Gastric cancer: Epidemiology, risk factors and prevention strategies

Comprehensive transcriptomic analyses identify KDM genes-related subtypes with different TME infiltrates in gastric cancer

Histone lysine demethylases (KDMs) have been reported in various malignances, which affect transcriptional regulation of tumor suppressor or oncogenes. However, the relationship between KDMs and formation of tumor microenvironment (TME) in gastric cancer (GC) remain unclear and need to be comprehensively analyzed.In the present study, 24 KDMs were obtained and consensus molecular subtyping was performed using the "NMF" method to stratify TCGA-STAD into three clusters. The ssGSEA and CIBERSORT algorithms were employed to assess the relative infiltration levels of various cell types in the TME. The KDM_score was devised to predict patient survival outcomes and responses to both immunotherapy and chemotherapy.Three KDM genes-related molecular subtypes were Figured out in GC with distinctive clinicopathological and prognostic features. Based on the robust KDM genes-related risk_score and nomogram, established in our work, GC patients' clinical outcome can be well predicted. Furthermore, low KDM genes-related risk_score exhibited the more effective response to immunotherapy and chemotherapy.This study characterized three KDM genes-related TME pattern with unique immune infiltration and prognosis by comprehensively analyses of transcriptomic profiling. Risk_score was also built to help clinicians decide personalized anticancer treatment for GC patients, including in prediction of immunotherapy and chemotherapy response for patients.

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.

Intersections between innate immune response and gastric cancer development

Worldwide, gastric cancer (GC) is the fifth most commonly diagnosed malignancy. It has a reduced prevalence but has maintained its poor prognosis being the fourth leading cause of deaths related to cancer. The highest mortality rates occur in Asian and Latin American countries, where cases are usually diagnosed at advanced stages. Overall, GC is viewed as the consequence of a multifactorial process, involving the virulence of the Helicobacter pylori (H. pylori) strains, as well as some environmental factors, dietary habits, and host intrinsic factors. The tumor microenvironment in GC appears to be chronically inflamed which promotes tumor progression and reduces the therapeutic opportunities. It has been suggested that inflammation assessment needs to be measured qualitatively and quantitatively, considering cell-infiltration types, availability of receptors to detect damage and pathogens, and presence or absence of aggressive H. pylori strains. Gastrointestinal epithelial cells express several Toll-like receptors and determine the first defensive line against pathogens, and have been also described as mediators of tumorigenesis. However, other molecules, such as cytokines related to inflammation and innate immunity, including immune checkpoint molecules, interferon-gamma pathway and NETosis have been associated with an increased risk of GC. Therefore, this review will explore innate immune activation in the context of premalignant lesions of the gastric epithelium and established gastric tumors.

Trends and Projections of Stomach Cancer Incidence in Hong Kong: A Population-Based Study

OBJECTIVES

The burden of stomach cancer remains high in Hong Kong. We sought to evaluate the associations of age, period, and birth cohort with the changing trend in the incidence of stomach cancer and to provide projections through 2030.

MATERIALS AND METHODS

We performed an age-period-cohort analysis and projections up to 2030 using data from the Hong Kong Cancer Registry. Additionally, we used a population decomposition algorithm to assess the drivers in the number of incident cases of stomach cancer in Hong Kong.

RESULTS

Among the 26,813 stomach cancer patients, from 1994 to 2018, the age-standardized incidence rate of stomach cancer decreased for both sexes. The incidence increased with age and was highest for those aged 85 years or older. Period relative risk (RR) showed a monotonic decreasing pattern throughout the study period for both sexes before 2010. Cohort RR for males was monotonically decreasing but changed little after the 1967-1971 birth cohort. In contrast, cohort RR for females declined in the pre-1927-1931 birth cohort but slowed down since. It is projected that there will be 906 male patients and 954 female patients in 2030. Decomposition analysis suggested that population growth and aging were associated with substantial changes in the number of incident cases of stomach cancer in Hong Kong.

CONCLUSIONS

Both period and cohort risk of developing stomach cancer in Hong Kong have slowed down or plateaued. Our study demonstrates that population aging and growth are the main drivers of the increased number of incident cases of stomach cancer in Hong Kong.

Comprehensive analysis of circular RNA-associated competing endogenous RNA networks and immune infiltration in gastric cancer

BACKGROUND

Circular RNA (circRNA) has been proved to be an important regulator of gastric cancer (GC). However, the role and regulatory mechanism of circrna related competitive endogenous RNA (ceRNA) in GC have not been established.

METHODS

CircRNA data and clinical data were obtained from the GEO and TCGA databases. The ceRNA networks were constructed and a function enrichment analysis was completed. Additionally, correlations between hub genes expression, immune cell infiltration, and clinical phenotypes were determined. The differentially expressed circRNAs and their downstream microRNAs (miRNAs) were validated by quantitative real-time polymerase chain reaction, and the hub genes were validated by western blot analysis. The migration and invasion ability of overexpressed hsa_circ_0002504 was determined by a transwell assay.

RESULTS

The ceRNA network contained 2 circRNAs, 3 miRNAs, and 55 messenger RNAs (mRNAs). 323 biological processes terms, 53 cellular components terms, 51 molecular functions terms, and 4 signaling pathways were revealed by the function enrichment analysis. The GSEA analysis revealed that the hub genes were positively correlated with the axon guidance and adhesion molecules pathways. The correlation analysis revealed that overexpressed EPHA4 and KCNA1 indicated poor tissue differentiation and were associated with clinically advanced stages of GC. The in vitro experiments showed that hsa_circ_0002504 was significantly down-regulated in GC cell lines. In addition, the overexpression of hsa_circ_0002504 led to a significant downregulation of hsa-miR-615-5p and hsa-miR-767-5p, as well as an upregulation of EPHA4, KCNA1, and NCAM1. Furthermore, it suppressed the migration and invasion ability of GC cells.

CONCLUSIONS

Hsa_circ_0002504 is a potential diagnostic biomarker for GC. High expression of EPHA4 and KCNA1 may indicate poor prognosis.

Synthesis of Gingerol-loaded Uio-66 nanoparticles and its anti-cancer effect against gastric cancer cell line (AGS)

BACKGROUND

Gastric cancer is the world's fifth most prevalent cancer and its treatments are associated with issues. In this investigation, a UIO-66 nanoparticle was loaded with Gingerol (UIO-66-Gin) as a great drug carrier vehicle for chemotherapy of the AGS cancer cell lines.

METHODS AND RESULTS

UIO-66-Gin characterization was performed using SEM, DLS and FTIR tests. The release profile of Gin from UIO-66 was also assessed. The cytotoxicity of UIO-66-Gin against AGS cells was assessed using MTT assay. Caspase3, Caspase9, Bax, and Bcl2 genes expression was evaluated via Real-time PCR and apoptosis rate was performed using flow-cytometry assay. Size analysis indicated the spherical shape of nano-formulation with the mean size of 174.3 nm. Release analysis indicated that there was a 50% Gin release from the nanocarrier was reported in roughly 21 h, which revealed the regulated release of bioactive compound from the UIO-66 formulation in PBS medium. After 48 and 72 h, various concentration of both the Gin and UIO-66-Gin started to induce cytotoxicity in cancerous cells. However, the induction of cytotoxicity was higher in cells treated with UIO-66-Gin. UIO-66-Gin could induce the expression of pro-apoptotic (Bax, Caspase3, and Caspase9) genes and down-regulate the expression of Bcl2 as anti-apoptotic gene rather than other formulation. Flowcytometry results indicated that the elevation of apoptotic rate in cells treated with UIO-66-Gin was significantly higher than Gin treated cells.

CONCLUSIONS

Our investigation revealed the potent anticancer effect and apoptotic induction ability of UIO-66-Gin against cancerous cells through altering the expression of genes involved in apoptosis.

Piceatannol enhances Beclin-1 activity to suppress tumor progression and its combination therapy strategy with everolimus in gastric cancer

The effects and regulation of Beclin-1-an autophagy-related protein-have not been fully defined, however, a negative correlation has been reported between Beclin-1 expression and carcinogenesis. Meanwhile, no compound has been shown to directly inhibit its activity. Here, we evaluate piceatannol, a naturally occurring polyphenolic compound, as a potential targeting agonist of Beclin-1, to assess its efficacy as an antitumor agent against gastric cancer. More specifically, we determine the effects of piceatannol treatment on cell viability using a monitoring system and colony forming assay. Piceatannol was found to efficiently inhibit the proliferation of several human gastric cancer cell lines. Autophagic flux is increased by piceatannol treatment, and correlates with inhibition of cell proliferation and colony formation. Additionally, microscale thermophoresis and surface plasmon resonance results show a direct interaction between piceatannol and Beclin-1, which reduces the phosphorylation activity of Beclin-1 at the Ser-295 site. Notably, piceatannol impairs the binding of Beclin-1 to Bcl-2 and enhances the recruitment of binding of UV radiation resistance-associated gene protein, which further triggers Beclin-1-dependent autophagy signaling. An increase in autophagic activity via treatment with the mTOR inhibitor, everolimus, effectively sensitizes piceatannol-induced antitumor effects. Xenograft models confirmed that piceatannol inhibits tumor development and elicits a potent synergistic effect with everolimus in vivo. Taken together, the findings of this study strongly support the application of combinatorial piceatannol and everolimus therapy in future clinical trials for gastric cancer patients.

