Current challenges in gastric cancer surgery: European perspective

A Path to High-Value Gastric Cancer Surgery Care Delivery

Objective

To evaluate the feasibility, safety, and effectiveness of a comprehensive regional program, including the Minimally Invasive Recovery and Empowerment Care (MIREC) pathway, that can significantly reduce hospital stays after laparoscopic gastrectomy without increasing adverse events.

Background

Cost-effectiveness and improving patient outcomes are crucial in providing quality gastric cancer care worldwide.

Methods

To compare the outcomes of gastric cancer surgery using 2 different models of care within an integrated healthcare system from February 2012 to March 2023. The primary endpoint was the length of hospital stay. The secondary endpoints were the need for intensive care unit care, emergency room (ER) visits, readmission, reoperation, and death within 30 days after surgery.

Results

There were 553 patients, 167 in the pre-(February 2012-April 2016) and 386 in the post-MIREC period (May 2016-March 2023). Perioperative chemotherapy utilization increased from 31.7% to 76.4% (P < 0.0001). Laparoscopic gastrectomy increased from 17.4% to 97.7% (P < 0.0001). Length of hospitalization decreased from 7 to 2 days (P < 0.0001), with 32.1% and 88% of patients discharged home on postoperative day 1 and postoperative day 2, respectively. When comparing pre- and post-MIREC, intensive care unit utilization (10.8% vs. 2.9%, P < 0.0001), ER visits (34.7% vs. 19.7%, P = 0.0002), and readmission (18.6% vs. 11.1%, P = 0.019) at 30 days were also considerably lower. In addition, more patients received postoperative adjuvant chemotherapy (31.4% to 63.5%, P < 0.0001), and the time between gastrectomy and starting adjuvant chemotherapy was also less (49-41 days; P = 0.002).

Conclusion

This comprehensive regional program, which encompasses regionalization care, laparoscopic approach, modern oncologic care, surgical subspecialization, and the MIREC pathway, can potentially improve gastric cancer surgery outcomes. These benefits include reduced hospital stays and lower complication rates. As such, this program can revolutionize how gastric cancer surgery is delivered, leading to a higher quality of care and increased value to patients.

Quality performance indicator compliance for the treatment of gastric adenocarcinoma

BACKGROUND

Quality performance indicators (QPI) are objective measurements of aspects of patient care that affect clinical outcome. This study investigates the compliance rate to published QPIs of gastric adenocarcinoma (GA) management, in a single institution, to determine areas of strong performance and those requiring improvement.

METHODS

All patients with GA treated from 2010 to 2015, and 2020 to 2021 were included. Electronic data in the form of clinic letters, operation notes, and histology and radiology reports were reviewed with ethics approval. QPI adherence was collected in binary form.

RESULTS

QPIs with high compliance rate include preoperative radiological staging and histological diagnosis, subspecialty surgeon training and pathology report documentation. QPIs with low compliance include perioperative chemotherapy (31.6%), postoperative radiological surveillance (32.5%) and minimally invasive approaches to surgical resection (12.5%).

CONCLUSIONS

QPIs from the systematic review are variably implemented in clinical practice, thus informing on their relevance to real world clinical practice whilst also identifying the areas requiring focus for improvement.

Machine learning applications in upper gastrointestinal cancer surgery: a systematic review

BACKGROUND

Machine learning (ML) has seen an increase in application, and is an important element of a digital evolution. The role of ML within upper gastrointestinal surgery for malignancies has not been evaluated properly in the literature. Therefore, this systematic review aims to provide a comprehensive overview of ML applications within upper gastrointestinal surgery for malignancies.

METHODS

A systematic search was performed in PubMed, EMBASE, Cochrane, and Web of Science. Studies were only included when they described machine learning in upper gastrointestinal surgery for malignancies. The Cochrane risk-of-bias tool was used to determine the methodological quality of studies. The accuracy and area under the curve were evaluated, representing the predictive performances of ML models.

RESULTS

From a total of 1821 articles, 27 studies met the inclusion criteria. Most studies received a moderate risk-of-bias score. The majority of these studies focused on neural networks (n = 9), multiple machine learning (n = 8), and random forests (n = 3). Remaining studies involved radiomics (n = 3), support vector machines (n = 3), and decision trees (n = 1). Purposes of ML included predominantly prediction of metastasis, detection of risk factors, prediction of survival, and prediction of postoperative complications. Other purposes were predictions of TNM staging, chemotherapy response, tumor resectability, and optimal therapy.

