-GRA in GC cells, and the results were consistent with the results of miR-328-3p overexpression (P < 0.05). Additional studies showed that 18β-GRA promoted autophagy flow by promoting autophagosome synthesis (P < 0.001). qPCR showed that the expression of STAT3 mRNA was downregulated after drug intervention (P < 0.05). Western blot analysis showed that the expression levels of STAT3 and p-STAT3 were significantly downregulated after drug intervention (P < 0.05).

CONCLUSION

18β-GRA promotes the synthesis of autophagosomes and inhibits GC cell proliferation by regulating the miR-328-3p/STAT3 signaling pathway.

Leisure-time physical activity and gastric cancer risk: A pooled study within the Stomach cancer Pooling (StoP) Project

BACKGROUND

Although physical activity (PA) has been recognized as a favourable factor in the prevention of various diseases, including certain forms of cancer, the relationship between PA and gastric cancer (GC) is not yet fully understood. This study aims to provide data from a pooled analysis of case-control studies within the Stomach cancer Pooling (StoP) Project to estimate the association between leisure-time PA and the occurrence of GC.

METHODS

Six case-control studies from StoP project collected data on leisure-time PA, for a total of 2,343 cases and 8,614 controls. Subjects were classified into three leisure-time PA categories, either none/low, intermediate or high, based on study-specific tertiles. We used a two-stage approach. Firstly, we applied multivariable logistic regression models to obtain study-specific odds ratios (ORs) and corresponding 95% confidence intervals (CIs) then, we used a random-effect models to obtain pooled effect estimates. We performed stratified analyses according to demographic, lifestyle and clinical covariates.

RESULTS

The meta-analysis showed ORs of GC with no significant differences between intermediate vs low and high vs low PA level (OR 1.05 [95%CI 0.76-1.45]; OR 1.23 [95%CI 0.78-1.94], respectively). GC risk estimates did not strongly differ across strata of selected covariates except for age ≤ 55 years old (high vs low level: OR 0.72 [95%CI 0.55-0.94]) and for control population-based studies (high vs low level: OR 0.79 [95%CI 0.68-0.93]).

CONCLUSIONS

No association was found between leisure time PA and GC, apart from a slight suggestion of decreased risk below age 55 and in control population-based studies. These results may reflect specific characteristics of GC at a younger age, or the presence of a cohort effect mediating and interacting with socioeconomic determinants of GC The different distribution of PA levels among hospitalized controls could have led to an underestimated effect of PA on GC risk.

Machine learning models predict the mTOR signal pathway-related signature in the gastric cancer involving 2063 samples of 7 centers

Gastric cancer, as a tumor with poor prognosis, has been widely studied. Distinguishing the types of gastric cancer is helpful. Using the transcriptome data of gastric cancer in our study, relevant proteins of mTOR signaling pathway were screened to identify key genes by four machine learning models, and the models were validated in external datasets. Through correlation analysis, we explored the relationship between five key genes and immune cells and immunotherapy. By inducing cellular senescence in gastric cancer cells with bleomycin, we investigated changes in the expression levels of HRAS through western blot. By PCA clustering analysis, we used the five key genes for gastric cancer typing and explored differences in drug sensitivity and enrichment pathways between different clustering groups. We found that the SVM machine learning model was superior, and the five genes (PPARA, FNIP1, WNT5A, HRAS, HIF1A) were highly correlated with different immune cells in multiple databases. These five key genes have a significant impact on immunotherapy. Using the five genes for gastric cancer gene typing, four genes were expressed higher in group 1 and were more sensitive to drugs in group 2. These results suggest that subtype-specific markers can improve the treatment and provide precision drugs for gastric cancer patients.

Integrated oxidative stress score for predicting prognosis in stage III gastric cancer undergoing surgery

Objective: This study aimed to develop a novel scoring system, named the integrated oxidative stress score (IOSS), based on oxidative stress indices to predict the prognosis in stage III gastric cancer. Methods: Retrospective analysis of stage III gastric cancer patients who were operated on between January 2014 and December 2016 were enrolled into this research. IOSS is a comprehensive index based on an achievable oxidative stress index, comprising albumin, blood urea nitrogen, and direct bilirubin. The patients were divided according to receiver operating characteristic curve into two groups of low IOSS (IOSS ≤ 2.00) and high IOSS (IOSS > 2.00). The grouping variable was performed by Chi-square test or Fisher's precision probability test. The continuous variables were evaluated by t-test. The disease free survival (DFS) and overall survival (OS) were performed by Kaplan-Meier and Log-Rank tests. Univariate Cox proportional hazards regression models and stepwise multivariate Cox proportional hazards regression analysis were determined to appraise the potential prognostic factors for DFS and OS. A nomogram of the potential prognostic factors by the multivariate analysis for DFS and OS was established with R software. In order to assess the accuracy of the nomogram in forecasting prognosis, the calibration curve and decision curve analysis were produced, contrasting the observed outcomes with the predicted outcomes. Results: The IOSS was significantly correlated with the DFS and OS, and was a potential prognostic factor in patients with stage III gastric cancer. Patients with low IOSS had longer survival (DFS: χ² = 6.632, p = 0.010; OS: χ² = 6.519, p = 0.011), and higher survival rates. According to the univariate and multivariate analyses, the IOSS was a potential prognostic factor. The nomograms were conducted on the potential prognostic factors to improve the correctness of survival prediction and evaluate the prognosis in stage III gastric cancer patients. The calibration curve indicated a good agreement in 1-, 3-, 5-year lifetime rates. The decision curve analysis indicated that the nomogram's predictive clinical utility for clinical decision was better than IOSS. Conclusion: IOSS is a nonspecific tumor predictor based on available oxidative stress index, and low IOSS is found to be a vigorous factor of better prognosis in stage III gastric cancer.

