Gastric Cancer Peritoneal Carcinomatosis Risk Score

Biomarker-Based Models Utilizing the Albumin-Fibrinogen Ratio Effectively Predict Peritoneal Metastasis in Patients with Gastric Cancer: A Retrospective Study

OBJECTIVE

Peritoneal carcinomatosis (PC) is a common pattern of recurrence in gastric cancer patients and is associated with a poor prognosis. This study aimed to evaluate the predictive value of the albumin-fibrinogen ratio (AFR) for PC in patients with gastric cancer and to develop two preoperative prediction models.

METHODS

A total of 745 gastric cancer patients were included in this study. Preoperative AFR, along with other serum markers and clinical tumor characteristics, was assessed. Univariate and multivariate logistic regression analyses were performed to determine the odds ratios (ORs) and 95% confidence intervals (CIs) of the independent variables. Propensity score matching (PSM) was used to control for potential confounders, and one-way ANOVA was conducted to evaluate differences in distribution between groups. Two prediction models incorporating the independent predictive indicators were constructed and validated via receiver operating characteristic (ROC) curves.

RESULTS

Poorly differentiated type (OR 2.679; P = 0.001), nondiffuse morphological type (OR 2.123; P = 0.040), BMI < 23.550 kg/m2 (OR 4.635; P = 0.001), AFR < 11.275 (OR 2.895; P = 0.003) and CA199 ≥ 73.615 U/mL (OR 2.040; P = 0.037) were identified as independent risk factors for PC in patients with gastric cancer. After PSM, the AFR remained the only inflammatory marker that was independently associated with PC (P = 0.003). AFR demonstrated consistent robustness in predicting PC across multiple sample sets. Among all the independent risk factors, the AFR had the highest area under the curve (AUC) for ROC analysis (AUC 0.648; 95% CI 0.580-0.715). Two combination models incorporating the AFR demonstrated enhanced predictive ability: Combination Model 1 (AUC 0.759; 95% CI 0.699-0.820) and Combination Model 2 (AUC 0.801; 95% CI 0.744-0.859).

CONCLUSIONS

The preoperative AFR serves as a useful indicator for predicting PC. Two reliable prediction models based on the AFR have been developed.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for gastric cancer with peritoneal metastases at an Australian centre

INTRODUCTION

Gastric cancer is a major cause of cancer mortality, with poorer prognosis in the presence of peritoneal metastases as low as 2.8-9 months. Systemic therapy has a limited role. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been shown to improve survival. This study evaluates survival of patients with gastric cancer and peritoneal metastases (GCPM) undergoing CRS and HIPEC at an Australian centre.

METHODS

A retrospective analysis was conducted on a prospectively collected database of patients who underwent CRS and HIPEC for GCPM from January 2009 to December 2023. Data included demographics, perioperative factors, histopathology and survival.

RESULTS

Twenty-four patients were identified, with median postoperative overall survival of 11.7 months (95% CI 8.6-34.2 months). Most patients had poorly differentiated adenocarcinoma (n = 23, 96%), with 14 (58%) exhibiting signet cell pathology. 62% (n = 15) received preoperative chemotherapy. Median PCI was 5, with a CC score of 0 in 96% of patients (n = 23). Clavien-Dindo III/IV morbidity was noted in 8 patients (33%) with no perioperative mortality. No survival differences were found between those with signet cell pathology and those without (10.6 vs. 11.7 months, p = 0.83), nor between those receiving preoperative chemotherapy and those who did not (11.7 vs. 10.6 months, p = 0.60). Age, sex, PCI, CC and tumour markers demonstrated correlations with survival in linear regression, but no individual factor significantly influenced outcomes.

CONCLUSION

CRS and HIPEC for low volume GCPM should be considered in select patients.

Treatment of Gastric Cancer Carcinomatosis

Patients with gastric cancer peritoneal metastases (GCPM) have Stage IV disease. Systemic therapy is a crucial aspect of their care. Patients with GCPM should have their tumors tested for HER2 and PD-L1 expression and microsatellite instability for potential targeted therapies. If patients with synchronous GCPM have stable disease following neoadjuvant therapy, surgical intervention can be considered. Patients with positive cytology or low-volume peritoneal disease (peritoneal carcinomatosis index [PCI] < 7) may "convert" to negative cytology or resolution of peritoneal metastases following intraperitoneal therapy and may be candidates for subsequent gastrectomy.

