The phosphatase PAC1 acts as a T cell suppressor and attenuates host antitumor immunity.

Cancer cells subvert immune surveillance through inhibition of T cell effector function. Elucidation of the mechanism of T cell dysfunction is therefore central to cancer immunotherapy. Here, we report that dual specificity phosphatase 2 (DUSP2; also known as phosphatase of activated cells 1, PAC1) acts as an immune checkpoint in T cell antitumor immunity. PAC1 is selectively upregulated in exhausted tumor-infiltrating lymphocytes and is associated with poor prognosis of patients with cancer. PAC1hi effector T cells lose their proliferative and effector capacities and convert into exhausted T cells. Deletion of PAC1 enhances immune responses and reduces cancer susceptibility in mice. Through activation of EGR1, excessive reactive oxygen species in the tumor microenvironment induce expression of PAC1, which recruits the Mi-2ß nucleosome-remodeling and histone-deacetylase complex, eventually leading to chromatin remodeling of effector T cells. Our study demonstrates that PAC1 is an epigenetic immune regulator and highlights the importance of targeting PAC1 in cancer immunotherapy.

CDKN2A somatic copy number amplification in normal tissues surrounding gastric carcinoma reduces cancer metastasis risk in droplet digital PCR analysis.

BACKGROUND: The CDKN2A gene is frequently affected by somatic copy number variations (SCNVs, including deletions and amplifications [SCNdel and SCNamp]) in the cancer genome. Using surgical gastric margin tissue samples (SMs) as the diploid reference in SCNV analysis via CDKN2A/P16-specific real-time PCR (P16-Light), we previously reported that the CDKN2A SCNdel was associated with a high risk of metastasis of gastric carcinoma (GC). However, the status of CDKN2A SCNVs in SMs and their clinical significance have not been reported. METHODS: Peripheral white blood cell (WBC) and frozen GC and SM tissue samples were collected from patients (n = 80). Droplet digital PCR (ddPCR) was used to determine the copy number (CN) of the CDKN2A gene in tissue samples using paired WBCs as the diploid reference. RESULTS: A novel P16-ddPCR system was initially established with a minimal proportion (or limit, 10%) of the detection of CDKN2A CN alterations. While CDKN2A SCNamp events were detected in both SMs and GCs, fewer CDKN2A SCNdel events were detected in SMs than in GCs (15.0% vs. 41.3%, P = 4.77E-04). Notably, significantly more SCNamp and fewer SCNdel of the CDKN2A gene were detected in SMs from GC patients without metastasis than in those from patients with lymph node metastasis by P16-ddPCR (P = 0.023). The status of CDKN2A SCNVs in SM samples was significantly associated with overall survival (P = 0.032). No cancer deaths were observed among the 11 patients with CDKN2A SCNamp. CONCLUSION: CDKN2A SCNVs in SMs identified by P16-ddPCR are prevalent and significantly associated with GC metastasis and overall survival.

MicroRNA-143-3p Inhibits Wilms' Tumor Cell Growth By Targeting the Ras/Raf/MEK/ERK Pathway.

Background: A previous study found that microRNA-143-3p (miR-143-3p) is a tumor suppressor in various types of human cancer. However, the roles and molecular mechanisms of miR-143-3p in the progression of Wilms' tumor (WT) remain to be clarified. The aim of the present study was to determine the expression and biological functions of miR-143-3p in WT. Material and Methods: The expression levels of miR-143-3p in primary WT tissues and adjacent tissues were determined using quantitative-reverse transcription polymerase chain reaction (qRT-PCR), and the association of the miR-143-3p expression level with various clinicopathological features of WT was investigated. Western blotting was used to evaluate the protein expression of the related signaling pathway. Results: The expression of miR-143-3p was significantly downregulated in WT tissues and its expression levels were closely associated with tumor stage and lymph node metastasis. Overexpression of miR-143-3p in SK-NEP-1 and G401 cell lines inhibited cell proliferation by G0/G1 cell cycle phase arrest and induction of apoptosis. Moreover, k-Ras, a unique oncogene, was confirmed as a direct target of miR-143-3p, and k-Ras messenger RNA (mRNA) expression was increased in WT tissues and inversely correlated with miR-143-3p. Knockdown of k-Ras by si-k-Ras could inhibit, whereas overexpression of k-Ras could promote. cell proliferation in WT cells. Meanwhile, overexpression of k-Ras reversed the inhibitory effects on WT cells induced by miR-143-3p mimics. Conclusion: Our findings indicate that miR-143-3p may be a potential novel prognostic biomarker and therapeutic target for WT.