Radiomics signature for prediction of long-term survival and recurrence patterns in patients with gastric cancer after radical gastrectomy: A multicenter study

BACKGROUND

This study aimed to develop and validate a radiomics score to predict the long-term survival and patterns of recurrence of gastric cancer (GC).

METHODS

A total of 513 patients who underwent radical gastrectomy for GC after curative resection between 2008 and 2016 at two institutions were analyzed. A radiomics score was generated using the least absolute shrinkage and selection operator Cox regression model on 327 patients and was validated in 186 patients. A nomogram consisting of the radiomics score and clinicopathological factors was created and compared with the tumor-lymph node-metastasis (TNM) staging system. Model performance was assessed using calibration, discrimination, and clinical usefulness.

RESULTS

The radiomics score was established based on five selected features. A higher score was significantly associated with poorer recurrence-free survival (RFS) and overall survival (OS) rates, both in the training and validation cohorts (P < 0.05). Multivariate analysis demonstrated that the radiomics score was an independent prognostic factor for both RFS and OS (P < 0.05). A nomogram incorporating the radiomics score had a significantly better prognostic value than the TNM system alone. Moreover, a high score was significantly associated with an increased risk of distant recurrence, a medium score was significantly associated with an increased risk of peritoneal recurrence, and a low score was significantly associated with an increased risk of locoregional recurrence, in the entire cohort (P < 0.05).

CONCLUSIONS

The newly proposed radiomics score may be a powerful predictor of long-term outcomes and recurrence patterns of GC. Further studies are warranted to confirm these findings.

Photodynamic therapy in combination with immune checkpoint inhibitors plus chemotherapy for first-line treatment in advanced or metastatic gastric or gastroesophageal junction cancer: A phase 2-3 clinical trial protocol

Introduction: The immune checkpoint inhibitor (ICI) has been approved as the first-line therapy for metastatic gastric cancer in China. The treatment response of immune checkpoint inhibitor is highly dependent on the immune condition within the tumor microenvironment. Photodynamic therapy (PDT) has a long history in cancer treatment, and recent studies showed it had an immunomodulatory effect on the tumor. Here we will conduct a trial to assess whether or not a combination with Photodynamic therapy will improve the outcomes of immune checkpoint inhibitor-based treatment in patients with advanced or metastatic gastric cancer. Methods: This study is a single-center, open-label, randomized controlled, phase 2-3 trial. Patients (18-65 years old) with untreated gastric or gastroesophageal junction adenocarcinoma will be eligible for this trial. Sixty participants will be enrolled and randomly divided into the test group (n = 30) and control group (n = 30) to receive photodynamic therapy in combination with immune checkpoint inhibitor plus chemotherapy and immune checkpoint inhibitor plus chemotherapy, respectively. The primary is progression-free survival (PFS). The secondary outcomes include objective response rates (ORRs) and the occurrence of adverse events. In addition, we will also assess the changes in peripheral blood mononuclear cells (PBMCs) and tumor microenvironment after photodynamic therapy treatment in the test group. Evaluation of the tumor response will be performed every two cycles for a maximum of eight cycles. Discussion: Photodynamic therapy has an immunomodulatory effect on the tumor microenvironment; however, this has not been demonstrated for gastric cancer in a clinical trial. Based on our experience of photodynamic therapy treatment in digestive tract tumors, we plan to conduct a randomized controlled trial on this topic. This will be the first study to evaluate the synergistic effect of photodynamic therapy with immunochemotherapy for patients with advanced gastric cancer. Ethics and dissemination: It was approved by the Institutional Research Ethics Committee of Lanzhou University Second Hospital (No. 2022A-491). When this trial is completed, it will be shared at conferences and submitted for a potential publication in a peer-reviewed journal. Clinical Trial Registration: http://www.chictr.org.cn/, identifier ChiCTR2200064280.

Inhibition of lysine-specific demethylase 1 enhances the sensitivity of the chemotherapeutic drug doxorubicin in gastric cancer cell

AIM

Lysine-Specific Demethylase 1 (LSD1) inhibitors have been developed and reached the clinic, but its effect in combination with cytotoxic chemotherapy is unclear. Here, we investigated the anti-tumor effect of LSD1 inhibitor GSK-LSD1 and its anti-tumor effect with the DNA damage drug doxorubicin (DOX) in gastric cancer (GC) cells.

METHODS

Cells were treated with different concentrations of GSK-LSD1 to examine the anti-tumor effect versus cell viability by MTT and cell cycle arrest by flow cytometry. To explore whether LSD1 inhibitors can increase the anti-tumor effect of DNA damage drugs, cells were treated with DOX for 48 h after pretreatment with GSK-LSD1 for 48 h. Cell viability was detected by MTT and apoptosis-related proteins were examined by Western blot. Furthermore, anti-tumor efficacy of combination GSK-LSD1 with DOX was also measured in MGC-803 xenografts model in nude mice.

RESULTS

The results showed that LSD1 was highly expressed in GC cell lines. Inhibition of LSD1 has a weak effect on cell viability and cell cycle. Moreover, LSD1 inhibitors pretreatment could significantly increase the anti-tumor effect of DOX. Further study found that inhibition of LSD1 can significantly enhance DOX-induced the apoptosis, accompanied by down-regulation of antiapoptotic Bcl-2 expression and up-regulation of proapoptotic Bax expression. We also confirmed that inhibition of LSD1 can sensitize the anti-tumor effect of DOX in vivo.

CONCLUSION

Our findings suggest that the LSD1 inhibitor GSK-LSD1 has a weak inhibitory effect on the viability and cell cycle of GC cells, but can enhance the sensitivity of DOX.

Detecting plasma hsa_circ_0061276 in patients with gastric cancer by reverse transcription-digital polymerase chain reaction

Background

The role of circular RNAs (circRNAs) in the occurrence of gastric cancer is still unclear. Therefore, the diagnostic value and mechanisms underlying hsa_circ_0061276 in the occurrence of gastric cancer were explored.

Methods

Reverse transcription-droplet digital polymerase chain reaction was used to detect the copy number of hsa_circ_0061276 in plasma from healthy individuals, as well as from patients with gastric precancerous lesions or early-stage or advanced gastric cancer. Plasmids overexpressing or knocking down hsa_circ_0061276 expression were transfected into gastric cancer cells. The effects on the growth, migration, and cell cycle distribution of gastric cancer cells were then analyzed. Finally, miRanda and RNAhybrid were used to explore the binding sites between hsa_circ_0061276 and microRNAs (miRNAs). A double luciferase reporter gene assay was used to confirm the miRNA sponge effect.

Results

The results show that plasma hsa_circ_0061276 copy number showed a trend of a gradual decrease when comparing healthy controls to the early cancer group and advanced gastric cancer group. Overexpression of hsa_circ_0061276 inhibited the growth and migration of gastric cancer cells. Through bioinformatic analyses combined with cellular experiments, it was found that hsa_circ_0061276 inhibited the growth of gastric cancer by binding to hsa-miR-7705.

Conclusion

Hsa_circ_0061276 may be a new biomarker for gastric cancer. The tumor suppressor role of hsa_circ_0061276 on gastric cancer likely occurs through a sponge effect on miRNAs such as hsa-miR-7705.

Correlation between imaging features on computed tomography and combined positive score of PD-L1 expression in patients with gastric cancer

OBJECTIVE

To explore the correlation between computed tomography (CT) features and combined positive score (CPS) of programmed cell death ligand 1 (PD-L1) expression in patients with gastric cancer (GC).

METHODS

This study reviewed an institutional database of patients who underwent GC operation without neoadjuvant chemotherapy between December 2019 and September 2020. The CPS results of PD-L1 expression of postoperative histological examination were recorded by pathology. Baseline CT features were measured, and their correlation with CPS 5 or 10 score groups of PD-L1 expression was analyzed.

