Identification of discrepancy between CTLA4 expression and CTLA4 activation in gastric cancer.

Objective: Recently, immune checkpoints blockers showed higher anti-tumor activity for advanced gastric cancer (GC). The purpose of the study is to find out predictive biomarkers related to anti-cytotoxic lymphocyte antigen 4 (CTLA4) therapy. Materials and methods: Datasets of gene expression omnibus (GEO), the cancer genome atlas (TCGA), and gene set enrichment analysis (GESA) were extracted. Differential expression of CTLA4 between cancer tissues and normal mucosa, enrichment of WT (wild type) vs. CTLA4_KO (knockout) upregulated gene set and clinical significance were analyzed. The expression of CTLA4, CD3, and granzyme A (GZMA) were validated on 30 cases of Chinese GC. Microsatellite instability (MSI) marker MLH1 and Epstein-Barr virus (EBV) marker EBER were examined on 30 cases of Chinese GC by immunohistochemistry and in situ hybridization. Results: CTLA4 was upregulated in GC tissue relative to normal mucosa in datasets of GSE27342 (fold change = 1.586, p < .001) and GSE63089 (fold change = 1.365, p < .001). Increased CTLA4 expression was positively related to CTLA4 activation. EBV-associated GC (EBVaGC) and microsatellite instability GC (MSIGC) disclosed higher CTLA4 levels than other GCs. Genomic stability GC (GSGC) also showed higher enrichment score of CTLA4 activation. CTLA4 activation resulted in shorter overall survival in GC. The expression level of CTLA4 was well correlated to expression levels of GZMA (R = 0.701, p < .001) and CD3 (R = 0.750, p < .001). Conclusions: Based on bioinformatics analysis, GSGC should be worth noticed as a potential GC subtypes responsive to anti-CTLA4 treatment.

Impact of pre-existing type-2 diabetes on patient outcomes after radical resection for gastric cancer: a retrospective cohort study.

BACKGROUND: The aim of this study was to evaluate the impact of pre-existing type-2 diabetes on postoperative recovery and prognosis in gastric cancer (GC) patients who underwent radical gastrectomy. RESEARCH DESIGN AND METHODS: From June 2001 to June 2011, a total of 1,014 eligible patients were enrolled. Among them, 67 patients were diagnosed with type-2 diabetes. The clinicopathologic features and prognostic data were compared between patients with type-2 diabetes (the DM group) and without diabetes (the non-DM group). RESULTS: Median survival was 68.3 months. The 5-year overall survival in the DM group was similar to that in the non-DM group (52.1 vs. 53.0 %, p = 0.411). Propensity score matching analysis demonstrated that the hazard ratio of death in the DM group was 1.191 (95 % confidential index 0.693-2.072; p = 0.531) compared to the-non DM group. Incidence of postoperative complications was higher in the DM group than in the non-DM group (17.9 vs. 8.1 %, p = 0.006). The DM remission rate was 46 % among patients who received Roux-en-Y reconstruction, and 13 % among patients who received Billroth II anastomosis (p = 0.009). The 5-year overall survival rate was 62.1 % for patients with cured or improved DM and 23.4 % for patients with worse or same DM status (p = 0.003). CONCLUSION: Type-2 diabetes can be cured by radical gastrectomy plus Roux-en-Y reconstruction in some GC patients. Pre-existing diabetes is associated with increased postoperative complications and decreased survival when it becomes worse after curative dissection for GC.

Evaluation of skeletonization of the hepatoduodenal ligament for the lower third gastric cancer by propensity score analysis.

BACKGROUND/AIMS: Effects and indications of no. 12b and 12p nodes dissection for gastric cancer are not determined yet. Here we retrospectively evaluated the effect of no. 12b and 12p nodes dissection for treatment of lower third gastric cancer (LTGC). METHODOLOGY: Between 2001 and 2010, 110 LTGC patients with no. 12b and 12p nodes dissection (SHDL group) and 138 patients without no. 12b and 12p nodes dissection (non-SHDL group) were enrolled in this study. Clinicopathological features and prognostic data were compared between the two groups. RESULTS: The nodal metastatic rate was 8.2% of no. 12b and 10.9% of no. 12p. The 5-year survival rate was 62.9% in the SHDL group and 51.4% in the non-SHDL group (p = 0.16). Multivariate analysis with and without propensity score adjustment showed that SHDL was a significantly prognostic factor. The hazard ratio for death after D2 surgery plus SHDL was 0.457 (95% CI: 0.25 to 0.821; p = 0.0085) compared to D2 surgery alone. More patients in the non-SHDL group had only lymph node recurrence compared to the SHDL group (4.3% vs. 0%, p = 0.035). CONCLUSIONS: Skeletonization of the hepatoduodenal ligament is associated with superior outcomes for LTGC patients especially for those with involved local hepatoduodenal nodes.