CONCLUSIONS

Machine Learning algorithms seem to contribute to the prediction of postoperative complications and the course of disease after upper gastrointestinal surgery for malignancies. However, due to the retrospective character of ML studies, these results require trials or prospective studies to validate this application of ML.

Hypoxia-induced HIF-1α/lncRNA-PMAN inhibits ferroptosis by promoting the cytoplasmic translocation of ELAVL1 in peritoneal dissemination from gastric cancer

Peritoneal metastasis (PM) is the main site of gastric cancer (GC) distant metastasis and indicates an extremely poor prognosis and survival. Hypoxia is a common feature of peritoneal metastases and up-regulation of hypoxia inducible factor 1 alpha (HIF-1α) may be a potential driver in the occurrence of PM. Ferroptosis is a recently discovered form of regulated cell death and closely related to the occurrence and development of tumors. However, the underlying mechanism link HIF-1α to ferroptosis in PM of GC remains unknown. Here, lncRNA-microarrays and RNA library construction/lncRNA-seq results shown that lncRNA-PMAN was highly expressed in PM and significantly modulated by HIF-1α. Upregulation of PMAN is associated with poor prognosis and PM in patients with GC. PMAN was up-regulated by HIF-1α and improved the stability of SLC7A11 mRNA by promoting the cytoplasmic distribution of ELAVL1, which was identified in RNA-pulldown/mass spectrometry results. Accumulation of SLC7A11 increases the level of l-Glutathione (GSH) and inhibits the accumulation of reactive oxygen species (ROS) and irons in the GC cells. Finally protect GC cells against ferroptosis induced by Erastin and RSL3. Our findings have elucidated the effect of HIF-1α/PMAN/ELAVL1 in GC cells ferroptosis and provides theoretical support for the potential diagnostic biomarkers and therapeutic targets for PM in GC.

•

HIF-1⍺ mediates abnormally high expression of PMAN in PM from GC under hypoxia.

•

GC cells suppress ferroptosis by relieving ROS and irons accumulation through HIF-1⍺/PMAN under hypoxia.

•

Inhibition of ferroptosis may contributes to the development of PM from GC.

•

Increased cytoplasmic translocation of ELAVL1 is a key intermediate factor in PMAN inhibition of ferroptosis.

NOL6 Regulates the Proliferation and Apoptosis of Gastric Cancer Cells via Regulating TP53I3, CDK4 and MCM7 Expression

Background

Gastric cancer (GC) is a prevalent cancer with high mortality and strong invasiveness, and the entire regulatory networks of GC is still unclear.

Objective

The aim of this study was to explore the specific mechanism of the effect of nucleolar protein 6 (NOL6) on the proliferation and apoptosis of GC cells.

Methods

The human gastric adenocarcinoma cell line HGC-27 and AGS were cultured. qRT-PCR was used to verify the expression level of NOL6 in GC cells; MTT and EdU were used to test cell proliferation; TUNEL staining and Flow cytometry were used to detect cell apoptosis; The downstream genes and pathways following NOL6 knockdown were explored through the microarray assay and ingenuity pathway analysis, and the downstream genes were finally verified by qRT-PCR and Western blotting. The xenograft mice were used to investigate the effect of NOL6 on GC in vivo.

Results

TCGA data analysis showed that NOL6 expression level was higher in GC cells than adjacent normal cells. Over-expression of NOL6 increased proliferation and colony formation, and inhibited the apoptotic rate in AGS and HGC-27 cells, while NOL6 knockdown induced the opposite effects. Through microarray assay and IPA analysis, NOL6-related downstream genes and critical signaling pathways were found. And we verified the relationship between downstream genes and GC. Additionally, NOL6 knockdown could decrease the weight and volume of tumor in the mice.

Conclusion

NOL6 knockdown could inhibit cell proliferation and induce cell apoptosis of GC, suggesting that NOL6 may serve as a potential therapeutic target for treating GC.