Gastric Cancer Risk in Association with Underweight, Overweight, and Obesity: A Systematic Review and Meta-Analysis

This study aimed to investigate the risk of gastric cancer (GC) in abnormal body mass index (BMI) groups. A systematic search was carried out on Embase, PubMed/Medline, and Scopus from January 2000 to January 2023. The pooled risk ratio (RR) with a 95% confidence interval (CI) was assessed using a random-effect model. Thirteen studies with total of 14,020,031 participants were included in this systematic review. The pooled RR of GC was 1.124 (95% CI, 0.968-1.304, I²: 89.08%) in underweight class, 1.155 (95% CI, 1.051-1.270, I²: 95.18%) in overweight class, and in 1.218 (95% CI, 1.070-1.386, I²: 97.65%) obesity class. There is no difference between cardia and non-cardia gastric cancer, while non-Asian race and female gender have higher risk of cancer, as Meta-regression of obesity and overweight classes showed. These findings suggest that there is a positive association between excess body weight and the risk of GC, with a higher impact in women than men and in non-Asian than Asian populations. Since abnormal weight is tied to various diseases, including GC, healthcare experts, and policymakers should continue interventions aiming to achieve a normal BMI range.

Updated Epidemiology of Gastric Cancer in Asia: Decreased Incidence but Still a Big Challenge

Despite the decline in incidence and mortality rates, gastric cancer (GC) is the fifth leading cause of cancer deaths worldwide. The incidence and mortality of GC are exceptionally high in Asia due to high H. pylori infection, dietary habits, smoking behaviors, and heavy alcohol consumption. In Asia, males are more susceptible to developing GC than females. Variations in H. pylori strains and prevalence rates may contribute to the differences in incidence and mortality rates across Asian countries. Large-scale H. pylori eradication was one of the effective ways to reduce GC incidences. Treatment methods and clinical trials have evolved, but the 5-year survival rate of advanced GC is still low. Efforts should be put towards large-scale screening and early diagnosis, precision medicine, and deep mechanism studies on the interplay of GC cells and microenvironments for dealing with peritoneal metastasis and prolonging patients' survival.

MicroRNA-372 acts as a double-edged sword in human cancers

MicroRNAs (miRNAs or miRs) are non-coding, single-stranded, endogenous RNAs that regulate various biological processes, most notably the pathophysiology of many human malignancies. It process is accomplished by binding to 3'-UTR mRNAs and controlling gene expression at the post-transcriptional level. As an oncogene, miRNAs can either accelerate cancer progression or slow it down as a tumor suppressor. MicroRNA-372 (miR-372) has been found to have an abnormal expression in numerous human malignancies, implying that the miRNA plays a role in carcinogenesis. It is both increased and downregulated in various cancers, and it serves as both a tumor suppressor and an oncogene. This study examines the functions of miR-372 as well as the LncRNA/CircRNA-miRNA-mRNA signaling pathways in various malignancies and analyses its potential prognostic, diagnostic, and therapeutic implications.

Tetrandrine inhibits migration and invasion of BGC-823 and MKN-45 cells by regulating PI3K/AKT/mTOR signaling pathway

Tetrandrine (Tet), a traditional Chinese herbal medicine extract, exhibits anti-cancer effect on many types of cancer. Nonetheless, the action mechanism of Tet in gastric cancer (GC) is still largely unclear. In the current study, proliferation, invasion, and migration of the BGC-823 and MKN-45 cells were effectively suppressed by Tet treatment in a dose-dependent manner. Moreover, Tet suppressed expression of the proliferation-associated protein PCNA, the interstitial cell phenotype N-cadherin, and the extracellular matrix-associated MMP-2 and MMP-9 in BGC-823 and MKN-45 cells in a dose-dependent manner. PI3K/AKT/mTOR, a cancer promoting signaling, was inactivated by Tet in a dose-dependent manner in BGC-823 and MKN-45 cells. Furthermore, our results demonstrated that the inhibition of Tet to PCNA, N-cadherin, MMP-2, and MMP-9 expression was partly rescuedby AKT inhibitor or mTOR inhibitor. In animal experiments, tumor growth was inhibited by Tet administration in a dose-dependent manner. In conclusion, the current data indicated that Tet had a critical effect on inhibiting BGC-823 and MKN-45 cells proliferation, migration, invasion, and tumor growth via regulating PI3K/AKT/mTOR signaling pathway, suggesting that Tet might be a potential treatment for GC.

CDH1 mutations recurrence and global clustering in genetically tested families with hereditary diffuse gastric cancer syndrome: results from a systematic study

The global distribution of germline CDH1 mutations in hereditary diffuse gastric cancer families, is highly heterogenous. The aim of this study was to determine if there is any geographic clustering of CDH1 mutations in families with the hereditary diffuse gastric cancer syndrome. Data from 1998 to 2021 were collected systematically according to the PRISMA guidelines. 571 germline CDH1 mutations were recorded worldwide, with 387 (67.8%) of them reported in 108 families. The largest clusters of CDH1 mutations were identified in central Europe, north America, northern Europe, New Zealand (Māori), and south America. A high penetrance risk for GC development was observed for c.1008G > T in New Zealand (Māori), c.1565 + 2insT in northern Europe, c.1901C > T in Portugal, and c.1003C > T in the USA. Our observations are consistent with a specific local clustering of some recurrent CDH1 mutations within specific countries.