RESULTS

Data for 153 patients with GC were collected. Among them, 124 were advanced GC patients, and 29 were early GC patients. None of the CT features significantly differed between CPS groups with a cutoff score of 5 and a score of 10 in patients with early GC. In advanced GC, the presence of lymph nodes with short diameters >10 mm was significantly different (P=0.024) between the CPS<5 and CPS≥5 groups. CT features such as tumor attenuation in the arterial phase, long and short diameter of the largest lymph node, the sum of long diameter of the two largest lymph nodes, the sum of short diameter of the two largest lymph nodes, and the presence of lymph nodes with short diameters >10 mm significantly differed between the CPS<10 and CPS≥10 groups in advanced GC. The sensitivity, specificity and area under receiver operating characteristic (ROC) curve of logistic regression model for predicting CPS≥10 was 71.7%, 50.0% and 0.671, respectively. Microsatellite instability (MSI) status was significantly different in CPS groups with cutoff score of 5 and 10 in advanced GC patients.

CONCLUSIONS

CT findings of advanced GC patients with CPS≥10 showed greater arterial phase enhancement and larger lymph nodes. CT has the potential to help screen patients suitable for immunotherapy.

Clinical Significance and Immune Infiltration Analyses of the Cuproptosis-Related Human Copper Proteome in Gastric Cancer

BACKGROUND

The human copper Cu proteome, also termed Cu-binding proteins (CBP), is responsible for transporting "free" Cu to the cell that is related to cuproptosis. However, their role in gastric cancer (GC) has not been reported.

METHODS

RNA expression data of 946 GC patients were collected. A series of machine learning and bioinformatic approaches were combined to build a CBP signature to predict survival and immune microenvironment and guide the priority treatment. Immunohistochemistry and multicolor immunofluorescence (mIF) in 1076 resection slides were used to verify immune features.

RESULTS

A CBP signature was constructed using the machine learning method from TCGA that classifies cases as CBP_low and CBP_high groups. Multivariable Cox analysis confirmed that the CBP signature was an independent prognostic factor in the training and validation cohorts. Additionally, GC patients with low CBPscores showed an increase in anti-tumor immune microenvironment, which was further verified by mIF in pathological resections following immunotherapy. Importantly, patients with low CBPscores had higher levels of TMB/MSI and responded well to immunotherapy.

CONCLUSIONS

We conducted the first and comprehensive CBP analysis of GC patients and established a clinically feasible CBP signature for predicting survival and response to treatment, which will be helpful for guiding personalized medicine.

Epithelial-mesenchymal transition-related long noncoding RNAs in gastric carcinoma

As an evolutionarily phenotypic conversion program, the epithelial-mesenchymal transition (EMT) has been implicated in tumour deterioration and has facilitated the metastatic ability of cancer cells via enhancing migration and invasion. Gastric cancer (GC) remains a frequently diagnosed non-skin malignancy globally. Most GC-associated mortality can be attributed to metastasis. Recent studies have shown that EMT-related long non-coding RNAs (lncRNAs) play a critical role in GC progression and GC cell motility. In addition, lncRNAs are associated with EMT-related transcription factors and signalling pathways. In the present review, we comprehensively described the EMT-inducing lncRNA molecular mechanisms and functional perspectives of EMT-inducing lncRNAs in GC progression. Taken together, the statements of this review provided a clinical implementation in identifying lncRNAs as potential therapeutic targets for advanced GC.

Dual roles of β-arrestin 1 in mediating cell metabolism and proliferation in gastric cancer

β-Arrestin 1 (ARRB1) has been recognized as a multifunctional adaptor protein in the last decade, beyond its original role in desensitizing G protein-coupled receptor signaling. Here, we identify that ARRB1 plays essential roles in mediating gastric cancer (GC) cell metabolism and proliferation, by combining cohort analysis and functional investigation using patient-derived preclinical models. Overexpression of ARRB1 was associated with poor outcome of GC patients and knockdown of ARRB1 impaired cell proliferation both ex vivo and in vivo. Intriguingly, ARRB1 depicted diverse subcellular localizations during a passage of organoid cultures (7 d) to exert dual functions. Further analysis revealed that nuclear ARRB1 binds with transcription factor E2F1 triggering up-regulation of proliferative genes, while cytoplasmic ARRB1 modulates metabolic flux by binding with the pyruvate kinase M2 isoform (PKM2) and hindering PKM2 tetramerization, which reduces pyruvate kinase activity and leads to cellular metabolism shifts from oxidative phosphorylation to aerobic glycolysis. As ARRB1 localization was shown mostly in the cytoplasm in human GC samples, therapeutic potential of the ARRB1-PKM2 axis was tested, and we found tumor proliferation could be attenuated by the PKM2 activator DASA-58, especially in ARRB1^high organoids. Together, the data in our study highlight a spatiotemporally dependent role of ARRB1 in mediating GC cell metabolism and proliferation and implies reactivating PKM2 may be a promising therapeutic strategy in a subset of GC patients.

Feasibility and reproducibility of a plasma-based multiplex DNA methylation assay for early detection of gastric cancer

BACKGROUND

Gastric cancer (GC) is a leading cause of cancer death and an important barrier to increasing life expectancy in China. Early detection of GC can significantly reduce its mortality rate.

METHODS

A new plasma-based multiplex DNA methylation assay combining simultaneous detection of three biomarkers (KCNQ5, C9orf50 and CLIP4) and one control gene (ACTB) was developed. It was used to examine 12 paired tissue samples and a training cohort of 151 plasma samples. Its performance was subsequently confirmed in validation cohort 1 (n = 105) and validation cohort 2 (n = 139).

RESULTS

Three methylation markers showed significantly higher methylation levels in GC tissues than in paired adjacent tissues. The assay showed a sensitivity of 67.9 % with a specificity of 86.6 % for GC detection in the training cohort, and the AUC was 0.786 (95 % CI: 0.701-0.855). The methylation levels in GC patients were significantly higher than those in benign gastric tumors and in control group. Meanwhile, the assay achieved a sensitivity of 65.5 % with a specificity of 90.0 % in the validation cohort 1, and the AUC was 0.805 (95 % CI: 0.716-0.876). In the validation cohort 2, its sensitivity and specificity were 73.7 % and 84.1 %, respectively, and the AUC was 0.851 (95 % CI: 0.776-0.909).

CONCLUSION

The plasma-based multiplex DNA methylation assay was highly specific for GC early detection. It has the potential to become an alternative approach to improve diagnosis of GC in the clinics.

Tertiary lymphoid structure patterns predicted anti-PD1 therapeutic responses in gastric cancer

OBJECTIVE

Recent studies have highlighted the distinct value of tertiary lymphoid structure (TLS) for immunotherapeutic response prediction. However, it remains unclear whether TLS could play such roles in gastric cancer (GC).

METHODS

In this study, tumor tissue slices from 292 GC patients from Zhongshan Hospital were firstly reviewed to explore the correlation between TLS and clinical characteristics. Subsequently, we curated 38 reported genes that may function as triggers of TLS and performed consensus molecular subtyping in public RNA-seq datasets to determine TLS patterns in GC. Based on the differentially expressed genes acquired from two TLS patterns, we quantified TLS-related genes on the principal component analysis (PCA) algorithm to develop TLS score. A Zhongshan immunotherapy cohort including 13 patients who received programmed cell death 1 (PD1) blockade therapy was established to conduct RNA sequencing analysis and multiplex immunohistochemistry (mIHC) tests using formalin-fixed and paraffin-embedded (FFPE) tissues. The corresponding TLS score and immune cell counts were further compared based on therapeutic response variations.

RESULTS

Mature TLS was revealed as an independent prognostic factor in 292 GC patients. Patients with higher TLS score was characterized by prolonged survival time and superior response to immunotherapy. TLS score was correlated with immunotherapy-related characters, such as microsatellite instability (MSI) and tumor mutation burden (TMB). In addition, RNA-seq data analysis in the Zhongshan immunotherapy cohort indicated that a higher TLS score was correlated with a superior response to PD1 blockade therapy. mIHC tests also revealed that PD1+CD8+ T cell counts were significantly increased in the high-TLS score group.

CONCLUSIONS

This study highlighted that TLS was significantly associated with immune landscape diversity and complexity. Quantitatively evaluating TLS patterns of individual tumor will strengthen our understanding of TME characteristics and promote more effective immunotherapy strategies.

Trastuzumab combined chemotherapy for the treatment of HER2-positive advanced gastric cancer: A systematic review and meta-analysis of randomized controlled trial

BACKGROUND

This systematic review and meta-analysis aimed to assess the efficacy of trastuzumab combined with chemotherapy for the treatment in HER2-positive advanced gastric cancer (HER2-PAGC).

