Feasibility of intraoperative pathologic examination for sentinel lymph nodes during sentinel node navigation surgery in early gastric cancer: results of pathologic protocol for SENORITA trial.

BACKGROUND: During sentinel node navigation surgery in patients with gastric cancer, intraoperative pathologic examination of sentinel nodes is crucial in determining the extent of surgery. In this study, we evaluated the feasibility and accuracy of intraoperative pathologic protocols using data from a prospective, multicenter, randomized trial. METHODS: A retrospective analysis was conducted using data from the SEntinel Node ORIented Tailored Approach trials from 2013 to 2016. All sentinel lymph nodes were evaluated during surgery with hematoxylin-eosin (HE) staining using a representative section at the largest plane for lymph nodes. For permanent histologic evaluation, sentinel basin nodes were stained with HE and cytokeratin immunohistochemistry in formalin-fixed, paraffin-embedded (FFPE) sections and examined with HE for three deeper-step sections at 200-µm intervals. The failure rate of identification by frozen section and the metastasis rate in non-sentinel basins were investigated. RESULTS: Of the 237 patients who underwent sentinel node basin dissection, 30 had lymph node metastases on permanent pathology. Thirteen patients had macrometastasis confirmed in frozen sections as well as FFPE sections (failure rate: 0%). Patients with negative sentinel nodes in frozen sections but micrometastasis in FFPE sections had no lymph node recurrence during the follow-up period (0%, 0/6). However, in cases with tumor-positive nodes in frozen sections, metastases in non-sentinel basins were detected in the paraffin blocks (8.3%, 2/24). CONCLUSIONS: The single-section HE staining method is sufficient for detecting macrometastasis via intraoperative pathological examination. If a negative frozen-section result is confirmed, sentinel basin dissection can be performed safely. Otherwise, standard surgery is required.

Estrogen-responsive cancer-associated fibroblasts promote invasive property of gastric cancer in a paracrine manner via CD147 production.

Estrogen signaling has been extensively studied, especially in cancers that express estrogen receptor alpha (ERα). However, little is known regarding the effect of estrogen on cancer-associated fibroblasts (CAFs). Here, we explored the role of estrogen signaling of CAFs in gastric cancer (GC) progression. We investigated the phenotypic changes in CAFs upon 17ß-estradiol (E2) treatment using ERα-negative/positive CAFs, and the conditioned media (CM) collected from these were compared with regard to cancer cell proliferation, migration, and invasion. A paracrine factor was found using a cytokine array and was confirmed using qRT-PCR, western blotting, and enzyme-linked immunosorbent assays. ERα-CD147-matrix metalloproteinase (MMP) axis was confirmed by knockdown experiments using specific siRNAs. We found that a subset of CAFs expressed ERα. ERα-positive CAFs were responsive to E2, inducing ERα expression in a dose-dependent manner. Although E2 did not induce the proliferation of ERα-positive CAFs, the CM from E2-bound ERα-positive CAFs significantly promoted cancer cell migration and invasion. Cytokine array revealed that CD147 was induced in ERα-positive CAFs upon E2 treatment; this was mediated via ERα. Increased CD147 upregulated MMP2 and MMP9 in CAFs, and also influenced cancer cells in a paracrine manner to increase MMPs and CD147 in cancer cells. High CD147 expression in tumor tissue was associated with a worse prognosis in GC patients. Our data suggest that estrogen signaling activation in CAFs and the byproduct CD147 are among the critical mediators between the interplay of CAFs and cancer cells to facilitate cancer progression.

Simultaneous establishment of pancreatic cancer organoid and cancer-associated fibroblast using a single-pass endoscopic ultrasound-guided fine-needle biopsy specimen.