The roles and molecular mechanisms of long non-coding RNA WT1-AS in the maintenance and development of gastric cancer stem cells

It has been proposed that cancer stem cells (CSCs) are responsible for almost all malignant phenotypes of tumors. Long non-coding RNA WT1 antisense RNA (WT1-AS) has been found to be implicated in lung cancer cell stemness. However, the roles and molecular mechanisms of WT1-AS in the development of gastric cancer stem cells (GCSCs) remain unknown. Our present study showed that WT1-AS negatively regulated WT1 expression in GCSCs. WT1-AS knockdown or Wilms' tumor 1 (WT1) overexpression improved GCSC proliferative and migratory capacities, inhibited GCSC apoptosis, potentiated the resistance of GCSCs to 5-FU, promoted GCSC EMT, induced HUVEC angiogenesis, enhanced GCSC stemness, and facilitated in-vitro 3D GCSC aggregate formation. WT1-AS overexpression exerted reverse effects. WT1-AS ameliorated the malignant phenotypes of GCSCs by down-regulating WT1 in vitro. WT1-AS inhibited tumor growth and metastasis, and reduced tumor stemness in GCSCs-derived (s.c., i.p., and i.v.) xenografts in vivo. Moreover, XBP1 was identified as an upstream regulator of WT1-AS in GCSCs. Also, 4 potential WT1-AS downstream targets (i.e. PSPH, GSTO2, FYN, and PHGDH) in GCSCs were identified. Additionally, CACNA2D1 was demonstrated to be a downstream target of the WT1-AS/WT axis. XBP1 or CACNA2D1 knockdown exerted an adverse effect on the maintenance of stem cell-like behaviors and characteristics of GCSCs. In conclusion, WT1-AS weakened the stem cell-like behaviors and characteristics of GCSCs in vitro and in vivo by down-regulating WT1. Investigations into the molecular mechanisms underlying the complex phenotypes of GCSCs might contribute to the better management of gastric cancer.

Development and validation of prognostic nomogram for patients with metastatic gastric adenocarcinoma based on the SEER database

The aim of this study was to investigate the prognostic factors affecting overall survival in patients with metastatic gastric adenocarcinoma and to establish a nomogram prediction model for comprehensive clinical application. Data from 2370 patients with metastatic gastric adenocarcinoma between 2010 and 2017 were retrieved from the surveillance, epidemiology, and end results database. They were randomly divided into a training set (70%) and a validation set (30%), univariate and multivariate Cox proportional hazards regressions were used to screen important variables that may affect overall survival and to establish the nomogram. The nomogram model was evaluated using a receiver operating characteristic curve, calibration plot, and decision curve analysis. Internal validation was performed to test the accuracy and validity of the nomogram. Univariate and multivariate Cox regression analyses revealed that, age, primary site, grade, and American joint committee on cancer. T, bone metastasis, liver metastasis, lung metastasis, tumor Size, and chemotherapy were identified as independent prognostic factors for overall survival and were included in the prognostic model to construct a nomogram. The prognostic nomogram showed good overall survival risk stratification ability for the area under the curve, calibration plots, and decision curve analysis in both the training and validation sets. Kaplan-Meier curves further showed that patients in the low-risk group had better overall survival. This study synthesizes the clinical, pathological, therapeutic characteristics of patients with metastatic gastric adenocarcinoma, establishes a clinically effective prognostic model, and that can help clinicians to better evaluate the patient's condition and provide accurate treatment.

Trends in gastric cancer mortality 1990-2019 in 36 countries worldwide, with predictions to 2025, and incidence, overall and by subtype

BACKGROUND

Gastric cancer (GC) incidence is declining heterogeneously worldwide. We aimed to calculate updated mortality trends for GC.

METHODS

We investigated time trends for selected countries using the World Health Organization database. We computed age-standardized mortality rates (ASMR) per 100,000 persons over the 1990-2019 period. We reported rates for the 2010-2014 and 2015-19 calendar periods, and the corresponding percent changes. We used joinpoint regression analysis to identify changes in the slope of mortality trends, and predict the number of deaths and rates for 2025. We also reported 2008-2012 incidence rates of cardia and noncardia GC.

RESULTS

Mortality trends from GC have been favorable since 1990 for all countries analyzed and the European Union (EU 27), in both sexes and all ages. GC mortality is predicted to decline in all countries for both sexes, except for French and US women aged 35-64 years, and Canadian men aged 35-64. The highest proportions of cardia GC were observed in Northern and Central Europe while the lowest ones in Southern and Eastern Europe. Elsewhere, the highest proportions were registered in countries with low incidence and mortality rates, whereas high-mortality countries showed lower proportions of cardia GC.

CONCLUSION

Observed and predicted GC mortality trends declined in most countries in both sexes, with few exceptions, likely due to the control of GC risk factors, in particular Hp infection.

The Rise of Gastrointestinal Cancers as a Global Phenomenon: Unhealthy Behavior or Progress?

The overall burden of cancer is rapidly increasing worldwide, reflecting not only population growth and aging, but also the prevalence and spread of risk factors. Gastrointestinal (GI) cancers, including stomach, liver, esophageal, pancreatic, and colorectal cancers, represent more than a quarter of all cancers. While smoking and alcohol use are the risk factors most commonly associated with cancer development, a growing consensus also includes dietary habits as relevant risk factors for GI cancers. Current evidence suggests that socioeconomic development results in several lifestyle modifications, including shifts in dietary habits from local traditional diets to less-healthy Western diets. Moreover, recent data indicate that increased production and consumption of processed foods underlies the current pandemics of obesity and related metabolic disorders, which are directly or indirectly associated with the emergence of various chronic noncommunicable conditions and GI cancers. However, environmental changes are not restricted to dietary patterns, and unhealthy behavioral features should be analyzed with a holistic view of lifestyle. In this review, we discussed the epidemiological aspects, gut dysbiosis, and cellular and molecular characteristics of GI cancers and explored the impact of unhealthy behaviors, diet, and physical activity on developing GI cancers in the context of progressive societal changes.

