Prognostic Effect of Tertiary Lymphoid Structures in Epstein-Barr Virus-Associated Gastric Carcinomas Measured by Digital Image Analysis.

Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is characterized by prominent tumor-infiltrating lymphocytes (TILs) and has a favorable prognosis. Tertiary lymphoid structures (TLS), characterized by ectopic aggregated lymphocytes with high-endothelial venules (HEV), are associated with favorable outcomes in various solid tumors. We hypothesized that EBVaGC, characterized by intense TILs, may be closely associated with TLS or HEV. To test this hypothesis, we digitally analyzed the TLS, HEV, and TILs in 73 surgically resected advanced EBVaGCs. For HEV, dual MECA-79 and CD31 dual immunohistochemistry were performed, and the ectopic expression of MECA-79 in tumor cells was measured. In 73 patients with EBVaGC, a high-TLS ratio was found in 29 (39.7%) cases, high-tumor-associated HEV density in 44 (60.3%) cases, and high-CD8+ TIL density in 38 (52.1%) cases. Ectopic tumor expression of MECA-79 was observed in 36 patients (49.3%) cases. A low-TLS ratio and tumor-associated HEV density were significantly associated with lymph node metastasis (P = .005 and .042, respectively). Ectopic MECA-79 expression was significantly associated with lymph node metastasis (P = .003). Patients with a low-TLS ratio (P = .038), low-HEV density (P = .042), and ectopic tumor MECA-79 expression (P = .032) had significantly worse prognoses. In conclusion, TLS ratio and HEV density affect the survival of patients with EBVaGC and may be related to the immune response that interrupts lymph node metastasis.

Single-cell transcriptome analysis reveals subtype-specific clonal evolution and microenvironmental changes in liver metastasis of pancreatic adenocarcinoma and their clinical implications.

BACKGROUND: Intratumoral heterogeneity (ITH) and tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) play important roles in tumor evolution and patient outcomes. However, the precise characterization of diverse cell populations and their crosstalk associated with PDAC progression and metastasis is still challenging. METHODS: We performed single-cell RNA sequencing (scRNA-seq) of treatment-naïve primary PDAC samples with and without paired liver metastasis samples to understand the interplay between ITH and TME in the PDAC evolution and its clinical associations. RESULTS: scRNA-seq analysis revealed that even a small proportion (22%) of basal-like malignant ductal cells could lead to poor chemotherapy response and patient survival and that epithelial-mesenchymal transition programs were largely subtype-specific. The clonal homogeneity significantly increased with more prevalent and pronounced copy number gains of oncogenes, such as KRAS and ETV1, and losses of tumor suppressor genes, such as SMAD2 and MAP2K4, along PDAC progression and metastasis. Moreover, diverse immune cell populations, including naïve SELLhi regulatory T cells (Tregs) and activated TIGIThi Tregs, contributed to shaping immunosuppressive TMEs of PDAC through cellular interactions with malignant ductal cells in PDAC evolution. Importantly, the proportion of basal-like ductal cells negatively correlated with that of immunoreactive cell populations, such as cytotoxic T cells, but positively correlated with that of immunosuppressive cell populations, such as Tregs. CONCLUSION: We uncover that the proportion of basal-like subtype is a key determinant for chemotherapy response and patient outcome, and that PDAC clonally evolves with subtype-specific dosage changes of cancer-associated genes by forming immunosuppressive microenvironments in its progression and metastasis.

Establishment of a patient-specific avatar organoid model derived from EUS-guided fine-needle biopsy for timely clinical application in pancreatic ductal adenocarcinoma (with video).

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) has the worst survival rate among tumors. At the time of diagnosis, more than 80% of PDACs are considered to be surgically unresectable, and there is an unmet need for treatment options in these inoperable PDACs. This study aimed to establish a patient-derived organoid (PDO) platform from EUS-guided fine-needle biopsy (EUS-FNB) collected at diagnosis and to determine its clinical applicability for the timely treatment of unresectable PDAC. METHODS: Patients with suspected PDAC were prospectively enrolled at the Samsung Medical Center from 2015 to 2019. PDAC tissues were acquired by means of EUS-FNB to establish PDAC PDOs, which were comprehensively analyzed for histology, genomic sequencing, and high-throughput screening (HTS) drug sensitivity test. RESULTS: PDAC PDOs were established with a success rate of 83.2% (94/113). It took approximately 3 weeks from acquiring minimal EUS-FNB specimens to generating sufficient PDAC PDOs for the simultaneous HTS drug sensitivity test and genomic sequencing. The high concordance between PDAC tissues and matched PDOs was confirmed, and whole-exome sequencing revealed the increased detection of genetic alterations in PDOs compared with EUS-FNB tissues. The HTS drug sensitivity test showed clinical correlation between the ex vivo PDO response and the actual chemotherapeutic response of the study patients in the real world (13 out of 15 cases). In addition, whole-transcriptome sequencing identified candidate genes associated with nab-paclitaxel resistance, such as ITGB7, ANPEP, and ST3GAL1. CONCLUSIONS: This PDAC PDO platform allows several therapeutic drugs to be tested within a short time window and opens the possibility for timely personalized medicine as a "patient avatar model" in clinical practice.

