Gastric carcinoma: Insights into risk factors, methods of diagnosis, possible lines of management, and the role of primary care

Mutations in Helicobacter pylori infected patients with chronic gastritis, intestinal type of gastric cancer and familial gastric cancer

BACKGROUND

Development of sequential changes of mucous leading to gastric cancer and familial cases of gastric cancer of intestinal type is widely connected with Helicobacter pylori infections. In this study we analysed variants of genes involved in cancerogenesis and inflammatory processes of intestines in patients infected with H.pylori. Our goal was to test whether mutations in these genes predestinate to development of gastric cancer, and whether there is a genetic factor that makes it more likely for infections with H.pylori to cause gastric cancer. As infections with H. pylori are relatively common, discovering such genetic predispositions could be used for establishing risk-groups and for planning treatments.

METHODS

Our studies cover analysis of variants in genes involved in cancerogenesis: TP53 (rs11540652, rs587782329, COSM10771), MSH2 (rs193922376), MLH1 (rs63750217), and inflammatory processes of intestine: NOD2 (rs2066847, rs2066842), IL1A (rs1800587) and IL1B (rs1143634) from H.pylori-infected patients.

RESULTS

Mutations were more common in the group of patients with gastric cancer of intestinal type and familial cases of gastric cancer in comparison with patients with chronic gastritis, chronic atrophic gastritis, intestinal metaplasia, dysplasia or gastric cancer (p-value = 0.00824), with the prevalence of p53 mutations in patients with familial gastric cancer vs. patients with other changes of mucosa (p-value = 0.000049). Additionally, gastric cancer patients have mainly genotype TT or CT of the rs2066842 variant of the NOD2 gene.

CONCLUSIONS

The lack of statistically significant changes of other interleukin genes involved in inflammatory processes may suggest the presence of H.pylori infection as a potential trigger for the development of the inflammatory process of the mucosa, leading through microbiota dysbiosis to the development of enteric gastric cancer. Mutations in analysed genes correlated with more severe mucosal changes, with a much more frequent presence of TP53 gene mutations, with a limited presence of other mutations in the familial history of gastric cancer.

Identification and classification of the genomes of novel microviruses in poultry slaughterhouse

Microviridae is a family of phages with circular ssDNA genomes and they are widely found in various environments and organisms. In this study, virome techniques were employed to explore potential members of Microviridae in a poultry slaughterhouse, leading to the identification of 98 novel and complete microvirus genomes. Using a similarity clustering network classification approach, these viruses were found to belong to at least 6 new subfamilies within Microviridae and 3 higher-level taxonomic units. Genome size, GC content and genome structure of these new taxa showed evident regularities, validating the rationality of our classification method. Our method can divide microviruses into about 45 additional detailed clusters, which may serve as a new standard for classifying Microviridae members. Furthermore, by addressing the scarcity of host information for microviruses, the current study significantly broadened their host range and discovered over 20 possible new hosts, including important pathogenic bacteria such as Helicobacter pylori and Vibrio cholerae, as well as different taxa demonstrated different host specificities. The findings of this study effectively expand the diversity of the Microviridae family, providing new insights for their classification and identification. Additionally, it offers a novel perspective for monitoring and controlling pathogenic microorganisms in poultry slaughterhouse environments.

Nomogram for predicting survival of patients with gastric cancer and multiple primary malignancies: a real-world retrospective analysis using the Surveillance, Epidemiology and End Results database

OBJECTIVES

Gastric cancer combined with multiple primary malignancies (GCM) is increasingly common. This study investigated GCM clinical features and survival time.

METHODS

Patients with GCM and GC only (GCO) were selected from the Surveillance, Epidemiology and End Results (SEER) database. Survival was compared between GCM and GCO groups using propensity score matching. Then, the GCM group was divided into a training cohort and a validation cohort. These cohorts were used to establish a nomogram for survival prediction in patients with GCM.

RESULTS

Survival time was significantly longer in the GCM group than in the GCO group. All-subsets regression was used to identify four variables for nomogram establishment: age, gastric cancer sequence, N stage, and surgery. The concordance index and time-dependent receiver operating characteristic curve indicated that the nomogram had favorable discriminative ability. Calibration plots of predicted and actual probabilities showed good consistency in both the training and validation cohorts. Decision curve analysis and risk stratification showed that the nomogram was clinically useful; it had favorable discriminative ability to recognize patients with different levels of risk.

CONCLUSIONS

Compared with GCO, GCM is a relatively indolent malignancy. The nomogram developed in this study can help clinicians to assess GCM prognosis.

MFAP2 enhances cisplatin resistance in gastric cancer cells by regulating autophagy

Background

Cisplatin (CDDP) is of importance in cancer treatment and widely used in advanced gastric cancer (GC). However, its clinical usage is limited due to its resistance, and the regulatory mechanism of CDDP resistance in GC has not yet been fully elucidated. In this study, we first conducted a comprehensive study to investigate the role of MFAP2 through bioinformatics analysis.

