Gastric Cancer最新文献

Background: Microsatellite instability (MSI)-high tumors represent a distinct, small-fraction subtype in esophagogastric junction cancer or gastric cancer (GC), yet their clinical significance remains poorly understood. This study aimed to investigate the prevalence and clinicopathological features of chemotherapy-naïve metastatic or recurrent MSI-high GC as a prescreening study for a phase II trial of nivolumab plus ipilimumab.

Methods: Key inclusion criteria included metastatic or recurrent adenocarcinoma of GC, ECOG performance status of 0 or 1, and no prior systemic therapy for metastatic or recurrent disease. MSI status was tested using multiplex PCR fragment analysis (MSI Testing Kit, FALCO). The primary endpoint was the prevalence of MSI-high GC.

Results: Between October 2020 and October 2022, 930 eligible patients from 75 centers in Japan were analyzed. The prevalence of MSI-high GC was 5.6% (95% CI 4.2-7.3). MSI-high GC was more frequently observed in females than males (9.6% vs 3.8%, p < 0.001), patients aged ≥ 70 years compared to those < 70 years (8.0% vs 2.8%, p < 0.001), in the lower stomach than other locations (10.5% vs 3.2%, p < 0.001), HER2-negative tumors than HER2-positive tumors (6.5% vs 1.8%, p = 0.02), and in patients without liver metastasis than those with liver metastasis (6.9% vs 2.2%, p = 0.004).

Conclusions: The prevalence of MSI-high tumors among chemotherapy-naïve patients with unresectable GC was 5.6%. These tumors were associated with female sex, older age, lower stomach, HER2-negative, and absence of liver metastasis. These findings would help assuming MSI-high tumors and may have significant implications for clinical practice and studies targeting this GC subtype.

Background: Gastric cancer (GC) shows limited response to immune checkpoint inhibitors due to its complex tumor immune microenvironment (TIME). This study explores the functions of various immune cells in the complex TIME in GC.

Methods: We assessed CD8 + T-cell infiltration of GC tissues by immunohistochemistry, and performed single-cell RNA sequencing (scRNA-seq) of tumor and normal tissues from 34 patients with GC.

Results: We categorized 157 GC patients into LOW, MID, and HIGH groups based on their CD8 + T-cell infiltration. Overall survival was notably lower for the HIGH and LOW groups compared with the MID group. Our scRNA-seq data analysis showed that CD8 + T-cell activity markers in the HIGH group were expressed at lower levels than in normal tissue, but the T-cell-attracting chemokine CCL5 was expressed at a higher level. Notably, CD8 + T-cells in the HIGH group displayed lower PD1 expression and higher CTLA4 expression. TCR repertoire analysis using only Epstein-Barr virus-negative cases showed that CD8 + T-cell receptor clonality was lower in the HIGH group than in the MID group. Furthermore, in the HIGH group, the antigen-presenting capacity of type 1 conventional dendritic cells was lower, the immunosuppressive capacity of myeloid-derived suppressor cells was higher, and the expression of CTLA4 in regulatory T-cells was higher.

Conclusion: The present data suggest that the infiltration of inactive CD8 + T-cells with low clonality is induced by chemotaxis in the HIGH group, possibly leading to a poor prognosis for patients with GC.

Background: In the past several decades, cisplatin (DDP), in combination with other drugs, has been used as the mainstay chemotherapy drug for the treatment of gastric cancer (GC). However, the clinical application of DDP is restricted because of its toxic side effects, it is imperative to explore less toxic and more effective treatment strategies. Dihydroartemisinin (DHA) has been shown to exert potent anticancer effects through ferroptosis in multiple malignancies and has shown high efficacy and safety.

Methods: Cell viability assay, live/dead staining assay, EDU proliferation assay, MitoTracker assay, BODIPY C11 assay and other cell assays in vitro were employed to observe DHA in combination with DDP inducing ferroptosis in GC. Subsequently, proteomic analysis integrated with database analysis and clinical sample detection were utilized to elucidate the mechanism of DHA inducing ferroptosis in GC both in vitro and in vivo.