Triple-regulated conditionally replicating adenovirus for effective and safer treatment of peritoneal carcinomatosis

There is no effective therapy for peritoneal carcinomatosis derived from gastric cancer. An ideal conditionally replicating adenovirus (CRA) that selectively replicates in and kills cancer cells has not been developed for gastric cancer-derived peritoneal carcinomatosis. Using our platform technology of CRA regulated and treating tumors with multiple factors (m-CRA), we generated two types of survivin-responsive m-CRAs, Surv.m-CRA-CMVp and Surv.m-CRA-CEAp, consisting of E1A downstream of the survivin promoter, and the mutated E1B gene downstream of the human cytomegalovirus immediate early gene enhancer/promoter and carcinoembryonic antigen promoter, respectively. Survivin mRNA was expressed at high and undetectable levels in two gastric cancer cells and eleven normal cells, respectively. Carcinoembryonic antigen was expressed at high and very low levels in MKN-45 gastric cancer and normal PrEC cells, respectively, and was not detected in other cell types. While both Surv.m-CRA-CEAp and Surv.m-CRA-CMVp exhibited potent cytotoxic effects on MKN-45 cells in vitro, Surv.m-CRA-CEAp significantly reduced cytotoxicity to normal cells compared to Surv.m-CRA-CMVp. Control mice that received an intraperitoneal injection of MKN-45 cells gradually lost body weight and died of peritoneal carcinomatosis within 98 days. In contrast, all mice receiving Surv.m-CRA-CEAp or Surv.m-CRA-CMVp-infected MKN-45 cells increased their body weight and survived 120 days. In conclusion, the triple-regulated Surv.m-CRA-CEAp enhances cancer specificity (i.e., safety) without reducing the potent therapeutic effect for carcinoembryonic antigen-positive gastric cancer-derived peritoneal carcinomatosis. The modified E1B promoter strategy of CRA facilitates the development of novel CRAs for the effective and safe treatment of a variety of refractory cancers.

A comprehensive overview of gastric cancer management from a surgical point of view

Despite advancements in medical care, surgical technologies, and the development of novel treatments over the past decade, the prognosis for patients with gastric cancer (GC) has only modestly improved. This is primarily due to the fact that the majority of patients are diagnosed at advanced stages or present with metastatic disease. Radical resection remains the cornerstone of potentially curative treatment, yet the overall 5-year survival rate remains below 35%. The management of GC varies globally, influenced by factors such as geographical disparities, patient comorbidities and performance status, surgical approaches, and available medical resources. Multidisciplinary collaboration and a multimodal treatment approach are essential for optimizing patient outcomes. Surgeons must stay updated on emerging surgical concepts and make informed decisions regarding patient selection, timing of intervention, and the adoption of appropriate surgical techniques to improve both quality of life and prognosis. This review aims to provide a surgical perspective on the management of GC across all stages, highlighting the importance of a comprehensive treatment approach. Endoscopic resection may be a viable option for early GC in patients with minimal risk of lymph node metastasis, particularly in elderly patients with high surgical risk or severe comorbidities. For advanced GC, neoadjuvant therapy followed by surgery could be a promising strategy to improve patient outcomes. Conversion surgery offers a potential survival benefit for patients who respond to treatment with tumor downstaging. The treatment of peritoneal carcinomatosis remains challenging; however, hyperthermic intraperitoneal chemotherapy combined with complete cytoreductive surgery or pressurized intraperitoneal aerosolized chemotherapy may prolong survival or improve quality of life in highly selected patients.

Regional Therapy Approaches for Gastric Cancer with Limited Peritoneal Disease

PURPOSE

Despite advances in systemic therapy, outcomes of patients with gastric cancer (GC) peritoneal carcinomatosis (PC) remain poor, in part because of poor penetrance of systemic therapy into peritoneal metastasis due to the plasma-peritoneal barrier and anarchic intra-tumoral circulation. Hence, regional treatment approach with administration of chemotherapy directly into the peritoneal cavity (intraperitoneal, IP) under various conditions, combined with or without cytoreductive surgery (CRS) has remained an area of significant research interest. The purpose of this review is to provide high-level evidence for regional treatment approaches in the management of GCPC with limited peritoneal disease.