Identification of maximal tumor size associated with negligible lymph node metastasis for endoscopic submucosal dissection of undifferentiated-type early gastric cancer.

BACKGROUND AND AIMS: When treating undifferentiated-type early gastric cancer (UD-EGC) that is limited to the mucosa (clinically T1a), endoscopic submucosal dissection (ESD) can be considered if the tumor is 2 cm or less and is not ulcerated. However, there is insufficient evidence to determine the relationships between tumor size and oncological safety of ESD in UD-EGC. METHODS: The pathology reports of Korean patients who were diagnosed with UD-EGC (n = 5286) were retrospectively reviewed. The cumulative incidence of lymph node metastasis (LNM) according to tumor size was evaluated in subgroups. The tumor-size cut-off was identified as the upper limit of the 95% confidence interval (CI) of cumulative LNM incidence that did not exceed 1.0%. RESULTS: We identified 1516 patients with non-ulcerated T1a tumors ≤2 cm in size. Among patients without lymphatic invasion, 1.5% (95% CI 0.91-2.16%) had LNM. In patients with poorly differentiated tubular adenocarcinoma (PD), LNM increased from 0 to 0.74% based on a tumor size of 1.0 cm. Regardless of tumor size, smaller percentages of undifferentiated-type (UD) and poorly cohesive carcinoma (PCC) patients experienced LNM than did those with PD. In non-ulcerated mucosal cancer without lymphatic invasion and tumor size ≤0.9 cm, no LNM was observed in patients with UD (95% CI 0-0.53%), PCC (95% CI 0-0.59%), or PD (95% CI 0-0.86%) histologic type. CONCLUSION: In patients diagnosed with non-ulcerated T1a UD-EGC, ESD can be performed if the tumor size is 0.9 cm or less, regardless of histologic type.

PIK3CA mutation subtype delineates distinct immune profiles in gastric carcinoma.

PIK3CA mutations in cancer regulate tumour immunogenicity. Given that PIK3CA mutation subtypes influence therapeutic responses to AKT inhibitor and that H1047R mutation confers selective growth advantages after immunotherapy, we hypothesised that immune phenotypes may depend on PIK3CA mutation subtypes. We investigated 133 gastric cancers (GCs) harbouring PIK3CA mutation [21 E542K (15.8%), 36 E545X (27.1%), 26 H1047X (19.5%), and 46 others (34.6%)]. Four patients (3.0%) had a combination of mutations (E542K + E545K in 3 patients and E545K + H1047R in 1 patient). Epstein-Barr virus (EBV) and microsatellite instability (MSI) status, PD-L1 (programmed death-ligand 1) combined positive score (CPS), and stromal tumour-infiltrating lymphocytes (TILs) were assessed. Concurrent genomic alterations, GeoMx digital spatial profiling (DSP), and OPAL multiplex immunohistochemistry (mIHC) were analysed, and correlation between the two assays was investigated. Of the 133 PIK3CA-mutant (PIK3CAm ) GCs, MSI-high GC was significantly frequent in the H1047X mutation subtype (p = 0.005), while EBV positivity did not affect the mutation subtypes. There was no significant survival difference between the E542K, E545X, and H1047X subgroups. However, in the subgroup analysis for EBV-positive GC, H1047Xm GC showed a trend towards shorter survival than E542K and E545Xm GC (p = 0.090 and 0.062). With DSP analysis, H1047Xm GC showed elevated VISTA (p = 0.0003), granzyme B (p < 0.0001), CD4 (p = 0.0001), and CD45 (p < 0.0001) expression compared with the E542Km or E545Xm GC subgroups, and only VISTA expression remained significant (p < 0.0001) using OPAL mIHC. DSP and OPAL analyses showed a moderate correlation of CD4 (ρ = 0.42, p = 0.004) and CD8 (ρ = 0.62, p < 0.001) expression levels in a comparison of six antibodies. Immune-related protein expression levels were evident when classified by the three PIK3CA hotspot mutations, and H1047Xm GC showed the highest immune-related protein expression compared with E542Km or E545Xm GC. Our results demonstrated distinct immune profiles in GC with PIK3CA hotspot mutations using GeoMx DSP and OPAL mIHC, and there was a correlation between the two multiplex platforms. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Prediction of epithelial-to-mesenchymal transition molecular subtype using CT in gastric cancer.

