Expression of Epstein-Barr virus genes in EBV-associated gastric carcinomas

AIM: To understand the expression of latent and lytic genes of Epstein-Barr virus (EBV) in EBV-associated gastric carcinoma (EBVaGC) and to explore the relationship between EBV-encoded genes and development of EBVaGC at molecular level, METHODS: One hundred and seventy-two gastric carcinoma tissues and 172 corresponding para-carcinoma tissues were tested for EBV genome by polymerase chain reaction (PCR)-Southern blotting. EBV-encoded small RNA (EBER) 1 of the PCR positive specimens was detected by in situ hybridization (ISH). Gastric carcinomas with positive EBER1 signals were classified as EBVaGCs. RT-PCR and Southern hybridization were applied to the detection of expression of nuclear antigen (EBNA) promoters (Qp, Wp and Cp), EBNA 1 and EBNA 2, latent membrane proteins (LMP) 1, 2A and 2B and lytic genes (immediate early genes BZLF1 and BRLF1, early genes BARF1 and BHRF1, late genes BcLF1 and BLLF1) in EBVaGCs. RESULTS: Eleven EBV positive samples existed in gastric carcinoma tissues (6.39%). No EBV positive sample was found in corresponding para-carcinoma tissues. The difference between EBV positivity in carcinoma tissues and corresponding para-carcinoma tissues was significant (x2 = 9.0909, P = 0.0026). Transcripts of Qp and EBNA1 were detected in all the 11 EBVaGCs, while both Wp and Cp were silent. EBNA2, LMP1 and LMP2B mRNA were absent in all the cases, while LMP2A mRNA was detected in 4 of the 11 cases. Of the 11 EBVaGCs, 7 exhibited BcLFl transcripts and 2 exhibited BHRF1 transcripts. The transcripts of BZLF1 and BARF1 were detected in 5 cases, respectively. No BLLF1 and BRLF mRNA were detected. CONCLUSION: The latent pattern of EBV in gastric carcinoma corresponds to the latency I/II. Some lytic infection genes are expressed in EBVaGCs tissues. BARF1 and BHRF1 genes may play an important role in tumorigenesis of gastric carcinoma.

Clinical and pathological characterization of epstein-barr virus-associated gastric carcinomas in portugal

AIM To determine the prevalence of epstein-barr virus(eb V)-associated gastric carcinomas in the North Region of Portugal and to study its clinicopathological characteristics. METHODS We have performed a retrospective study including a total of 179 consecutive patients with gastric cancer(GC) submitted to gastrectomy during 2011 at the Portuguese Oncology Institute of Porto. Clinical and pathological data was collected from individual clinical records and inserted on a database with unique codification. Tumour tissues were collected from the institutional tumour bank. eb V was detected by in situ hybridization for the detection of eb V-encoded small RNAs(ebe Rs) and eb V latent proteins(LMP1 and LMP2 A) were detected by immunohistochemistry.RESULTS The analysis showed that eb V-associated gastric carcinomas(eb Va GC) represents 8.4%(15/179) of all GC cases, with a significant differential distribution among histological types(P < 0.001): 100%(3/3) of medullary carcinomas, 100%(1/1) of adenosquamous carcinoma, 8.7%(8/92) of tubular adenocarcinomas, 8.0%(2/25) of mixed carcinomas and 2%(1/51) in poorly cohesive carcinomas. The analysis revealed a higher predominance of eb Va GC in the upper third and middle(cardia, fundus and body) of the stomach(P = 0.041), a significant lower number of regional lymph nodes invasion(P = 0.025) and a tendency for better prognosis(P = 0.222). eb V latent protein expression revealed that all eb Va GC cases were LMP1-negative, nevertheless 6 cases(40%) expressed LPM2 A, which reveals that these cases show a distinct eb V-Latency profile(latency II-like).CONCLUSION eb Va GC represents 8.4% of all GC in the North Region of Portugal. The eb V-infected patients have specific clinic-pathological features that should be further explored to develop new strategies of management and treatment.