METHODS

A review of the current literature and ongoing clinical trials for regional IP therapies for GCPC was performed. Studies included in this review comprise of phase III randomized controlled trials, non-randomized phase II studies, high-impact retrospective studies, and active ongoing clinical trials for each available IP modality.

RESULTS

The three common IP approaches are heated intraperitoneal chemotherapy (HIPEC), normothermic intraperitoneal chemotherapy (NIPEC) and more recently introduced, pressurized intraperitoneal aerosolized chemotherapy (PIPAC). These IP approaches have been combined with systemic therapy and/or CRS with varying degrees of promising results, demonstrating evidence of improvements in survival rates and peritoneal disease control. Patient selection, optimization of systemic therapy, and completeness of cytoreduction have emerged as major factors influencing the design of contemporary and ongoing trials.

CONCLUSION

IP chemotherapy has a clear role in the management of patients with GCPC, and when combined with CRS in appropriately selected patients has the potential to significantly improve survival. Ongoing and upcoming IP therapy clinical trials hold great promise to shape the treatment paradigm for GCPC.

Regional Immunotherapy for Peritoneal Carcinomatosis in Gastroesophageal Cancer: Emerging Strategies to Re-Condition a Maladaptive Tumor Environment

Peritoneal carcinomatosis originating from gastric/gastroesophageal junction cancer (GC-PC) occurs in a defined subset of gastric cancer patients with unique clinical, pathologic, molecular and immunologic characteristics that create significant obstacles to effective treatment with modern therapy. Although systemic chemo- and immuno- therapy have yielded disappointing results in GC-PC, recent advances in the characterization of GC-PC and peritoneal immune biology present new opportunities for targeted therapeutics. In this review article, we discuss the distinct properties of GC-PC and the peritoneal immune environment as they pertain to current and investigative treatment strategies. We discuss pre-clinical studies and clinical trials relevant to the modulation of the peritoneal environment as a therapeutic intervention in GC-PC. Finally, we present a road map for future combinatorial strategies based on the conception of the peritoneal cavity as a bioreactor. Within this isolated compartment, prevailing immunosuppressive conditions can be altered through regional interventions toward an adaptive phenotype that would support the effectiveness of regionally delivered cellular therapy products. It is hoped that novel combination strategies would promote efficacy not only in the sequestered peritoneal environment, but also via migration into the circulation of tumor-reactive lymphocytes to produce durable systemic disease control, thereby improving oncologic outcome and quality of life in patients with GC-PC.

Development of the oncolytic virus, CF33, and its derivatives for peritoneal-directed treatment of gastric cancer peritoneal metastases

BACKGROUND

Gastric cancer (GC) that metastasizes to the peritoneum is fatal. CF33 and its genetically modified derivatives show cancer selectivity and oncolytic potency against various solid tumors. CF33-hNIS and CF33-hNIS-antiPDL1 have entered phase I trials for intratumoral and intravenous treatments of unresectable solid tumors (NCT05346484) and triple-negative breast cancer (NCT05081492). Here, we investigated the antitumor activity of CF33-oncolytic viruses (OVs) against GC and CF33-hNIS-antiPDL1 in the intraperitoneal (IP) treatment of GC peritoneal metastases (GCPM).

METHODS

We infected six human GC cell lines AGS, MKN-45, MKN-74, KATO III, SNU-1, and SNU-16 with CF33, CF33-GFP, or CF33-hNIS-antiPDL1 at various multiplicities of infection (0.01, 0.1, 1.0, and 10.0), and performed viral proliferation and cytotoxicity assays. We used immunofluorescence imaging and flow cytometric analysis to verify virus-encoded gene expression. We evaluated the antitumor activity of CF33-hNIS-antiPDL1 following IP treatment (3×105 pfu × 3 doses) in an SNU-16 human tumor xenograft model using non-invasive bioluminescence imaging.