METHODS

This systematic review and meta-analysis was designed using randomized controlled trials that compared trastuzumab in combination with chemotherapy and chemotherapy alone. A comprehensive search was conducted in the following databases from their inception onwards: PubMed, EMBASE, Cochrane Library, WANGFANG, and CNKI. We also searched other literature sources to avoid missing relevant studies. Two reviewers independently performed all record selection, data collection, and methodological assessments. Any confusion was resolved by discussion or referral to a third reviewer. If there were ample data from eligible studies, we performed a fixed-effects meta-analysis. Whenever this was not possible, we conducted a narrative synthesis.

RESULTS

Meta-analysis results showed that trastuzumab in combination with chemotherapy achieved better outcomes on response rate (trastuzumab plus CFC vs CFC: odds ratio [OR] = 1.56, 95% confidence interval [CI] [1.17-2.09], I2 = 0%, P < .003; trastuzumab plus OT vs OT: OR = 2.97, 95% CI [1.74-5.09], I2 = 0%, P < .0001; and trastuzumab plus CC vs CC: OR = 2.62, 95% CI [1.84-3.73], I2 = 0%, P < .0001), and disease control rate (trastuzumab plus CFC vs CFC: OR = 1.61, 95% CI [1.17-2.21], I2 = 0%, P = .004; trastuzumab plus OT vs OT: OR = 4.29, 95% CI [2.33-7.90], I2 = 0%, P < .0001; and trastuzumab plus CC vs CC: OR = 2.99, 95% CI [1.99-4.48], I2 = 0%, P < .0001). However, there were no significant differences in the adverse events.

CONCLUSIONS

The results of this study revealed that the efficacy of trastuzumab combined with chemotherapy was superior to that of chemotherapy alone for the treatment of HER2-PAGC. The 2 modalities showed similar safety profiles.

Chaperonin-containing tailless complex polypeptide 1 subunit 6A links with aggravating tumor features and disease-free survival in surgical gastric cancer patients: A long-term follow-up study

BACKGROUND

Chaperonin-containing tailless complex polypeptide 1 subunit 6A (CCT6A) promotes several gastrointestinal-cancer malignant behaviors, while its clinical value in surgical gastric cancer is not clear. Hence, we aimed to investigate this issue.

METHODS

Totally, tumor and adjacent specimens from 262 surgical gastric cancer patients were collected for measuring CCT6A protein level by immunohistochemistry (IHC) staining; meanwhile, specimens from 109 patients were used for evaluating CCT6A mRNA expression by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

RESULTS

CCT6A IHC score and CCT6A mRNA expression were upregulated in the tumor tissue compared with the adjacent tissue (both P<0.001). Besides, elevated CCT6A IHC score was correlated with larger tumor size (P<0.001), advanced T stage (P=0.001), N stage (P=0.003) and tumor node metastasis (TNM) stage (P=0.001). Meanwhile, increased CCT6A mRNA expression was associated with higher T stage (P=0.008) and TNM stage (P=0.020). Besides, CCT6A protein high (P=0.017) and CCT6A mRNA high (P=0.047) were correlated with unfavorable disease-free survival (DFS), whereas neither CCT6A protein nor CCT6A mRNA expression was related to the overall survival (OS) (both P>0.05). Additionally, the multivariable Cox's proportional hazards regression analysis revealed that CCT6A protein high was independently correlated with shorter DFS (adjusted hazard ratio (HR): 2.032, P=0.005), but not with OS.

CONCLUSION

CCT6A is upregulated with its overexpression linking with advanced T stage, TNM stage and unfavorable DFS in surgical gastric cancer patients.

Hydroxysafflor yellow B induces apoptosis via mitochondrial pathway in human gastric cancer cells

OBJECTIVES

Hydroxysafflor yellow B (HSYB) is extracted from the petals of the safflower, a Chinese medicine. Relevant research results have demonstrated that HSYA can suppress the abnormal tumour cell proliferation and induce cell apoptosis. However, the properties of HSYB have rarely been reported, especially its antitumour effects on gastric cancer (GC).

METHODS

SGC-7901 and BGC-823 cells were treated with different concentrations of HSYB. Cell proliferation inhibition rate was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation detection. The changes in morphology of cells was observed by Hoechst 33258 staining. Cell apoptosis was evaluated by Annexin V-FITC/PI (fluoresceinisothiocyanate/propidium iodide) double staining. JC-1 was used to detect the level of mitochondrial membrane potential (MMP). The protein levels of cleaved-caspase-3, cleaved-caspase-9, APAF-1, cytoplasmic cytochrome C, BAX and BCL-2 were examined by western blot.

KEY FINDINGS

HSYB significantly suppressed the proliferation of SGC-7901 and BGC-823 cells. Hoechst 33258 staining assay showed that HSYB treatment triggered apoptotic morphology and the apoptotic rates were significantly increased after being treated with HSYB and the mitochondrial membrane potential was gradually decreased in human GC cells. In addition, Western blot analysis revealed that the levels of cleaved-caspase-3 and cleaved-caspase-9 were remarkably increased in HSYB-treated BGC-823 and SGC-7901 cells. And, the levels of apoptotic protease activating factor-1 (APAF-1) and cytoplasmic cytochrome C were remarkably up-regulated in HSYB-treated cells. At the same time, HSYB could up-regulate the level of BAX and down-regulate the level of BCL-2.

CONCLUSIONS

Our data suggest that HSYB could induce GC cell apoptosis via the mitochondrial pathway.

Microbiota and the Immune System-Actors in the Gastric Cancer Story

Simple Summary

Stomach cancer is one of the most commonly diagnosed cancers in the world. Although the number of new cases is decreasing year by year, the death rate for this type of cancer is still high. The heterogeneous course and the lack of symptoms in the early stages of the disease mean that the diagnosis is made late, which translates into a worse prognosis for such patients. That is why it is so important to analyze potential risk factors that may increase the risk of developing gastric cancer and to search for new effective methods of treatment. These requirements are met by the analysis of the composition of the gastric microbiota and its relationship with the immune system, which is a key element in the human anti-cancer fight. This publication was created to systematize the current knowledge on the impact of dysbiosis of human microbiota on the development and progression of gastric cancer. Particular emphasis was placed on taking into account the role of the immune system in this process.

Abstract

Gastric cancer remains one of the most commonly diagnosed cancers in the world, with a relatively high mortality rate. Due to the heterogeneous course of the disease, its diagnosis and treatment are limited and difficult, and it is associated with a reduced prognosis for patients. That is why it is so important to understand the mechanisms underlying the development and progression of this cancer, with particular emphasis on the role of risk factors. According to the literature data, risk factors include: changes in the composition of the stomach and intestinal microbiota (microbiological dysbiosis and the participation of Helicobacter pylori), improper diet, environmental and genetic factors, and disorders of the body’s immune homeostasis. Therefore, the aim of this review is to systematize the knowledge on the influence of human microbiota dysbiosis on the development and progression of gastric cancer, with particular emphasis on the role of the immune system in this process.

Assessment of Outcomes From 1-Year Surveillance After Detection of Early Gastric Cancer Among Patients at High Risk in Japan

IMPORTANCE

Single endoscopic examination often misses early gastric cancer (GC), even when both high-definition white light imaging and narrow-band imaging are used. It is unknown whether new GC can be detected approximately 1 year after intensive index endoscopic examination.

OBJECTIVE

To examine whether new GC can be detected approximately 1 year after intensive index endoscopic examination using both white light and narrow-band imaging.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study was a preplanned secondary analysis of a randomized clinical trial involving 4523 patients with a high risk of GC who were enrolled between October 1, 2014, and September 22, 2017. Data were analyzed from December 26, 2019, to April 21, 2021. Participants in the clinical trial received index endoscopy to detect early GC via 2 examinations of the entire stomach using white light and narrow-band imaging. The duration of follow-up was 15 months. The secondary analysis included 107 patients with newly detected GC (case group) and 107 matched patients without newly detected GC (control group) within 15 months after index endoscopy.

INTERVENTIONS

Surveillance endoscopy was scheduled between 9 and 15 months after index endoscopy. If new lesions suspected of being early GC were detected during surveillance endoscopy, biopsies were obtained to confirm the presence of cancer.

MAIN OUTCOMES AND MEASURES

The primary end point was the rate of new GC detected within 15 months after index endoscopy. The main secondary end point was identification of risk factors associated with new GC detected within 15 months after index endoscopy.