Synchronous Multiple Primary Gastric Carcinomas： A Case Report

IntroductionCarcinomas of the stomach are the most common malignant tumors in China. Due to the recent developments in diagnostic techniques and instrumentation, the early detection of gastric carcinoma （GC） has increased. Yet synchronous multiple primary gastric carcinomas, de- fined as 2 or more primary gastric carcinomas occurring in 1 patient simultaneously, are not frequently seen. The etiology of synchronous tumors is still unclear, and their coexistence can be problematic for surgeons, oncologists and pathologists in regards to diagnosis, treat- ment, and follow-up. Research has focused mainly on such issues as the frequency of occurrence of primary multiple carcinomas, identi- fication of high-risk groups, early diagnosis, treatment methods, and prognostic factors. The purpose of this article is to present a rare case of synchronous tumors and to review the literature addressing the surgical treatment for patients with multiple cancers.

Co-expression of CDX2 and MUC2 in gastric carcinomas: Correlations with clinico-pathological parameters and prognosis

AIM: To evaluate the role of CDX2 homeobox protein as a predictor for cancer progression and prognosis as well as its correlation with MUC2 expression. CDX2 represents a transcription factor for various intestinal genes (including MUC2) and thus an important regulator of intestinal differentiation, which could previously be identified in gastric carcinomas and intestinal metaplasia. METHODS: Formalin-fixed and paraffin-embedded tissues from 190 gastric carcinoma patients were stained with monodonal antibodies recognizing CDX2 and MUC2, respectively. Immunoreactivity was evaluated semiquantitatively and statistical analyses including x2 tests, uni- and multi-variate survival analyses were performed. RESULTS: CDX2 was mostly expressed in a nuclear or supranuclear pattern,whereas MUC2 showed an almost exclusive supranuclear reactivity.Both antigens were present in >80% of areas exhibiting intestinal metaplasia. An immunoreactivity in >5% of the tumor area was observed in 57% (CDX2) or in 21% (MUC2) of the carcinomas.The presence of both molecules did not correlate with WHO, Lauren and Goseki classification (with the exception of a significantly stronger MUC2 expression in mucinous tumors). CDX2 correlated with a lower pT and pN stage in the subgroups of intestinal and stage I cancers and was associated with MUC2 positivity.A prognostic impact of CDX2 or MUC2 was not observed. CONCLUSION: CDX2 and MUC2 play an important role in the differentiation of normal, inflamed, and neoplastic gastric tissues. According to our results, loss of CDX2 may represent a marker of tumor progression in early gastric cancer and carcinomas with an intestinal phenotype.

Immunoexpression of cyclooxygenase-2 in primary gastric carcinomas and lymph node metastases

AIM: To evaluate immunoexpression of cyclooxygenase-2 (COX-2) in primary gastric carcinomas and respective lymph node metastases. METHODS: Immunohistochemistry to analyze COX-2 expression was performed on tissue microarray slices obtained from 36 specimens of gastrectomy and satellite lymph nodes from patients with gastric carcinoma. RESULTS: Immunostaining was seen in most cases, and COX-2 expression was higher in lymph node me-tastases than in corresponding primary gastric tumors of intestinal, diffuse and mixed carcinomas, with a statistically signif icant difference in the diffuse histotype (P = 0.0108). CONCLUSION: COX-2 immunoexpression occurs frequently in primary gastric carcinomas, but higher expression of this enzyme is observed in lymph node metastases of the diffuse histotype.

Methylation of GATA-4 and GATA-5 and development of sporadic gastric carcinomas

AIM:To understand the implication of GATA-4 and GATA-5 methylation in gastric carcinogenesis.METHODS: Methylation status of GATA-4 and GATA-5 CpG islands in human gastric mucosa samples, including normal gastric biopsies from 45 outpatients, gastric dysplasia [low-grade gastric intraepithelial neoplasia (GIN), n = 30; indefinite, n = 77], and 80 paired spo- radic gastric carcinomas (SGC) as well as the adjacent non-neoplastic gastric tissues was analyzed by methylation specific polymerase chain reaction (MSP) and confirmed by denatured high performance liquid chromatography (DHPLC). Immunohistochemical staining was used to detect protein expression. The correlation between GATA-4 and GATA-5 methylation and clinicopathological characteristics of patients including Helicobacter pylori (H. pylori) infection was analyzed.RESULTS:GATA-4 and GATA-5 methylation was frequently observed in SGCs (53.8% and 61.3%, respectively) and their corresponding normal tissues (41.3% and 46.3%) by MSP. The result of MSP was consistent with that of DHPLC. Loss of both GATA-4 and GATA-5 proteins was associated with their methylation in SGCs (P = 0.01). Moreover, a high frequency of GATA-4 and GATA-5 methylation was found in both gastric low-grade GIN (57.1% and 69.0%) and indefinite for dysplasia (42.9% and 46.7%), respectively. However, GATA-4 and GATA-5 methylation was detected only in 4/32 (12.5%) and 3/39 (7.7%) of normal gastric biopsies. GATA-4 methylation in both normal gastric mucosa and low-grade GIN was also significantly associated with H. pylori infection (P=0.023 and 0.027, two-sides).CONCLUSION: Epigenetic inactivation of GATA-4 (and GATA-5) by methylation of CpG islands is an early freuent event during gastric carcinogenesis and is significantly correlated with H. pylori infection.