Methods

The Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were applied to downloadgene expression data and clinicopathologic data, and the differentially expressed genes (DEGs) were further analyzed. Then, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and survival analysis were conducted. Furthermore, according to the clinicopathological characteristics of TCGA, clinical correlation analysis was conducted, and a receiver operating characteristic curve (ROC) was plotted.

Results

We revealed that FAP, INHBA and MFAP2 were good diagnostic factors of GC. However, the mechanism of MFAP2 in GC remains elusive, especially in the aspect of chemotherapy resistance. We developed the CDDP-resistant cell line, and found that MFAP2 was upregulated in CDDP-resistant cells, and MFAP2-knockdown improved CDDP sensitivity. Finally, we found that MFAP2 enhanced CDDP resistance by inducing autophagy in drug-resistant cell lines.

Conclusions

The above results suggested that MFAP2 could affect the chemotherapy resistance by altering the level of autophagy in GC patients as a potential therapeutic target.

Knowledge and Awareness About Gastric Cancer Among the General Population in Al-Baha City, Saudi Arabia

Background Gastric cancer is a significant health concern worldwide, and its incidence varies across different populations. This study aimed to assess the level of knowledge and awareness of gastric cancer among the general population in Al-Baha City, Saudi Arabia.  Methodology This is a cross-sectional study that was conducted among the residents of Al-Baha city older than 18 years. The study was conducted based on a questionnaire that has been developed by a previous study. Data were initially recorded in an Excel sheet before being exported to the SPSS program, version 25 for data analysis. Results The survey included 426 respondents from Al-Baha city, Saudi Arabia, with 56.8% being females and the majority being in the age groups (21-30 years). Alcohol consumption (mean=4.5, SD= 0.77), smoking cigarettes or Shisha (mean= 4.38, SD=0.852), family history of gastric cancer (mean= 4, SD=1.008), a past medical history of gastric cancer (mean= 3.99, SD=0.911), stomach ulcer (mean=3.76, SD=0.898), and consumption of smoked food (mean= 3.69, SD=0.956) are the most widely recognized risk factors. The most highly recognized symptoms are gastrointestinal bleeding (mean= 4.03, SD=0.875), abdominal lump (mean= 3.94, SD=0.926), weight loss (mean= 3.93, SD=0.963), recurrent nausea and vomiting (mean=3.76, SD=0.956), and abdominal pain (mean= 3.57, SD=0.995). The study also identified several subgroups of the population that may benefit from targeted educational programs, including individuals in the age group of 41-50 years and those in non-medical occupations. Conclusion The study found that participants had a moderate level of knowledge about the risk factors and symptoms of gastric cancer, with significant variability among different subgroups of the population. Further research is needed to investigate the prevalence and risk factors of gastric cancer in Saudi Arabia and other similar populations, to develop effective prevention and management strategies for this disease.

Cancer-associated fibroblast-released extracellular vesicles carrying miR-199a-5p induces the progression of​ gastric cancer through regulation of FKBP5-mediated AKT1/mTORC1 signaling pathway

Accumulating evidence has unfolded the significance of extracellular vesicles (EVs) in diseases and cancers. Here, we attempted to discuss the role of cancer-associated fibroblasts (CAFs)-derived EVs containing miR-199a-5p in gastric tumorigenesis. Upregulated miR-199a-5p was first identified in cancer cells. Then, we selected CAFs for isolation of EVs which were co-cultured with AGS cells. We observed successful delivery of miR-199a-5p via CAF-derived EVs. Besides, miR-199a-5p promoted malignant properties of AGS cells. Moreover, miR-199a-5p downregulated FKBP5, leading to upregulated phosphorylation level of AKT1, which promoted the malignant phenotypes of AGS cells by activating mammalian target of rapamycin complex 1(mTORC1). Exosomal miR-199a-5p from CAFs promoted gastric tumorigenesis in vivo. Our findings point toward the critical role of CAFs-derived EVs carrying miR-199a-5p in gastric cancer progression.