Genetic and epigenetic instability induced by betel quid associated chemicals

Over the years, betel quid chewing and tobacco use have attracted considerable interest as they are implicated as the most likely causative risk factors of oral and esophageal cancers. Although areca nut use and betel quid chewing may lead to apoptosis, chronic exposure to areca nut and slaked lime may promote pre-malignant and malignant transformation of oral cells. The putative mutagenic and carcinogenic mechanisms may involve endogenous nitrosation of areca and tobacco alkaloids as well as the presence of direct alkylating agents in betel quid and smokeless tobacco. Metabolic activation of carcinogenic N-nitrosamines by phase-I enzymes is required not only to elicit the genotoxicity via the reactive intermediates but also to potentiate the mutagenicity with the sporadic alkylations of nucleotide bases, resulting in the formation of diverse DNA adducts. Persistent DNA adducts provides the impetus for genetic and epigenetic lesions. The genetic and epigenetic factors cumulatively influence the development and progression of disorders such as cancer. Accumulation of numerous genetic and epigenetic aberrations due to long-term betel quid (with or without tobacco) chewing and tobacco use culminates into the development of head and neck cancers. We review recent evidence that supports putative mechanisms for mutagenicity and carcinogenicity of betel quid chewing along with tobacco (smoking and smokeless) use. The detailed molecular mechanisms of the extent of accumulation and patterns of genetic alterations, indicative of the prior exposure to carcinogens and alkylating agents because of BQ chewing and tobacco use, have not yet been elucidated.

Risk factors in the development of gastric adenocarcinoma in the general population: A cross-sectional study of the Wuwei Cohort

Several risk factors have been identified for the development of gastric adenocarcinoma (GAC), where the control group was usually a healthy population. However, it is unclear at what stage known risk factor exert their influence toward the progression to cancer. Based on the Wuwei Cohort, we enrolled 1,739 patients with chronic non-atrophic gastritis (no-CAG), 3,409 patients with chronic atrophic gastritis (CAG), 1,757 patients with intestinal metaplasia (IM), 2,239 patients with low-grade dysplasia (LGD), and 182 patients with high-grade dysplasia (HGD) or GAC to assess the risk factors between each two consecutive stages from no-CAG to GAC/HGD using adjusted logistic regression. We found that different groups of risk factors were associated with different stages. Age, occupation of farmer, low annual family income, Helicobacter pylori (H. pylori) infection, drinking, eating hot food, histories of gastritis and peptic ulcer were associated with the development of CAG. Age, illiteracy, H. pylori infection, smoking, eating hot food, eating quickly, and histories of gastritis and gallbladder diseases were associated with the progression to IM from CAG. Male, occupation of farmer and history of peptic ulcer were associated with the development of LGD from IM. Age, male and polyp history appeared to be risk factors associated with the development of GAC/HGD from LGD. In conclusion, it seems that most risk factors function more as a set of switches that initiated the GAC carcinogenesis. H. Pylori eradication and control of other risk factors should be conducted before IM to decrease the incidence of GAC.

Signaling pathways of oxidative stress response: the potential therapeutic targets in gastric cancer

Gastric cancer is one of the top causes of cancer-related death globally. Although novel treatment strategies have been developed, attempts to eradicate gastric cancer have been proven insufficient. Oxidative stress is continually produced and continually present in the human body. Increasing evidences show that oxidative stress contributes significantly to the development of gastric cancer, either through initiation, promotion, and progression of cancer cells or causing cell death. As a result, the purpose of this article is to review the role of oxidative stress response and the subsequent signaling pathways as well as potential oxidative stress-related therapeutic targets in gastric cancer. Understanding the pathophysiology of gastric cancer and developing new therapies for gastric cancer depends on more researches focusing on the potential contributors to oxidative stress and gastric carcinogenesis.

Knockdown of Circ_0003506 Impedes Radioresistance, Cell Growth, Migration and Invasion in Gastric Cancer

BACKGROUND

Radioresistance is a major obstacle for clinical treatment of gastric cancer (GC). has_circ_0003506 (circ_0003506) was reported as an oncogenic factor in GC, but its effect on radioresistant GC is unclear.

AIMS

This study aimed to explore the role of circ_0003506 in radioresistance and regulatory mechanism.

METHODS

The expression detection was performed by real-time polymerase chain reaction. Cell survival was analyzed by colony formation assay. Cell proliferation was measured by Cell Counting Kit-8 assay and colony formation assay. Cell migration and invasion were examined using transwell assay. Cell apoptosis was assessed by flow cytometry. The target binding was confirmed via dual-luciferase reporter assay. The protein level was determined through western blot. Animal assay was performed for the functional exploration of circ_0003506 on radiosensitivity in vivo.

RESULTS

Circ_0003506 was upregulated in radioresistant GC cells. Downregulation of circ_0003506 inhibited radioresistance to repress proliferation, migration and invasion but increase apoptosis in radioresistant GC cells. Circ_0003506 was a sponge of miR-1256. The effects of si-circ_0003506 on radioresistant GC cells were reverted by miR-1256 inhibitor. MiR-1256 suppressed tumor progression in radioresistant GC cells by downregulating bone morphogenetic protein type 2 receptor. Circ_0003506 regulated the level of bone morphogenetic protein type 2 receptor by targeting miR-1256. Downregulating circ_0003506 increased radiosensitivity of GC in vivo via regulating miR-1256 and bone morphogenetic protein type 2 receptor.

CONCLUSION

Knockdown of circ_0003506 suppressed radioresistance in GC through the regulation of miR-1256/bone morphogenetic protein type 2 receptor axis. Circ_0003506 might be a therapeutic target in radiotherapy of GC.

Gastric cancer incidence trends in China and Japan from 1990 to 2019: Disentangling age-period-cohort patterns

BACKGROUND

Recent data have shown divergent trends in gastric cancer (GC) incidence between China and Japan; however, the cause for has not been explored.

METHODS

We retrieved GC incidence data from 1990 to 2019 from the Global Burden of Disease study, stratified by sex for both countries. We analyzed annual average percentage change (AAPC) via a joinpoint regression model and estimated the effects of age, period, and cohort via the age-period-cohort model.