Mechanisms inactivating the gene for E-cadherin in sporadic gastric carcinomas

AIM： To study the role of CDH1/E-cadherin （E-cad） gene alteration profiles including mutation, loss of heterozygosity （LOH）, promoter polymorphism and hypermethylation in mechanisms of CDH1 inactivation in gastric carcinoma （GC）. METHODS： Specimens were collected surgically from 70 patients with GC. Allelotyping PCR and detection of LOH, denaturing high pressure liquid chromatography and DNA sequencing, restriction fragment length polymorphism analysis, methylation specific PCR, and immunohistochemical staining were used. RESULTS： Promoter polymorphism was not a major mechanism of E-cad inactivation. Only one truncating mutation was found in a diffuse type tumor （3%）. Both LOH and promoter hypermethylation were major mechanisms of E-cad inactivation, but interestingly, there was a negative association between the fraction of allelic loss （LOH） in tumors and hypermethylation of CDH1. Therefore LOH and hypermethylation were two different tumorigenic pathways involved in GC. CONCLUSION： Given the findings that somatic mutation was extremely low and the relationship between LOH and hypermethylation was inverse, any two combinations of these three factors cannot fulfill the classical two-hit hypothesis of CDH1 inactivation. Thus, other mechanisms operating at the transcriptional level or at the post-translational level might be required to induce E-cadherin inactivation.

H pylori (CagA) and Epstein-Barr virus infection in gastric carcinomas:Correlation with p53 mutation and c-Myc,Bcl-2 and Bax expression

AIM: To investigate the interrelationship between H pylori and Epstein-Barr virus (EBV) infection in the gastric carcinogenesis having in focus the p53 mutation and the c-Myc, Bcl-2 and Bax expression. METHODS: seventy-one gastric carcinoma tissues were assessed by polymerase chain reaction (PCR) for H pylori and in situ hybridization for EBV. c-Myc, Bcl-2 and Bax expression were detected by immunohistochemistry and single-stranded conformational polymorphism (SSCP) for p53 mutation. RESULTS: The positivity rates for H pylori and EBV were 94.4% and 8.45%, respectively. The majority of the cases displayed only the H pylori presence. All EBV positive cases were also H pylori positive. None infectious agent was observed in 5.55% of the cases. The intestinal type tumor was more frequent in the co-infected and non-infected groups. The female predominated in the non-infected group showing statistical significance (70.4% vs 29.6%, P=0.039). The Bcl-2 was only detected in the group exclusively infected by H pylori. However, c-Myc and Bax were detected in the three groups but with a low frequency in the co-infected group. Mutation of p53 was present in all groups, with the highest frequencies in the H pylori positive groups. CONCLUSION: The frequency of H pylori infection in gastric carcinomas was high. The presented data indicated that gastric carcinogenesis has different pathways depending of the presence of the two investigated infectious agents, suggesting a possible involvement of H pylori with apoptotic process. The low expression of c-Myc and Bax in the EBV-positive groups suggests that EBV may inhibit the expression of these proteins. Nevertheless, p53 mutation shows to be a relevant alteration, independent of both infectious agents.