RESULTS

Among 4523 patients (mean [SD] age, 70.6 [7.5] years; 3527 men [78.0%]; all of Japanese ethnicity) enrolled in the clinical trial, 4472 received index endoscopy; the rate of early GC detected on index endoscopy was 3.0% (133 patients). Surveillance endoscopy was performed in 4146 of 4472 patients (92.7%) who received an index endoscopy; the rate of new GC detected within 15 months after index endoscopy was 2.6% (107 patients). Among 133 patients for whom early GC was detected during index endoscopy, 110 patients (82.7%) received surveillance endoscopy within 15 months after index endoscopy; the rate of newly detected GC was 10.9% (12 patients). For the secondary analysis of risk factors associated with newly detected GC, characteristics were well balanced between the 107 patients included in the case group vs the 107 patients included in the matched control group (mean [SD] age, 71.7 [7.2] years vs 71.8 [7.0] years; 94 men [87.9%] in each group; 82 patients [76.6%] vs 87 patients [81.3%] with a history of gastric neoplasm). Multivariate analysis revealed that the presence of open-type atrophic gastritis (odds ratio, 6.00; 95% CI, 2.25-16.01; P < .001) and early GC detection by index endoscopy (odds ratio, 4.67; 95% CI, 1.08-20.21; P = .04) were independent risk factors associated with new GC detection.

CONCLUSIONS AND RELEVANCE

In this study, the rate of new GC detected by surveillance endoscopy approximately 1 year after index endoscopy was similar to that of early GC detected by index endoscopy. These findings suggest that 1-year surveillance is warranted for patients at high risk of GC.

Performance of Salivary Extracellular RNA Biomarker Panels for Gastric Cancer Differs between Distinct Populations

Gastric cancer (GC) has the fifth highest incidence among cancers and is the fourth leading cause of cancer-related death GC has predominantly a higher number of cases in certain ethnic groups such as the Korean population. GC found at an early stage is more treatable and has a higher survival rate as compared with GC found at a late stage. However, a diagnosis of GC is often delayed due to the lack of early symptoms and available screening programs in United States. Extracellular RNA (exRNA) is an emerging paradigm; exRNAs have the potential to serve as biomarkers in panels aimed at early detection of cancer. We previously reported the successful use of a panel of salivary exRNA for detecting GC in a high-prevalence Korean cohort, and that genetic changes reflected cancer-associated salivary exRNA changes. The current study is a case-control study of salivary exRNA biomarkers for detecting GC in an ethnically distinct U.S. cohort. A model constructed for the U.S. cohort combined demographic characteristics and salivary miRNA and mRNA biomarkers for GC and yielded an area under the receiver operating characteristic (ROC) curve (AUC) of 0.78. However, the constituents of this model differed from that constructed for the Korean cohort, thus, emphasizing the importance of population-specific biomarker development and validation.

Effect of aqueous extract of seed of broccoli on inflammatory cytokines and Helicobacter pylori infection: a randomized, double-blind, controlled trial in patients without atrophic gastritis

The purpose of this study was to investigate the anti-inflammatory effect of an aqueous extract of seed of broccoli (AESB) in Helicobacter pylori (HP)-infected patients without atrophic gastritis. This was a double-centre, randomized, double-blind, controlled study. A total of 110 HP-infected subjects were randomized to receive either AESB or placebo for 2 months. Inflammatory cytokine (IL-8, IFN-γ, TNF-α, CRP, IL-17A, IL-1β, IL-18), pepsinogen I, II (PG I, PG II), and gastrin-17 (G-17) measurements and ¹³C-urea breath tests were performed at baseline and at 60 days. At 60 days, there was no significant difference in any of the inflammatory cytokines, pepsinogen or gastrin between the two groups. However, IL-8, IFN-γ, PG I, PG I/PG II ratio (PGR), and G-17 were reduced by 9.02 pg/mL, 5.08 pg/mL, 24.56 ng/mL, 1.75 and 0.3 pmol/L, respectively, in the AESB group compared with baseline (all P < 0.05). The HP eradication rates in the AESB group and placebo group were 11.11 and 3.70% at 60 days, respectively (P > 0.05). No treatment-related adverse events were reported. Thus, AESB may reduce the risk of gastric mucosal lesions and decrease the risk of gastric cancer by relieving inflammatory cytokines. The safety profile of AESB was satisfactory. This study is registered with the Chinese Clinical Trials Registry (Registration No. ChiCTR2100054249).

The Role of SETBP1 in Gastric Cancer: Friend or Foe

Background

Gastric cancer (GC) remains a common disease with a poor prognosis worldwide. The SET binding protein 1 (SETBP1) has been implicated in the pathogenesis of several cancers and plays a dual role as an oncogene and a tumor suppressor gene. However, the role and underlying mechanism of SETBP1 in GC remain unclear.

Materials and Methods

We used next-generation RNA sequencing (RNA-seq) data from The Cancer Genome Atlas (TCGA) to explore the correlation between SETBP1 expression and tumor progression. We then quantified SETBP1 expression in GC cells with real-time quantitative polymerase chain reactions (RT-qPCR). The chi-square test and logistic regression were used to assess the correlation between SETBP1 expression and clinicopathological features. Kaplan-Meier survival analysis and Cox proportional hazards regression model were used to assess the relationship between SETBP1 expression and survival. Finally, gene set enrichment analyses (GSEA) were used to examine GC-related signaling pathways in low and high SETBP1 expressing samples.

Results

We found SETBP1 expression levels in GC tissues to be significantly lower than in adjacent non-tumor tissues in the TCGA database. In addition, SETBP1 expression differed significantly between groups classified by tumor differentiation. Furthermore, SETBP1 expression in diffuse-type GC was significantly higher than in intestinal-type GC. However, it did not differ significantly across pathological- or T-stage groups. RT-qPCR and comprehensive meta-analysis showed that SETBP1 expression is downregulated in GC cells and tissues. Interestingly, SETBP1 expression in poorly- or un-differentiated GC cells was higher than in well-differentiated GC cells. Moreover, the chi-square test and logistic regression analyses showed that SETBP1 expression correlates significantly with tumor differentiation. Kaplan–Meier curves indicated that patients with relatively high SETBP1 expression had a poor prognosis. Multivariate analyses indicated that SETBP1 expression might be an important predictor of poor overall survival in GC patients. GSEA indicated that 20 signaling pathways were significantly enriched in samples with high and low SETBP1 expression.

Conclusion

SETBP1 may play a dual role in GC progression.

The global, regional and national burden of stomach cancer and its attributable risk factors from 1990 to 2019

We aimed to estimate the incidence, mortality, and disability-adjusted life-years (DALYs) of stomach cancer at the global, regional, and national levels. Stomach cancer resulted in 1.3 million (1.2-1.4 million) incident cases, 9.5 hundred thousand (8.7-10.4 hundred thousand) deaths, and 22.2 million (20.3-24.1 million) DALYs in 2019. The age-standardized incidence rate, death rate and DALY rate were 15.6 (14.1-17.2), 11.9 (10.8-12.8), and 268.4 (245.5-290.6) per 100,000 person-years, respectively. Between 1990 and 2019, the global age-standardized incidence rate, death rate, and DALY rate decreased by - 30.5% (- 36.7 to - 22.9), - 41.9% (- 47.2 to - 36.3), and - 45.6% (- 50.8 to - 39.8), respectively. In 2019, most of the global numbers of incidence, death and DALYs were higher among males than females. A considerable burden of stomach cancer was attributable to smoking and a high-sodium diet. Although the global age-standardized incidence and death rates have decreased, continued growth in absolute numbers in some regions, especially in East Asia, poses a major global public health challenge. To address this, public health responses should be tailored to fit each country's unique situation. Primary and secondary prevention strategies with increased effectiveness are required to reduce the incidence and mortality of stomach cancer, particularly in populations with a high disease burden.

Quantification of Tumor Abnormal Proteins in the Diagnosis and Postoperative Prognostic Evaluation of Gastric Cancer

Background:

Abnormal glycosylation of proteins has been identified in almost all types of cancers and is closely related to the cancer progression, metastasis, and survival of cancer patients. This study was to explore the values of serum tumor abnormal protein (TAP), an abnormal glycochain protein, in the diagnosis and prognosis of gastric cancer (GC).

Methods:

A total of 335 GC patients were included as the study group, and another 335 subjects served as the control group. Tumor abnormal protein expression was compared between the 2 groups. Correlation analysis was used to assess the correlations of TAP with clinicopathological factors. Gastric cancer patients were divided into training set and test set at a ratio of 2:1. Univariate and multivariate Cox regression analyses in training set were used to evaluate the prognostic significance of TAP in GC patients and explore the independent risk factors for overall survival (OS) and disease-free survival (DFS) to establish a prognostic model, followed by testing of the model. According to the median of TAP, 335 GC patients were divided into 2 groups to plot the survival curves of OS and DFS.

Results:

Tumor abnormal protein expression in the study group was significantly higher than in the control group. Taking the best cut-off value of TAP (110.128 μm²) as the diagnostic criteria for GC, the sensitivity and specificity of TAP were 83.58% and 97.61%, respectively, and the area under the receiver operating characteristics (ROC) curve was 0.935, which was not inferior to computed tomography (CT). Tumor abnormal protein expression was an independent risk factor for OS and DFS. The prognostic predictive value of TAP was better than that of pathological stage in GC patients. The model with TAP was effective in predicting prognosis.