RESULTS

The age-standardized incidence rate trends for GC decreased in both countries and both sexes, but the reduction was more pronounced in Japan because the AAPC for Japanese males (AAPC = -2.65%; 95% CI, -2.98 to -2.32) was eight times greater than that of Chinese males (AAPC = -0.30%; 95% CI, -0.5 to -0.09). The age and cohort effects on the trend are similar in both countries: the risk of GC incidence increased with age among the Chinese and the Japanese but was lower among younger birth cohorts. The two countries showed contrasting trends over the study period; although the risk of GC rapidly decreased for Japanese males and females, it increased by twofold among Chinese males.

CONCLUSIONS

The period effect is the main reason for the divergent trends in age-standardized incidence rate for GC in China and Japan. By comparing national cancer control programs in both countries, we concluded that countries with a high prevalence of GC, such as China, can learn from Japan's experience in controlling GC by actively conducting national population screening, which is expected to facilitate both prevention and treatment of GC.

LAY SUMMARY

More than one-half of all new gastric cancer (GC) worldwide occur in China and Japan, but the reasons for the different incidence trends have not been thoroughly analyzed. Analysis using the age-period-cohort model confirmed that the cohort effect was the main reason for the decline in age-standardized incidence rate (ASIR) for GC and that the period effect may be the main reason for the divergent trends in gastric cancer ASIR in China and Japan.

Bioinformatics Prediction and Machine Learning on Gene Expression Data Identifies Novel Gene Candidates in Gastric Cancer

Gastric cancer (GC) is one of the five most common cancers in the world and unfortunately has a high mortality rate. To date, the pathogenesis and disease genes of GC are unclear, so the need for new diagnostic and prognostic strategies for GC is undeniable. Despite particular findings in this regard, a holistic approach encompassing molecular data from different biological levels for GC has been lacking. To translate Big Data into system-level biomarkers, in this study, we integrated three different GC gene expression data with three different biological networks for the first time and captured biologically significant (i.e., reporter) transcripts, hub proteins, transcription factors, and receptor molecules of GC. We analyzed the revealed biomolecules with independent RNA-seq data for their diagnostic and prognostic capabilities. While this holistic approach uncovered biomolecules already associated with GC, it also revealed novel system biomarker candidates for GC. Classification performances of novel candidate biomarkers with machine learning approaches were investigated. With this study, AES, CEBPZ, GRK6, HPGDS, SKIL, and SP3 were identified for the first time as diagnostic and/or prognostic biomarker candidates for GC. Consequently, we have provided valuable data for further experimental and clinical efforts that may be useful for the diagnosis and/or prognosis of GC.

circXRCC5 foster gastric cancer growth and metastasis by the HNRNPC/circXRCC5/miR-655-3p/RREB1/UBA2 positive feedback loop

Gastric cancer (GC) is one of the most common malignancies, leading to millions of deaths each year. Here, we investigated the molecular mechanisms of GC, with a focus on circXRCC5/miR-655-3p/RREB1/UBA2 axis. circXRCC5 was identified in 62 paired cancer specimens and adjacent normal tissues by genome-wide bioinformatics analysis and verified by qRT-PCR and Sanger sequencing. Knockdown or exogenous expression of circXRCC5 was performed to validate the functional significance of circXRCC5 using both in vitro and in vivo assays, including CCK-8, colony formation, EdU incorporation, transwell system, as well as animal experiments. RNA immunoprecipitation, biotinylated RNA pull-down, ChIP, and dual-luciferase assays were employed to validate the regulatory network of circXRCC5/miR-655-3p/RREB1/UBA2. Frequently elevated circXRCC5 in GC tissues and cell lines was associated with poor prognosis of GC patients. Functionally, circXRCC5 overexpression facilitated GC cell proliferation, migration, and invasion, as well as promoted tumor growth and metastasis in vivo. Mechanistically, circXRCC5 served as a sponge of miR-655-3p to induce upregulation of RREB1. RREB1 was identified as a transcriptional activator of UBA2, thus contributing to GC tumorigenesis. Moreover, RNA binding protein (RBP) HNRNPC was proved to interact with circXRCC5 to promote circXRCC5 biogenesis. Collectively, circXRCC5 facilitates GC progression through the HNRNPC/circXRCC5/miR-655-3p/RREB1/UBA2 axis, which might bring novel therapeutic strategies for GC treatment.

Meat consumption and risk of esophageal and gastric cancer in the Golestan Cohort Study, Iran

Red meat and processed meat are associated with some gastrointestinal cancers. Our study aims to investigate the association of different meat types with esophageal and gastric cancer (EC, GC) in a high-risk population. The Golestan Cohort Study (GCS) is a population-based cohort of 50 045 individuals aged 40 to 75 from northeast Iran. Detailed data on different exposures were collected using validated questionnaires. We considered quintiles of meat consumption, using grams and density (g/1000 kcal/day). We calculated intake of red, processed, organ and white meat, as well as total red meat, including the first three. We used proportional hazards regression models to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the association between meat types and cancer. During 12 years of follow-up, out of 49 585 participants (57.4% women), 369 developed EC (48.2% women) and 368 developed GC (27.5% women), including 309 esophageal squamous cell, 20 esophageal adenocarcinomas, 216 cardia and 95 non-cardia GC. No association was found for EC except for red meat among females (HR for one quintile increase 1.13, 95% CI = 1.00-1.27). The risk of GC increased for intake of total red meat (HR 1.08, 95% CI = 1.00-1.17) and red meat separately (HR 1.09, 95% CI = 1.00-1.18). The HR for red meat and non-cardia GC was 1.23 (95% CI = 1.02-1.48). No associations were observed for other types of meat. In conclusion, in this high-risk population red meat intake is associated with GC, but not EC, suggesting a substantial role of this modifiable factor in determining the burden of GC.