OBJECTIVES: To develop a prediction model with computed tomography (CT) images and to build a nomogram incorporating known clinicopathologic variables for individualized estimation of epithelial-to-mesenchymal transition (EMT) subtype gastric cancer. METHODS: Patients who underwent primary resection of gastric cancer (GC) and molecular subgroup analysis (n = 451) were reviewed. Multivariable analysis using a stepwise variable selection method was performed to build a predictive model for EMT subtype GC. A nomogram using the results of the multivariable analysis was constructed. An optimal cutoff value of total prognostic points of the nomogram for the prediction of EMT subtype was determined. The predictive model for the EMT subtype was internally validated by bootstrap resampling method. RESULTS: There were 88 patients with EMT subtype and 363 patients with non-EMT subtype based on transcriptome analysis. The patient's age, Lauren classification, and mural stratification on CT were variables selected for the predictive model. The area under the curve (AUC) of the model was 0.865, and the validated AUC of the bootstrap sample was 0.860. The optimal cutoff value of total prognostic points for the prediction of EMT subtype was 94.622, with 90.9% sensitivity, 67.2% specificity, and 71.8% accuracy. CONCLUSION: A predictive model using patient's age, Lauren classification, and mural stratification on CT for EMT molecular subtype GC was made. A nomogram was built which would serve as a useful screening tool for an individualized estimate of EMT subtype. KEY POINTS: • A predictive model for epithelial-to-mesenchymal transition (EMT) subtype incorporating patient's age, Lauren classification, and mural stratification on CT was built. • The predictive model had high diagnostic accuracy (area under the curve (AUC) = 0.865) and was validated (bootstrap AUC = 0.860). • Adding CT findings to clinicopathologic variables increases the accuracy of the predictive model than using only.

IL-7Rαlow CD8+ T Cells from Healthy Individuals Are Anergic with Defective Glycolysis.

Effector memory (EM) CD8+ T cells expressing lower levels of IL-7R α (IL-7Rαlow) from healthy individuals are partly compromised in vitro, but the identity of these cells has remained unclear. In this study, we demonstrate that human IL-7Rαlow EM CD8+ T cells are naturally occurring anergic cells in vivo and impaired in proliferation and IL-2 production but competent in IFN-γ and TNF-α production, a state that can be restored by IL-2 stimulation. IL-7Rαlow EM CD8+ T cells show decreased expression of GATA3 and c-MYC and are defective in metabolic reprogramming toward glycolysis, a process required for the proliferation of T cells. However, IL-7Rαlow EM CD8+ T cells can proliferate with TCR stimulation in the presence of IL-2 and IL-15, suggesting that these cells can be restored to normality or increased activity by inflammatory conditions and may serve as a reservoir for functional immunity.

BAT26 Only Microsatellite Instability with High Tumor Mutation Burden-A Rare Entity Associated with PTEN Protein Loss and High PD-L1 Expression.

Detecting microsatellite instability (MSI) in advanced cancers is crucial for clinical decision-making, as it helps in identifying patients with differential treatment responses and prognoses. BAT26 is a highly sensitive MSI marker that defines the mismatch repair (MMR) status with high sensitivity and specificity. However, isolated BAT26-only instability is rare and has not been previously reported. Of the 6476 cases tested using pentaplex MSI polymerase chain reaction, we identified two BAT26-only instability cases (0.03%) in this study. The case #1 patient was diagnosed with endometrial adenocarcinoma without MMR germline mutations. The endometrial tumor showed BAT26-only instability, partial loss of MLH1/PMS2 protein expression, and a high programmed cell death ligand 1 (PD-L1) combined positive score (CPS = 8). The tumor exhibited a somatic phosphatase and tensin homolog (PTEN) R303P missense mutation and loss of the PTEN protein. On a comprehensive cancer panel sequencing with ≥500 genes, the tumor showed an MSI score of 11.38% and high tumor mutation burden (TMB) (19.5 mt/mb). The case #2 patient was diagnosed with colorectal carcinoma with proficient MMR and PTEN protein loss without PTEN alteration, as well as a high PD-L1 CPS (CPS = 10). A pathogenic KRAS A146T mutation was detected with an MSI score of 3.36% and high TMB (13 mt/mb). In conclusion, BAT26-only instability is very rare and associated with PTEN protein loss, high TMB, and a high PD-L1 score. Our results suggest that patients with BAT26-only instability may show good responses to immunotherapy.