Considering the critical roles of cancer-associated fibroblasts (CAFs) in pancreatic cancer, recent studies have attempted to incorporate stromal elements into organoid models to recapitulate the tumor microenvironment. This study aimed to evaluate the feasibility of patient-derived organoid (PDO) and CAF cultures by using single-pass endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) samples from prospectively enrolled pancreatic cancer patients. The obtained samples were split into two portions for PDO and CAF cultures. PDOs and CAFs were cultured successfully in 54.4% (31/57) and 47.4% (27/57) of the cases, respectively. Both components were established in 21 cases (36.8%). Various clinicopathologic factors, including the tumor size, tumor location, clinical stage, histologic subtype, and tumor differentiation, did not influence the PDO establishment. Instead, the presence of necrosis in tumor samples was associated with initial PDO generation but no further propagation beyond passage 5 (P = 0.024). The "poorly cohesive cell carcinoma pattern" also negatively influenced the PDO establishment (P = 0.018). Higher stromal proportion in tumor samples was a decisive factor for successful CAF culture (P = 0.005). Our study demonstrated that the coestablishment of PDOs and CAFs is feasible even with a single-pass EUS-FNB sample, implying an expanding role of endoscopists in future precision medicine.

miR-4742-5p promotes invasiveness of gastric cancer via targeting Rab43: An in vitro study.

miRNA (miR)-4742-5p is a recently identified microRNA regarding progression and metastasis in gastric cancer (GC). However, the biological function of this novel miRNA is largely unknown. We identified that the miR-4742-5p expression level was variably increased in GC cell lines. Suppression of miR-4742-5p using miR-inhibitor reduced the proliferation, migration, and invasion of GC cells with high miR-4742-5p expression, whereas overexpression of miR-4742-5p-mimic enhanced the aforementioned properties in GC cells with low miR-4742-5p expression. miR-4742-5p expression induced the decreases of Zo-1 and E-cadherin expression as well as the increases of vimentin and N-cadherin expression, leading to epithelial-mesenchymal transition (EMT) of cancer cells. RNA sequencing results indicated Ras-related GTP-binding protein 43 (Rab43) as a potential target gene. We identified that the expression of Rab43 is associated with activation of AKT and nuclear factor-kappa B (NF-κB) which are key oncogenic pathways in cancer cells. Our results demonstrate a new component in GC progression, promising a potential therapeutic strategy.

RIPK3 activation induces TRIM28 derepression in cancer cells and enhances the anti-tumor microenvironment.

BACKGROUND: Necroptosis is emerging as a new target for cancer immunotherapy as it is now recognized as a form of cell death that increases tumor immunogenicity, which would be especially helpful in treating immune-desert tumors. De novo synthesis of inflammatory proteins during necroptosis appears especially important in facilitating increased anti-tumor immune responses. While late-stage transcription mediated by NF-κB during cell death is believed to play a role in this process, it is otherwise unclear what cell signaling events initiate this transactivation of inflammatory genes. METHODS: We employed tandem-affinity purification linked to mass spectrometry (TAP-MS), in combination with the analysis of RNA-sequencing (RNA-Seq) datasets to identify the Tripartite Motif Protein 28 (TRIM28) as a candidate co-repressor. Comprehensive biochemical and molecular biology techniques were used to characterize the role of TRIM28 in RIPK3 activation-induced transcriptional and immunomodulatory events. The cell composition estimation module was used to evaluate the correlation between RIPK3/TRIM28 levels and CD8+ T cells or dendritic cells (DC) in all TCGA tumors. RESULTS: We identified TRIM28 as a co-repressor that regulates transcriptional activity during necroptosis. Activated RIPK3 phosphorylates TRIM28 on serine 473, inhibiting its chromatin binding activity, thereby contributing to the transactivation of NF-κB and other transcription factors, such as SOX9. This leads to elevated cytokine expression, which then potentiates immunoregulatory processes, such as DC maturation. The expression of RIPK3 has a significant positive association with the tumor-infiltrating immune cells populations in various tumor type, thereby activating anti-cancer responses. CONCLUSION: Our data suggest that RIPK3 activation-dependent derepression of TRIM28 in cancer cells leads to increased immunostimulatory cytokine production in the tumor microenvironment, which then contributes to robust cytotoxic anti-tumor immunity.