Perioperative or postoperative adjuvant oxaliplatin with S-1 versus adjuvant oxaliplatin with capecitabine in patients with locally advanced gastric or gastro-oesophageal junction adenocarcinoma undergoing D2 gastrectomy (RESOLVE): an open-label, superiority and non-inferiority, phase 3 randomised controlled trial.

BACKGROUND: The optimal perioperative chemotherapeutic regimen for locally advanced gastric cancer remains undefined. We evaluated the efficacy and safety of perioperative and postoperative S-1 and oxaliplatin (SOX) compared with postoperative capecitabine and oxaliplatin (CapOx) in patients with locally advanced gastric cancer undergoing D2 gastrectomy. METHODS: We did this open-label, phase 3, superiority and non-inferiority, randomised trial at 27 hospitals in China. We recruited antitumour treatment-naive patients aged 18 years or older with historically confirmed cT4a N+ M0 or cT4b Nany M0 gastric or gastro-oesophageal junction adenocarcinoma, with Karnofsky performance score of 70 or more. Patients undergoing D2 gastrectomy were randomly assigned (1:1:1) via an interactive web response system, stratified by participating centres and Lauren classification, to receive adjuvant CapOx (eight postoperative cycles of intravenous oxaliplatin 130 mg/m2 on day one of each 21 day cycle plus oral capecitabine 1000 mg/m2 twice a day), adjuvant SOX (eight postoperative cycles of intravenous oxaliplatin 130 mg/m2 on day one of each 21 day cycle plus oral S-1 40-60 mg twice a day), or perioperative SOX (intravenous oxaliplatin 130 mg/m2 on day one of each 21 day plus oral S-1 40-60 mg twice a day for three cycles preoperatively and five cycles postoperatively followed by three cycles of S-1 monotherapy). The primary endpoint, assessed in the modified intention-to-treat population, 3-year disease-free survival to assess the superiority of perioperative-SOX compared with adjuvant-SOX and the non-inferiority (hazard ratio non-inferiority margin of 1·33) of adjuvant-SOX compared with adjuvant-CapOx. Safety analysis were done in patients who received at least one dose of the assigned treatment. This study is registered with ClinicalTrials.gov, NCT01534546. FINDINGS: Between Aug 15, 2012, and Feb 28, 2017, 1094 patients were screened and 1022 (93%) were included in the modified intention-to-treat population, of whom 345 (34%) patients were assigned to the adjuvant-CapOx, 340 (33%) patients to the adjuvant-SOX group, and 337 (33%) patients to the perioperative-SOX group. 3-year disease-free survival was 51·1% (95% CI 45·5-56·3) in the adjuvant-CapOx group, 56·5% (51·0-61·7) in the adjuvant-SOX group, and 59·4% (53·8-64·6) in the perioperative-SOX group. The hazard ratio (HR) was 0·77 (95% CI 0·61-0·97; Wald p=0·028) for the perioperative-SOX group compared with the adjuvant-CapOx group and 0·86 (0·68-1·07; Wald p=0·17) for the adjuvant-SOX group compared with the adjuvant-CapOx group. The most common grade 3-4 adverse events was neutropenia (32 [12%] of 258 patients in the adjuvant-CapOx group, 21 [8%] of 249 patients in the adjuvant-SOX group, and 30 [10%] of 310 patients in the perioperative-SOX group). Serious adverse events were reported in seven (3%) of 258 patients in adjuvant-CapOx group, two of which were related to treatment; eight (3%) of 249 patients in adjuvant-SOX group, two of which were related to treatment; and seven (2%) of 310 patients in perioperative-SOX group, four of which were related to treatment. No treatment-related deaths were reported. INTERPRETATION: Perioperative-SOX showed a clinically meaningful improvement compared with adjuvant-CapOx in patients with locally advanced gastric cancer who had D2 gastrectomy; adjuvant-SOX was non-inferior to adjuvant-CapOx in these patients. Perioperative-SOX could be considered a new treatment option for patients with locally advanced gastric cancer. FUNDING: National Key Research and Development Program of China, Beijing Scholars Program 2018-2024, Peking University Clinical Scientist Program, Taiho, Sanofi-Aventis, and Hengrui Pharmaceutical. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Construction and Validation of a Risk-Scoring Model that Preoperatively Predicts Lymph Node Metastasis in Early Gastric Cancer Patients.