Cancer-associated fibroblasts induce an aggressive phenotypic shift in non-malignant breast epithelial cells via interleukin-8 and S100A8.

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment have been associated with tumor progression in breast cancer. Although crosstalk between breast cancer cells and CAFs has been studied, the effect of CAFs on non-neoplastic breast epithelial cells is not fully understood to date. Here, we investigated the effect of CAFs on aggressive phenotypes in non-neoplastic MCF10A breast epithelial cells. CAFs induced epithelial-to-mesenchymal transition (EMT) and invasive phenotype in MCF10A cells. S100A8, a potential prognostic marker in several cancers, was markedly increased in MCF10A cells by CAFs. S100A8 was crucial for CAFs-induced invasive phenotype of MCF10A cells. Among cytokines increased by CAFs, interleukin (IL)-8 induced S100A8 through transcription factors p65 NF-κB and C/EBPß. In a xenograft mouse model with MCF10A cells and CAFs, tumor was not developed, suggesting that coinjection with CAFs may not be sufficient for in vivo tumorigenicity of MCF10A cells. Xenograft mouse tumor models with MDA-MB-231 breast carcinoma cells provided an in vivo evidence for the effect of CAFs on breast cancer progression as well as a crucial role of IL-8 in tumor growth and S100A8 expression in vivo. Using a tissue microarray of human breast cancer, we showed that S100A8 expression was correlated with poor outcomes. S100A8 expression was more frequently detected in cancer-adjacent normal human breast tissues than in normal breast tissues. Together, this study elucidated a novel mechanism for the acquisition of invasive phenotype of non-neoplastic breast cells induced by CAFs, suggesting that targeting IL-8 and S100A8 may be an effective strategy against breast cancer.

PD-L1 expression in gastric cancer: interchangeability of 22C3 and 28-8 pharmDx assays for responses to immunotherapy.

Recent clinical trials have shown the promising therapeutic effects of pembrolizumab and nivolumab in patients with advanced gastric cancer. Currently, the programmed death ligand-1 (PD-L1) 22C3 pharmDx assay is the only companion diagnostic assay for assessing the safety and effectiveness of pembrolizumab. The purpose of this study was to compare 22C3 pharmDx and 28-8 pharmDx, a complementary diagnostic assay for nivolumab, in gastric cancer. In this study, 22C3 and 28-8 pharmDx assays were performed on the same formalin-fixed, paraffin-embedded tissue blocks of gastric adenocarcinoma clinical samples (n = 55). The concordance rate was evaluated using combined positive score (CPS) cutoffs of 1, 10, and 50. PD-L1 positivity with CPS ≥ 1 was 45.5% using the 22C3 pharmDx assay and 49.1% using the 28-8 pharmDx assay. At a CPS cutoff of 1, the overall percentage agreement was 96.4%. The positive and negative percentage agreements were 93.3% and 100%, respectively. All cases positive for PD-L1 using the 22C3 pharmDx assay were also positive using the 28-8 pharmDx assay. At a CPS cutoff of 10, the overall percentage agreement was 96.4%. At a CPS cutoff of 50, the two assays exhibited 100% concordance. Nonspecific cytoplasmic staining in the background tissues and tumor cells was often observed in the 28-8 pharmDx assay. When the results of the two assays were matched for response to immunotherapy, the overall response rate was higher in patients with a PD-L1 CPS ≥ 1 than in PD-L1-negative patients (22C3 pharmDx, P = 0.001; 28-8 pharmDx, P = 0.002). In conclusion, PD-L1 22C3 and 28-8 pharmDx assays were highly comparable at CPS cutoffs of 1, 10, and 50 in gastric cancer. These results provide evidence for the potential interchangeability of the two PD-L1 assays in gastric cancer.

MicroRNA signatures associated with lymph node metastasis in intramucosal gastric cancer.