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.

Quantitation of ligand is critical for ligand-dependent MET signalling activation and determines MET-targeted therapeutic response in gastric cancer.

BACKGROUND: Despite the promising preclinical antitumor activity of MET-targeting therapies, most clinical trials have failed. We introduced a new concept of quantitation of stroma-induced hepatocyte growth factor (HGF) to assess the actual MET signalling activity in gastric cancer (GC). METHODS: We treated serially diluted HGF and conditioned media (CM) from cancer-associated fibroblasts (CAFs) on low MET-expressing cancer cells and investigated the phenotypical and signalling changes. Stromal proportion and MET expression in GC samples were assessed, and gene set enrichment analysis (GSEA) from the public database was performed. The antitumor effect of anti-MET treatment was examined, especially when cancer cells were activated in a ligand-dependent manner. RESULTS: Relatively high doses of HGF or high-concentrated CM fully activated MET signalling cascades and promoted cell proliferation/invasion. High stromal proportion denoted worse patient survival in MET-positive GCs than in MET-negative ones. GSEA showed that the gene sets regarding proliferation, migration, and CAF as well as MET pathway signature were enriched in simultaneously MET- and HGF-positive samples. Sufficient ligand-dependent MET signalling activation increased the sensitivity to crizotinib. CONCLUSIONS: We conclude that patients whose tumours have a high stromal proportion and at least low MET expression may benefit more from MET-targeted therapies.

Factors affecting the diagnostic yield of endoscopic transpapillary forceps biopsy in patients with malignant biliary strictures.

BACKGROUND AND AIM: Transpapillary biliary forceps biopsy (TBFB) is a common method to obtain histological evidence for the differential diagnosis of biliary stricture. This study aimed to evaluate the factors associated with a positive cancer diagnosis from TBFB and the number of tissue samples required to increase the diagnostic yield in patients with malignant biliary strictures. METHODS: A total of 376 patients who underwent TBFB for investigation of biliary stricture were included. Factors affecting the diagnostic yield of TBFB were determined using univariate analysis and multivariate logistic regression analyses. RESULTS: Bile duct cancer (odds ratio [OR] = 3.50, P = 0.002), intraductal growing type (OR = 9.01, P = 0.001), and number of tissue samples (n < 5 vs 5 ≤ n < 10, OR = 4.13, P = 0.01; n < 5 vs n ≥ 10, OR = 12.25, P < 0.001; 5 ≤ n < 10 vs n ≥ 10, OR = 2.97, P = 0.046) were significant factors associated with positive results for malignancy. In patients with periductal infiltrating-type bile duct cancer, the number of tissue samples was a significant factor for diagnostic sensitivity (54.3% in the n < 5 group, 83.3% in the 5 ≤ n < 10 group and 98.2% in the n ≥ 10 group) (P < 0.001). CONCLUSIONS: Bile duct cancer, intraductal growing type, and five or more tissue samples were significant predictors of positive TBFB results in patients with malignant biliary stricture. Increasing the number of tissue samples by five or more led to higher sensitivity in bile duct cancer patients with the periductal infiltrating type.

Alterations in the Rho pathway contribute to Epstein-Barr virus-induced lymphomagenesis in immunosuppressed environments.

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphomas (EBV+-DLBLs) tend to occur in immunocompromised patients, such as the elderly or those undergoing solid organ transplantation. The pathogenesis and genomic characteristics of EBV+-DLBLs are largely unknown because of the limited availability of human samples and lack of experimental animal models. We observed the development of 25 human EBV+-DLBLs during the engraftment of gastric adenocarcinomas into immunodeficient mice. An integrated genomic analysis of the human-derived EBV+-DLBLs revealed enrichment of mutations in Rho pathway genes, including RHPN2, and Rho pathway transcriptomic activation. Targeting the Rho pathway using a Rho-associated protein kinase (ROCK) inhibitor, fasudil, markedly decreased tumor growth in EBV+-DLBL patient-derived xenograft (PDX) models. Thus, alterations in the Rho pathway appear to contribute to EBV-induced lymphomagenesis in immunosuppressed environments.