Immunoregulation and clinical significance of neutrophils/NETs-ANGPT2 in tumor microenvironment of gastric cancer

Although significant progress has been made in the study of gastric cancer (GC), clinicians lack reliable protein markers for accurate diagnosis and tumor stratification. Neutrophil extracellular traps (NETs) are networks of extracellular fibers composed of DNA from neutrophils. We have previously reported that abundant NETs are deposited in GC, damaging human umbilical vein endothelial cells (HUVECs) and triggering the release of tissue factors, leading to a hypercoagulable state in GC. However, the specific effects of NETs on HUVECs are unclear. We aimed to explore the functional changes caused by NETs on HUVECs, providing evidence that NETs may fuel GC progression. Through quantitative proteomics, we identified 6182 differentially expressed proteins in NET-stimulated HUVECs by TMT. The reliability of the TMT technique was confirmed by parallel reaction monitoring (PRM) analysis of 17 differentially expressed proteins. Through bioinformatics analysis, we found that NETs upregulate ANGPT2 in HUVECs. We comprehensively analyzed the prognosis, biological function, immune response, and therapeutic value of ANGPT2 in GC. We found that overexpression of ANGPT2 in GC is associated with poor prognosis and potentially regulates multiple biological functions. At the same time, ANGPT2 also predicted immunotherapeutic and chemotherapeutic responses in GC. In conclusion, NETs promoted ANGPT2 overexpression in the GC microenvironment. In the future, the neutrophil/NETs-ANGPT2 axis may provide a new target for the treatment of GC.

Outcomes and Prognostic Factors of Metastatic Gastric Cancer: A Single-Center Experience

Background

Gastric cancer (GC) carries a poor survival outcome despite the availability of many therapeutic agents active in treatment. In this study, we aimed to evaluate the survival outcomes of metastatic GC treatment from a single center in Saudi Arabia and identify possible prognostic factors.

Methodology

Data on patients diagnosed with metastatic GC between December 2009 and November 2013 were collected and analyzed.

Results

During this period, 41 patients were diagnosed with a median age at diagnosis of 52 years, and 56.1% of patients were males. Only four (9.2%) patients had human epidermal growth factor receptor 2 overexpression. Overall, 83% were treated with oxaliplatin-based chemotherapy. The median progression-free survival (PFS) and overall survival (OS) were 4.1 and 15.4 months, respectively. Female sex was an independent prognostic factor for better PFS and OS. Normal lymphocyte count was associated with improved PFS.

Conclusions

Our study highlights poor outcomes in patients with metastatic GC and the need for further research in this field.

Tegaserod Maleate Suppresses the Growth of Gastric Cancer In Vivo and In Vitro by Targeting MEK1/2

Gastric cancer (GC) ranks fifth in global incidence and fourth in mortality. The current treatments for GC include surgery, chemotherapy and radiotherapy. Although treatment strategies for GC have been improved over the last decade, the overall five-year survival rate remains less than 30%. Therefore, there is an urgent need to find novel therapeutic or preventive strategies to increase GC patient survival rates. In the current study, we found that tegaserod maleate, an FDA-approved drug, inhibited the proliferation of gastric cancer cells, bound to MEK1/2 and suppressed MEK1/2 kinase activity. Moreover, tegaserod maleate inhibited the progress of gastric cancer by depending on MEK1/2. Notably, we found that tegaserod maleate suppressed tumor growth in the patient-derived gastric xenograft (PDX) model. We further compared the effect between tegaserod maleate and trametinib, which is a clinical MEK1/2 inhibitor, and confirmed that tegaserod maleate has the same effect as trametinib in inhibiting the growth of GC. Our findings suggest that tegaserod maleate inhibited GC proliferation by targeting MEK1/2.

Gastric cancer incidence, mortality and burden in adolescents and young adults: a time-trend analysis and comparison among China, South Korea, Japan and the USA

OBJECTIVES

To evaluate and compare the burden of gastric cancer in adolescents and young adults (GCAYA) among China, South Korea, Japan and the USA, four countries with similar or different rates of gastric cancer (GC) incidence, development levels and cancer control strategies.

DESIGN

This population-based observational study collected the epidemiological data of GCAYA from the Global Burden of Diseases Study 2019. The trend magnitude and directions over time for incidence and mortality of GCAYA were analysed and compared among four countries.

MAIN OUTCOMES AND MEASURES

Outcomes included new cases, deaths, mortality-to-incidence ratios (MIRs), disability-adjusted life years, and their age-standardised rates and estimated annual percentage changes (AAPCs).

RESULTS

There were 49 008 new cases and 27 895 deaths from GCAYA in 2019, nearly half of which occurred in China. The AAPCs for the age-standardised incidence and mortality rate were 0.3 (-0.1 to 0.7), -3.6 (-3.7 to -3.4), -3.2 (-3.8 to -2.6), -0.1 (-0.6 to 0.5) and -2.0 (-2.3 to -1.6), -5.6 (-6.2 to -5.0), -4.4 (-4.7 to -4.1), -0.7 (-1.0 to -0.3) in China, South Korea, Japan and the USA, respectively. The incidence rate for females in the USA rose by 0.4% annually. GC ranks fifth, first, fourth and ninth in China, South Korea, Japan and the USA regarding burdens caused by cancer in adolescents and young adults. The MIRs declined constantly in South Korea and China, and the MIR in the USA became the highest in 2019.

CONCLUSIONS

Although not covered by prevention and screening programmes, variations in disease burden and time trends may reflect variations in risk factors, cancer control strategies and treatment accessibility of GC among the four countries. Investigating the reasons behind the varying disease burden and changing trends of GCAYA across countries will inform recommendations for prevention measures and timely diagnosis specific to this underserved population to further decrease the GC burden.

Peptic ulcer as mediator of the association between risk of gastric cancer and socioeconomic status, tobacco smoking, alcohol drinking and salt intake

BACKGROUND

Peptic ulcer disease (PUD) and gastric cancer (GC) are more prevalent in individuals with low socioeconomic status (SES) and share several risk factors. The aim of this study was to investigate the mediating role of PUD in the association between established risk factors and GC.