Epstein-Barr virus-associated lymphoepithelioma-like early gastric carcinomas and endoscopic submucosal dissection: Case series

Epstein-Barr virus (EBV)-associated lymphoepithelioma-like gastric carcinoma (LELC) is characterized by a lower lymph node (LN) metastasis rate and a higher survival rate than other forms of gastric cancer. Although current prognosis for LELC is favorable, the most common approach is radical gastrectomy involving an extensive D2 lymph node dissection. Here, we report four cases of EBV-associated early LELC that were treated by an alternative approach, endoscopic submucosal dissection (ESD). The long-term outcome of this procedure is discussed. All patients were treated by ESD en bloc, and all ESD specimens showed tumor-free lateral resection margins. None of the lesions showed lymphovascular invasion. A pathological examination of ESD specimens revealed submucosal invasion of more than 500 &#x003bc;m in all four cases. One patient underwent additional radical surgery post-ESD; no residual tumor or LN metastasis was noted in the surgical specimen. The other three patients did not undergo additional surgery, either because of severe comorbidity or their refusal to undergo operation, but were subjected to medical follow-up. None of the ESD-treated patients reported local recurrence or distant metastases during the 27-32 mo of follow-up after ESD.

Differential expression of apoptosis related proteins and nitric oxide synthases in Epstein Barr associated gastric carcinomas

AIM： To determine the incidence of Epstein Barr virus associated gastric carcinoma （GC） in Brazil and compare the expressions of apoptosis related proteins and nitric oxide synthases between EBV positive and negative gastric carcinoma. METHODS： In situ hybridization of EBV-encoded small RNA-1 （EBER-1） and PCR was performed to identify the presence of EBV in GCs. Immunohistochemistry was used to identify expressions of bcl-2, bcl-xl, bak, bax, p53, NOS-1, NOS-2, and NOS-3 proteins in 25 EBV positive GCs and in 103 EBV negative GCS. RESULTS： 12% of the cases of GC （25/208） showed EBER-1 and EBNA-1 expression. The cases were preferentially of diffuse type with intense lymphoid infiltrate in the stroma. EBV associated GCs showed higher expression of bcl-2 protein and lower expression of bak protein than in EBV negative GCs. Indeed, expressions of NOS-1 and NOS-3 were frequently observed in EBV associated GCs. CONCLUSION： Our data suggest that EBV infection may protect tumor cells from apoptosis, giving them the capacity for permanent cell cycling and proliferation. In addition, EBV positive GCs show high expression of constitutive NOS that could influence tumor progression and aggressiveness.

Helicobacter pylori infection in relation to E-cadherin gene promoter polymorphism and hypermethylation in sporadic gastric carcinomas

AIM: To study Helicobacter pylori (H pylori) infection in relation to E-cadherin (E-cad) promoter polymorphism and hypermethylation in GCs.METHODS: Specimens were taken from representative cancerous lesions and adjacent non-cancerous epithelia of 67 resected GCs. Hpyloriwas detected by real-time PCR of the cagA gene from non-neoplastic epithelium.E-cad promoter polymorphism and hypermethylation were determined by restriction fragment length polymorphism analysis and methylation-specific PCR, respectively. Expression of E-cad protein was determined by immunohistochemistry.RESULTS: Hpyloriwas found in 57% of patients with GC.H pylori infection was more frequently found in tumors with the -160C/C genotype than those with the -160C/A and -160A/A genotypes (74% vs47%, P = 0.02). Hpylori infection was associated with E-cad methylation in nonneoplastic epithelium; however, no significant difference in H pylori was observed between methylated and unmethylated cancerous lesions.CONCLUSION: Patients with the -160C/C genotype might require Hpyloriinfection to promote the inactivation of CDH1, suggesting that Hpylori infection might affect GC in an initial stage because polymorphism is germ line.Mechanism of hypermethylation of CDH1 promoter in GC is complex, and Hpyloriinfection might affect it in an initial stage.