Targeting interleukin-6 as a strategy to overcome stroma-induced resistance to chemotherapy in gastric cancer.

BACKGROUND: Although the tumor stroma in solid tumors like gastric cancer (GC) plays a crucial role in chemo-resistance, specific targets to inhibit the interaction between the stromal and cancer cells have not yet been utilized in clinical practice. The present study aims to determine whether cancer-associated fibroblasts (CAFs), a major component of the tumor stroma, confer chemotherapeutic resistance to GC cells, and to discover potential targets to improve chemo-response in GC. METHODS: To identify CAF-specific proteins and signal transduction pathways affecting chemo-resistance in GC cells, secretome and transcriptome analyses were performed. We evaluated the inhibiting effect of CAF-specific protein in in vivo and in vitro models and investigated the expression of CAF-specific protein in human GC tissues. RESULTS: Secretome and transcriptome data revealed that interleukin-6 (IL-6) is a CAF-specific secretory protein that protects GC cells via paracrine signaling. Furthermore, CAF-induced activation of the Janus kinase 1-signal transducer and activator of transcription 3 signal transduction pathway confers chemo-resistance in GC cells. CAF-mediated inhibition of chemotherapy-induced apoptosis was abrogated by the anti-IL-6 receptor monoclonal antibody tocilizumab in various experimental models. Clinical data revealed that IL-6 was prominently expressed in the stromal portion of GC tissues, and IL-6 upregulation in GC tissues was correlated with poor responsiveness to chemotherapy. CONCLUSIONS: Our data provide plausible evidence for crosstalk between GC cells and CAFs, wherein IL-6 is a key contributor to chemoresistance. These findings suggest the potential therapeutic application of IL-6 inhibitors to enhance the responsiveness to chemotherapy in GC.

Functional loss of ARID1A is tightly associated with high PD-L1 expression in gastric cancer.

Notwithstanding remarkable treatment success with anti-PD-1 monoclonal antibody, oncogenic mechanism of PD-L1 regulation in gastric cancer (GC) remains poorly understood. We hypothesized that ARID1A might be related to tumor PD-L1 expression in GC. We found that tumor PD-L1 positivity was associated with loss of ARID1A and showed trend toward better survival of patients with various molecular subtypes of GC (experimental set, n = 273). Considering heterogeneous ARID1A expression, we validated this using whole tissue sections (n = 159) and found that loss of ARID1A was correlated with microsatellite instability-high (MSI-H), Epstein-Barr virus (EBV), and PD-L1 positivity. Furthermore, for patients with MSI-H tumors, the degree of PD-L1 expression was significantly higher in ARID1A-deficient tumors. After ARID1A knockdown in GC cell lines, total and membranous PD-L1 protein, and PD-L1 mRNA levels were increased based on Western blot, flow cytometry, and qRT-PCR, respectively. With IFN-γ treatment, PD-L1 expression was significantly increased both in ARID1A-deficient cancer cells and controls, but the increase was not more pronounced in the former. Loss of ARID1A increased PD-L1 via activating AKT signaling, while LY294002 (PI3K inhibitor) decreased PD-L1 levels. Furthermore, we found that 3 MSI-H tumors showing highest expression of PD-L1 had simultaneous KRAS mutation and loss of ARID1A, suggesting a possible synergistic role boosting PD-L1. Our results strongly indicate that loss of ARID1A is tightly associated with high PD-L1 expression in GC. These results would increase our understanding of the oncogenic mechanism of PD-L1 regulation in GC, and also help to find the optimal candidates for immunotherapy.