Although a certain proportion of intramucosal carcinomas (IMCs) of the stomach does metastasize, the majority of patients are currently treated with endoscopic resection without lymph node dissection, and this potentially veils any existing metastasis and may put some patients in danger. In this regard, biological markers from the resected IMC that can predict metastasis are warranted. Here, we discovered unique miRNA expression profiles that consist of 21 distinct miRNAs that are specifically upregulated (miR-628-5p, miR-1587, miR-3175, miR-3620-5p, miR-4459, miR-4505, miR-4507, miR-4720-5p, miR-4742-5p, and miR-6779-5p) or downregulated (miR-106b-3p, miR-125a-5p, miR-151b, miR-181d-5p, miR-486-5p, miR-500a-3p, miR-502-3p, miR-1231, miR-3609, and miR-6831-5p) in metastatic (M)-IMC compared to nonmetastatic (N)-IMC, or nonneoplastic gastric mucosa. Intriguingly, most of these selected miRNAs showed stepwise increased or decreased expression from nonneoplastic tissue to N-IMC to M-IMC. This suggests that common oncogenic mechanisms are gradually intensified during the metastatic process. Using a machine-learning algorithm, we demonstrated that such miRNA signatures could distinguish M-IMC from N-IMC. Gene ontology and pathway analysis revealed that TGF-ß signaling was enriched from upregulated miRNAs, whereas E2F targets, apoptosis-related, hypoxia-related, and PI3K/AKT/mTOR signaling pathways, were enriched from downregulated miRNAs. Immunohistochemical staining of samples from multiple institutions indicated that PI3K/AKT/mTOR pathway components, MAPK1, phospho-p44/42 MAPK, and pS6 were highly expressed and the expression of SMAD7, a TGF-ß pathway component, was decreased in M-IMC, which could aid in distinguishing M-IMC from N-IMC. The miRNA signature discovered in this study is a valuable biological marker for identifying metastatic potential of IMCs, and provides novel insights regarding the metastatic progression of IMC.

Microsatellite Instability and Effectiveness of Adjuvant Treatment in pT1N1 Gastric Cancer: A Multicohort Study.

BACKGROUND: Microsatellite status is a prognostic biomarker in advanced gastric cancer. This retrospective study aimed to investigate the usefulness of microsatellite status in predicting prognosis and response to adjuvant treatment in pT1N1 gastric cancer. PATIENTS AND METHODS: Among 875 patients who underwent radical gastrectomy for pT1N1 gastric cancer at two tertiary hospitals, 838 with available microsatellite instability (MSI) data were included and classified into two groups according to microsatellite status: microsatellite stable (MSS) and MSI-high (MSI-H). Recurrence-free survival rate and risk factors for tumor recurrence were analyzed. RESULTS: Of 838 gastric cancer patients, 100 (11.9%) were MSI-H and 307 (36.6%) received adjuvant treatment. During median follow-up of 70 months, 42 (5.0%) patients experienced gastric cancer recurrence; hematogenous recurrences were the most common (45.2%). Recurrence-free survival was similar in the MSS and MSI-H groups (p = 0.27), and adjuvant treatment did not show an oncological benefit over surgery alone for pT1N1 gastric cancer (p = 0.53). On univariate analysis, age, operation period, and Lauren classification were significantly associated with tumor recurrence, while adjuvant treatment and MSI status were not associated with tumor recurrence. On multivariate analysis, MSI status was not associated with tumor recurrence, and adjuvant treatment worsened the tumor recurrence risk [hazard ratio (HR) 2.373, 95% confidence interval (CI) 1.125-5.006, p = 0.023). CONCLUSION: MSI status may not be a prognostic factor for tumor recurrence or a predictor of response to adjuvant treatment in pT1N1 gastric cancer patients. Considering that the effect of adjuvant treatment to decrease the risk of tumor recurrence is not clear, it may not be indicated in pT1N1 patients.

Prognostic significance of sarcopenia in microsatellite-stable gastric cancer patients treated with programmed death-1 inhibitors.

BACKGROUND: Sarcopenia has been underscored as a significant predictor of poor prognosis in cancer patients undergoing immunotherapy with programmed death-1 (PD-1) inhibitors. We aimed to investigate the prognostic significance of computed tomography (CT)-determined sarcopenia in patients with microsatellite-stable (MSS) gastric cancer (GC) treated with PD-1 inhibitors. METHODS: We retrospectively assessed patients with MSS GC who had been treated with PD-1 inhibitors from March 2016 to June 2019. Pre-treatment sarcopenic status was determined by analyzing L3 skeletal muscle index with abdominal CT. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and the differences in survival probability according to sarcopenic status were compared using the log-rank test. Cox proportional hazards regression analyses were performed to identify predictors of PFS and OS. RESULTS: Of 149 patients with MSS GC (mean age, 57.0 ± 12.3 years; 93 men), 79 (53.0%) had sarcopenia. Patients with sarcopenia had significantly shorter PFS than patients without sarcopenia (median, 1.4 months vs. 2.6 months; P = 0.026). Sarcopenia was independently associated with shorter PFS (adjusted hazard ratio [HR], 1.79; 95% confidence interval [CI], 1.10-2.93; P = 0.020). Patients with sarcopenia had shorter OS than patients without sarcopenia (median, 3.6 months vs. 4.9 months; P = 0.052), but sarcopenia itself was not a significant prognostic factor for OS (adjusted HR, 1.01; 95% CI, 0.58-1.75; P = 0.974). CONCLUSIONS: CT-determined sarcopenia is an independent prognostic factor for PFS in patients with MSS GC treated with PD-1 inhibitors.