S100A4 Is a Strong Negative Prognostic Marker and Potential Therapeutic Target in Adenocarcinoma of the Stomach and Esophagus

Deregulated Wnt-signaling is a key mechanism driving metastasis in adenocarcinoma of the gastroesophageal junction and stomach (AGE/S). The oncogene S100A4 was identified as a Wnt-signaling target gene and is known to promote metastasis. In this project, we illuminate the role of S100A4 for metastases development and disease prognosis of AGE/S. Five gastric cancer cell lines were assessed for S100A4 expression. Two cell lines with endogenous high S100A4 expression were used for functional phenotyping including analysis of proliferation and migration after stable S100A4 knock-down. The prognostic value of S100A4 was evaluated by analyzing the S100A4 expression of tissue microarrays with samples of 277 patients with AGE/S. S100A4 knock-down induced lower migration in FLO1 and NCI-N87 cells. Treatment with niclosamide in these cells led to partial inhibition of S100A4 and to reduced migration. Patients with high S100A4 expression showed lower 5-year overall and disease-specific survival. In addition, a larger share of patients in the S100A4 high expressing group suffered from metachronous metastasis. This study identifies S100A4 as a negative prognostic marker for patients with AGE/S. The strong correlation between S100A4 expression, metastases development and patient survival might open opportunities to use S100A4 to improve the prognosis of these patients and as a therapeutic target for intervention in this tumor entity.

circ_AKT3 knockdown suppresses cisplatin resistance in gastric cancer

Background

Circular RNAs (circRNAs) are associated with cisplatin resistance in gastric cancer (GC). This study aims to explore the role of circRNA AKT serine/threonine kinase 3 (circ_AKT3) in the resistance of GC to cisplatin.

Methods

42 sensitive and 23 resistant GC patients were recruited for tissue collection. The cisplatin-resistant GC cells MKN-7/DDP and HGC-27/DDP were used for in vitro study. circ_AKT3, microRNA-206 (miR-206) and protein tyrosine phosphatase non-receptor type 14 (PTPN14) levels were detected via quantitative reverse transcription real-time PCR (qPCR) and Western blot. Cisplatin resistance was assessed by detecting P-glycoprotein (P-gp) level, half maximal inhibitory concentration (IC₅₀) of cisplatin and cell apoptosis. The target relationship between miR-206 and circ_AKT3 or PTPN14 was analyzed via dual-luciferase reporter and RNA pull-down assays. The role of circ_AKT3 in vivo was assessed using xenograft model.

Results

circ_AKT3 level was increased, but miR-206 was declined in cisplatin-resistant GC tissues and cells. circ_AKT3 knockdown or miR-206 overexpression decreased the level of P-gp and IC₅₀ of cisplatin and increased apoptosis of MKN-7/DDP and HGC-27/DDP cells. Additionally, circ_AKT3 targeted miR-206, and regulated cisplatin resistance by interacting with miR-206. PTPN14 was regulated by circ_AKT3 through miR-206 as a bridge. Also, circ_AKT3 knockdown decreased xenograft tumor growth.

Conclusion

circ_AKT3 knockdown suppressed cisplatin resistance using miR-206/PTPN14 axis in cisplatin-resistant GC cells.

Palliative Gastrectomy vs. Gastrojejunostomy for Advanced Gastric Cancer: A Systematic Review and Meta-Analysis

Background: Advanced gastric cancer is the fifth leading cause of cancer-related deaths. Patients with metastatic advanced gastric cancer commonly develop a gastric outlet obstruction that considerably worsens their quality of life. Surgical interventions such as gastrojejunostomy and palliative gastrectomy are commonly administered to alleviate this obstruction. However, whether one intervention is better than another at improving morbidity- and mortality-related outcomes is unclear. Thus, in this meta-analysis, we compare outcomes of palliative gastrectomy and gastrojejunostomy (overall hospital stay length, time to oral intake, survival, and complication rates) in patients with metastatic advanced gastric cancer to identify the best procedure.

Objective: To compare morbidity and mortality outcomes of palliative gastrectomy and gastrojejunostomy in patients with metastatic advanced gastric cancer.

Methods: We followed the PRISMA guidelines to systematically search Web of Science, EMBASE, CENTRAL, Scopus, and MEDLINE for relevant studies. We conducted a random-effects meta-analysis to find differential outcomes between palliative gastrectomy and gastrojejunostomy among variables such as time to oral intake, overall hospital stay length, complication rates, and survival in patients with metastatic advanced gastric cancer.