Neural Invasion is a Significant Contributor to Peritoneal Recurrence in Signet Ring Cell Gastric Carcinoma.

BACKGROUND: Gastric signet ring cell carcinoma (SRC) has shown a favorable outcome in early stages but has a worse prognosis than non-SRC in advanced stages. However, the cause for this stage-dependent prognostic impact has not been determined. This study aimed to compare clinicopathologic features and recurrence patterns between gastric SRC and non-SRC in a cohort of Eastern patients. METHODS: This study reviewed the prospectively collected data of 764 patients undergoing curative resection for gastric cancer from 2005 to 2008. The demographics, clinicopathologic characteristics, disease-specific survival (DSS) rate, and recurrence-free survival (RFS) rate of the patients were analyzed. RESULTS: The SRC patients (n = 176) had a worse prognosis than the non-SRC patients (n = 588), especially in stages T3 and T4. Peritoneal recurrence and the incidence of neural invasion (NI) were significantly increased in the SRC patients, albeit only in stages T3 and T4. In the T3 and T4 patients with NI, peritoneal recurrence occurred more frequently in SRC than in non-SRC (28.7% vs. 13.7%; p = 0.001), but not in the T3 and T4 patients without NI. Only in the patients with NI, SRC led to a significantly shorter DSS (67.6 vs. 90.7 months; p = 0.008) and RFS (67.1 vs. 80.3 months; p = 0.036) than non-SRC. CONCLUSIONS: This report is the first to present the relationship between NI and peritoneal recurrence as the cause of stage-dependent prognoses for SRC. A better understanding of NI may lend insight into cancer spread and recurrence, especially in gastric SRC.

A prospective randomized trial of EUS-guided tissue acquisition using a 25-gauge core biopsy needle with and without a stylet.

BACKGROUND: Endoscopic ultrasound (EUS)-guided tissue acquisition has become the most effective method of obtaining specimens from a solid lesion adjacent to the gastrointestinal tract. No data exist regarding the use of a stylet in the core biopsy needle during EUS-guided tissue acquisition. The aims of this study were to evaluate the feasibility, safety, and diagnostic yield of a 25-gauge core biopsy needle without (S-) a stylet and to compare its performance with that of a 25-gauge core biopsy needle with (S+) a stylet in patients with solid lesions adjacent to the gastrointestinal tract. METHODS: From November 2013 to January 2016, we performed 114 EUS-guided tissue acquisitions for the diagnosis of solid lesions adjacent to the gastrointestinal tract in a randomized controlled trial. Patients were randomly assigned to the S+ group (n = 57) or the S- group (n = 57). EUS-guided tissue acquisition was performed using a 25-gauge core biopsy needle without an on-site cytopathologist. RESULTS: There were no significant differences in technical success (100 vs. 100%, p = 1.000), the mean number of needle passes (7.0 ± 1.6 vs. 6.8 ± 1.5, p = 0.556), needle malfunction (0 vs. 1.8%, p = 1.000), or complications (1.8 vs. 0%, p = 1.000) between the S+ and S- groups. Both groups exhibited comparable outcomes with respect to cytological diagnostic accuracy (93.0 vs. 91.2%, p = 1.000) and histological diagnostic accuracy (86.0 vs. 87.7%, p = 1.000) for malignancy. The procedure time was significantly shorter in the S- group than in the S+ group (32.4 ± 11.7 vs. 39.7 ± 8.6 min, p < 0.001). CONCLUSIONS: EUS-guided tissue acquisition using a 25-gauge core biopsy needle without a stylet did not decrease the diagnostic yield for malignancy and was associated with a shorter procedure time than that associated with a stylet.

Discoidin domain receptor 1 activity drives an aggressive phenotype in gastric carcinoma.