RESULTS

CF33-OVs showed dose-dependent infection, replication, and killing of both diffuse and intestinal subtypes of human GC cell lines. Immunofluorescence imaging showed virus-encoded GFP, hNIS, and anti-PD-L1 antibody scFv expression in CF33-OV-infected GC cells. We confirmed GC cell surface PD-L1 blockade by virus-encoded anti-PD-L1 scFv using flow cytometry. In the xenograft model, CF33-hNIS-antiPDL1 (IP; 3×105 pfu × 3 doses) treatment significantly reduced peritoneal tumors (p<0.0001), decreased amount of ascites (62.5% PBS vs 25% CF33-hNIS-antiPDL1) and prolonged animal survival. At day 91, seven out of eight mice were alive in the virus-treated group versus one out of eight in the control group (p<0.01).

CONCLUSIONS

Our results show that CF33-OVs can deliver functional proteins and demonstrate effective antitumor activity in GCPM models when delivered intraperitoneally. These preclinical results will inform the design of future peritoneal-directed therapy in GCPM patients.

STAGING LAPAROSCOPY IS STILL A VALUABLE TOOL FOR OPTIMAL GASTRIC CANCER MANAGEMENT

BACKGROUND

Complete surgical resection is the main determining factor in the survival of advanced gastric cancer patients, but is not indicated in metastatic disease. The peritoneum is a common site of metastasis and preoperative imaging techniques still fail to detect it.

AIM

The aim of this study was to evaluate the role of staging laparoscopy in the staging of advanced gastric cancer patients in a Western tertiary cancer center.

METHODS

A total of 130 patients with gastric adenocarcinoma who underwent staging laparoscopy from 2009 to 2020 were evaluated from a prospective database. Clinicopathological characteristics were analyzed to identify factors associated with the presence of peritoneal metastasis and were also evaluated the accuracy and strength of agreement between computed tomography and staging laparoscopy in detecting peritoneal metastasis and the change in treatment strategy after the procedure.

RESULTS

The peritoneal metastasis was identified in 66 (50.76%) patients. The sensitivity, specificity, and accuracy of computed tomography in detecting peritoneal metastasis were 51.5, 87.5, and 69.2%, respectively. According to the Kappa coefficient, the concordance between staging laparoscopy and computed tomography was 38.8%. In multivariate analysis, ascites (p=0.001) and suspected peritoneal metastasis on computed tomography (p=0.007) were statistically correlated with peritoneal metastasis. In 40 (30.8%) patients, staging and treatment plans changed after staging laparoscopy (32 patients avoided unnecessary laparotomy, and 8 patients, who were previously considered stage IVb by computed tomography, were referred to surgical treatment).

CONCLUSION

The staging laparoscopy demonstrated an important role in the diagnosis of peritoneal metastasis, even with current advances in imaging techniques.

Predictors of peritoneal metastasis of gastric origin

Background

Gastric adenocarcinoma is one of the most aggressive forms of cancer. Despite marked advancements in radiological techniques, peritoneal deposits are still only discovered during laparotomies in a significant number of cases. The role of surgery in the management of metastatic gastric cancer is very limited, reducing the value of conducting laparotomies. In addition, conducting laparoscopies for the purposes of properly staging every case of gastric cancer is difficult, especially in healthcare systems with limited resources. It is thus crucial to investigate all possible predictors of peritoneal metastasis of gastric cancer, with the aim of reserving the use of laparoscopies to cases known to have high incidences of peritoneal metastasis despite negative radiological results.

Patients and methods

This is a case control study that included all cases of gastric adenocarcinoma that had presented to the National Cancer Institute–Cairo University between January 2018 and December 2019. The ‘cases’ group encompassed all gastric adenocarcinoma patients who were found to have peritoneal metastasis, whilst the ‘control’ group included those patients who were apparently metastasis-free. Comparisons were made between the two groups in terms of demographics, tumor characteristics, and results of laboratory tumor marker investigations.