Results: From 963 studies, we found 7 eligible studies with 642 patients (70.3 ± 4.7 years) who had undergone palliative gastrectomy or gastrojejunostomy. Our meta-analysis revealed an insignificant (p > 0.05) differences in terms of overall survival duration (Hedge's g, 1.22), complication risks (odds ratio, 1.35), and time to oral intake (g, 0.62) and hospital stay length (g, 0.12) between patients undergoing gastrojejunostomy and palliative gastrectomy.

Conclusion: In this present study we observed no statistically significant differences in terms of morbidity and mortality outcomes after palliative gastrectomy and gastrojejunostomy in patients with metastatic advanced gastric cancer. Therefore, no conclusions can be drawn for the variables evaluated. This study provides a preliminary overview of the risks associated with gastrojejunostomy and palliative gastrectomy to help gastroenterologists manage patients with metastatic advanced-stage gastric cancer.

The effect of splicing MST1R in gastric cancer was enhanced by lncRNA FENDRR

Gastric cancer (GC) poses a serious threat to human health worldwide. Serine/arginine rich splicing factor 1 (SRSF1) has been reported to serve regulatory roles during the tumorigenesis of GC. In addition, the macrophage stimulating 1 receptor (MST1R) signaling pathway was found to participate in the progression of GC. However, the association between MST1R and SRSF1 in the tumorigenesis of GC remains unclear. The expression levels of MST1R and the recepteur d'origine nantais (RON) Δ160 splicing variant were analyzed in cells using western blotting and immunofluorescence staining. Co-immunoprecipitation assays were used to investigate the interaction between SRSF1 and MST1R. A Cell Counting Kit-8 assay was performed to analyze cell viability. Flow cytometry and Transwell assays were used to determine cell apoptosis and invasiveness levels. The potential interaction between SFSR1 and long non-coding RNAs (lncRNAs) was investigated with an online bioinformatics tool. The findings of the present study revealed that the expression levels of MST1R and RON Δ160 were significantly upregulated in GC Kato III cells. SRSF1 was found to be regulated by the lncRNA FOXF1 adjacent non-coding developmental regulatory RNA (FENDRR). The knockdown of SRSF1 or FENDRR downregulated the expression levels of MST1R in Kato III cells. In addition, the expression levels of RON Δ160 were markedly downregulated in Kato III cells following the knockdown of FENDRR. Meanwhile, SRSF1 directly bound to MST1R, while this phenomenon was partially reversed by FENDRR short interfering RNA. FENDRR could interact with SRSF1 in Kato III cells and the knockdown of FENDRR also induced the apoptosis of GC cells. In conclusion, the findings of the present study suggested that the lncRNA FENDRR may function as an oncogene during the progression of GC by regulating alternative splicing of MST1R and SRSF1 expression levels. lncRNA FENDRR may serve as a potential marker for the diagnosis or target for the treatment of GC.

Evaluation of Important Molecular Pathways and Candidate Diagnostic Biomarkers of Noninvasive to Invasive Stages in Gastric Cancer by In Silico Analysis

Gastric cancer affects millions of people each year; it is the fifth deadliest cancer globally. Due to failure to perform routine tests such as endoscopy, it is usually diagnosed in the invasive stages. Therefore, finding diagnostic biomarkers in blood can help to speed up the initial diagnosis of cancer. This study aimed to find appropriate diagnostic biomarkers in the extracellular matrix of noninvasive to invasive stages of gastric cancer patients, using bioinformatics analysis. First, we selected the appropriate datasets from the GEO database. We evaluated the genes' signaling pathways, biological processes, and molecular functions. More accurately, we assessed the genes, in which their protein products are released into the extracellular matrix; we evaluated their protein network. Then, we validated the candidate proteins in the GEPIA and TCGA databases. The extracellular matrix, tyrosine kinase receptors, and immune response pathways are effective factors, which are related to the highly expressed genes and metabolism; cell cycle pathways are also impressive on low-expression genes. 69 highly expressed proteins are released into the extracellular matrix. After drawing the protein network, 5 proteins were selected as more suitable candidates for further studies. These proteins' expression significantly increases in the human samples, and the survival chart showed up to about 80% mortality in the individuals over time. With integrated bioinformatics analysis, BGN, LOX, MMP-9, SERPINE1, and TGFB1 proteins have been selected as suitable diagnostic biomarkers for noninvasive to invasive stages of gastric cancer. Further studies are needed to evaluate more precise mechanisms between these proteins.