METHODS

We conducted a pooled analysis of 12 studies from the Stomach Cancer Pooling Project Consortium, including a total of 4877 GC cases and 11 808 controls. We explored the mediating role of PUD in the association between SES, tobacco smoking, heavy alcohol drinking and salt intake, and GC. Also, we assessed the ORs and 95% CIs of the risk factors and both PUD and GC.

RESULTS

PUD mediated 36% of the smoking effect mainly among men. Other risk factors were only slightly mediated by PUD (SES, 5.3%; heavy alcohol drinking, 3.3%; and salt intake, 2.5%). No significant difference was found when excluding PUD diagnosed within 2 years from GC.

CONCLUSIONS

Our study provides innovative information on the mechanism of stomach mucosal damage leading to PUD and GC, with respect to the effect of tobacco smoking in particular.

Progress in cancer epidemiology: avoided deaths in Europe over the last three decades

Progress in cancer epidemiology and prevention has been a key determinant of the fall in cancer mortality in Europe. Using mortality and population figures from the WHO and Eurostat databases, we estimated the number of averted cancer deaths in the EU27 over the period 1989-2021, for both sexes, for all cancers, and nine major cancer sites. We also computed the avoided deaths for all cancers in five major European countries and the UK. We estimated a total of 4 958 000 (3 339 000 men and 1 619 000 women) avoided deaths for all neoplasms over the period 1989-2021 and 348 000 (246 000 men and 102 000 women) in 2021 alone in the EU27. For both sexes, we estimated 1 679 000 avoided deaths for stomach cancer, 747 000 for colorectum, 227 000 for bladder, 102 000 for leukemias. Avoided deaths for lung cancer accounted for 1 156 000 in men, while no reduction was estimated for women. For breast and uterine cancer, avoided deaths were about 300 000, for ovary 105 000 and for prostate 352 000. In the UK, a total of 1 061 000 (721 000 men and 340 000 women) deaths was avoided. Elimination of tobacco may avoid a further 20% of cancer mortality by 2050. Control of alcohol, overweight and obesity, and occupational and environmental carcinogens may avoid an additional 10% of cancer deaths. A similar reduction may be due to optimal adoption of cervical, colorectal, breast, and probably, lung and prostate cancer screening. Thus, primary and secondary cancer prevention can avoid an additional third of cancer deaths in Europe up to 2050.

What are the late effects of older gastric cancer survivors?: A scoping review

Objective

Methods

Results

Conclusions

ARIH2 regulates the proliferation, DNA damage and chemosensitivity of gastric cancer cells by reducing the stability of p21 via ubiquitination

Ariadne homolog 2 (ARIH2) is a key member of the RING-between-RING (RBR) E3 ligase family, which is characterized by an RBR domain involved in the polyubiquitination process. However, the molecular mechanism and biological function of ARIH2 in the pathogenesis of gastric cancer remain unclear. In this paper, we found that high ARIH2 expression is correlated with poor prognosis in gastric cancer patients and that ARIH2 can significantly promote the proliferation of gastric cancer cells. The effect of ARIH2 knockdown on colony formation and tumorigenesis of gastric cancer cells was also shown both in vivo and in vitro. Further mechanistic investigations revealed that ARIH2 interacts with p21 and induces p21 ubiquitination, and that the K48 residue of ubiquitin and the K161 residue of p21 play key roles in ARIH2-mediated p21 ubiquitination. We identified ARIH2 as an E3 ligase of p21 by an in vitro ubiquitination assay. In addition, ARIH2 knockdown induced DNA damage, and then induced cell apoptosis and regulated the chemosensitivity of gastric cancer cells after combined treatment with 5-fluorouracil. Generally, our results indicated that ARIH2 promotes the proliferation of gastric cancer cells and regulates p21 expression. These data demonstrate the need to further evaluate the potential therapeutic implications of ARIH2 in gastric cancer.

Roles and mechanisms of miR-195-5p in human solid cancers

Cancer persists as a worldwide disease that contributes to high morbidity and mortality rates. As a class of non-coding RNA, microRNAs (miRNAs) are one kind of important regulators in cancer and frequently implicated in tumor development and progression. Emerging experiments have suggested that miRNA-195-5p (miR-195-5p) can regulate neoplastic processes in many pathways. For instance, miR-195-5p can not only regulate proliferation, migration and invasion of tumor cells but also promote tumor cell apoptosis. Furthermore, low expression of miR-195-5p could induce drug resistance. Our review focuses on the expression of miR-195-5p in various tumors and elucidates the related mechanisms of which miR-195-5p participates in tumor biology, as well as summarizes the roles of miR-195-5p in tumor progression. We believe that miR-195-5p might have potential utility as a novel diagnostic biomarker and therapeutic target for cancer.

Does Adding a Cardia Biopsy Improve Gastric Intestinal Metaplasia Detection Rate by the Sydney System Protocol?

BACKGROUND

The Sydney system offers a standard biopsy protocol for detection and follow-up of gastric preneoplastic lesions such as intestinal metaplasia (IM). The highest frequency of cardia-type gastric adenocarcinoma (GA) in Iran has been documented in the north-western part of the country. This study aims to investigate the effect of the addition of mucosal biopsies of gastric cardia to the standard Sydney protocol on the rate of detection of IM in the asymptomatic residents of this high-risk region for proximal gastric cancer.

METHODS

A retrospective new analysis was performed on the previous data obtained in cross-sectional endoscopic screening in 2000 as well as a biopsy study of 508 asymptomatic volunteer residents in Meshkinshahr district, Ardabil province. The screening study was conducted in a group of residents aged 40 years and older who did not have any previous GI or hemodynamic problems.