Conclusion:

Tumor abnormal protein is an effective indicator for early screening and prognostic evaluation of GC and can also assist the clinical diagnosis and treatment of GC.

Effect of Helicobacter pylori Eradication on Gastric Cancer Prevention: Updated Report From a Randomized Controlled Trial With 26.5 Years of Follow-up

BACKGROUND & AIMS

Helicobacter pylori infection is considered as the most important risk factor in the pathogenesis of gastric cancer. This study aims to evaluate the long-term effects of H pylori eradication treatment on the incidence and mortality of gastric cancer among a high-risk population.

METHODS

This prospective, randomized, placebo-controlled trial was conducted in a high-risk area in southern China in July 1994. A total of 1630 asymptomatic, H pylori-infected individuals were randomly assigned to receive standard triple therapy for H pylori eradication (n = 817) or placebo (n = 813), and were followed up until December 2020. The primary outcome was incidence of gastric cancer. Total and cause-specific mortalities were the secondary outcomes.

RESULTS

During 26.5 years of follow-up, 21 participants (2.57%) in the treatment arm and 35 (4.31%) in the placebo arm were diagnosed with gastric cancer. Participants receiving H pylori treatment had a lower incidence of gastric cancer compared with their placebo counterparts (hazard ratio [HR], 0.57; 95% CI, 0.33-0.98). More obvious risk reduction was observed among those without premalignant gastric lesions (HR, 0.37; 95% CI, 0.15-0.95) and those without dyspepsia symptoms at baseline (HR, 0.44; 95% CI, 0.21-0.94). Furthermore, compared with 32 cases of gastric cancer observed among 527 participants with persistent H pylori infection in the placebo group, only 16 were identified in 625 subjects with successful eradication in the treatment group (HR, 0.46; 95% CI, 0.26-0.83). However, there were no statistically significant differences for any mortality end points between the 2 groups.

CONCLUSIONS

Eradication of H pylori might confer a long-term protection against gastric cancer in high-risk populations, especially for infected individuals without precancerous gastric lesions at baseline.

Combined risk factors and risk of upper gastrointestinal cancer mortality in the Linxian general population

We aimed to explore the association of combined risk factors with risk of death from upper gastrointestinal (UGI) cancer, including esophageal squamous cell carcinoma (ESCC), gastric cardia carcinoma (GCC) and gastric noncardia carcinoma (GNCC) in the Linxian Nutrition Intervention Trial (NIT) cohort. The NIT cohort included 29 584 healthy adults. A combined risk score (CRS) was calculated using a point system method based on 10 risk factors collected at baseline, including gender, smoking, alcohol drinking, body mass index, family history of UGI cancer, drinking tap water, tooth loss and consumption of fresh fruit, eggs and meat. Possible score ranged from 0 to 31, and higher score indicated as poorer health status. Subjects were divided into three groups by the CRS (<12 points, 12 to 20 points and >20 points). The group of CRS <12 points was considered as the reference. During the 30-year follow-up, we identified 4553 UGI cancer deaths. Compared to subjects with a CRS <12 points, the adjusted HRs for CRS of 12 to 20 points and >20 points were 1.69 (95% CI: 1.56-1.83) and 3.06 (95% CI: 2.82-3.33) for UGI cancer mortality, respectively (P_trend  < .001). Comparable associations were also observed for ESCC, GCC and GNCC mortality. Results remained similar across different age groups (P_interaction  > .05). All HRs observed in the second half follow-up period were stronger than that observed in the first half follow-up period. Our study indicated that higher CRS was associated with increased risk of UGI cancer mortality. Appropriate measures should be taken to reduce unhealthy lifestyles.

Textbook outcome, chemotherapy compliance, and prognosis after radical gastrectomy for gastric cancer: A large sample analysis

BACKGROUND

This study aims to analyze the effect of textbook outcome (TO) on the long-term prognosis and adjuvant chemotherapy (AC) compliance of patients with gastric cancer (GC) in a single institute.

MATERIALS AND METHODS

Consecutive patients who underwent radical gastrectomy with pathological stage I-III at Union Hospital of Fujian Medical University from January 2010 to June 2017 were included. TO was defined as receiving a complete-potentially curative status, ≥15 lymph nodes examined, hospital stay ≤21 days, and freedom from intraoperative and postoperative complications, re-intervention in 30 days, 30-day readmission to the hospital or intensive care unit, and 30-day postoperative mortality.

RESULTS

Totally 3993 patients were included, of which 3361 (84.2%) patients achieved TO. The overall, disease-specific, and recurrence-free survival of patients achieving TO were significantly better than those of patients without achieving TO (all P < 0.05). The total number of AC cycles was greater and the interval from surgery to first AC was shorter in the TO group compared with the Non-TO group. Age >65 years old, open surgery, pT3-4 stage, and total radical gastrectomy (TG) were identified as related high-risk factors for failure to achieve TO. Laparoscopic surgery facilitated TO achievement in high-risk groups.

CONCLUSION

TO is a reliable indicator of favorable prognosis of patients with GC and contributes to postoperative chemotherapy compliance. Age ≤65 years old, non-TG, pT1-2 stage, and laparoscopic surgery may promote the achievement of TO.

Hsa_circ_0000285 contributes to gastric cancer progression by upregulating FN1 through the inhibition of miR-1278

Background

Gastric cancer (GC) is one of the most severe cancers worldwide, particularly in China. Circular RNA (circRNA) plays an essential role in GC. Hsa_circ_0000285 regulates the progression of several cancers. However, its role in GC has not been reported. This study elucidated the molecular mechanism and role of hsa_circ_0000285 in GC progression.

Methods

GC cells were transfected with silencers of hsa_circ_0000285 and fibronectin 1 (FN1), an inhibitor of miR‐1278, and their negative controls (NC). Mice were injected with short hairpin (sh) RNAs targeting hsa_circ_0000285 or NC. The expression levels of hsa_circ_0000285, miR‐1278, and FN1 were assessed using western blotting and reverse transcription quantitative real‐time polymerase chain reaction (qRT‐PCR). Several assays were used to evaluate cell proliferation, invasion, and apoptosis. Tumor burden was also analyzed. The interactions between miR‐1278, hsa_circ_0000285, and FN1 were ascertained using dual‐luciferase reporter assays. An RNA immunoprecipitation (RIP) assay was used to assess the enrichment of hsa_circ_0000285 and miR‐1278 in GC.

Results

Hsa_circ_0000285 was significantly overexpressed in the GC tissues. Silencing hsa_circ_0000285 inhibited cell proliferation and invasion, promoted apoptosis, and inhibited tumor development. Hsa_circ_0000285 sponged miR‐1278. Inhibition of miR‐1278 in vitro reversed the effects of hsa_circ_0000285 silencing on GC progression. MiR‐1278 targeted FN1, and silencing FN1 neutralized the effects of miR‐1278 inhibitors on GC progression.

Conclusions

The hsa_circ_0000285/miR‐1278/FN1 axis regulated GC progression. In addition, it may serve as a potential therapeutic biomarker for GC.

Application of a novel scoring system for gastric cancer opportunistic screening in hospital visits

Background

A novel scoring system and screening procedure for gastric cancer (GC) screening was proposed based on the national conditions of China, which state that endoscopy professionals and facilities are relatively limited compared with the large Chinese population.

Methods

A novel scoring system for gastric cancer screening was used to retrospectively analyse the patients who met the screening procedure from April 2017 to December 2019 in our hospital. We divided all of the patients into three groups: low-risk group (0–11 scores), medium-risk group (12–16 scores), and high-risk group (17–23 scores). Statistical analysis was performed on the detection rate of gastric cancer and precursors of gastric cancer among these three groups.

Results

A total of 6701 patients were enrolled in this study, including 4,352(64.95%) in the low-risk group, 1,948 patients (29.07%) in the medium-risk group, and 401 patients (5.98%) in the high-risk group. The total detection rate of gastric cancer was 2.84% (190/6,701), with a 0.94% rate (41/4,352) in the low-risk group, a 5.18% rate (101/1,948) in the medium-risk group, and a 11.97% rate (48/401) in the high-risk group. There were statistically significant differences in the detection rate of gastric cancer among these three groups (all P < 0.05). The detection rate of early gastric cancer was 46.31% (88/190) among all of the detected gastric cancers in this study. In addition, the detection rates of differentiated gastric cancer and precursors of gastric cancer in the medium-risk group and high-risk group were significantly higher than those in the low-risk group. In addition, the area under the curve (AUC) of the receiver operating characteristic curve (ROC) of the novel scoring system in differentiating GC was 0.79.