Identification of anti-Epstein-Barr virus (EBV) antibody signature in EBV-associated gastric carcinoma.

BACKGROUND: Around 10% of gastric carcinomas (GC) contain Epstein-Barr virus (EBV) DNA. We characterized the GC-specific antibody response to this common infection, which may provide a noninvasive method to detect EBV-positive GC and elucidate its contribution to carcinogenesis. METHODS: Plasma samples from EBV-positive (n = 28) and EBV-negative (n = 34) Latvian GC patients were immune-profiled against 85 EBV proteins on a multi-microbial Nucleic Acid Programmable Protein Array (EBV-NAPPA). Antibody responses were normalized for each sample as ratios to the median signal intensity (MNI) across all antigens, with seropositivity defined as MNI ≥ 2. Antibodies with ≥ 20% sensitivity at 95% specificity for tumor EBV status were verified by enzyme-linked immunosorbent assay (ELISA) and validated in independent samples from Korea and Poland (n = 24 EBV-positive, n = 65 EBV-negative). RESULTS: Forty anti-EBV IgG and eight IgA antibodies were detected by EBV-NAPPA in ≥ 10% of EBV-positive or EBV-negative GC patients, of which nine IgG antibodies were discriminative for tumor EBV status. Eight of these nine were verified and seven were validated by ELISA: anti-LF2 (odds ratio = 110.0), anti-BORF2 (54.2), anti-BALF2 (44.1), anti-BaRF1 (26.7), anti-BXLF1 (12.8), anti-BRLF1 (8.3), and anti-BLLF3 (5.4). The top three had areas under receiver operating characteristics curves of 0.81-0.85 for distinguishing tumor EBV status. CONCLUSIONS: The EBV-associated GC-specific humoral response was exclusively directed against lytic cycle immediate-early and early antigens, unlike other EBV-associated malignancies such as nasopharyngeal carcinoma and lymphoma where humoral response is primarily directed against late lytic antigens. Specific anti-EBV antibodies could have utility for clinical diagnosis, epidemiologic studies, and immune-based precision treatment of EBV-positive GC.

Single patient classifier as a prognostic biomarker in pT1N1 gastric cancer: Results from two large Korean cohorts.

OBJECTIVE: Benefits of adjuvant treatment in pT1N1 gastric cancer (GC) remain controversial. Additionally, an effective biomarker for early GC is the need of the hour. The prognostic and predictive roles of single patient classifier (SPC) were validated in stage II/III GC. In this study, we aimed to elucidate the role of SPC as a biomarker for pT1N1 GC. METHODS: The present retrospective biomarker study (NCT03485105) enrolled patients treated for pT1N1 GC between 1996 and 2012 from two large hospitals (the Y cohort and S cohort). For SPC, mRNA expression of four classifier genes (GZMB, WARS, SFRP4 and CDX1) were evaluated by real-time reverse transcription-polymerase chain reaction assay. The SPC was revised targeting pT1 stages and the prognosis was stratified as high- and low-risk group by the expression of SFRP4, a representative epithelial-mesenchymal transition marker. RESULTS: SPC was evaluated in 875 patients (n=391 and 484 in the Y and S cohorts, respectively). Among 864 patients whose SPC result was available, 41 (4.7%) patients experience GC recurrence. According to revised SPC, 254 (29.4%) patients were classified as high risk [123 (31.5%) and 131 (27.1%) in the Y and S cohorts, respectively]. The high risk was related to frequent recurrence in both Y and S cohort (log-rank P=0.023, P<0.001, respectively), while there was no difference byGZMB and WARS expression. Multivariable analyses of the overall-cohort confirmed the high risk of revised SPC as a significant prognostic factor [hazard ratio (HR): 4.402 (2.293-8.449), P<0.001] of GC. A significant difference was not detected by SPC in the prognosis of patients in the presence and absence of adjuvant treatment (log-rank P=0.670). CONCLUSIONS: The present study revealed the revised SPC as a prognostic biomarker of pT1N1 GC and suggested the use of the revised SPC for early-stage GC as like stage II/III.