Detection and location of Helicobacter pylori in human gastric carcinomas

AIM: To define the infection status of Helicobacter pylori in 109 patients with gastric cancers and H pylori localization in gastric carcinoma tissues in South China. METHODS: The incidence of H pylori infection in gastric carcinomas was estimated by polymerase chain reaction (PCR), simultaneously; both morphological features and the localization of H pylori in gastric carcinomas were demonstrated by Warthin-Starry (WS) staining. The relationships between H pylori infection and the clinical-pathologic factors of gastric carcinomas were analyzed by software SPSS10.0. RESULTS: H pylori was found in 42 (39.03%) and 58 (53.21%) cases of 109 patients with gastric carcinomas by PCR and WS, respectively. H pylori infection rate detected in gastric carcinomas by WS was higher than that by PCR (X2=9.735, P<0.005<0.01). WS stain showed that H pylori existed in the gastric antrum mucus, mucosal gland of normal tissues adjacent to gastric carcinomas and the gland, mucus pool of cancer tissues. The positive rate of H pylori in normal tissues adjacent to carcinomas was higher than that in cancer tissues (X2=15.750, P<0.005 <0.01). No significant differences in age, sex, site, histological types and lymph node metastasis were found between H pylori-positive gastric carcinomas and H pylori-negative cases by both methods, but there were statistically significant differences of H pylori positive rate between early and advanced stage of gastric carcinomas (X2= 4.548 or 5.922, P= 0.033 or 0.015<0.05). CONCLUSION: These results suggested that H pylori infection might play a certain role in the early stage of carcinogenesis of human gastric mucosa epithelia.

Expression of ATP7B in human gastric cardiac carcinomas in comparison with distal gastric carcinomas

AIM： To analyze expression of ATP7B in gastric cardiac adenocarcinomas, its clinicopathologic significance, in comparison with distal gastric adenocarcinomas. METHODS： Immunohistochemical avidin-biotin peroxidase complex method was applied to detect the expression of ATP7B in 49 cases of cardiac carcinomas, the corresponding adjacent non-neoplastic epithelium and 55 cases of distal gastric carcinomas. RESULTS： The proportion of ATP7B positive samples in gastric cardiac carcinomas （51.0%, 25 of 49） was significantly higher than that in the corresponding adjacent non-neoplastic epithelium （22.4%, 11 of 49） （P = 0.003）. ATP7B expression in poorly differentiated gastric cardiac carcinomas was significantly higher than that in well/moderately differentiated gastric cardiac carcinomas （P = 0.030）. ATP7B expression in gastric cardiac carcinomas was independent of age, tumor size, nodal stage and metastasis status. ATP7B protein was detected in 30.9% （17/55 cases） of distal gastric carcinomas, markedly lower than that in gastric cardiac carcinomas （P = 0.037）. CONCLUSION： ATP7B protein is frequently overexpressecl in gastric cardiac carcinomas, and correlated with the differentiation of cardiac carcinoma. ATP7B expression in gastric cardiac carcinomas is significantly higher than that in distal gastric carcinomas, which might partially explain the difference of chemotherapy response and prognosis between these two gastric carcinomas.

Mitochondrial DNA alterations in the progression of gastric carcinomas:Unexplored issues and future research needs

Gastric cancer is the second most frequent cause of cancer death worldwide.Patients infected with Helicobacter pylori(H.pylori)are at increased risk of gastric cancer.H.pylori induces genomic instability in both nuclear and mitochondrial(mt)DNA of gastric epithelial cells.Changes in mt DNA represent an early event during gastric tumorigenesis,and thus may serve as potential biomarkers for early detection and prognosis in gastric carcinoma.This review article summarizes the mt DNA mutations that have been reported in gastric carcinomas and their precancerous conditions.Unexplored research topics,such as the role of mt DNA alterations in an alternative pathway of gastric carcinogenesis,are identified and directions for future research are suggested.

Methylation of hMLH1 and hMSH2 promoters in gastric carcinomas

Objective: To study the correlation of the methylation of the promoters of hMLH1 and hMSH2 with microsatellite instability (MSI) in the tissues of gastric carcinomas. Methods: A total of 68 sporadic cases of gastric carcinoma were studied. Ten specimens of normal gastric mucosa served as control. Methylation of hMLHl and hMSH2 was observed with methylation-specific PCR, and MSI analyzed with PCR-based techniques. Results: No methylation of hMLHl and hMSH2 was found in 10 specimens of normal gastric mucosa. Methylation of hMLHl was detected in 11 cases (16. 2%) of gastric cancers and MSI in at least one locus was found in 17 cases (25%) of the 68 with aid of 5 microsatellite markers, in which eight were MSI-H (≥2loci showed instability) nine MSI-L (only one locus showed instability), and fifty-one were MSS (no instability at any marker). The frequency of methylation was significantly high in MSI-H (87. 5%) than in MSI-L (11.1%) and MSS (5. 9%). CP<0. 01 - 0. 001) but there was no difference of methylation frequency between the cases with MSI-L and those with MSS. Conclusion: Methylation of hMLHl promoter is involved to the MSI pathway but not to the loss of heterozygosity (LOH) pathway in gastric carcinogenesis.

