The Japanese guidelines for gastric cancer screening have been revised based on the new studies. Radiographic and endoscopic screenings for gastric cancer are recommended for population-based ...screening in Japan.
Abstract
Background
Although the incidence and mortality of gastric cancer have gradually decreased, its burden remains in East Asian countries. Gastric cancer screening has been performed in Japan since 1983, and the introduction of new screening techniques has been eagerly anticipated.
Objective
To promote evidence-based screening, the Japanese guidelines for gastric cancer screening have been revised based on the new studies.
Methods
The guidelines for gastric cancer screening have been developed according to a previously established method. To assess evidence regarding the effectiveness of the screening methods, a systematic review was conducted based on an analytic framework including clinical questions aiming at reducing mortality from gastric cancer. The following methods were assessed for gastric cancer screening: upper gastrointestinal series (radiographic screening), gastrointestinal endoscopy (endoscopic screening), Helicobacter pylori antibody test and serum pepsinogen tests. Based on the balance of the benefits and harms of each screening method, recommendations for population-based and opportunistic screenings were formulated.
Findings
After the Japanese guidelines for gastric cancer screening were published in 2005, several observational studies on radiographic and endoscopic screenings have been reported. Three case–control studies have evaluated mortality reduction from gastric cancer by endoscopic screening. Notably, evidence of the H. pylori antibody and serum pepsinogen tests was insufficient. Although false-positive results, false-negative results, and complications were observed in endoscopic and radiographic screenings, the complication rates were higher in endoscopic screening than in radiographic screening. Overdiagnosis was not estimated directly in both methods.
Recommendations
Radiographic and endoscopic screenings for gastric cancer are recommended for population-based and opportunistic screenings. The H. pylori antibody and serum pepsinogen tests are not recommended for population-based screening because of insufficient evidence.
The first planned interim analysis (median follow-up, 3 years) of the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer confirmed that the oral fluoropyrimidine derivative S-1 significantly ...improved overall survival, the primary end point. The results were therefore opened at the recommendation of an independent data and safety monitoring committee. We report 5-year follow-up data on patients enrolled onto the ACTS-GC study.
Patients with histologically confirmed stage II or III gastric cancer who underwent gastrectomy with D2 lymphadenectomy were randomly assigned to receive S-1 after surgery or surgery only. S-1 (80 to 120 mg per day) was given for 4 weeks, followed by 2 weeks of rest. This 6-week cycle was repeated for 1 year. The primary end point was overall survival, and the secondary end points were relapse-free survival and safety.
The overall survival rate at 5 years was 71.7% in the S-1 group and 61.1% in the surgery-only group (hazard ratio HR, 0.669; 95% CI, 0.540 to 0.828). The relapse-free survival rate at 5 years was 65.4% in the S-1 group and 53.1% in the surgery-only group (HR, 0.653; 95% CI, 0.537 to 0.793). Subgroup analyses according to principal demographic factors such as sex, age, disease stage, and histologic type showed no interaction between treatment and any characteristic.
On the basis of 5-year follow-up data, postoperative adjuvant therapy with S-1 was confirmed to improve overall survival and relapse-free survival in patients with stage II or III gastric cancer who had undergone D2 gastrectomy.
To assess the prognostic significance of immunological and nutritional-based indices, including the prognostic nutritional index (PNI), neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ...ratio in gastric cancer.
We retrospectively reviewed 632 gastric cancer patients who underwent gastrectomy between 1998 and 2008. Areas under the receiver operating characteristic curve were calculated to compare the predictive ability of the indices, together with estimating the sensitivity, specificity and agreement rate. Univariate and multivariate analyses were performed to identify risk factors for overall survival (OS). Propensity score analysis was performed to adjust variables to control for selection bias.
Each index could predict OS in gastric cancer patients in univariate analysis, but only PNI had independent prognostic significance in multivariate analysis before and after adjustment with propensity scoring (hazard ratio, 1.668; 95% confidence interval: 1.368-2.035). In subgroup analysis, a low PNI predicted a significantly shorter OS in patients with stage II-III disease (P = 0.019, P < 0.001), T3-T4 tumors (P < 0.001), or lymph node metastasis (P < 0.001). Canton score, a combination of PNI, NLR, and platelet, was a better indicator for OS than PNI, with the largest area under the curve for 12-, 36-, 60-mo OS and overall OS (P = 0.022, P = 0.030, P < 0.001, and P = 0.024, respectively). The maximum sensitivity, specificity, and agreement rate of Canton score for predicting prognosis were 84.6%, 34.9%, and 70.1%, respectively.