Results

Patients with peritoneal metastasis were statistically significantly younger than those who had no apparent metastasis (mean ± SD 51.4 ± 12.5 and 56.2 ± 12.6 respectively; P = 0.020). Significant associations were found between a finding of peritoneal metastasis and (i) a middle tumor site (P = 0.002); (ii) tumor thickening morphology (P < 0.001); (iii) undifferentiated histopathology (P = 0.040); (iv) tumor grade III (P < 0.001); (v) lower lymphocyte counts of < 1.9/ml (P = 0.030); and (vi) high levels of CA 19-9 of > 37 units/ml (P = 0.032).

Conclusion

Tumor pathological criteria, including tumor site, degree of differentiation, shape, and grading, as well as laboratory findings of low lymphocytic counts and high levels of CA 19-9 appear to be reliable predictors of the presence of peritoneal metastasis from a gastric adenocarcinoma.

Situación actual de la laparoscopía de estadificación en pacientes con cáncer gástrico en Colombia: ¿Cómo lo estamos haciendo?

Introducción. La laparoscopía de estadificación permite identificar con gran precisión el compromiso locorregional avanzado y metastásico a peritoneo en los pacientes con cáncer gástrico. Las guías internacionales aún difieren en las indicaciones para incluir este procedimiento como parte del proceso de estadificación. Métodos. Se diseñó una encuesta dirigida a cirujanos residentes en Colombia, sobre el uso de la laparoscopía de estadificación en los pacientes con cáncer gástrico. Se analizaron los resultados y con base en la evidencia disponible se proponen algunas pautas en las indicaciones y técnica del procedimiento. Resultados. Respondieron la encuesta 74 cirujanos; el 43,8 % considera que el objetivo de la laparoscopía de estadificación es descartar la carcinomatosis peritoneal. El 54,1 % realiza el procedimiento en estadios tempranos, sin embargo, el 48,6 % considera realizarla solo en pacientes con sospecha de carcinomatosis por imágenes. Las áreas evaluadas con mayor frecuencia por los cirujanos (más del 85 %) son la superficie hepática, las cúpulas diafragmáticas, los recesos parietocólicos y la pelvis. Las zonas evaluadas en menor frecuencia son la válvula ileocecal (40,5 %) y el ligamento de Treitz (39 %). El 33 % de los cirujanos no toma rutinariamente citología peritoneal. Conclusión. Este trabajo muestra la tendencia de los cirujanos en el uso de la laparoscopía de estadificación en pacientes con cáncer gástrico. A pesar de encontrar resultados muy positivos en relación con las indicaciones y técnica del procedimiento, es necesario analizar la evidencia disponible para su uso según cada escenario y mejorar la sistematización del procedimiento.

Delivery of LINC00589 via mesoporous silica nanoparticles inhibits peritoneal metastasis in gastric cancer

Peritoneal metastasis is one of the common forms of metastasis in gastric cancer (GC). In this study, we identified the expression pattern of LINC00589 in GC patients and investigate the biological function in GC cells. RNA-pulldown assay was performed to explore the underlying molecular mechanism. Further, we utilize polyethyleneimine-modified mesoporous silica nanoparticles (PMSNs) as the nanocarriers for delivery of LINC00589 encoding plasmid and tested its therapeutic potential for GC with peritoneal dissemination. We revealed that LINC00589 was downregulated in GC tissues and suppressed the metastatic ability of GC cells. Mechanistically, LINC00589 exerted tumor suppressive function by promoting hnRNPA1 protein ubiquitination and proteasomal degradation, thus blocking alternative splicing of PKM to PKM2. Furthermore, LINC00589 delivered by PMSNs could suppress the peritoneal metastasis of GC in vivo and in vitro. This work may provide a new treatment option in GC peritoneal metastasis.

Diagnostic laparoscopy is underutilized in the staging of gastric adenocarcinoma regardless of hospital type: An US safety net collaborative analysis

BACKGROUND

Diagnostic laparoscopy (DL) is a key component of staging for locally advanced gastric adenocarcinoma (GA). We hypothesized that utilization of DL varied between safety net (SNH) and affiliated tertiary referral centers (TRCs).

METHODS

Patients diagnosed with primary GA eligible for DL were identified from the US Safety Net Collaborative database (2012-2014). Clinicopathologic factors were analyzed for association with use of DL and findings on DL. Overall survival (OS) was analyzed by Kaplan-Meier method.