RESULTS

Intestinal metaplasia at the Sydney protocol sampling sites was detected in 107 samples belonging to 76 of the 508 (14.99%) volunteers. Twenty-one patients had IM at the cardia. Of these, five patients had IM-cardia (IM only at the cardia). Therefore, adding a cardia biopsy to the set of biopsies diagnosed five more IM cases which were not diagnosed on the standard Sydney protocol (P=0.062).

CONCLUSION

The addition of a biopsy from the cardia to the Sydney protocol biopsy set does not seem to improve the frequency of detection of IM in the residents of this high-risk geographic area for proximal gastric carcinoma.

Association between Vitamin B12 and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Epidemiological Studies

Epidemiological studies focusing on the association between vitamin B₁₂ and gastric cancer risk reported inconsistent findings. We conducted a systematic review and meta-analysis to assess the relationship. PubMed (Medline), Web of science and EMBASE databases were systematically searched. A total of nine studies involving 3,494 cases of with gastric cancer and 611,638 participants were included. The result showed that there is no significant association between vitamin B₁₂ intake and the risk of gastric cancer (OR = 0.88, 95% CI: 0.69-1.12, P = 0.303). Nevertheless, high intake of vitamin B₁₂ might decrease the risk of gastric cancer in Helicobacter pylori (Hp)-negative people (OR = 0.83, 95% CI: 0.62-0.99, P = 0.044), but increase the cancer risk in Hp-positive populations (OR = 1.66, 95% CI: 1.27-2.16, P = 10^-4). Additionally, further analysis indicated that excessive vitamin B₁₂ might increase the risk of non-cardia gastric cancer (OR = 1.15, 95% CI: 1.01-1.33, P = 0.006). A negative association between vitamin B₁₂ intake and gastric cancer risk was found in nonsmokers (OR = 0.83, 95% CI: 0.71-0.96, P = 0.012) but not in smokers (OR = 1.08, 95% CI: 0.71-1.47, P = 0.619). In conclusion, although we found no convincing evidence that vitamin B₁₂ intake is associated with the risk of gastric cancer, it is important to maintain the relative stability of vitamin B₁₂ for people with Hp infection.

Evaluation of CSTB and DMBT1 expression in saliva of gastric cancer patients and controls

Background

Gastric cancer (GC) is the fifth most common cancer and the third cause of cancer deaths globally, with late diagnosis, low survival rate, and poor prognosis. This case-control study aimed to evaluate the expression of cystatin B (CSTB) and deleted in malignant brain tumor 1 (DMBT1) in the saliva of GC patients with healthy individuals to construct diagnostic algorithms using statistical analysis and machine learning methods.

Methods

Demographic data, clinical characteristics, and food intake habits of the case and control group were gathered through a standard checklist. Unstimulated whole saliva samples were taken from 31 healthy individuals and 31 GC patients. Through ELISA test and statistical analysis, the expression of salivary CSTB and DMBT1 proteins was evaluated. To construct diagnostic algorithms, we used the machine learning method.

Results

The mean salivary expression of CSTB in GC patients was significantly lower (115.55 ± 7.06, p = 0.001), and the mean salivary expression of DMBT1 in GC patients was significantly higher (171.88 ± 39.67, p = 0.002) than the control.

Multiple linear regression analysis demonstrated that GC was significantly correlated with high levels of DMBT1 after controlling the effects of age of participants (R² = 0.20, p < 0.001).

Considering salivary CSTB greater than 119.06 ng/mL as an optimal cut-off value, the sensitivity and specificity of CSTB in the diagnosis of GC were 83.87 and 70.97%, respectively. The area under the ROC curve was calculated as 0.728. The optimal cut-off value of DMBT1 for differentiating GC patients from controls was greater than 146.33 ng/mL (sensitivity = 80.65% and specificity = 64.52%). The area under the ROC curve was up to 0.741.

As a result of the machine learning method, the area under the receiver-operating characteristic curve for the diagnostic ability of CSTB, DMBT1, demographic data, clinical characteristics, and food intake habits was 0.95. The machine learning model’s sensitivity, specificity, and accuracy were 100, 70.8, and 80.5%, respectively.

Conclusion

Salivary levels of DMBT1 and CSTB may be accurate in diagnosing GCs. Machine learning analyses using salivary biomarkers, demographic, clinical, and nutrition habits data simultaneously could provide affordability models with acceptable accuracy for differentiation of GC by a cost-effective and non-invasive method.

Survival benefits of gastrectomy compared to conservative observation for older patients with resectable gastric cancer: a propensity score matched analysis

PURPOSE

Radical gastrectomy is considered the first choice of curative treatment for older patients with gastric cancer (GC). However, there is limited data on the survival benefits of gastrectomy for older patients with GC.

METHODS

This was a retrospective observational study where medical records of patients aged ≥ 75 years with clinically resectable primary GC, comprising 115 patients who underwent radical surgery (S group) and 33 patients who received conservative therapy (non-S group) (total cohort) and 44 propensity-matched patients (matched cohort), were reviewed. Survival and independent risk factors, including comorbidities and systemic nutritional and inflammatory statuses, were evaluated.

RESULTS

In the total cohort, the 5-year overall survival (OS) in the S group was significantly higher than that in the non-S group (53.7% vs 19.7%, P < 0.0001). In the matched cohort, the 3-year OS in the S group was significantly higher than that in the non-S group (59.4% vs 15.9%, P < 0.01). Multivariate analysis of the total cohort showed that no surgery was an independent prognostic factor for poor OS (hazard ratio (HR) 3.70, 95% confidence interval (CI) 1.91-7.20, P = 0.0001). In the S group in the total cohort, the multivariate analysis showed that renal disease (HR 2.51, 95% CI 1.23-5.12, P < 0.05) was an independent prognostic factor for poor OS.

CONCLUSIONS

Gastrectomy for older patients improved the prognosis; however, careful patient selection is essential, especially among those with renal disease.