OBJECTIVE: The aim of this study was to create a risk-scoring model to preoperatively predict the incidence of lymph node metastasis (LNM) in early gastric cancer (EGC) patients to guide treatment. METHODS: To construct the risk-scoring model, we retrospectively analyzed a primary cohort of 548 EGC patients. Univariate analysis and logistic regression were performed. A risk-scoring model for predicting LNM in EGC patients was developed based on preoperative factors, and another cohort of 73 patients was then analyzed to validate the model. RESULTS: In the primary cohort, LNM was pathologically confirmed in 72 (13.1%) patients. In the multivariate analysis, the presence of ulceration and tumor size on gastroscopy, undifferentiated histological type, and presence of enlarged lymph nodes on computed tomography or endoscopic ultrasonography were independent risk factors for LNM. A 17-point risk-scoring model was developed to predict LNM risk. The cut-off score of the model was 8, and the area under the receiver operating characteristic curve (AUC) of the model was 0.835 [95% confidence interval (CI) 0.784-0.886]. In the validation cohort, the AUC of the model was 0.829 (95% CI 0.699-0.959). CONCLUSIONS: We developed and validated an effective 17-point risk-scoring model that could preoperatively predict LNM for EGC patients.

Prognostic and predictive value of mismatch repair deficiency in gastric and gastroesophageal junction adenocarcinoma patients receiving neoadjuvant or adjuvant chemotherapy.

BACKGROUND AND OBJECTIVES: Evidence is inconclusive regarding the prognostic significance of deficient DNA mismatch repair (dMMR) in gastric and gastroesophageal junction (GEJ) adenocarcinoma patients receiving chemotherapy. We aim to explore such associations with a large cohort. METHODS: We retrospectively identified a consecutive cohort of patients who had histology proven gastric or GEJ adenocarcinoma and received neoadjuvant chemotherapy plus surgery or upfront surgery plus adjuvant chemotherapy. MMR status was assessed by immunohistochemistry staining on surgical specimen. The association of MMR status with tumor regression grade (TRG), overall survival (OS), and disease-free survival (DFS) were analyzed. RESULTS: In total, 1568 patients received neoadjuvant or adjuvant chemotherapy, of which 128 (8.2%) had dMMR tumors. No significant difference was found in the frequencies of TRG categories between proficient MMR (pMMR) and dMMR tumors (p = .62). Among patients receiving neoadjuvant chemotherapy, dMMR status was associated with better OS (log-rank p = .044) and DFS (log-rank p = .022) in the univariate analysis; this association became nonsignificant after adjusting for pathologic stages and other prognostic factors. Similar results were found for patients receiving adjuvant chemotherapy. CONCLUSIONS: dMMR status was not significantly associated with OS and DFS among gastric and GEJ adenocarcinoma patients with neoadjuvant and adjuvant platinum and fluorouracil-based chemotherapy.

The clinical value and usage of inflammatory and nutritional markers in survival prediction for gastric cancer patients with neoadjuvant chemotherapy and D2 lymphadenectomy.

BACKGROUND: The clinical values of inflammatory and nutritional markers remained unclear for gastric cancer with neoadjuvant chemotherapy (NACT). METHODS: The inflammatory, nutritional markers and their changes were analyzed for locally advanced gastric cancer with NACT. The predictive value was evaluated by the Cox proportional hazards regressions under three hypothesized scenarios. The nomograms including independent prognostic factors were plotted for survival prediction. RESULTS: A total of 225 patients were included in the study. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index, and hemoglobin (Hgb) were significantly reduced, and the body mass index was significantly increased after NACT (all P < 0.05). The pre-NACT NLR [hazard ratio (HR) = 1.176, P = 0.059] showed a trend to correlate with the overall survival (OS) when only pre-NACT markers available; The post-NACT Hgb (HR = 0.982, P = 0.015) was the independent prognostic factor when only post-NACT markers available; The post-NACT Hgb (HR = 0.984, P = 0.025) and the change value of LMR (HR = 1.183, P = 0.036) were the independent prognostic factors when both pre- and post-NACT markers available. The nomogram had a similar Harrell's C-statistic compared to ypTNM stage (0.719 vs. 0.706). CONCLUSION: For locally advanced gastric cancer, the NACT could significantly decrease some inflammatory markers. The pre-NACT NLR, the post-NACT Hgb and the change value of LMR had some values in survival prediction combined with age, sex, tumor location and the clinical stages under different clinical scenarios. The elevated initial NLR, the preoperative anemia and the greater change value of LMR implied a poor prognosis.