UBC12-mediated SREBP-1 neddylation worsens metastatic tumor prognosis.

Activation of sterol regulatory element-binding protein 1 (SREBP-1), a master lipogenic transcription factor, is associated with cancer metabolism and metabolic disorders. Neddylation, the process of adding NEDD8 to its substrate, contributes to diverse biological processes. Here, we identified SREBP-1 as a substrate for neddylation by UBC12 and explored its impact on tumor aggressiveness. In cell-based assays, SREBP-1 neddylation prolonged SREBP-1 stability with a decrease in ubiquitination. Consequently, NEDD8 overexpression facilitated proliferation, migration, and invasion of SK-Hep1 liver tumor cells. MLN4924 (an inhibitor of the NEDD8-activating enzyme-E1) treatment or UBC12 knockdown prevented SREBP-1 neddylation and tumor cell phenotype change. This effect was corroborated in an in vivo xenograft model. In human specimens, SREBP-1, UBC12, and NEDD8 were all upregulated in hepatocellular carcinoma (HCC) compared to nontumorous regions. Moreover, SREBP-1 levels positively correlated with UBC12. In GEO database analyses, SREBP-1 levels were greater in metastatic HCC samples accompanying UBC12 upregulation. In HCC analysis, tumoral SREBP-1 and UBC12 levels discriminated overall patient survival rates. Additionally, MLN4924 treatment destabilized SREBP-1 in MDA-MB-231 breast cancer cells and in the tumor cell xenograft. SREBP-1 and UBC12 were also highly expressed in human breast cancer tissues. Moreover, most breast cancers with lymph node metastasis displayed predominant SREBP-1 and UBC12 expressions, which compromised overall patient survival rates. In summary, SREBP-1 is neddylated by UBC12, which may contribute to HCC and breast cancer aggressiveness through SREBP-1 stabilization, and these events can be intervented by MLN4924 therapy. Our findings may also provide potential reliable prognostic markers for tumor metastasis.

Outcomes of endoscopic submucosal dissection for intestinal-type adenocarcinoma with anastomosing glands of the stomach.

BACKGROUND AND AIM: Gastric intestinal-type adenocarcinoma with anastomosing glands (IAAG) is characterized by architectural abnormality with frequent anastomosing glands and low-grade cytologic atypia. Clinicopathologic features and long-term outcomes of endoscopic submucosal dissection (ESD) for IAAG remain unclear. METHODS: This study included 2828 patients who underwent ESD for early gastric cancers (EGCs) (78 IAAGs [2.6%] and 2893 well-differentiated [WD] or moderately differentiated [MD] EGCs [97.4%]). Clinicopathologic features and short-term and long-term outcomes of ESD for IAAG were reviewed and compared with those for WD or MD EGCs. RESULTS: Gastric IAAGs were larger and more likely to be confined to the lamina propria than WD or MD EGCs. Histological heterogeneity, flat or depressed lesion and lateral resection margin (LRM) involvement were observed with significantly higher frequencies in IAAGs than in WD or MD EGCs. En bloc with R0 resection and curative resection rates of IAAGs were 79.5% and 73.1%, respectively, and both were significantly lower than those of WD or MD EGCs (93.8% and 82.9%). LRM involvement accounted for 57.1% of the non-curative resection cases in gastric IAAGs. Half of IAAGs with LRM involvement had a crawling pattern at tumor periphery. Among patients undergoing curative ESD for IAAG, no recurrences occurred during a median 52 months of follow-up. No lymph node metastasis was found in any of IAAG patients undergoing additional surgery after ESD. CONCLUSIONS: Gastric IAAGs have distinct clinicopathologic features from WD or MD EGCs. Given the favorable long-term outcomes after curative resection, ESD can be indicated for early gastric IAAGs.

Bridging genomics and phenomics of gastric carcinoma.