Genomic characterization of peritoneal lavage cytology-positive gastric cancer

Objective: Positive peritoneal lavege cytology(CY1) gastric cancer is featured by dismal prognosis, with high risks of peritoneal metastasis. However, there is a lack of evidence on pathogenic mechanism and signature of CY1and there is a continuous debate on CY1 therapy. Therefore, exploring the mechanism of CY1 is crucial for treatment strategies and targets for CY1 gastric cancer.Methods: In order to figure out specific driver genes and marker genes of CY1 gastric cancer, and ultimately offer clues for potential marker and risk assessment of CY1, 17 cytology-positive gastric cancer patients and 31matched cytology-negative gastric cancer patients were enrolled in this study. The enrollment criteria were based on the results of diagnostic laparoscopy staging and cytology inspection of exfoliated cells. Whole exome sequencing was then performed on tumor samples to evaluate genomic characterization of cytology-positive gastric cancer.Results: Least absolute shrinkage and selection operator(LASSO) algorithm identified 43 cytology-positive marker genes, while Mut Sig CV identified 42 cytology-positive specific driver genes. CD3G and CDKL2 were both driver and marker genes of CY1. Regarding mutational signatures, driver gene mutation and tumor subclone architecture, no significant differences were observed between CY1 and negative peritoneal lavege cytology(CY0).Conclusions: There might not be distinct differences between CY1 and CY0, and CY1 might represent the progression of CY0 gastric cancer rather than constituting an independent subtype. This genomic analysis will thus provide key molecular insights into CY1, which may have a direct effect on treatment recommendations for CY1and CY0 patients, and provides opportunities for genome-guided clinical trials and drug development.

Effect of cetuximab plus FOLFOX4 regimen on clinical outcomes in advanced gastric carcinoma patients receiving evidence-based care

BACKGROUND Although chemotherapy is effective for treating advanced gastric carcinoma(aGC),it may lead to an adverse prognosis.Establishing a highly effective and low-toxicity chemotherapy regimen is necessary for improving efficacy and outcomes in aGC patients.AIM To determine the efficacy and safety of cetuximab(CET)combined with the FOLFOX4 regimen(infusional fluorouracil,folinic acid,and oxaliplatin)as firstline therapy for patients with aGC,who received evidence-based care(EBC).METHODS A total of 117 aGC patients who received EBC from March 2019 to March 2022 were enrolled.Of these,60 in the research group(RG)received CET+FOLFOX4 as first-line therapy,whereas 57 in the control group(CG)received FOLFOX4.The efficacy[clinical response rate(RR)and disease control rate(DCR)],safety(liver and kidney dysfunction,leukopenia,thrombocytopenia,rash,and diarrhea),serum tumor marker expression[STMs;carbohydrate antigen(CA)19-9,CA72-4,and carcinoembryonic antigen(CEA)],inflammatory indicators[interleukin(IL)-2 and IL-10],and quality of life(QOL)of the two groups were compared.RESULTS A markedly higher RR and DCR were observed in the RG compared with the CG,with an equivalent safety profile between the two groups.RG exhibited notably reduced CA19-9,CA72-4,CEA,and IL-2 levels following treatment,which were lower than the pre-treatment levels and those in the CG.Post-treatment IL-10 was statistically increased in RG,higher than the pre-treatment level and the CG.Moreover,a significantly improved QOL was evident in the RG.CONCLUSION The CET+FOLFOX4 regimen is highly effective as first-line treatment for aGC patients receiving EBC.It facilitates the suppression of STMs,ameliorates the serum inflammatory microenvironment,and enhances QOL,without increased adverse drug effects.

Impact of liver metastasis on immunotherapy in gastric carcinoma

The editorial discusses the impact of liver metastasis on immunotherapy efficacy in gastric cancer(GC)patients.Liver metastasis can hinder the effectiveness of immunotherapy by altering the immune microenvironment,leading to systemic loss of T-cells and reduced treatment response.Studies suggest that liver meta-stases serve as a negative baseline factor for immunotherapy efficacy,resulting in poorer progression-free survival and objective response rates.Strategies such as liver-mediated radiotherapy may help improve treatment outcomes by reshaping the liver’s immune microenvironment and reducing T-cell depletion.Understand-ing the complex interplay between liver metastasis and immunotherapy response is crucial for optimising patient care in GC.