A panel of DNA methylated markers predicts metastasis of pN0M0 gastric carcinoma: a prospective cohort study.

BACKGROUND: The aim of this prospective study was to evaluate the feasibility of predicting GC metastasis using CDH1, GFRA1, P16 and ZNF382 DNA methylation as biomarkers. METHODS: 198 GC patients without metastasis at the time of surgery resection were recruited into the double-blind cohort (NCT02159339). Gene methylation was analysed using MethyLight assays. GC metastasis and survival data were obtained from 178 patients with 94.7% compliance during follow-up. RESULTS: Twenty six cases of metastasis and 5 cases of recurrence were observed in 178 cases (17.4%) during the follow-up (median, 62.7 months). The GC metastasis rate for GFRA1 methylation-positive patients was significantly reduced compared with GFRA1 methylation-negative patients (odds ratio [OR]: 0.23, 95% confidence interval [CI] 0.08-0.66). Similar results were also observed using ZNF382 methylation as a predictor (OR: 0.17, 95% CI 0.06-0.47). A risk score including methylation of GFRA1 and ZNF382 was generated. The metastasis rate was significantly increased in high-risk GC patients (OR: 4.71, 95% CI: 1.85-12.00). GC patients with high risk had a shorter overall survival, especially for patients with stage I GC (P = 0.024). CONCLUSIONS: The combination of GFRA1 and ZNF382 methylation is a biomarker panel for the prediction of GC metastasis.

Impact of postoperative major complications on long-term survival after radical resection of gastric cancer.

BACKGROUND: This study was designed to evaluate the impact of postoperative major complications on long-term survival following curative gastrectomy. METHODS: This retrospective study included 239 patients with gastric cancer undergoing gastrectomy at the Beijing Cancer Hospital from February 2012 to January 2013. Survival curves were compared between patients with major complications (mC group) and those without major complications (NmC group). Multivariate analysis was conducted to identify independent prognostic factors. RESULTS: Postoperative complication and mortality rates were 24.7 and 0.8%, respectively. The severity of complications was graded in accordance with the Clavien-Dindo classification. The incidence of minor complications (grades I-II) and major complications (grades III-V) was 9.2 and 15.5%, respectively. The 3-year overall survival (OS) and disease-free survival (DFS) rates were better in the NmC group than in the mC group (p = 0.014, p = 0.013). Multivariate analysis identified major complications as an independent prognostic factor for OS and DFS. After stratification by pathological stage, this trend was also observed in stage II patients. CONCLUSIONS: Postoperative major complications adversely affect OS and DFS. The prevention and early diagnosis of complications are essential to minimize the negative effects of complications on surgical safety and long-term patient survival.

Different prognostic implication of ypTNM stage and pTNM stage for gastric cancer: a propensity score-matched analysis.

BACKGROUND: Pathological stage is considered as the best prognosis indicator for gastric cancer. With the increasing use of neoadjuvant chemotherapy (NACT), the latest TNM staging included a new pathological stage of ypTNM for patients with NACT. However, no study has investigated if ypTNM stage has the same prognostic implication as pTNM stage for gastric cancer. METHODS: We retrospectively selected eligible patients within a prospectively maintained database containing all patients treated with gastric cancer in Peking University Cancer Hospital from 2007 to 2015 using overall survival as the outcome. Patients using ypTNM and pTNM were 1:1 matched by propensity scores (PS) calculated from a model containing variables associated with ypTNM use or survival. Overall survival was compared by unconditional Cox regression. Conventional multivariate analysis was conducted to corroborate PS matching results. RESULTS: 1441 patients were included in the analysis with a median follow-up of 37 months (range = 2-106). The matched sample contained 756 patients. After PS matching, patients with specific ypTNM stage were 1.34 (95%CI = 1.05-1.72, P = 0.019) times more likely to die than patients with the same pTNM stage. Similar to the results of PS matching, multivariate Cox regression yielded a hazard ratio (HR) of 1.35 (95%CI = 1.09-1.67, P = 0.006). Subgroup analysis indicated this survival difference between ypTNM and pTNM stage varied by the specific TNM stage of patients. The HR was 3.44 (95%CI = 1.06-11.18, P = 0.040) and 1.28 (95%CI = 1.00-1.62, P = 0.048) for patients in stage I and III, respectively; whereas for stage II patients, no significant difference was observed (HR = 1.37, 95%CI = 0.78-2.38, P = 0.27). CONCLUSION: Gastric cancer patients with specific ypTNM stage had worse prognosis compared to those at the same stage defined by pTNM.