Retrospective Evaluation of Factors Affecting Lymph Node Retrieval Following Gastrectomies with Oncologic Intent

BACKGROUND

Adequate lymphadenectomy is an important factor affecting survival in gastric cancer patients. Retrieval and examination of at least 15 lymph nodes is recommended in order to properly stage gastric malignancies. The objectives of this study were to evaluate the proportion of patients undergoing inadequate lymphadenectomies and possible risk factors for inadequate surgery.

METHODS

This was a retrospective study that included patients, 18 years and older, who underwent gastrectomies with oncologic intent in the Hillel Yaffe Medical Center. We analyzed the association of demographic, clinical, and pathological variables with adequate number of lymph nodes.

RESULTS

The retrieval of less than 15 lymph nodes was reported in 51% (53/104) patients undergoing gastrectomies with oncologic intent. The extent of surgery was the only variable associated with inadequate lymphadenectomy on univariate analysis: subtotal/proximal versus total gastrectomy (P=0.047). Differences observed for previous surgery (P=0.193), T stage (P=0.053), N stage (P=0.051), and lymphovascular invasion (P=0.14) did not reach significance. Subtotal/proximal gastrectomy resulted in inadequate resection of lymph nodes in 56% of the patients, while this occurred in only 30% of the patients undergoing total gastrectomy (relative risk 1.865; 95% CI 0.93, 3.741). Logistic regression confirmed that only subtotal/proximal versus total gastrectomy was associated with inadequate number of lymph nodes resected (P=0.043).

DISCUSSION AND CONCLUSION

In this study we analyzed the association of patient, tumor, and surgery-related factors on adequate lymphadenectomy in patients undergoing gastrectomies for possible gastric cancer. Larger extent of the surgery (total, rather than subtotal/proximal gastrectomy) was revealed to be the only indicator positively associated with adequate lymphadenectomy.

Accumulation of Nicotinamide N-Methyltransferase (NNMT) in Cancer-associated Fibroblasts: A Potential Prognostic and Predictive Biomarker for Gastric Carcinoma

Nicotinamide N-methyltransferase (NNMT), a major metabolic regulator, has been identified as a predictor of cancer prognosis in ovarian and colorectal cancers. The study aims to evaluate the significance of stromal NNMT in gastric cancer (GC). Expression of stromal NNMT in 612 GC and 92 non-malignant tissues specimens was investigated by immunohistochemistry (IHC). The association between NNMT expression and occurrence of cancer or patient outcome was further analyzed, and the factors contributing to disease prognosis were evaluated by multiple Cox models. Stromal NNMT expression was higher in the malignant tissue (p<0.001). NNMT expression was significantly associated with GC stage (p=0.006). Compared to stromal "NNMT-low" cases, "NNMT-high" cases has lower disease-specific survival (hazard ratio [HR], 2.356; 95% confidence interval [CI] = 1.591-3.488; p<0.001) and disease-free survival (HR = 2.265; 95% CI = 1.529-3.354; p<0.001), as observed by multivariate Cox analysis after adjusting for stromal NNMT expression with other factors such as tumor grade and size. Notably, patients with stage II NNMT-low GC might be negatively affected by adjuvant chemotherapy, but lower stromal NNMT expression predicted a more favorable prognosis for GC. Our study confirmed that stromal NNMT expression is significantly increased in GC, which predicts an unfavorable post-operative prognosis for GC.

Transforming growth factor-β1 induces connective tissue growth factor expression and promotes peritoneal metastasis of gastric cancer

Transforming growth factor-β1 (TGF-β1) is involved in human cancer development and progression. Nonetheless, the role of TGF-β1 as regards peritoneal metastasis of gastric cancer has not been completely characterized. In the present study, we investigated the exact role of TGF-β1 on peritoneal metastasis of gastric cancer. The results indicated that human peritoneal mesothelial cells (HPMCs) exposed to TGF-β1 or serum-free conditional medium (SF-CM) of SGC7901 that produced a large amount of TGF-β1 became exfoliated, apoptosis and exhibited signs of injury, and the tumor-mesothelial cell adhesion significantly increased. Connective tissue growth factor (CTGF) expression was also increased when HPMCs were exposed to TGF-β1 or SF-CM of SGC7901. However, these effects were significantly decreased when HPMCs were exposed to SF-CM of SGC7901-TGFβS, a TGF-β1 knockdown stable cell line. Animal studies revealed that nude mice injected with SGC7901-TGFβS cells featured a smaller number of peritoneal seeding nodules and lower expression of CTGF in ascites than the control cell lines. These findings suggest that TGF-β1 promotes peritoneal metastasis of gastric cancer and induces CTGF expression. Therefore, blockage of TGF-β1 or TGF-β1 signaling pathway might prevent and treat peritoneal metastasis of gastric cancer.