Conclusion

The screening strategy based on the novel scoring system can significantly improve the efficiency of gastric cancer opportunistic screening in hospital visits. Gastroscopy should be strongly recommended for patients in the medium-risk group and high-risk group, and detailed gastroscopy should be adopted as early as possible to improve the detection rate of early gastric cancer.

Long noncoding RNA BBOX1-AS1 promotes the progression of gastric cancer by regulating the miR-361-3p/Mucin 13 signaling axis

Gastric cancer (GC) places a heavy burden on global health, and the information on the molecular mechanism of the progression of GC is still inadequate. Long noncoding RNA (LncRNA) has been confirmed to be widely involved in regulating the progression of GC. Our aim in this study was to explore the role and potential regulatory mechanism of lncRNA BBOX1-AS1 in GC. The expression levels of BBOX1-AS1, miR-361-3p, and MUC13 in GC tissues and cells were evaluated using quantitative real-time polymerase chain reaction and western blotting. The silencer of BBOX1 antisense RNA 1 (BBOX1-AS1) and mucin 13 (MUC13), the mimics and inhibitor of miR-361-3p, and their negative controls were used to alter the expression of these genes. Luciferase reporter, pull-down, and RNA immunoprecipitation assays were performed to verify the correlation between miR-361-3p, BBOX1-AS1, and MUC13. GC cell proliferation, invasion, and apoptosis were detected by cell counting kit-8, transwell, and flow cytometry assays, respectively. An in vivo functional experiment was performed to assess the effect of BBOX1-AS1 on GC. The results showed that BBOX1-AS1 was significantly upregulated in GC tissues. Silencing of BBOX1-AS1 inhibited GC cell proliferation and invasion and inhibited tumor growth in vivo, whereas it promoted apoptosis. MiR-361-3p was significantly downregulated in GC and counteracted the inhibitory effects of BBOX1-AS1 on GC progression. MUC13, which is targeted by miR-361-3p, is significantly upregulated in GC. MUC13 silencing inhibited GC progression was aborgated by miR-361-3p inhibitor. Collectively, BBOX1-AS1 silencing inhibits GC progression by regulating the miR-361-3p/MUC13 axis, providing a potential therapeutic biomarker for GC.

Association of Adjuvant Chemotherapy With Overall Survival Among Patients With Locally Advanced Gastric Cancer After Neoadjuvant Chemotherapy

Importance

Neoadjuvant chemotherapy (NAC) is a standard treatment option for locally advanced gastric cancer (LAGC); however, the indications for adjuvant chemotherapy (AC) in patients with LAGC who received NAC remain controversial.

Objective

To compare survival rates between patients with LAGC who received AC and those who did not after NAC followed by surgery.

Design, Setting, and Participants

This multicenter, international cohort study included 353 patients with LAGC undergoing curative-intent gastrectomy after NAC at 2 tertiary referral teaching hospitals in China between June 1, 2008, and December 31, 2017. To externally validate the findings in the Chinese patients, 109 patients from the US and Italy between June 1, 2006, and June 30, 2013, were reviewed. The follow-up period of the Chinese patients was completed in December 2020, and the follow-up period of the Western patients was completed between February and July 2017. Data analysis was performed from December 1, 2020, to February 28, 2021.

Exposures

Patients who received AC and those who did not were propensity score matched to evaluate the association of AC with survival.

Main Outcomes and Measures

Overall survival (OS), disease-free survival, and disease-specific survival.

Results

Of 353 patients from China (275 [78.1%] male; mean [SD] age, 58.0 [10.7] years), 262 (74.1%) received AC and 91 (25.9%) did not. After propensity score matching, the 3-year OS was significantly higher in patients who received AC (60.1%; 95% CI, 53.1%-68.1%) than in those who did not (49.3%; 95% CI, 39.8%-61.0%) (P = .02). Lymph node ratio (LNR) was significantly associated with AC benefit (P < .001 for interaction), and a plot of the interaction between LNR and AC demonstrated that AC was associated with improved OS in patients with higher (≥9%) LNRs (3-year OS: 46.6% vs 21.7%; P < .001), but not in patients with LNRs less than 9% (3-year OS: 73.9% vs 71.3%; P = .30). When stratified by AC cycles, only those patients who completed at least 4 AC cycles exhibited a significant survival benefit in the 6-month (hazard ratio, 0.56; 95% CI, 0.33-0.96; P = .03) and 9-month landmark analysis (hazard ratio, 0.50; 95% CI, 0.27-0.94; P = .03). In the external cohort, improved OS with AC administration was also found in patients with LNRs of 9% or greater (3-year OS: 53.0% vs 26.3%; P = .04).

Conclusions and Relevance

In this cohort study, the administration of AC after NAC and resection of LAGC was associated with improved prognosis in patients with LNRs of 9% or greater. These findings suggest that LNR might be valuable in AC selection in future decision-making processes.

Development of a prognostic metabolic signature in stomach adenocarcinoma

PURPOSE

The growth and aggressiveness of Stomach adenocarcinoma (STAD) is significantly affected by basic metabolic changes. This study aimed to identify metabolic gene prognostic signatures in STAD.

METHODS

An integrative analysis of datasets from the Cancer Genome Atlas and Gene Expression Omnibus was performed. A metabolic gene prognostic signature was developed using univariable Cox regression and Kaplan-Meier survival analysis. A nomogram model was developed to predict the prognosis of STAD patients. Finally, Gene Set Enrichment Analysis (GESA) was used to explore the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways significantly associated with the risk grouping.

RESULTS

A total of 327 metabolism-related differentially expressed genes were identified. Three subtypes of STAD were identified and nine immune cell types, including memory B cell, resting and activated CD4+ memory T cells, were significantly different among the three subgroups. A risk score model including nine survival-related genes which could separate high-risk patients from low-risk patients was developed. The prognosis of STAD patients likely benefited from lower expression levels of genes, including ABCG4, ABCA6, GPX8, KYNU, ST8SIA5, and CYP19A1. Age, radiation therapy, tumor recurrence, and risk score model status were found to be independent risk factors for STAD and were used for developing a nomogram. Nine KEGG pathways, including spliceosome, pentose phosphate pathway, and citrate TCA cycle were significantly enriched in GESA.

CONCLUSION

We propose a metabolic gene signature and a nomogram for STAD which might be used for predicting the survival of STAD patients and exploring prognostic markers.

Epidemiology of stomach cancer

Despite a decline in incidence and mortality during the last decades, stomach cancer is one of the main health challenges worldwide. According to the GLOBOCAN 2020 estimates, stomach cancer caused approximately 800000 deaths (accounting for 7.7% of all cancer deaths), and ranks as the fourth leading cause of cancer deaths in both genders combined. About 1.1 million new cases of stomach cancer were diagnosed in 2020 (accounting for 5.6% of all cancer cases). About 75% of all new cases and all deaths from stomach cancer are reported in Asia. Stomach cancer is one of the most lethal malignant tumors, with a five-year survival rate of around 20%. There are some well-established risk factors for stomach cancer: Helicobacter pylori infection, dietary factors, tobacco, obesity, and radiation. To date, the most important way of preventing stomach cancer is reduced exposure to risk factors, as well as screening and early detection. Further research on risk factors can help identify various opportunities for more effective prevention. Screening programs for stomach cancer have been implemented in a few countries, either as a national or opportunistic screening of high-risk individuals only. Generally, due to its high aggressiveness and heterogeneity, stomach cancer still remains a severe global health problem.

From Helicobacter pylori infection to gastric cancer: Current evidence on the immune response

Gastric cancer (GC) is the result of a multifactorial process whose main components are infection by Helicobacter pylori (H. pylori), bacterial virulence factors, host immune response and environmental factors. The development of the neoplastic microenvironment also depends on genetic and epigenetic changes in oncogenes and tumor suppressor genes, which results in deregulation of cell signaling pathways and apoptosis process. This review summarizes the main aspects of the pathogenesis of GC and the immune response involved in chronic inflammation generated by H. pylori.

Gastric Cancer Screening Methods: A Comparative Study of the Chinese New Gastric Cancer Screening Score and Kyoto Classification of Gastritis

Objective

To evaluate the Chinese new gastric cancer screening score (i.e., Li's score) and Kyoto Classification of Gastritis for screening gastric cancer.

Methods

A total of 702 patients were scored using the two scoring methods. Gastric atrophy, intestinal metaplasia, and gastric cancer (including early gastric cancer) were compared between the two scoring methods. The area under the ROC curve, sensitivity, and specificity of the two scoring methods were evaluated.