Genetic alterations are the starting point leading to numerous changes in clinical and pathologic features (phenotypes) of individual cancers; however, their inter-relationships in gastric cancers (GC) are unclear. We performed massive parallel sequencing of 381 cancer-related genes and compared the results with clinical and pathologic findings in 330 GC. High tumor mutation burden (TMB) accounted for 11% of GC (n = 37) and all 19 MSI-H GCs were high TMB. High TMB was significantly more frequent in intestinal-type by Lauren, tumor with higher host cellular immune response, earlier AJCC stage and favorable prognosis. The most significantly mutated genes were TP53 (54%), ARID1A (23%), CDH1 (22%), PIK3CA (12%), RNF43 (10%) and KRAS (9%). For receptor tyrosine kinases, amplifications detected by immunohistochemistry were higher than sequencing (HER2, 9.1% vs. 5.8%; EGFR, 11.2% vs. 6.1%; FGFR2, 4.6% vs. 3.9%, c-MET, 3.4% vs. 0.9%). PTEN protein loss (22%) correlated well with underlying PTEN alterations while ATM loss (27%) was not significantly correlated with genetic alterations of ATM. p53 protein expression predicted alterations of TP53 with high sensitivity (97.8%) and low (15.9%) specificity. The poorly cohesive histology/CDH1-mutant GC subgroup showed the worst survival (p < 0.001). PD-L1 expression was significantly associated with MSI-H, MLH1 loss, ATM loss, MET positivity, higher host immune response, and genetic alterations of ARID1A, BRD3, PIK3CA, KRAS, MAP3K13, CDH2, PTEN and ESR1. The merged clinical, pathology and genomics of GC provide a better understanding of GC and new insights into the treatment of GC.

Feasibility of Endoscopic Resection in Early Gastric Cancer with Lymphovascular Invasion.

BACKGROUND: Lymphovascular invasion (LVI) is associated with the risk of lymph node metastasis (LNM) and poor survival in gastric cancer patients; however, it is unclear whether LVI is a non-curative criteria component in all patients. We evaluated the risk factors of LNM in LVI-positive early gastric cancer (EGC) patients and identified a subgroup with a negligible LNM risk to assess the feasibility of endoscopic resection in these patients. METHODS: The clinicopathologic and survival data of patients undergoing surgery for gastric cancer were reviewed; LVI-positive EGC patients were selected. Logistic regression analysis was used to test the associations of potential risk factors with LNM, and Kaplan-Meier analysis was used to compare survival curves. RESULTS: LVI was detected in 1243 (15.5%) patients. In the multivariate logistic analysis, larger tumor size (odds ratio [OR] 1.23, 95% confidence interval [CI] 1.16-1.31; p < 0.001), presence of ulcer (OR 1.80, 95% CI 1.15-2.82; p = 0.010), undifferentiated histology (OR 1.64, 95% CI 1.25-2.16; p < 0.001), submucosal invasion (OR 2.28, 95% CI 1.38-3.76; p = 0.001), middle (OR 2.12, 95% CI 1.26-3.55; p = 0.004) or lower third location (OR 2.28, 95% CI 1.32-3.60; p = 0.002), and younger age (OR 0.98, 95% CI 0.97-0.99; p = 0.002) independently predicted LNM in LVI-positive EGC patients. LVI-positive patients fulfilling the absolute endoscopic resection criteria did not have LNM and there was no significant difference in the overall (p = 0.928) and disease-specific survival (p = 0.821) between these patients and those with LVI-negative EGC. CONCLUSIONS: Additional surgery after endoscopic resection might be unnecessary in LVI-positive patients meeting the absolute criteria for endoscopic resection.

Prognostic Impact of Microsatellite Instability in Asian Gastric Cancer Patients Enrolled in the ARTIST Trial.

BACKGROUND: Caucasian patients with microsatellite instability (MSI)-high gastric cancer (GC) may have better prognosis but worse outcomes. OBJECTIVE: Here we explored the prognostic role of MSI in Asian patients. METHODS: This post hoc analysis comprehended radically resected GC patients randomized to XP (capecitabine/cisplatin) or XPRT. MSI status was assessed by combining immunohistochemistry with multiplex polymerase chain reaction. The MSI prognostic effect on disease-free survival (DFS) and overall survival (OS) was evaluated. RESULTS: 393 tissue samples were analyzed and 35 (9%) were MSI-high. This subgroup was characterized by: older age, Borrmann classification 1-2, antral localization, T3-4 stage, and intestinal type. At univariable analysis, the microsatellite-stable subgroup showed a trend toward a worse prognosis as compared to the MSI-high group: 3-year DFS was 76.3 versus 85.4% (p = 0.122); 3-year OS was 81.7 versus 91.4% (p = 0.046). Multivariable analyses confirmed it in both DFS (hazard ratio, HR = 2.32 [95% CI 0.91, 5.88]; p = 0.077) and OS (HR = 3.17 [95% CI 0.97, 10.43]; p = 0.057). CONCLUSIONS: MSI-high status was associated with specific clinical-pathological features and a trend toward better outcomes of Asian GC patients.