MicroRNA-130a-3p suppresses cell migration and invasion by inhibition of TBL1XR1-mediated EMT in human gastric carcinoma.

MiR-130a-3p was found to play tumor suppressor role in most human cancers, except for gastric cancer. However, in this study, we demonstrated that miR-130a-3p was significantly down-regulated in gastric carcinoma (GC) tissues compared with adjacent non-neoplastic tissues, and decreased miR-130a-3p expression was associated with shorter overall survival (OS) and was an independent prognostic factor for OS in GC patients. Over-expression of miR-130a-3p remarkably inhibited not only GC cell migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro, but also tumorigenesis and lung metastasis in the chick embryo chorioallantoic membrane (CAM) assay in vivo. Conversely, inhibition of miR-130a-3p resulted in opposite phenotype changes in GC cells. Furthermore, TBL1XR1 was identified as a direct target of miR-130a-3p, and reintroduction of TBL1XR1 into miR-130a-3p-transfected MGC-803 cells reversed the inhibitory effects of miR-130a-3p on GC cell migration, invasion and EMT. Taken together, our data suggested that miR-130a-3p suppressed aggressive phenotype of GC cells partially by direct targeting and decreasing TBL1XR1 and subsequent EMT process.

Staging laparoscopy for locally advanced gastric cancer in Chinese patients: a multicenter prospective registry study.

BACKGROUND: Staging laparoscopy(SL) is a recommended technique for the staging of Gastric Cancer(GC) and provides the indication for a radical surgery. Considering the medical practice in China, the standardized and regular usage of SL is yet to be spread. However, existing guidelines vary and make an ambiguity of indication for SL. Besides, the specific indication for Chinese patients remains a niche. This study aims to the essential, missing information of Chinese patients and tries to normalize the indication of LS in medical practice in China. METHODS: The study is a prospective, multicenter cohort study being conducted in China with a total of 450 patients, all diagnosed with locally advanced gastric cancer (cT2-4 N0-3 M0, no evidence of intra-abdominal dissemination) through Computed Tomography(CT) and/or Endoscopic Ultrasonography(EUS). Peritoneal lavage is regularly performed during the SL. Multivariate Cox regression model and receiver-operator characteristic(ROC) analysis will be used to analyze the significant risk factors of intra-abdominal metastasis(including peritoneal dissemination and a positive cytological result). DISCUSSION: This confirmatory study will provide us with the specific positive rate of intraabdominal metastasis of GC in China, compared with empirical evidence of 20%. We expect this trial will contribute to our discovery of the specific risk factors of intra-abdominal metastasis of Chinese patients and to the stimulating and performing of minimally invasive surgical procedures. TRIAL REGISTRATION: ClinicalTrials.gov : registration number NCT02172690 .

The effect of preoperative treatments on lymph node counts after total gastrectomy in esophagogastric adenocarcinoma.

OBJECTIVES: This study aims to explore the effects of preoperative treatments on lymph nodes (LNs) counts after total gastrectomy with D2 lymphadenectomy in esophagogastric adenocarcinoma. METHODS: A retrospective analysis was performed for 446 patients with locally advanced esophagogastric adenocarcinoma. The patients were divided into three groups: surgery first (SF), preoperative chemotherapy (PCT), and preoperative chemoradiotherapy (PCRT). Clinical-pathological data were analyzed. RESULTS: The case number in SF, PCT, and PCRT groups was 281, 109, and 56, respectively, and the median total LNs count was 32.0 (10.0-102.0), 31.0 (12.0-62.0), and 25.5 (10.0-50.0), respectively, (P < 0.001). Univariate and multivariate analyses demonstrated the total LNs count was lower in PCRT than SF/PCT (P < 0.001), and had no correlation with tumor regression grades (TRGs). Subgroup comparison showed radiation target LNs count was lower in PCRT than SF/PCT (P < 0.001), and peritarget LNs count was lower in PCRT than SF (P = 0.002). CONCLUSION: For esophagogastric adenocarcinoma, PCRT reduced total LNs count after total gastrectomy with D2 lymphadenectomy, whereas PCT did not. In the PCRT group, LNs count was lower in both radiation target and peritarget areas than in the SF group but only in radiation target area than in the PCT group. The correlation between TRGs and total LNs count remained unclear.