Gender Differences in Gastric Cancer Survival: 99,922 Cases Based on the SEER Database

OBJECTIVES

To evaluate gender differences in initial presentation, pathology and outcomes with GC (GC).

METHODS

The 1973-2013 Surveillance Epidemiology and End Results (SEER) 17-registry database was analysed for renal tumours from 1973 to 2013 coded as primary site "stomach". After various exclusions, a final study group of 99,922 cases with complete data was obtained. Demographic variables analysed included age, sex, marital status and race. Tumour variables included size, stage at diagnosis, grade, primary site, treatment and histology. Primary outcome variables included overall survival (OS) and cancer-specific survival (CSS).

RESULTS

Overall, 96,501 gastric cancer patients were identified. Of those, 34,862 (36.2%) were women. For woman, log-rank test showed that OS and CSS were significantly longer in man (p < 0.0001). In Cox regression analysis, woman was associated with a significantly improved OS [(HR of death in 1973 to 2003 = 0.87, 95% CI = 0.85-0.89, P < 0.001) (HR of death in 2004 to 2013 = 0.94, 95% CI = 0.91-0.97, P < 0.001)] and cancer-specific survival [(HR of death in 1973 to 2003 = 0.90, 95% CI = 0.87-0.92, P < 0.001) (HR of death in 2004 to 2013 = 0.90, 95% CI = 0.87-0.93, P < 0.001)]. When performing a Kaplan-Meier curve analysis after propensity score matching, gender persisted to be a significant survival of woman for OS and CSS.

CONCLUSIONS

Men present with larger, higher stage, higher grade GC than women. OS and CSS are better in women, which is significantly different.

Treatment of Gastric Cancer Patients During COVID-19 Pandemic: The West is More Vulnerable

The outbreak of the COVID-19 is currently the biggest international concern. Treatment of gastric cancer (GC) patients in the pandemic era with high hospital burden and under severe oncological/surgical resource constraints should implicate a need for resource re-allocation with a new "pandemic" GC treatment algorithm. The neoadjuvant/perioperative (radio-)chemotherapy is applied in the majority of advanced GC cases with poor postoperative therapy compliance. In the East, radical surgery is frequently used in the first instance, with adjuvant chemotherapy reserved for patients with a high risk of recurrence. Moreover, the elderly population might be effectively treated by surgery alone, thus saving oncological resources for younger people who need a more aggressive approach. In this framework, prioritization is a key concept based on the severity of symptoms and the need for urgent (surgical) intervention. High-risk and marginally effective surgery should be replaced with definitive radio- and/or chemotherapy. The pandemic framework to provide optimal care for GC patients must be based on multidisciplinary decision-making and include all anti-cancer treatment options: surgery, systemic therapy, and radiotherapy. The priority and staffing dictate adherence to the new algorithm. We believe that these priorities may improve the delivery of care to all, including elderly GC patients.

A cohort study and meta-analysis of the evidence for consideration of Lauren subtype when prescribing adjuvant or palliative chemotherapy for gastric cancer

Background

The association between the survival or efficacy of chemotherapy and the Lauren subtype of gastric cancer (GC) remains unclear. We aimed to clarify whether patients with different Lauren subtypes have different survival after treatment with systemic chemotherapy: intestinal gastric cancer (IGC) patients survived better than patients with mixed type gastric cancer (MGC) or diffuse gastric cancer (DGC) after treatment with systemic chemotherapy.

Patients & methods

Relevant studies for the meta-analysis were identified through searching Pubmed, Embase, Cochrane and Ovid up to March 2020. We also included our own prospectively collected cohort of patients that were followed over a 10-year period. Sub-group and sensitivity analyses were also performed.