RESULTS

Among 233 eligible patients, 69 (30%) received DL, of which 24 (35%) were positive for metastatic disease. Forty percent of eligible SNH patients underwent DL compared to 21.5% at TRCs. Lack of insurance was significantly associated with decreased use of DL (OR 0.48, p < 0.01), while African American (OR 6.87, p = 0.02) and Asian race (OR 3.12, p ≤ 0.01), signet ring cells on biopsy (OR 3.14, p < 0.01), and distal tumors (OR 1.62, p < 0.01) were associated with increased use. Median OS of patients with a negative DL was better than those without DL or a positive DL (not reached vs. 32 vs. 12 months, p < 0.005, Figure 1).

CONCLUSIONS

Results from DL are a strong predictor of OS in GA; however, the procedure is underutilized. Patients from racial minority groups were more likely to undergo DL, which likely accounts for higher DL rates among SNH patients.

Postoperative follow-up for gastric cancer needs to be individualized according to age, tumour recurrence pattern, and recurrence time

BACKGROUND

Few studies have reported the association between the pattern and time point of recurrence in different groups stratified by age in postoperative survival of patients with gastric cancer.

METHODS

The clinicopathological data and recurrence data of 2028 patients with GC who underwent curative surgery from January 2010 to March 2015 were enrolled in this study. Patients were grouped according to age: young group (YG) (≤45 years old) (n = 180) and non-young group (OG) (>45 years old) (n = 1848).

RESULTS

A total of 2028 patients were enrolled. The young group had better 5-year OS and DFS than the non-young group. In peritoneal recurrence, the cumulative incidence of recurrence in YG was higher than that in OG (P < 0.001). In distant recurrence, the cumulative incidence of recurrence YG was always lower than that of OG (P = 0.004). Recurrence hazard function varied over time between the two groups:in the peritoneal metastasis, the recurrence hazard for YG was higher and earlier than that of OG and the YG was observed during five years after surgery with two recurrence peaks in 8.5 months and in 41.5 months. In distant recurrence, the recurrence hazard for OG had an earlier and higher single peak than that of YG (6.0 months).

CONCLUSION

The recurrence characteristics of patients with gastric cancer after curative resection between young group and older group are different. Personalized follow-up strategies should be developed according to the age and time point after operation for the early detection of recurrence and making decision for further treatment.

Risk Factors for Metachronous Isolated Peritoneal Metastasis after Preoperative Chemotherapy and Potentially Curative Gastric Cancer Resection: Results from the CRITICS Trial

Simple Summary

Around 20% of gastric cancer patients develop peritoneal metastasis after preoperative chemotherapy and curative surgery. Patients with peritoneal metastasis as a single site of metastasis may potentially benefit from prophylactic strategies. In this post-hoc analysis of the international phase III CRITICS trial, we aim to identify factors that can distinguish patients at high risk for developing peritoneal metastasis as a single site. Diffuse or mixed histological subtype, tumors with serosal involvement (ypT4) and advanced lymph node stage (ypN3 or a tumor positive lymph node ratio >20%) were independent risk factors for isolated peritoneal metastasis after preoperative chemotherapy and curative surgery. The combination of these risk factors identifies a subgroup that may benefit from treatment strategies that aim to prevent peritoneal metastasis.

Abstract

Gastric cancer (GC) patients at high risk of developing peritoneal metastasis (PM) as a single site of metastasis after curative treatment may be candidates for adjuvant prophylactic strategies. Here we investigated risk factors for metachronous isolated PM in patients who were treated in the CRITICS trial (NCT00407186). Univariable and multivariable analyses on both metachronous isolated PM and ‘other events’, i.e., (concurrent) distant metastasis, locoregional recurrence or death, were performed using a competing risk model and summarized by cumulative incidences. Isolated PM occurred in 64 of the 606 (11%) included patients. Diffuse or mixed histological subtype, ypT4 tumor stage and LN^high (ypN3 lymph node stage or a lymph node ratio >20%) were independent risk factors for isolated PM in both univariable and multivariable analyses. Likewise, LN^high was an independent risk factor for ‘other events’. Patients with tumors who were positive for all three independent risk factors had the highest two-year cumulative incidence of 43% for isolated PM development. In conclusion, diffuse or mixed histological subtype, ypT4 and LN^high were identified as independent risk factors for isolated PM in patients treated with preoperative chemotherapy followed by surgical resection. The combination of these factors may identify a subgroup that may benefit from PM-preventing treatment strategies.