The 8th edition of the American Joint Committee on Cancer tumor-node-metastasis staging system for gastric cancer is superior to the 7th edition: results from a Chinese mono-institutional study of 1663 patients.

BACKGROUND: We investigated the superiority of the 8th edition of the tumor-node-metastasis (TNM) system for patients in China with gastric cancer. METHODS: The survival outcomes of 1663 patients with gastric cancer undergoing radical resection were analyzed. RESULTS: In the 8th edition system, homogeneous 5-year survival rates among different pathological TNM (pTNM) categories belonging to the same stage were observed. However, in the 7th edition system, the differences of 5-year survival rate among pTNM categories belonging to the same stage were observed in stages IIB (P = 0.010), IIIB (P = 0.004), and IIIC (P < 0.001). For patients in the pT1-3 (P < 0.001) and pT4a (P < 0.001) categories, there were significant differences in survival between patients in the pN3a and pN3b categories. Furthermore, partial cases (pT4bN0M0/T4aN2M0) of stage IIIB were downstaged to stage IIIA in the 8th edition system, and the 5-year survival rate of these patients was significantly better than that of patients in stage IIIB in the 8th edition system. Similarly, the 5-year survival rate of patients in p4bN2M0/T4aN3aM0 downstaged from stage IIIC to IIIB was significantly better than that of patients in stage IIIC. Compared with the 7th edition system, the 8th edition system had a higher likelihood ratio and linear trend chi-squared score and a smaller Akaike information criteria value. CONCLUSIONS: The 8th edition system is superior to the 7th edition system in terms of homogeneity, discriminatory ability, and monotonicity of gradients for Chinese patients with gastric cancer.

Clonality analysis of synchronous gastro-oesophageal junction carcinoma and distal gastric cancer by whole-exome sequencing.

Gastro-oesophageal junction (GEJ) carcinoma and distal gastric cancer (GC) have distinct epidemiology and clinical features and their relationship is uncertain. Synchronous multiple gastric cancers located mostly at proximal and distal sites provide rare specimens for investigating the comprehensive genomic relationships among these cancers in the context of identical genetic circumstances. Formalin-fixed, paraffin-embedded (FFPE) samples from 12 patients with synchronous GEJ carcinoma and distal GC were collected in this study. Whole-exome sequencing (WES) was performed using normal tissues as a control. Mutational profiling, clonality analysis, a detailed clinico-pathological review, determination of MSI status, EBER in situ hybridization (ISH), and programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunohistochemical staining were performed. Twenty-three of the 24 samples were microsatellite-stable (MSS). Subclonal analysis revealed that nine pairs of GEJ and distal GC tumours in neoadjuvant chemotherapy naïve patients developed independently from different origins. Two patients who received neoadjuvant chemotherapy shared clonal origins with highly similar somatic alterations. The remaining one patient who shared a rare mutation died within 6.2 months at the N3 stage. However, the enriched pathway identified from the overall mutation spectra in distal GC and GEJ carcinoma showed the close relationship of these cancers. Thus, although these cancers may have similar characteristics, histopathological and genetic profiling from single tumour specimens may still underestimate the mutational burden and somatic heterogeneity of multiple GCs. In addition, this series of cases also showed a PD-L1 expression rate of 58.3% and 66.7% in distal GC and GEJ carcinoma, respectively, with all the cases expressing PD-1. This result suggests the potential benefit of immunotherapeutic treatments. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

[Effect of MicroRNA-199 on Proliferation and Migration of Gastric Carcinoma Cells].