BACKGROUND: Discoidin domain receptor 1 (DDR1), a receptor tyrosine kinase that utilizes collagen as a ligand, is a key molecule in the progression of solid tumors as it regulates the interaction of cancer cells with the tumor stroma. However, the clinical relevance of DDR1 expression in gastric carcinoma is yet to be investigated. Here, we assessed the role of DDR1 in mediating the aggressive phenotype of gastric carcinoma and its potential as a therapeutic target. METHODS: We conducted DDR1 immunohistochemistry using a tissue microarray of 202 gastric carcinoma specimens. We examined the effect of collagen-induced activation of DDR1 on cell signaling, tumorigenesis, and cell migration in gastric cancer cell lines, and tumor growth in a xenograft animal model of gastric cancer. RESULTS: Our results showed that 50.5% of gastric cancer tissues are positive for DDR1 expression, and positive DDR1 expression was significantly correlated with a poor prognosis (P = 0.015). In a subgroup analysis, DDR1 expression was prognostically meaningful only in patients receiving adjuvant treatment (P = 0.013). We also demonstrated that collagen was able to activate DDR1 and increase the clonogenicity and migration of gastric cancer cells. We observed that a DDR1 inhibitor, 7rh benzamide, suppressed tumor growth in gastric cancer xenografts. CONCLUSIONS: Our findings suggest a key role for DDR1 signaling in mediating the aggressive phenotype of gastric carcinoma. Importantly, inhibition of DDR1 is an attractive strategy for gastric carcinoma therapy.

Intratumor stromal proportion predicts aggressive phenotype of gastric signet ring cell carcinomas.

OBJECTIVE: The aim of this study was to evaluate the prognostic significance of the intratumor stromal proportion in gastric signet ring cell (SRC) carcinomas. BACKGROUND: Cancer stroma, as exemplified by cancer-associated fibroblasts (CAFs), plays critical roles in cancer proliferation, invasion, and metastasis. METHODS: One hundred seventy-five SRC carcinoma cases were classified according to the intratumor desmoplastic stromal proportion to then analyze the clinicopathologic characteristics of stroma-rich cases. We also investigated the impact of CAFs on the migration as well as on the phenotypic changes of gastric SRC carcinomas in vitro. Furthermore, we performed RNA sequencing of a pair of CAFs and normal-tissue-associated fibroblasts. RESULTS: Stroma-rich SRC carcinomas (64 of 175 cases, 36.5%) were associated with female patients (P = 0.045), large tumor size (P = 0.007), higher T category (P < 0.001), and the presence of perineural invasion (P = 0.018). Patients with stroma-rich SRC carcinomas had a significantly shorter disease-free survival (P < 0.001) and overall survival (P < 0.001). However, in a subgroup analysis, the prognostic significance of the stromal proportion correlated only with patients with T3/4 disease. From multivariate analysis, the high stromal proportion is an independent prognostic factor to predict worse disease-free survival (hazard ratio 2.288; P = 0.001) and overall survival (hazard ratio 2.503; P = 0.001). We found that CAFs enhanced the migratory abilities of cancer cells through the epithelial-mesenchymal transition, and RNA sequencing results confirmed these findings. CONCLUSIONS: The intratumor stromal proportion could be a useful prognostic biomarker and a potential therapeutic target in gastric SRC carcinomas.

Non-neoplastic pathology results after endoscopic submucosal dissection for gastric epithelial dysplasia or early gastric cancer.