Results

In our prospective cohort, the overall survival (OS) of IGC patients receiving systemic chemotherapy (chemoIGC) [median OS 5.01 years, interquartile range (IQR) 2.63-6.71] was significantly higher than that of DGC patients receiving the same chemotherapy (chemoDGC) (median OS 1.33 years, IQR 0.78-3.33, p = 0.0001). After adjusting for age, gender and cancer stage, there was a significant difference in OS in patients treated with chemotherapy based on the Lauren classification of GC {hazard ratio (HR) for OS of the IGC versus DGC 0.33, [95% confidence interval (CI), 0.17-0.65; p < 0.001]}. In the IGC patients, the adjusted HR associated with chemotherapy was 0.26 (95% CI, 0.12-0.56; p = 0.001), whereas the association was 0.64 (95% CI, 0.30-1.33; p = 0.23) in the DGC patient group.In our meta-analysis, 33 studies comprising 10,246 patients treated with systemic chemotherapy (chemoIGC n = 4888, chemoDGC n = 5358) met all the selection criteria. While we accounted for much of the heterogeneity in these studies, we found that chemoIGC patients showed significantly improved OS [HR, 0.76 (95% CI, 0.71-0.82); p < 0.00001] when compared with similarly treated chemoDGC patients.

Conclusion

Our results support the consideration of Lauren subtype when prescribing systemic chemotherapy for GC, particularly for MGC or DGC, which may not benefit from chemotherapy. Lauren classification should be considered to stratify chemotherapy regimens to GC patients in future clinical trials, with particular relevance to MGC or DGC, which is more difficult to treat with current regimens.

The importance of Epstein-Barr virus infection in the systemic treatment of patients with gastric cancer

The Epstein-Barr virus (EBV) may directly cause the development of EBV-associated gastric cancer (EBVaGC). The prevalence of EBVaGC ranges from 4% to 18%, with a 2-fold higher frequency in males, and in tumors arising in the gastric cardia or corpus and 4 times higher frequency in gastric stump carcinoma. The vast majority of EBVaGC are lymphoepithelioma-like carcinomas. Despite extensive nodal involvement and distant metastases at initial diagnosis, EBVaGC seems to be a distinct etiologic entity with a favorable prognosis. However, the lymphoepithelioma-like carcinomas subtype in EBVaGC cannot be recognized in the current molecular classifications. Neither is there an association between EBV positivity and survival of patients after curative gastrectomy if they received standard adjuvant chemotherapy, nor EBV positivity and prediction of response to neoadjuvant platinum/5-FU-based chemotherapy. Alterations in chemokines and PD-L1 provide theoretical justification for clinical evaluation of immune checkpoint therapy in EBVaGC. Moreover, a higher degree of host immune response was demonstrated in EBVaGC. The current histologic and molecular GC classification does not influence clinical practice. Further research is expected to find convenient methods to assess gastric subtypes in day-to-day practice and to tailor therapy to improve overall survival.

Curcumin micelles suppress gastric tumor cell growth by upregulating ROS generation, disrupting redox equilibrium and affecting mitochondrial bioenergetics

A proposed novel mechanism of anticancer activity of curcumin micelles through redox equilibrium in gastric cancer.

Triptonide effectively suppresses gastric tumor growth and metastasis through inhibition of the oncogenic Notch1 and NF-κB signaling pathways

Gastric cancer ranks as the third leading cause of cancer-related death worldwide. The uncontrolled tumor growth and robust metastasis are key factors to cause the cancer patient death. Mechanistically, aberrant activation of Notch and NF-κB signaling pathways plays pivotal roles in the initiation and metastasis of gastric cancer. Despite great efforts have been made in recent decades, the effective drug against the advanced and metastatic gastric cancer is still lacking in the clinical setting. In this study, we found that triptonide, a small molecule (MW358) purified from the traditional Chinese medicinal herb Tripterygium wilfordii Hook F, effectively suppressed tumor growth and metastasis in xenograft mice without obvious toxicity at the doses we tested, resulting in potent anti-gastric cancer effect with low toxicity. Triptonide markedly inhibited human metastatic gastric cancer cell migration, invasion, proliferation, and tumorigenicity. Molecular mechanistic studies revealed that triptonide significantly reduced Notch1 protein levels in metastatic gastric cancer cells through degrading the oncogenic protein Notch1 via the ubiquitin-proteasome pathway. Consequently, the levels of Notch1 downstream proteins RBPJ, IKKα, IKKβ were significantly diminished, and nuclear factor-kappa B (NF-κB) phosphorylation was significantly reduced. Together, triptonide effectively suppresses gastric cancer growth and metastasis via inhibition of the oncogenic Notch1 and NF-κB signaling pathways. Our findings provide a new strategy and drug candidate for treatment of the advanced and metastatic gastric cancer.