Results: In this study, we found that DHA combined with DDP can synergistically inhibit the proliferation, invasion and migration of GC cells and induce ferroptosis. Further studies have shown that DHA acts in combination with DDP to induce ferroptosis in GC cells by inhibiting GPX4 in vivo and in vitro.

Conclusion: In summary, this study is the first to report that DHA and DDP synergically promote ferroptosis in GC cells, the combination of DDP and DHA is a promising strategy from the perspective of toxicity of DDP, which may be a promising therapeutic approach.

Background: Few studies have focussed on using histological phenotype to evaluate prognostic factors after adjuvant chemotherapy (AC) in patients with pStage II/III gastric cancer. We evaluated the impact of histological type based on the World Health Organization classification.

Methods: Overall, 348 patients with pStage II/III advanced gastric cancer undergoing R0 gastrectomy without neoadjuvant chemotherapy were included. Of these, 143 underwent AC. Univariate and multivariate analyses for prognostic factors of relapse-free survival (RFS) and overall survival (OS) were performed in all patients and patients receiving AC. Moreover, long-term survivals were compared by histological phenotype between patients with and without AC.

Results: Multivariate analysis in all patients revealed that histologically poorly cohesive carcinoma with not otherwise specified and signet ring cell subtype (PCC-NOS/SRC) and pN 2/3 independently and adversely affected RFS. Alternatively, male sex, poor PS and pN 2/3 adversely affected OS. In multivariate analysis of patients receiving AC, longer tumour size (≥ 80 mm), histologically PCC-NOS/SRC phenotype and pN 3 independently influenced RFS. Multivariate analysis in this population for OS revealed that pN 3 and poor postoperative immune-nutritional status significantly induced worse OS. Comparison of RFS and OS by histological phenotype between patients with and without AC showed that AC had no efficacy for improving long-term survivals in histologically PCC phenotype.

Conclusions: Histologically PCC phenotype by WHO classification, particularly PCC-NOS/SRC phenotypes, showed poor long-term RFS even after AC in patients with pStage II and III gastric cancer. An effective chemotherapeutic regimen needs to be developed for this specific subtype of gastric cancer.

Background: The primary treatment for gastric cancer (GC) is surgical resection, particularly for locally advanced cases. While laparoscopic gastrectomy (LG) has shown short- and long-term benefits, robotic gastrectomy (RG) offers enhanced precision and may lead to better outcomes, especially in advanced-stage disease.

Methods: This retrospective study analyzed data from 1538 patients with pathological Stage I-III GC who underwent RG or LG between 2014 and 2021. Propensity score matching created 466 matched pairs. Perioperative outcomes, 3 year overall survival (OS), 3 year recurrence-free survival (RFS), and recurrence patterns were compared between RG and LG.

Results: RG demonstrated significantly shorter operative time (235.5 vs. 242.5 min, p = 0.001), less blood loss (19.1 vs. 33.4 ml, p < 0.001), and shorter hospital stay (7.9 vs. 9.7 days, p < 0.001). Overall complications did not differ significantly (p = 0.183), but RG had lower rates of anastomotic leakage (p = 0.045) and pancreatic fistula (p = 0.024). No significant differences in OS were observed in the overall cohort or by stage. Similarly, RFS showed no significant differences in the overall cohort (3 year RFS: RG 86.81% vs. LG 83.04%, p = 0.1347). By stage, no differences were found in stage I or II, but in stage III, RG showed better 3 year RFS (67.52% vs. 52.97%, p = 0.0424). RG also had lower recurrence rates (9.0% vs. 14.8%, p = 0.0061), with fewer liver (p = 0.0069) and lymph node metastases (p = 0.0223).

Conclusion: RG demonstrated superior short-term outcomes and comparable three-year OS to laparoscopic gastrectomy, with improved three-year RFS and reduced recurrence in Stage III, likely facilitated by earlier adjuvant chemotherapy initiation.