BACKGROUND AND STUDY AIMS: Endoscopists sometimes face paradoxical cases in which the endoscopic submucosal dissection (ESD) specimen reveals a non-neoplastic pathology result. The aims of the study were to determine the reasons for such results, and to compare the endoscopic characteristics of non-neoplastic and conventional neoplastic pathology groups after ESD. PATIENTS AND METHODS: A total of 1186 gastric ESDs performed between February 2005 and December 2011 were retrospectively reviewed. The ESD specimens included 52 (4.4 %) that were confirmed as negative or indefinite for neoplasia. Patient characteristics and endoscopic and pathological data were reviewed and compared. RESULTS: Non-neoplastic pathology after ESD was due to complete removal of the lesion at biopsy in 45 cases (86.5 %), pathology overestimation in 5 (9.6 %), and incorrect localization of the original tumor with subsequent ESD performed at the wrong site in 2 (3.8 %). The mean length and surface area of the non-neoplastic lesions were 9.2 ±â€Š2.6 mm and 49.6 ±â€Š23.6 mm (2), respectively. Mean sampling ratios were 3.0 ±â€Š1.5 mm/fragment and 16.3 ±â€Š10.0 mm(2)/fragment. Compared with 1134 cases confirmed as neoplastic on the final ESD specimen, non-neoplastic cases showed a significantly smaller tumor size and surface area, and lower sampling ratios in a logistic regression analysis adjusted for potential confounders (P < 0.001 for all). CONCLUSIONS: Complete lesion removal by biopsy, pathology overestimation, and incorrect localization of the original tumor with subsequent ESD at the wrong site were the main reasons for non-neoplastic results after ESD. Small tumor size and surface area, and low sampling ratios were associated with non-neoplastic pathology results after ESD.

Loss of ACSS2 expression predicts poor prognosis in patients with gastric cancer.

BACKGROUND: Recent studies have demonstrated that acetyl-CoA synthetase 2 (ACSS2) plays a critical role in cancer cell survival; however, the role of ACSS2 in gastric carcinogenesis has not been determined. METHODS: We investigated the expression of ACSS2 in human gastric cancer (GC) tissues using immunohistochemistry, and analyzed its clinicopathological correlation and prognostic relevance. RESULTS: Among 350 GCs, 219 cases (62.6%) were classified as ACSS2-low, whereas 131 cases (37.4%) were ACSS2-high. Loss of ACSS2 expression (ACSS2-low) was more frequently observed in undifferentiated histology (P = 0.002), in cases with MLH1-loss (P = 0.003), and in cases with SIRT3-low (P < 0.001). The ACSS2-low cases showed significantly lower mean disease-free survival (DFS, 68.5 vs. 81.8 months; P = 0.025) and overall survival (OS, 73.5 vs. 86.6 months; P = 0.029). In multivariate analysis, loss of ACSS2 expression was identified as one of the independent prognostic factors predicting worse DFS (HR: 1.547, P = 0.018) and OS (HR: 1.476, P = 0.036). CONCLUSIONS: We revealed that the loss of ACSS2 expression is a reliable independent poor prognostic factor in GC. Our results may expand our understanding of the involvement of glucose metabolism, including the role of ACSS2, in the pathogenesis of GC.

ALDH1 is a prognostic factor for patients treated with neoadjuvant chemoradiotherapy and radical resection for stage III rectal cancer.

BACKGROUND AND OBJECTIVES: The factors relating to changes within a tumor after preoperative chemoradiotherapy associated with rectal cancer prognosis remain to be determined. The aim of this study was to investigate the expression of CD133 and ALDH1 and to analyze the predictive and prognostic roles in patients with rectal cancer after chemoradiotherapy. METHODS: We analyzed the expression levels of ALDH1 and CD133 in patients with middle and lower rectal cancers who underwent preoperative chemoradiotherapy between March 2005 and December 2011. RESULTS: The expression of CD133 was not associated with survival. The 5-year overall survival rates were lower in patients with high ALDH1 expression compared to low ALDH1 expression in stage III rectal cancer (61.0% vs. 89.7%, P=0.031). Cox multivariate analysis demonstrated that high ALDH1 expression (HR, 5.425; 95% CI, 1.116-26.373; P=0.036), cT (HR, 12.861; 95% CI, 2.188-75.591; P=0.005), and pN2 (HR, 28.481; 95% CI, 4.757-170.518; P<0.001) were independently associated with overall survival in 51 patients with stage III rectal cancer. CONCLUSIONS: Expression of ALDH1 indicates a more aggressive feature of stage III rectal cancer and can stratify stage III rectal cancer into different survival groups.