PNI is an independent prognostic factor for OS in gastric cancer. Canton score can be a novel preoperative prognostic index in gastric cancer.
Chemotherapy is the preferred treatment for advanced stage gastric cancer (GC) patients and chemotherapy resistance is the major obstacle to effective cancer therapy. Increasing evidence suggests ...that mesenchymal stem cells (MSCs) make important contributions to development of drug resistance. However, the underlying mechanism remains elusive. In this study, we discovered that abundant MSCs in tumor tissues predicted a poor prognosis in GC patients. MSCs promoted stemness and chemoresistance in GC cells through fatty acid oxidation (FAO) in vitro and in vivo. Mechanically, transforming growth factor β1 (TGF-β1) secretion by MSCs activated SMAD2/3 through TGF-β receptors and induced long non-coding RNA (lncRNA) MACC1-AS1 expression in GC cells, which promoted FAO-dependent stemness and chemoresistance through antagonizing miR-145-5p. Moreover, pharmacologic inhibition of FAO with etomoxir (ETX) attenuated MSC-induced FOLFOX regiment resistance in vivo. These results suggest that FAO plays an important role in MSC-mediated stemness and chemotherapy resistance in GC and FAO inhibitors in combination with chemotherapeutic drugs present as a promising strategy to overcome chemoresistance.
Laparoscopic distal gastrectomy is accepted as a more effective approach to conventional open distal gastrectomy for early-stage gastric cancer. However, efficacy for locally advanced gastric cancer ...remains uncertain.
To compare 3-year disease-free survival for patients with locally advanced gastric cancer after laparoscopic distal gastrectomy or open distal gastrectomy.
The study was a noninferiority, open-label, randomized clinical trial at 14 centers in China. A total of 1056 eligible patients with clinical stage T2, T3, or T4a gastric cancer without bulky nodes or distant metastases were enrolled from September 2012 to December 2014. Final follow-up was on December 31, 2017.
Participants were randomized in a 1:1 ratio after stratification by site, age, cancer stage, and histology to undergo either laparoscopic distal gastrectomy (n = 528) or open distal gastrectomy (n = 528) with D2 lymphadenectomy.
The primary end point was 3-year disease-free survival with a noninferiority margin of -10% to compare laparoscopic distal gastrectomy with open distal gastrectomy. Secondary end points of 3-year overall survival and recurrence patterns were tested for superiority.
Among 1056 patients, 1039 (98.4%; mean age, 56.2 years; 313 30.1% women) had surgery (laparoscopic distal gastrectomy n=519 vs open distal gastrectomy n=520), and 999 (94.6%) completed the study. Three-year disease-free survival rate was 76.5% in the laparoscopic distal gastrectomy group and 77.8% in the open distal gastrectomy group, absolute difference of -1.3% and a 1-sided 97.5% CI of -6.5% to ∞, not crossing the prespecified noninferiority margin. Three-year overall survival rate (laparoscopic distal gastrectomy vs open distal gastrectomy: 83.1% vs 85.2%; adjusted hazard ratio, 1.19; 95% CI, 0.87 to 1.64; P = .28) and cumulative incidence of recurrence over the 3-year period (laparoscopic distal gastrectomy vs open distal gastrectomy: 18.8% vs 16.5%; subhazard ratio, 1.15; 95% CI, 0.86 to 1.54; P = .35) did not significantly differ between laparoscopic distal gastrectomy and open distal gastrectomy groups.
Among patients with a preoperative clinical stage indicating locally advanced gastric cancer, laparoscopic distal gastrectomy, compared with open distal gastrectomy, did not result in inferior disease-free survival at 3 years.
ClinicalTrials.gov Identifier: NCT01609309.
Gastroesophageal adenocarcinoma (GEA) has a poor prognosis and few therapeutic options. Utilizing a 73-gene plasma-based next-generation sequencing (NGS) cell-free circulating tumor DNA (ctDNA-NGS) ...test, we sought to evaluate the role of ctDNA-NGS in guiding clinical decision-making in GEA.
We evaluated a large cohort (
= 2,140 tests; 1,630 patients) of ctDNA-NGS results (including 369 clinically annotated patients). Patients were assessed for genomic alteration (GA) distribution and correlation with clinicopathologic characteristics and outcomes.