CXCL1 promotes tumor growth through VEGF pathway activation and is associated with inferior survival in gastric cancer.

The chemokine (C-X-C motif) ligand 1 (CXCL1) regulates tumor-stromal interactions and tumor invasion. However, the precise role of CXCL1 on gastric tumor growth and patient survival remains unclear. In the current study, protein expressions of CXCL1, vascular endothelial growth factor (VEGF) and phospho-signal transducer and activator of transcription 3 (p-STAT3) in primary tumor tissues from 98 gastric cancer patients were measured by immunohistochemistry (IHC). CXCL1 overexpressed cell lines were constructed using Lipofectamine 2000 reagent or lentiviral vectors. Effects of CXCL1 on VEGF expression and local tumor growth were evaluated in vitro and in vivo. CXCL1 was positively expressed in 41.4% of patients and correlated with VEGF and p-STAT3 expression. Higher CXCL1 expression was associated with advanced tumor stage and poorer prognosis. In vitro studies in AGS and SGC-7901 cells revealed that CXCL1 increased cell migration but had little effect on cell proliferation. CXCL1 activated VEGF signaling in gastric cancer (GC) cells, which was inhibited by STAT3 or chemokine (C-X-C motif) receptor 2 (CXCR2) blockade. CXCL1 also increased p-STAT3 expression in GC cells. In vivo, CXCL1 increased xenograft local tumor growth, phospho-Janus kinase 2 (p-JAK2), p-STAT3 levels, VEGF expression and microvessel density. These results suggested that CXCL1 increased local tumor growth through activation of VEGF signaling which may have mechanistic implications for the observed inferior GC survival. The CXCL1/CXCR2 pathway might be potent to improve anti-angiogenic therapy for gastric cancer.

Efficacy of adjuvant XELOX and FOLFOX6 chemotherapy after D2 dissection for gastric cancer.

AIM: To compare the efficacy of capecitabine and oxaliplatin (XELOX) with 5-fluorouracil, folinic acid and oxaliplatin (FOLFOX6) in gastric cancer patients after D2 dissection. METHODS: Between May 2004 and June 2010, patients in our gastric cancer database who underwent D2 dissection for gastric cancer at the First Affiliated Hospital of Sun Yat-Sen University were retrospectively analyzed. A total of 896 patients were enrolled into this study according to the established inclusion and exclusion criteria. Of these patients, 214 received the XELOX regimen, 48 received FOLFOX6 therapy and 634 patients underwent surgery only without chemotherapy. Overall survival was compared among the three groups using Cox regression and propensity score matched-pair analyses. RESULTS: Patients in the XELOX and FOLFOX6 groups were younger at the time of treatment (median age 55.2 years; 51.2 years vs 58.9 years), had more undifferentiated tumors (70.1%; 70.8% vs 61.4%), and more lymph node metastases (80.8%; 83.3% vs 57.7%), respectively. Overall 5-year survival was 57.3% in the XELOX group which was higher than that (47.5%) in the surgery only group (P = 0.062) and that (34.5%) in the FOLFOX6 group (P = 0.022). Multivariate analysis showed that XELOX therapy was an independent prognostic factor (hazard ratio = 0.564, P < 0.001). After propensity score adjustment, XELOX significantly increased overall 5-year survival compared to surgery only (58.2% vs 44.2%, P = 0.025) but not compared to FOLFOX6 therapy (48.5% vs 42.7%, P = 0.685). The incidence of grade 3/4 adverse reactions was similar between the XELOX and FOLFOX6 groups, and more patients suffered from hand-foot syndrome in the XELOX group (P = 0.018). CONCLUSION: Adjuvant XELOX therapy is associated with better survival in patients after D2 dissection, but does not result in a greater survival benefit compared with FOLFOX6 therapy.