BRAF V600E mutations are frequent in dysembryoplastic neuroepithelial tumors and subependymal giant cell astrocytomas.

BACKGROUND: BRAF mutation has received a great deal of attention in neuro-oncology field, recently. This study aimed to investigate the incidence and the clinical significance of BRAF(V600E) in low-grade glial tumors. METHODS: An institutional cohort of 105 brain tumors (51 dysembryoplastic neuroepithelial tumors (DNTs), 14 subependymal giant cell astrocytomas (SEGAs), 12 glioblastoma with neuronal marker expression (GBM-N), and 28 pleomorphic xanthoastrocytomas (PXAs)) from 100 patients were investigated for the presence of BRAF(V600E) by direct sequencing. RESULTS: We found frequent BRAF(V600E) in DNTs (26/51, 51%), SEGAs (6/14, 42.9%), and PXAs (14/28, 50%). In DNTs, BRAF(V600E) was more commonly detected in tumors with extra-temporal location (68.2% vs. 37.9%; P = 0.032). The diagnostic subgroups of tuberous sclerosis complex were not correlated with BRAF(V600E) in patients with SEGA (P = 0.533). One PXA case revealed a unique duplication mutation (p.Thr599dup) of codon 599. All GMB-N cases did not carry BRAF mutation. CONCLUSIONS: Our data indicate that BRAF(V600E) is a common genetic alteration in low-grade glial tumors with neuronal component or differentiation. High frequency of BRAF(V600E) in DNTs and SEGAs would be useful in the differential diagnosis, and also offers a potential specific treatment targeting BRAF(V600E) .

Endoscopic ultrasound-guided sampling of solid pancreatic masses: 22-gauge aspiration versus 25-gauge biopsy needles.

BACKGROUND: Biopsy needles have recently been developed to obtain both cytological and histological specimens during endoscopic ultrasound (EUS). We conducted this study to compare 22-gauge (G) fine needle aspiration (FNA) needles, which have been the most frequently used, and new 25G fine needle biopsy (FNB) needles for EUS-guided sampling of solid pancreatic masses. METHODS: We conducted a retrospective cohort study of all EUS-guided sampling performed between June 2010 and October 2013. During the study period, 76 patients with pancreatic masses underwent EUS-guided sampling with a 22G FNA needle (n = 38) or a 25G FNB needle (n = 38) for diagnosis. An on-site cytopathologist was not present during the procedure. Technical success, the number of needle passes, cytological diagnostic accuracy, cytological sample quality (conventional smear and liquid-based preparation), histological diagnostic accuracy, and complications were reviewed and compared. RESULTS: There were no significant differences in technical success (100% for both), the mean number of needle passes (5.05 vs. 5.55, P = 0.132), or complications (0% for both) between the 22G FNA group and the 25G FNB group. The 22G FNA and 25G FNB groups exhibited comparable outcomes with respect to cytological diagnostic accuracy (97.4% vs. 89.5%, P = 0.358) and histological diagnostic accuracy (34.2% vs. 52.6%, P = 0.105). In the cytological sample quality analysis, the 25G FNB group exhibited higher scores for the amount of diagnostic cellular material present (22G FNA: 0.92 vs. 25G FNB: 1.32, P = 0.030) and the retention of appropriate architecture (22G FNA: 0.97 vs. 25G FNB: 1.42, P = 0.010) in the liquid-based preparation. The 25G FNB group showed a better histological diagnostic yield for specific tumor discrimination compared with the 22G FNA group (60 % vs. 32.4%, P = 0.018). CONCLUSIONS: Use of the 25G FNB needle was technically feasible, safe, efficient, and comparable to use of the standard 22G FNA needle in patients with solid pancreatic masses in the absence of an on-site cytopathologist. The cytological sample quality in the liquid-based preparation and the histological diagnostic yield for specific tumor discrimination of EUS-guided sampling using a 25G FNB needle were significantly higher than those using a 22G FNA needle.