Background: Single nucleotide polymorphisms (SNPs) are associated with various diseases, including gastric cancer. The ADAMTS14 gene is linked to multiple types of cancer. However, the relationship between ADAMTS14 and its genetic polymorphisms with susceptibility to gastric cancer (GC) and prognosis remains unclear.

Methods: A case-control study was conducted involving 855 patients diagnosed with gastric cancer (GC) and an equal number of cancer-free controls. Following rigorous statistical analysis, molecular experiments were performed to elucidate the functional significance of the SNPs in the context of GC.

Results: ADAMTS14 rs3740440 (OR = 1.45, p = 0.014) shows a significant association with increased GC risk, while rs11572 (OR = 0.42, p < 0.001) is associated with protection against GC. Moreover, patients with the (CG + GG) genotype of rs3740440 exhibit a poor prognosis (HR = 1.68, p = 0.007). Mechanistically, luciferase reporter assays revealed that the G allele of rs3740440 disrupts the binding of hsa-miR-4294 and hsa-miR-3198 to the 3' untranslated region (3' UTR) of ADAMTS14, leading to increased expression of ADAMTS14 and the promotion of malignant behaviors in GC cells.

Conclusions: Our findings underscore the significant role of ADAMTS14 SNPs in both the risk and prognosis of gastric cancer (GC), providing valuable insights into the underlying molecular mechanisms. Specifically, rs3740440 disrupts the interaction between ADAMTS14 and miRNA, resulting in increased expression of ADAMTS14. This heightened expression enhances its malignant biologic behaviors, indicating that rs3740440 could be a potential predictive marker for gastric cancer risk and prognosis.

Background: Within the tumor microenvironment (TME), the association of B lymphocytes (B cells) with prognosis and therapy response in gastric cancer (GC) remains poorly characterized. We investigated the predictive and prognostic value of B cells, including their spatial organization within the TME, in one of the largest multi-cohort studies to date.

Methods: Using CD20 immunohistochemistry, we evaluated B cell density in resection specimens from 977 patients with resectable GC across three cohorts, including the randomized phase III Korean CLASSIC trial. The relationship between CD20 density, clinicopathological characteristics, and overall survival (OS) was analyzed. Digital spatial profiling of 1063 regions of interest from 15 patients was performed to characterize B cell distribution within different regions of interest (ROIs) using the NanoString GeoMx platform.

Results: CD20 density was significantly higher in diffuse-type GC compared to intestinal-type (p = 0.000012). Patients with CD20-low diffuse-type GC had the shortest OS in the CLASSIC trial (median OS: 49 vs 62 months, HR: 1.9, 95% CI: 1.2-3.0, p = 0.003) and in a Japanese cohort (median OS: 49 vs 67 months, HR: 2.2, 95% CI: 1.2-4.0, p = 0.011). This survival difference was not seen in patients treated with adjuvant chemotherapy (median OS: 62 vs 63 months, HR: 1.8, 95% CI: 0.88-3.5, p = 0.108). Spatial profiling revealed significant B cell enrichment within tumor ROIs compared to the stroma, particularly in diffuse-type GC.

Conclusions: Low CD20 positivity, especially in diffuse-type GC, is linked to poor prognosis and may identify patients who could benefit from chemotherapy. These findings underscore the role of B cells in GC.

Purpose: The purpose of this study is to explore the causal relationship between gut microbiota and gastrointestinal (GI) cancers and to investigate the potential mediating factors influencing the development of GI cancers.

Methods: Using data from genome-wide association studies (GWAS), we employed two-sample Mendelian randomization (TSMR) to explore the relationship among gut microbiota, inflammatory cytokines and GI cancers. Subsequently, a multivariable Mendelian randomization (MVMR) analysis was meticulously conducted to perform a mediation analysis, thereby estimating the proportion of mediation effects conferred by inflammatory cytokines.