Results

Both of the two scoring methods found that gastric atrophy, intestinal metaplasia, and gastric cancer (including early gastric cancer) were all significantly higher in the medium-risk and high-risk group patients than those in the low-risk group patients. According to the Kyoto Classification of Gastritis, patients in the high-risk group had more gastric atrophy, intestinal metaplasia, and gastric cancer than those in the medium-risk group patients. Gastric atrophy, intestinal metaplasia, and gastric cancer in the low-risk and medium-risk group patients evaluated by the Li score were all significantly higher than those in patients with corresponding risk level evaluated by Kyoto Classification of Gastritis, respectively. The area under the ROC curve of the Li score was 0.702, and the sensitivity and specificity were 57.6% and 85.3%, respectively. The area under the ROC curve of the Kyoto Classification of Gastritis was 0.826, and the sensitivity and specificity were 75.4% and 83.6%, respectively.

Conclusion

Both Li's score and Kyoto Classification of Gastritis showed good screening value for gastric cancer, but Kyoto Classification of Gastritis was more sensitive than the Li score.

Novel prognostic marker LINC00205 promotes tumorigenesis and metastasis by competitively suppressing miRNA-26a in gastric cancer

Rapid proliferation and metastasis of gastric cancer (GC) resulted in a poor prognosis in the clinic. Previous studies elucidated that long non-coding RNA (LncRNA) LINC00205 was upregulated in various tumors and participated in tumor progression. The aim of our study was to investigate the regulating role of LINC00205 in tumorigenesis and metastasis of GC. Both public datasets and our data showed that the LINC00205 was highly expressed in GC tissues and several cell lines. Notably, GC patients with high level of LINC00205 had a poor prognosis in our cohort. Mechanistically, knockdown of LINC00205 by shRNAs suppressed GC cells proliferation, migration, invasion remarkably, and induced cell cycle arrest. Based on bioinformatics prediction, we found that LINC00205 might act as a competitive endogenous RNA (ceRNA) through targeting miR-26a. The level of miR-26a had negatively correlated with LINC00205 expression and was decreased among GC cell lines, tissues, and serum samples. Our results for the first time confirmed that miR-26a was a direct target of LINC00205 and might have the potential to become a plasma marker for clinical tumor diagnosis. Indeed, LINC00205 knockdown resulted in the dramatic promotion of miR-26a expression as well as inhibition of miR-26a potential downstream targets, such as HMGA2, EZH2, and USP15. These targets were essential for cell survival and epithelial-mesenchymal transition. Importantly, LINC00205 was able to remodel the miR-26a-mediated downstream silence, which identified a new mechanism of malignant transformation of GC cells. In conclusion, this study revealed the regulating role of the LINC00205/miR-26a axis in GC progression and provided a new potential therapeutic strategy for GC treatment.

A Practical Nomogram for Predicting the Prognosis of Elderly Patients with Gastric Adenocarcinoma After Gastrectomy

Purpose

To establish a pragmatic prognostic nomogram for predicting the survival of elderly patients undergoing gastrectomy for gastric adenocarcinoma.

Patients and Methods

Data of elderly patients undergoing gastrectomy for gastric adenocarcinoma between 2004 and 2015 were obtained from the Surveillance, Epidemiology, and End Results database. Prognostic factors were identified by the Kaplan–Meier method and the Cox proportional hazards model. Based on these factors, we developed a nomogram to predict the overall survival (OS) and gastric cancer-specific survival (GCSS). Concordance index (C-index) and calibration curve are employed to assess the predictive accuracy of the model. Decision curve analysis (DCA) and receiver operating characteristic curve (ROC) analysis are applied to further appraise the clinical utility of the model.

Results

A total of 8401 cases were incorporated into this research. After univariate and multivariate analyses, nine prognostic factors of OS were identified, including age (P < 0.001), race (P < 0.001), marital status (P < 0.001), tumor site (P < 0.001), tumor size (P = 0.024), differentiation (P < 0.001), T stage (P < 0.001), N stage (P < 0.001), and M stage (P < 0.001); ten prognostic factors of GCSS were identified, including age (P < 0.001), race (P < 0.001), tumor site (P < 0.001), tumor size (P = 0.002), differentiation (P < 0.001), T stage (P < 0.001), N stage (P < 0.001), M stage (P < 0.001), radiotherapy (P < 0.001) and chemotherapy (P < 0.001). The C-index of the constructed nomogram for OS was 0.708 (95% CI: 0.701–0.715) while for GCSS was 0.745 (95% CI: 0.737–0.753). The calibration curves of the nomogram predictions and actual observations displayed good agreement for the 3- and 5-year OS and GCSS probabilities. The results of DCA and the area under the curve calculated by ROC analysis showed that the developed model was superior than TNM stage.

Conclusion

The nomogram we established could accurately predict the prognosis of individual elderly patients who underwent gastrectomy for gastric adenocarcinoma.

Advances in Treatment Models of Advanced Gastric Cancer

The prognosis of advanced gastric cancer (AGC) is extremely poor, and the therapeutic effect of traditional palliative chemotherapy is far from satisfactory. To overcome this bottleneck, palliative surgery resection, perioperative chemotherapy combined with surgical resection, hyperthermic intraperitoneal chemotherapy (HIPEC), pressurized intraperitoneal aerosol chemotherapy (PIPAC), radiation therapy, molecular-targeted therapy have been explored in AGC. Although considerable progress has been achieved, there is still no overwhelming therapeutic method. Due to the high heterogeneity of AGC, it is particularly vital to reshaped the paradigm of gastric cancer therapy according to the characteristics of clinical classifications and molecular subtypes.

The efficiency of MSC‐based targeted AIE nanoparticles for gastric cancer diagnosis and treatment: An experimental study

Mesenchymal stem cells (MSCs), due to their tumor tropism, are strongly recruited by various solid tumors and mobilized by inflammatory signals in the tumor microenvironment. However, effective cellular uptake is critical for MSC‐based drug delivery. In this study, we synthesized a spherical copolymer, polyethylenimine–poly(ε‐caprolactone), with aggregation‐induced emission (AIE) material and the anticancer drug, paclitaxel, coloaded onto its inner core. This was followed by the addition of a transactivator of transcription (TAT) peptide, a type of cell‐penetrating peptide, to modify the nanoparticles (NPs). Finally, the MSCs were employed to carry the TAT‐modified AIE‐NPs drug to the tumor sites and assist in simultaneous cancer diagnosis and targeted tumor therapy. In vitro, the TAT‐modified AIE‐NPs showed good biocompatibility, targeting, and stability in an aqueous solution besides high drug‐loading and encapsulation efficiency. In vitro, the AIE‐NPs exhibited a controllable release under a mildly acidic environment. The in vivo and in vitro studies showed high antitumor efficacy and low cytotoxicity of the AIE‐NP drug, whereas biodistribution confirmed the tumor tropism of MSCs. To summarize, the MSC‐based AIE‐NP drugs loaded with TAT possessed good biocompatibility and high antitumor efficacy via the enhanced NP‐drug uptake. In addition, the tumor tropism of MSCs provided selective drug uptake by the tumor cells and thus reduced the systemic side effects.

Temporal trend of gastric cancer burden along with its risk factors in China from 1990 to 2019, and projections until 2030: comparison with Japan, South Korea, and Mongolia

Background

Identifying and projecting the epidemiological burden of gastric cancer (GC) can optimize the control strategies, especially in high-burden areas.

Methods

We collected incidence, deaths, disability-adjusted life-years (DALYs), age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), age-standardized DALY rate (ASDR) of GC from 1990 to 2019 in China, Japan, South Korea, and Mongolia from the Global Burden of Disease Study 2019. The average annual percentage change (AAPC) was calculated to quantify the temporal trends, and the projection was estimated by applying the Bayesian age-period-cohort model.

Results

In China, the ASIR of GC declined slightly from 37.56/100000 in 1990 to 30.64/100000 in 2019 (AAPC of − 0.41), while the declines of ASMR and ASDR were pronounced (AAPC of − 1.68 and − 1.98, respectively), which were weaker than Japan and South Korea. Although the age-standardized rates of gastric cancer in most countries have declined overall in the past 30 years, the downward trend in the last 4 years has become flattened. Smoking remained one main contributor to DALYs of GC in China, Japan, South Korea, and Mongolia, with more than 24%. The contribution from high-sodium diet was similar between men and women, and kept relatively stable over the three decades. The predicted ASMRs among the four East Asian countries continued to decline until 2030, but the absolute deaths would still increase significantly, especially in South Korea and Mongolia.

Conclusions

Although the age-standardized rates of GC in most countries have declined, the absolute burden of GC in the world, especially in China and Mongolia, is on the rise gradually. Low socio-demographic index and aging along with Helicobacter pylori infection, smoking, and high-salt diet were the main risk factors of GC occurrence and should be paid more attention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-021-00340-6.