The Clinical Significance and Functional Role of miR-466 in Gastric Cancer Peritoneal Metastasis

The prognosis of metastasis gastric cancer patients remains poor and the identification of novel molecular markers will improve the management of gastric cancer patients. The present study aimed to investigate the clinical significance and functional role of miR-466 in gastric cancer peritoneal metastasis. miR-466 expression was confirmed by RT-qPCR. The biological functions were examined by MTT assay, Transwell migration, and invasion assays. The Kaplan-Meier survival curve and multivariate Cox regression analysis were used to investigate the clinical role of miR-466. The logistic regression analysis was performed to reveal the risk factors associated with peritoneal metastasis. miR-466 expression was downregulated in gastric cancer cell lines, tumor tissues, and peritoneal metastasis tissues compared with respective controls. Increased miR-466 expression inhibited proliferation, migration, and invasion of gastric cancer cells. Besides, the lower expression of miR-466 in gastric cancer patients was associated with peritoneal dissemination. Furthermore, multivariate Cox proportional hazard regression analyses demonstrated miR-466 expression level as an independent predictor of prognosis of gastric cancer. The present study provides novel evidence for the clinical and biological significance of miR-466 expression as a possible biomarker for the prognosis and identifying patients with peritoneal metastasis, as well as a potential therapeutic target in patients with gastric cancer.

Apolipoprotein C-II induces EMT to promote gastric cancer peritoneal metastasis via PI3K/AKT/mTOR pathway

BACKGROUND

Peritoneal metastasis (PM) occurs frequently in patients with gastric cancer (GC) and confers poor survival. Lipid metabolism acts as a non-negligible regulator in epithelial-mesenchymal transition (EMT), which is crucial for the metastasis of GC. As apolipoprotein C2 (APOC2) is a key activator of lipoprotein lipase for triglyceride metabolism, the exact mechanism of APOC2 remains largely unknown in GC.

METHODS

Tandem mass tags identified differentially expressed proteins between human PM and GC tissues, and showed that APOC2 overexpressed in PM tissues, which was further confirmed by immunoblotting, immunohistochemistry, and ELISA. Global gene expression changes were identified in APOC2 knockdown cells via RNA-sequencing. The role of APOC2 in lipid metabolism of GC cells was assessed via the Seahorse XF analyzer and lipid staining assays. The biological role of APOC2 in GC cells was determined by 3D Spheroid invasion, apoptosis, colony formation, wound healing, transwell assay, and mouse models. The interaction between APOC2 and CD36 was analyzed by co-immunoprecipitation and biolayer interferometry. The underlying mechanisms were investigated using western blot technique.

RESULTS

APOC2 overexpressed in GC PM tissues. Upregulation of APOC2 correlated with a poor prognosis in GC patients. APOC2 promoted GC cell invasion, migration, and proliferation via CD36-mediated PI3K/AKT/mTOR signaling activation. Furthermore, APOC2-CD36 axis upregulated EMT markers of GC cells via increasing the phosphorylation of PI3K, AKT, and mTOR. Knockdown either APOC2 or CD36 inhibited the malignant phenotype of cancer cells, and delayed GC PM progression in murine GC models.

CONCLUSION

APOC2 cooperates with CD36 to induce EMT to promote GC PM via PI3K/AKT/mTOR pathway. APOC2-CD36 axis may be a potential target for the treatment of aggressive GC.