Relationship between the expressions of PD-L1 and tumour-associated fibroblasts in gastric cancer

Previous studies have focused on the changes of tumour cells in immune escape, and less is known about the effect of tumour microenvironment (TME) on immune escape. Tumour-associated fibroblasts (TAF) is an important part of the TME and has special physiological and biochemical characteristics, but the specific mechanism has not been clarified. In order to investigate the effect of TAF on the expression of PD-L1 in gastric cancer cells, gastric cancer cell lines MNK45, SGC7901 were non-contact co-culturing with TAF 1, 3 and 7 d via transwell. PD-L1 mRNA and protein expression were detected using qRT-PCR and FCM. Then, 95 cases of gastric cancer tissues were selected and evaluated PD-L1 and TAF expressions by immunohistochemical examination. The results showed that the mRNA and protein expression of PD-L1 in the experiment group were significantly higher than that in the control group. PD-L1 expression was associated with massive lymphocyte infiltration, diffuse/mixed histology and intratumoral TAFs in gastric cancers. In conclusion, TAFs promoted the growth in gastric cancer cell lines by increased the PD-L1 expression.

The Probe Based Confocal Laser Endomicroscopy (pCLE) in Locally Advanced Gastric Cancer: A Powerful Technique for Real-Time Analysis of Vasculature

Probe based confocal laser endomicroscopy (pCLE) is an advanced technique which provides imaging of gastrointestinal mucosa at subcellular resolution and, importantly, a valid tool for the evaluation of microvasculature during endoscopic examination. In order to assess intratumoral vascularization and the efficiency of blood flow in locally advanced gastric cancer, we examined 57 patients through pCLE imaging. The vascular alterations in gastric cancer were mainly characterized by leakage and by the presence of tortuous and large size vessels. Defects in blood flow were detected very rarely. No association between the angiogenic score and the gastric tumor site or histological type was observed. Interestingly, no correlation was also found with the tumor grading indicating that the vascular angiogenic anomalies in gastric cancer represent an early pathological event to be observed and detected. The majority of patients displayed unchanged vascular alterations following neoadjuvant chemotherapy and this positively correlated with stable or progressive disease, suggesting that an unaltered angiogenic score could per se be indicative of poor therapeutic efficacy. Different vascular parameters were evaluated by immunofluorescence using bioptic samples and the vessel density did not correlate with clinical staging, site or histologic type. Interestingly, only CD105, Multimerin-2 and GLUT1 were able to discriminate normal from tumoral gastric mucosa. Taken together, these findings indicate that functional and structural angiogenic parameters characteristic of tumor blood network were fully detectable by pCLE. Moreover, the evaluation of tumor vasculature by real-time assessment may provide useful information to achieve tailored therapeutic interventions for gastric cancer patients.

MIR100HG: a credible prognostic biomarker and an oncogenic lncRNA in gastric cancer

The MIR100HG expression was observed to be up-regulated or down-regulated in human cancer tissues depending on tumor types. However, there was no report about the role of MIR100HG in gastric cancer. In our study, we first found levels of MIR100HG expression were increased in gastric cancer cell lines and tissue samples compared with normal gastric epithelial cell line and adjacent normal gastric mucosa tissue samples, respectively. Moreover, high MIR100HG expression was positively associated with clinical stage, tumor invasion, lymph node metastasis, and distant metastasis in gastric cancer patients. Survival analysis showed MIR100HG expression was negative correlated with clinical outcome in gastric cancer patients from The Cancer Genome Atlas (TCGA) database or our study, and high MIR100HG expression served as an independent poor prognostic factor for gastric cancer patient's overall survival. The study in vitro suggested down-regulation of MIR100HG expression inhibits cell proliferation, migration, and invasion in gastric cancer. In conclusion, MIR100HG is a credible prognostic biomarker and functions as an oncogenic lncRNA in gastric cancer.