Immunosuppressive tumor microenvironment in gastric signet-ring cell carcinoma

Gastric signet-ring cell carcinoma(GSRCC)is a subtype of gastric cancer with distinct phenotype and high risk of peritoneal metastasis.Studies have shown that early GSRCC has a good prognosis,while advanced GSRCC is insensitive to radiotherapy,chemotherapy or immune checkpoint blockade therapy.With technological advancement of single-cell RNA sequencing analysis and cytometry by time of flight mass cytometry,more detailed atlas of tumor microenvironment(TME)in GSRCC and its association with prognosis could be investigated extensively.Recently,two single-cell RNA sequencing studies revealed that GSRCC harbored a unique TME,manifested as highly immunosuppressive,leading to high immune escape.The TME of advanced GSRCC was enriched for immunosuppressive factors,including the loss of CXCL13+-cluster of differentiation 8+-Tex cells and declined clonal crosstalk among populations of T and B cells.In addition,GSRCC was mainly infiltrated by follicular B cells.The increased proportion of SRCC was accompanied by a decrease in mucosaassociated lymphoid tissue-derived B cells and a significant increase in follicular B cells,which may be one of the reasons for the poor prognosis of GSRCC.By understanding the relationship between immunosuppressive TME and poor prognosis in GSRCC and the underlying mechanism,more effective immunotherapy strategies and improved treatment outcomes of GSRCC can be anticipated.

Quantitative parameters in novel spectral computed tomography:Assessment of Ki-67 expression in patients with gastric adenocarcinoma

BACKGROUND The level of Ki-67 expression has served as a prognostic factor in gastric cancer.The quantitative parameters based on the novel dual-layer spectral detector computed tomography(DLSDCT)in discriminating the Ki-67 expression status are unclear.AIM To investigate the diagnostic ability of DLSDCT-derived parameters for Ki-67 expression status in gastric carcinoma(GC).METHODS Dual-phase enhanced abdominal DLSDCT was performed preoperatively in 108 patients with gastric adenocarcinoma.Primary tumor monoenergetic CT attenuation value at 40-100 kilo electron volt(kev),the slope of the spectral curve(λ_(HU)),iodine concentration(IC),normalized IC(nIC),effective atomic number(Z^(eff))and normalized Z^(eff)(nZ^(eff))in the arterial phase(AP)and venous phase(VP)were retrospectively compared between patients with low and high Ki-67 expression in gastric adenocarcinoma.Spearman’s correlation coefficient was used to analyze the association between the above parameters and Ki-67 expression status.Receiver operating characteristic(ROC)curve analysis was performed to compare the diagnostic efficacy of the statistically significant parameters between two groups.RESULTS Thirty-seven and 71 patients were classified as having low and high Ki-67 expression,respectively.CT_(40 kev-VP),CT_(70 kev-VP),CT_(100 kev-VP),and Z^(eff)-related parameters were significantly higher,but IC-related parameters were lower in the group with low Ki-67 expression status than the group with high Ki-67 expression status,and other analyzed parameters showed no statistical difference between the two groups.Spearman’s correlation analysis showed that CT_(40 kev-VP),CT_(70 kev-VP),CT_(100 kev-VP),Z^(eff),and n Z^(eff) exhibited a negative correlation with Ki-67 status,whereas IC and nIC had positive correlation with Ki-67 status.The ROC analysis demonstrated that the multi-variable model of spectral parameters performed well in identifying the Ki-67 status[area under the curve(AUC)=0.967;sensitivity 95.77%;specificity 91.89%)].Nevertheless,the differentiating capabilities of singlevariable model were moderate(AUC value 0.630-0.835).In addition,the nZ_(VP)^(eff) and nIC_(VP)(AUC 0.835 and 0.805)showed better performance than CT_(40 kev-VP),CT_(70 kev-VP) and CT_(100 kev-VP)(AUC 0.630,0.631 and 0.662)in discriminating the Ki-67 status.CONCLUSION Quantitative spectral parameters are feasible to distinguish low and high Ki-67 expression in gastric adenocarcinoma.Z^(eff) and IC may be useful parameters for evaluating the Ki-67 expression.