Programmed Death-Ligand 1 (PD-L1) Positivity and Factors Associated with Poor Prognosis in Patients with Gastric Cancer: An Umbrella Meta-Analysis

Gastric cancer (GC) is one of the most common malignancies throughout the world with late diagnosis and poor prognosis. The expression of programmed death-ligand 1 (PD-L1) in GC is attributed to immune evasion and tumor progression. PD-L1 positivity has both predictive and prognostic biomarker potential. Aiming to summarize a large amount of research and to provide a definitive conclusion to the conflicting results on the prognostic significance of PD-L1 expression in GC, we performed an umbrella review based on existing meta-analyses which were published recently (2016-2021) and indexed in the PubMed database. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used in August 2021 to screen articles, and data extraction with quality assessment was performed on the selected meta-analyses. Review Manager (RevMan) 5.3 software was used to analyze the HR and OR with a 95% confidence interval (CI) among PD-L1 positive GC patients. We also assessed the between-study heterogeneity (I ²). Forest and Funnel plots were obtained, and a P-value of <0.05 was considered statistically significant. A total of 567 articles were screened, and we selected three meta-analyses with a total of 40 studies conducted over a period of 14 years. In our umbrella review, a total of 8,419 GC patients with an average PD-L1 positivity of 39% were analyzed. We found that PD-L1 positivity in GC patients is associated with poor prognosis (pooled HR =1.44, 95% CI: 1.24-1.68, P<0.00001) having higher mortality reducing the chances of overall survival (OS). However, there are no significant differences in PD-L1 expression among different lymph node (LN) metastases (OR=1.31, 95% CI: 0.98-1.74, P=0.07) and tumor, node, and metastasis (TNM) stages (OR=1.13, 95% CI: 0.80-1.58, P=0.50). Early identification of PD-L1 expression may help tailor cost-effective and targeted immunotherapy among GC patients. More research is needed to further understand how PD-L1 affects LN metastasis and tumor invasion.

Second Primary Cancers After Gastric Cancer, and Gastric Cancer as Second Primary Cancer

Background

Second primary cancers (SPCs) are increasing, which may negatively influence patient survival. Gastric cancer (GC) has poor survival and when it is diagnosed as SPC it is often the cause of death. We wanted to analyze the risk of SPCs after GC and the risk of GC as SPC after any cancer. Such bidirectional analysis is important in relation to fatal cancers because SPCs may be under-reported in the short-term survival period.

Methods

Cancers were obtained from the Swedish Cancer Registry from years 1990 through 2015. Standardized incidence ratios (SIRs) were used to estimate bidirectional relative.

Results

We identified 23,137 GC patients who developed 1042 SPCs (4.5%); 2158 patients had GC as SPC. While the risk for three SPCs was increased after GC, seven first primary cancers were followed by an increased risk of GC as SPC, including esophageal, colorectal, bladder, squamous cell skin and breast cancers and non-Hodgkin lymphoma. Breast cancer, which was followed by a diagnosis of second GC, showed an excess of lobular histology.

Conclusion

Multiple primary cancers in the same individuals may signal genetic predisposition. Accordingly, the association of GC with breast cancer may be related to mutations in the CDH1 gene, and clustering of colorectal, small intestinal and bladder cancers could be related to Lynch syndrome. The third line of findings supports a contribution of immune dysfunction on the increased risk of GC as SPC after skin cancer and non-Hodgkin lymphoma. Early detection of GC in the risk groups could save lives.

MiRNA-339 targets and regulates ZNF689 to inhibit the proliferation and invasion of gastric cancer cells

BACKGROUND

Gastric cancer (GC) is the most common malignant tumor of the digestive system, and its mortality rate ranks first among malignant tumors. However, the pathogenesis of GC has not yet been fully elucidated. This study found that microRNA (miRNA)-339 is abnormally expressed in GC tissues. However, the role and molecular mechanism of miRNA-339 in the occurrence and development of GC are still unclear.

METHODS

Fluorescence quantitative polymerase chain reaction (qPCR) was used to detect the expression level of miRNA-339 in GC tissues and adjacent tissues and analyze the correlation with the clinicopathological characteristics of GC patients. Cell counting kit-8 (CCK-8) and Transwell experiments detected the effect of overexpression of miRNA-339 on the proliferation, invasion, and migration of GC cells. The luciferase reporter gene detected the downstream target molecules regulated by miRNA-339, and western blot was employed to detect the effect of overexpression of miRNA-339 on the expression of ZNF689.

RESULTS

The results of fluorescence qPCR showed that miRNA-339 was less expressed in GC tissues compared with adjacent tissues, and it was correlated with the patient's clinical tumor, node, metastasis (TNM) grade and lymph node metastasis. Cell function experiments showed that overexpression of miRNA-339 can significantly inhibit the proliferation, invasion, and migration of GC cells. The luciferase reporter gene showed that miRNA-339 can bind to the 3'-UTR region of ZNF689, and overexpression of miRNA-339 can significantly inhibit the expression of ZNF689 in GC cells. Overexpression of ZNF689 can significantly block the ability of overexpression of miRNA-339 to inhibit the proliferation and migration of GC cells.

CONCLUSIONS

miRNA-339 inhibits the proliferation and invasion of GC cells through targeted regulation of the expression of ZNF689. In addition, the expression level of miRNA-339 can be used as a biomarker for the prognosis of GC.