Treatment history, tumor site, and disease burden dictated tumor-DNA shedding and consequent ctDNA-NGS maximum somatic variant allele frequency. Patients with locally advanced disease having detectable ctDNA postoperatively experienced inferior median disease-free survival (
= 0.03). The genomic landscape was similar but not identical to tissue-NGS, reflecting temporospatial molecular heterogeneity, with some targetable GAs identified at higher frequency via ctDNA-NGS compared with previous primary tumor-NGS cohorts. Patients with known microsatellite instability-high (MSI-High) tumors were robustly detected with ctDNA-NGS. Predictive biomarker assessment was optimized by incorporating tissue-NGS and ctDNA-NGS assessment in a complementary manner. HER2 inhibition demonstrated a profound survival benefit in
-amplified patients by ctDNA-NGS and/or tissue-NGS (median overall survival, 26.3 vs. 7.4 months;
= 0.002), as did EGFR inhibition in
-amplified patients (median overall survival, 21.1 vs. 14.4 months;
= 0.01).
ctDNA-NGS characterized GEA molecular heterogeneity and rendered important prognostic and predictive information, complementary to tissue-NGS.
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CircRNA has emerged as a new non-coding RNA that plays crucial roles in tumour initiation and development. 'MiRNA sponge' is the most reported role played by circRNAs in many tumours. The AKT/mTOR ...axis is a classic signalling pathway in cancers that sustains energy homeostasis through energy production activities, such as the Warburg effect, and blocks catabolic activities, such as autophagy. Additionally, the AKT/mTOR axis exerts a positive effect on EMT, which promotes tumour metastasis.
We detected higher circNRIP1 expression in gastric cancer by performing RNA-seq analysis. We verified the tumour promotor role of circNRIP1 in gastric cancer cells through a series of biological function assays. We then used a pull-down assay and dual-luciferase reporter assay to identify the downstream miR-149-5p of circNRIP1. Western blot analysis and immunofluorescence assays were performed to demonstrate that the circNRIP1-miR-149-5p-AKT1/mTOR axis is responsible for the altered metabolism in GC cells and promotes GC development. We then adopted a co-culture system to trace circNRIP1 transmission via exosomal communication and RIP experiments to determine that quaking regulates circNRIP1 expression. Finally, we confirmed the tumour suppressor role of microRNA-133a-3p in vivo in PDX mouse models.
We discovered that knockdown of circNRIP1 successfully blocked proliferation, migration, invasion and the expression level of AKT1 in GC cells. MiR-149-5p inhibition phenocopied the overexpression of circNRIP1 in GC cells, and overexpression of miR-149-5p blocked the malignant behaviours of circNRIP1. Moreover, it was proven that circNRIP1 can be transmitted by exosomal communication between GC cells, and exosomal circNRIP1 promoted tumour metastasis in vivo. We also demonstrated that quaking can promote circNRIP1 transcription. In the final step, the tumour promotor role of circNRIP1 was verified in PDX models.
We proved that circNRIP1 sponges miR-149-5p to affect the expression level of AKT1 and eventually acts as a tumour promotor in GC.
Recent data supports a significant role for immune checkpoint inhibitors in the treatment of solid tumours. Here, we evaluate gastric and gastro-oesophageal junction (G/GEJ) adenocarcinomas for their ...expression of programmed death-ligand 1 (PD-L1), infiltration by CD8+ T cells and the relationship of both factors to patient survival.
Thirty-four resections of primary invasive G/GEJ were stained by immunohistochemistry for PD-L1 and CD8 and by DNA in situ hybridisation for Epstein-Barr virus (EBV). CD8+ T cell densities both within tumours and at the tumour-stromal interface were analysed using whole slide digital imaging. Patient survival was evaluated according to PD-L1 status and CD8 density.
12% of resections showed tumour cell membranous PD-L1 expression and 44% showed expression within the immune stroma. Two cases (6%) were EBV positive, with one showing membranous PD-L1 positivity. Increasing CD8+ densities both within tumours and immune stroma was associated with increasing percentage of tumour (p=0.027) and stromal (p=0.005) PD-L1 expression. Both tumour and immune stromal PD-L1 expression and high intratumoral or stromal CD8+ T cell density (>500/mm
) were associated with worse progression-free survival (PFS) and overall survival (OS).
PD-L1 is expressed on both tumour cells and in the immune stroma across all stages and histologies of G/GEJ. Surprisingly, we demonstrate that increasing CD8 infiltration is correlated with impaired PFS and OS. Patients with higher CD8+ T cell densities also have higher PD-L1 expression, indicating an adaptive immune resistance mechanism may be occurring. Further characterisation of the G/GEJ immune microenvironment may highlight targets for immune-based therapy.
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