Objective To detect the expression of microRNA(miR)-199 in gastric carcinoma tissues and cell lines, and further explore the effect and molecular mechanism of miR-199 on the proliferation and migration of gastric carcinoma cell lines. Methods Reverse transcriptase-polymerse chain reaction was used to detect the expression of miR-199 in gastric carcinoma and adjacent normal tissue obtained from 51 patients and in gastric carcinoma cell lines and human gastric epithelial cell line GES-1. The gastric carcinoma cell lines over-expressing and low-expressing miR-199 were established to detect their proliferation and migration abilities. Dual-luciferase reporter assay was performed to detect the regulatory effect of miR-199 on the 3'untranslated region of TBL1XR1. Western blot was used to explore the miR-199-related mechanism. Results The relative expression of miR-199 in gastric carcinoma tissues was significantly lower than that in the adjacent normal tissue (0.2635±0.0303 vs. 1.6700±0.9613, t=13.95, P<0.001). The relative expressions of miR-199 in gastric carcinoma cell lines AGS (0.81, t=9.13, P<0.001), SGC-7901 (0.83, t=8.88, P<0.001), MKN28 (0.58, t=10.80, P<0.001), KATO-3 (0.60, t=10.31, P<0.001), MKN-45 (0.27, t=13.10, P<0.001) were significantly lower than that in the normal gastric cell line GES-1 (2.1). In miR-199 over-expressed cell lines, the cell proliferation and migration significantly decreased as compared with the control group of gastric carcinoma cells (731±13 vs. 345±18, t=24.90, P<0.001), and in miR-199 low-expressed group, the cell proliferation and migration increased compared with the control group of gastric carcinoma cells (257±16 vs. 657±8, t=32.59, P<0.001). Dual-luciferase reporter assay proved that miR-199 directly targeted on the 3' untranslated region of TBL1XR1. Western blot analysis showed that miR-199 inhibited the expression of TBL1XR1. Conclusion The over-expression of miR-199 in gastric carcinoma is associated with the decreased ability of proliferation and migration of gastric carcinoma cells by targeting TBL1XR1.

Oxaliplatin plus S-1 or capecitabine as neoadjuvant or adjuvant chemotherapy for locally advanced gastric cancer with D2 lymphadenectomy: 5-year follow-up results of a phase II-III randomized trial.

OBJECTIVE: To compare the effect of neoadjuvant chemotherapy (NACT) with adjuvant chemotherapy (ACT) using oxaliplatin plus S-1 (SOX) or capecitabine (CapeOX) on gastric cancer patients with D2 lymphadenectomy. METHODS: This was a two-by-two factorial randomized phase II-III trial, and registered on ISRCTN registry (No. ISRCTN12206108). Locally advanced gastric cancer patients were randomized to neoadjuvant SOX, neoadjuvant CapeOX, adjuvant SOX, or adjuvant CapeOX arms. Primary analysis was performed on an intention-to-treat (ITT) basis using overall survival (OS) as primary endpoint. RESULTS: This trial started in September 2011 and closed in December 2012 with 100 patients enrolled. Treatment completion rate was 56%, 52%, 38% and 30% in the four arms, respectively. NACT group had fewer dropouts due to unacceptable toxicity (P=0.042). Surgical complication rate did not differ by the four groups (P=0.986). No survival significant difference was found comparing NACT with ACT (P=0.664; 5-year-OS: 70% vs. 74% respectively), nor between the SOX and CapeOX groups (P=0.252; 5-year-OS: 78% vs. 66% respectively). Subgroup analysis showed SOX significantly improved survival in patients with diffuse type (P=0.048). CONCLUSIONS: No significant survival difference was found between NACT and ACT. SOX and CapeOX had good safety and efficacy as neoadjuvant regimens. Diffuse type patients may survive longer due to SOX.

Anatomical variation of infra-pyloric artery origination: A prospective multicenter observational study (IPA-Origin).

OBJECTIVE: Infra-pyloric artery (IPA) is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA. METHODS: We did this prospective, multicenter, open-label, observational study at gastric surgery departments of 34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ2 tests and Fisher's tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov (No. NCT03071237). RESULTS: Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419 (97.7%) patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398 (95.0%) patients, including gastroduodenal artery (GDA) in 154 (36.8%) patients, anterior superior pancreaticoduodenal artery (ASPDA) in 130 (31.0%) patients, and right gastroepiploic artery (RGEA) in 114 (27.2%) patients. Fifteen (3.6%) patients were identified with multiple IPA and 6 (1.4%) patients were identified as IPA absence. The differences in the distribution of surgical approach (P=0.003) and geographic area (P=0.030) were statistically significant. No difference was shown in sex, age, gastrectomy type, tumor location, and clinical T, N and M stage. CONCLUSIONS: Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions. Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery.