Results: TSMR analysis established a causal relationship between 23 gut microbiota taxa and 11 inflammatory cytokines with GI cancers. Specifically, 7 gut microbiota taxa were associated with an increased risk of gastric cancer (GC), 6 with small intestine cancer, and 10 with colorectal cancer (CRC). Among the inflammatory cytokines, 4 were linked to GC risk, 3 to small intestine cancer, and to CRC. Mediation analysis further indicatedthat tumor necrosis factor ligand superfamily member 12 (TNFSF12) mediated 9.703% (95% CI 0.108%~15.891%) of the total effect of genus Ruminiclostridium9 on GC.

Conclusion: Our findings support a causal relationship between gut microbiota, inflammatory cytokines, and GI cancers. These biomarkers provide new insights into the mechanisms underlying GI cancers and have the potential to improve strategies forprevention, diagnosis, and treatment.

Background: The role of janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling remains unclear in gastric solid-type poorly differentiated adenocarcinoma. The present study investigates the clinicopathological significance of JAK2, STAT3, and STAT4 expression in solid-type poorly differentiated adenocarcinoma.

Methods: We retrospectively enrolled 102 participants with primary solid-type poorly differentiated adenocarcinoma. We categorized participants according to deficient or proficient mismatch repair status (46 and 56 participants, respectively). Expression of phosphorylated JAK2 (pJAK2), phosphorylated STAT3 (pSTAT3), and STAT4 were analyzed via immunohistochemistry. We analyzed differences in protein expression in relation to mismatch repair status, and associations of high/low protein expression with clinicopathological characteristics and prognoses.

Results: Deficient mismatch repair was found to be associated with high pJAK2 (p = 0.038) and STAT4 (p = 0.023) expression in contrast to proficient mismatch repair. Log-rank analysis revealed high pSTAT3 and low STAT4 expression to be significantly correlated with reduced overall survival (p = 0.001). Multivariate analysis revealed high pSTAT3 and low STAT4 expression to be independent indicators of unfavorable prognosis (hazard ratio = 2.751, p = 0.030), as was proficient mismatch repair status (hazard ratio = 3.819, p = 0.012).

Conclusions: High expression of pJAK2 and STAT4 is more frequent in deficient compared with proficient mismatch repair in solid-type poorly differentiated adenocarcinoma. High pSTAT3 and low STAT4 expression could be a useful prognostic indicator in solid-type poorly differentiated adenocarcinoma.

Background: Findings from previous gastric cancer microbiome studies have been conflicting, potentially due to patient and/or tumor heterogeneity. The intratumoral gastric cancer microbiome and its relationship with clinicopathological variables have not yet been characterized in detail. We hypothesized that variation in gastric cancer microbial abundance, alpha diversity, and composition is related to clinicopathological characteristics.

Methods: Metagenomic analysis of 529 GC samples was performed, including whole exome sequencing data from The Cancer Genome Atlas (TCGA) and whole genome sequencing data from the 100,000 Genomes Project. Microbial abundance, alpha diversity, and composition were compared across patient age, sex, tumor location, geographic origin, pathological depth of invasion, pathological lymph node status, histological phenotype, microsatellite instability status, and TCGA molecular subtype.

Results: Gastric cancer microbiomes resembled previous results, with Prevotella, Selenomonas, Stomatobaculum, Streptococcus, Lactobacillus, and Lachnospiraceae commonly seen across both cohorts. Within the TCGA cohort, microbial abundance and alpha diversity were greater in gastric cancers with microsatellite instability, lower pathological depth of invasion, intestinal-type histology, and those originating from Asia. Microsatellite instability status was associated with microbiome composition in both cohorts. Sex and pathological depth of invasion were associated with microbiome composition in the TCGA cohort.

Conclusion: The intratumoral gastric cancer microbiome appears to differ according to clinicopathological factors. Certain clinicopathological factors associated with favourable outcomes in gastric cancer were observed to be associated with greater microbial abundance and diversity. This highlights the need for further work to understand the underlying biological mechanisms behind the observed microbiome differences and their potential clinical and therapeutic impact.