Development and validation of RNA binding protein-applied prediction model for gastric cancer

RNA-binding proteins (RBPs) have been reported to be associated with the occurrence and progression of multiple cancers, but the role in gastric adenocarcinoma remains poorly understood. The present study aims to uncover potential RBPs associated with the survival of gastric adenocarcinoma, as well as corresponding biologic properties and signaling pathways of these RBPs. RNA sequencing and clinical data of GC were obtained from The Cancer Genome Atlas (n=373) and the Gene Expression Omnibus (GSE84437, n=433) database. Tumor samples in TCGA were randomly divided into the training and internal testing group by R software. A total of 238 DERBPs were selected for univariate and multivariate Cox regression analyses. Five pivotal RBP genes (RNASE2, METTL1, ANG, YBX2 and LARP6) were screened out and were used to construct a new prognostic model. Survival relevance and prediction accuracy of model were tested via Kaplan-Meier (K-M) curves and receiver operating characteristic (ROC) curves in internal and external testing groups. Further analysis has also showed that this model could serve as an independent prognosis-related parameter. A prognostic nomogram has been eventually developed, and presents a good performance of prediction.

Prognostic value of CEA/CA72-4 immunohistochemistry in combination with cytology for detecting tumor cells in peritoneal lavage in gastric cancer

Aim: To study the value and efficiency of CEA/CA72-4 immunohistochemistry in detecting free tumor cells from peritoneal lavage, in order to provide reliable lab information for subsequent intraperitoneal chemotherapy. Methods: A total of 112 progressive gastric cancer patients were enrolled from Oct. 2016 to Oct 2017, who were pathologically diagnosed as gastric cancer after surgery. Peritoneal lavage was respectively collected during operation. Cytology and CEA/CA72-4 immunohistochemistry of peritoneal lavage samples was performed. Overall survival and recurrence free survival was analyzed. Results: Cytology showed 16 positive cases (14.29%), CEA immunohistochemistry showed 29 positive cases (25.89%), CA72-4 immunohistochemistry showed 33 positive cases (29.46%). McNemar's test showed significant difference in positivity between cytology (CY+) and CEA/CA72-4 immunohistochemistry (IHC+). Kappa test showed consistency between immunohistochemistry of CEA and CA72-4 with cytology. Patients with CY+/IHC+ had the poorest overall survival (OS) as well as recurrence free survival (RFS), followed by those with CY+ or IHC+, while those with CY-/IHC- had higher OS and RFS. The differences of OS and RFS in IHC+ group were worse than that in IHC- group. Kaplan-Meier analysis showed that positive CEA/CA72-4 IHC revealed poorer prognosis than the negative cases. Conclusions: Due to the limitation of cytology, combination of cytology and immunohistochemistry appears to be more efficient for predicting prognosis of progressive gastric cancer.

Gastric cancer in young patients: a separate entity with aggressive features and poor prognosis

PURPOSE

To investigate the clinicopathological features and survival outcomes between young and old patients with gastric cancer (GC), and further determine the role of young age in the prognosis of GC.

METHODS

Patients with stage I-III gastric adenocarcinomas undergoing curative surgery were enrolled, divided into young (aged 18-49 years, YG), middle-aged (50-59 years, MG), and old (≥ 60 years, OG) groups. Exclusion criteria were neoadjuvant therapy and history of malignant tumors. Clinicopathological features, overall survival (OS), disease-free survival (DFS), and recurrence patterns were compared among three groups.

RESULTS

1131 patients were finally included, with 270, 314, and 547 cases in the YG, MG, and OG, respectively. Compared to others, YG had higher proportion of female, middle-third gastric cancer, poor differentiation, N3b stage, and adjuvant chemotherapy. YG demonstrated poorer 5-year OS than MG (62.4% vs. 70.8%, P = 0.019), but better than OG (62.4% vs. 58.7%, P = 0.031). YG also suffered inferior 5-year DFS (75.2% vs. 82.8%, P = 0.040) compared with MG, and higher incidence of peritoneal recurrence than MG (15.1% vs. 5.2%, P < 0.001) and OG (15.1% vs. 4.1%, P < 0.001). Multivariate analysis identified young age as the independent prognostic factor for OS [hazard ratio (HR) = 1.347, 95% CI 1.018-1.781, P = 0.037], DFS (HR = 1.601, 95% CI 1.079-2.376, P = 0.019), and peritoneal recurrence (HR = 2.936, 95% CI 1.505-5.726, P = 0.002).

CONCLUSIONS

Young GC patients demonstrated aggressive features with poor prognosis and enhanced management may be warranted for this subgroup.