Prognostic significance of the total number of harvested lymph nodes for lymph node-negative gastric cancer patients.

BACKGROUND: The relationship between the number of harvested lymph nodes (HLNs) and prognosis of gastric cancer patients without an involvement of lymph nodes has not been well-evaluated. The objective of this study is to further explore this issue. METHODS: We collected data from 399 gastric cancer patients between November 2006 and October 2011. All of them were without metastatic lymph nodes. RESULTS: Survival analyses showed that statistically significant differences existed in the survival outcomes between the two groups allocated by the total number of HLNs ranging from 16 to 22. Therefore, we adopted 22 as the cut-off value of the total number of HLNs for grouping (group A: HLNs <22; group B: HLNs≥22). The intraoperative and postoperative characteristics, including operative blood loss (P=0.096), operation time (P=0.430), postoperative hospital stay (P=0.142), complications (P=0.552), rate of reoperation (P=0.966) and postoperative mortality (P=1.000), were comparable between the two groups. T-stage-stratified Kaplan-Meier analyses revealed that the 5-year survival rate of patients at the T4 stage was better in group B than in group A (76.9% vs. 58.5%; P=0.004). An analysis of multiple factors elucidated that the total number of HLNs, T stage, operation time and age were independently correlated factors of prognosis. CONCLUSIONS: Regarding gastric cancer patients without the involvement of lymph nodes, an HLN number ≥22 would be helpful in prolonging their overall survival, especially for those at T4 stage. The total number of HLNs was an independent prognostic factor for this population of patients.

The optimal extent of gastrectomy for middle-third gastric cancer: distal subtotal gastrectomy is superior to total gastrectomy in short-term effect without sacrificing long-term survival.

BACKGROUND: The optimal extent of gastrectomy for middle-third gastric cancer remains controversial. In our study, the short-term effects and longer-term survival outcomes of distal subtotal gastrectomy and total gastrectomy are analysed to determine the optimal extent of gastrectomy for middle-third gastric cancer. METHODS: We retrospectively collect and analyse clinicopathologic data and follow-up outcomes from a prospectively collected database at the Peking University Cancer Hospital. Patients with middle-third gastric adenocarcinoma who underwent curative resection are enrolled in our study. RESULTS: We collect data of 339 patients between January 2005 and October 2011. A total of 144 patients underwent distal subtotal gastrectomy, and 195 patients underwent total gastrectomy. Patients in the total gastrectomy group have longer operative duration (P < 0.001) and postoperative hospital stay (P = 0.001) than those in the distal subtotal gastrectomy group. In the total gastrectomy group, more lymph nodes are harvested (P < 0.001). Meanwhile, the rate of postoperative complications is lower in the distal subtotal gastrectomy group than in the total gastrectomy group (8% vs 15%, P = 0.047). Further analysis demonstrates that the rate of anastomosis leakage is lower in the distal subtotal gastrectomy group than in the total gastrectomy group (0% vs 4%, P = 0.023). Kaplan-Meier (log rank test) analysis shows a significant difference in overall survival between the two groups. The 5-year overall survival rates in the distal subtotal gastrectomy and total gastrectomy groups are 65% and 47%, respectively (P < 0.001). Further stage-stratified analysis reveals that no statistical significance exists in 5-year survival rate between the distal subtotal gastrectomy and total gastrectomy groups at the same stage. Multivariate analysis shows that age (P = 0.046), operation duration (P < 0.001), complications (P = 0.037), usage of neoadjuvant chemotherapy (P < 0.001), tumor size (P = 0.012), presence of lymphovascular invasion (P = 0.043) and N stage (P < 0.001) are independent prognostic factors for survival. CONCLUSIONS: For patients with middle-third gastric cancer, distal subtotal gastrectomy shortens the operation duration and postoperative hospital stay and reduces postoperative complications. Meanwhile, the long-term survival of patients with distal subtotal gastrectomy is similar to that of those with total gastrectomy at the same stage. The extent of gastrectomy for middle-third gastric cancer is not an independent prognostic factor for survival.