Regional but fatal: Intraperitoneal metastasis in gastric cancer

N6-methyladenosine RNA modification in stomach carcinoma: Novel insights into mechanisms and implications for diagnosis and treatment

N6-methyladenosine (m6A) RNA methylation is crucially involved in the genesis and advancement of gastric cancer (GC) by controlling various pathobiological aspects including gene expression, signal transduction, metabolism, cell death, epithelial-mesenchymal transition, angiogenesis, and exosome function. Despite its importance, the exact mechanisms by which m6A modification influences GC biology remain inadequately explored. This review consolidates the latest advances in uncovering the mechanisms and diverse roles of m6A in GC and proposes new research and translational directions. Key regulators (writers, readers, and erasers) of m6A, such as METTL3/14/16 and WTAP, significantly affect cancer progression, anticancer immune response, and treatment outcomes. m6A modification also impacts immune cell infiltration and the tumor microenvironment, highlighting its potential as a diagnostic and prognostic marker. Interactions between m6A methylation and non-coding RNAs offer further novel insights into GC development and therapeutic targets. Targeting m6A regulators could enhance immunotherapy response, overcome treatment resistance, and improve oncological and clinical outcomes. Models based on m6A can precisely predict treatment response and prognosis in GC. Additional investigation is needed to fully understand the mechanisms of m6A methylation and its potential clinical applications and relevance (e.g., as precise markers for early detection, prediction of outcome, and response to therapy and as therapeutic targets) in GC. Future research should focus on in vivo studies, potential clinical trials, and the examination of m6A modification in other types of cancers.

Identification of gastric cancer subtypes based on disulfidptosis-related genes: GPC3 as a novel biomarker for prognosis prediction

Gastric cancer (GC) is the fourth most common cancer type. "Disulfidptosis," a distinct form of cell death, is initiated through aberrant intracellular disulfide metabolism. Here, we identified various GC subtypes based on disulfidptosis-related genes (DRGs) and constructed a risk score model to identify relevant genes to help predict patient prognosis and guide treatment. We downloaded RNA sequencing (RNA-seq) data from the TCGA-STAD database, performed a difference analysis, and combined the data with GSE84437 to successfully perform an unsupervised clustering analysis based on DRGs and differentially expressed genes (DEGs). Risk-scoring models were established by screening prognosis-related DEGs. The GC samples were segregated into high-risk (HR) and low-risk (LR) groups according to their risk scores. We then evaluated the genes screened with the model in terms of prognosis, tumor, and immune cell infiltration. The response of patients with GC to immunological therapy was assessed using tumor mutational burden, microsatellite instability, and tumor immune dysfunction and exclusion scores. Using unsupervised cluster analysis, we identified two DRG clusters and two gene clusters that differed in prognosis and tumor microenvironment. A six-gene model was developed for risk score assessment. The LR group demonstrated superior performance compared to the HR group in terms of immunity, exhibiting greater sensitivity to immunotherapy. Thereafter, we selected the model gene GPC3 for single-gene analysis and verified it by experimental validation. The results demonstrated that GPC3 can serve as a standalone biomarker with promising clinical applicability in the prognostic prediction and clinical management of GC.

Molecular and Clinicopathologic Impact of GNAS Variants Across Solid Tumors

PURPOSE

The molecular drivers underlying mucinous tumor pathogenicity are poorly understood. GNAS mutations predict metastatic burden and treatment resistance in mucinous appendiceal adenocarcinoma. We investigated the pan-cancer clinicopathologic relevance of GNAS variants.

METHODS

We assessed 58,043 patients with Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (IMPACT)-sequenced solid tumors to identify oncogenic variants, including GNAS, associated with mucinous tumor phenotype. We then performed comprehensive molecular analyses to compare GNAS-mutant (mut) and wild-type tumors across cancers. Gene expression patterns associated with GNAS-mut tumors were assessed in a The Cancer Genome Atlas cohort. Associations between GNAS variant status and peritoneal metastasis, first-line systemic therapy response, progression-free survival (PFS), and overall survival (OS) were determined using a propensity-matched subcohort of patients with metastatic disease.

RESULTS

Mucinous tumors were enriched for oncogenic GNAS variants. GNAS was mutated in >1% of small bowel, cervical, colorectal, pancreatic, esophagogastric, hepatobiliary, and GI neuroendocrine cancers. Across these cancers, GNAS-mut tumors exhibited a generally conserved C-to-T mutation-high, aneuploidy-low molecular profile with co-occurring prevalent KRAS variants (65% of GNAS-mut tumors) and fewer TP53 alterations. GNAS-mut tumors exhibited recurrently comutated alternative tumor suppressors (RBM10, INPPL1) and upregulation of MAPK and cell surface modulators. GNAS-mut tumors demonstrate an increased prevalence of peritoneal metastases (odds ratio [OR], 1.7 [95% CI, 1.1 to 2.5]; P = .006), worse response to first-line systemic therapy (OR, 2.2 [95% CI, 1.3 to 3.8]; P = .003), and shorter PFS (median, 5.6 v 7.0 months; P = .047). In a multivariable analysis, GNAS mutated status was independently prognostic of worse OS (hazard ratio, 1.25 [95% CI, 1.01 to 1.56]; adjusted P = .04).

CONCLUSION

Across the assessed cancers, GNAS-mut tumors exhibit a conserved molecular and clinical phenotype defined by mucinous tumor status, increased peritoneal metastasis, poor response to first-line systemic therapy, and worse survival.

Targeting non-coding RNAs as a promising biomarker in peritoneal metastasis: Background, mechanism, and therapeutic approach

Peritoneal metastasis (PM) pathophysiology is complex and not fully understood. PM, originating from gastrointestinal (GI) cancer, is a condition that significantly worsens patient prognosis due to its complex nature and limited treatment options. The non-coding RNAs (ncRNAs) have been shown to play pivotal roles in cancer biology, influencing tumorigenesis, progression, metastasis, and therapeutic resistance. Increasing evidence has demonstrated the regulatory functions of different classes of ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in PM. Identifying biomarkers for early detection of PM is a crucial step towards improving patient outcomes, and how ncRNA profiles correlate with survival rates, response to therapy, and recurrence risks have raised much attention in recent years. Additionally, exploring innovative therapeutic approaches utilizing ncRNAs, such as targeted therapy and gene silencing, may offer new horizons in treating this dire condition. Recent advances in systemic treatments and the development of novel loco-regional therapies have opened doors to multimodal treatment approaches. Radical surgeries combined with hyperthermic intraperitoneal chemotherapy (HIPEC) have shown promising results, leading to extended patient survival. Current research is focused on the molecular characterization of PM, which is crucial for early detection and developing future therapeutic strategies. By summarizing the latest findings, this study underscores the transformative potential of ncRNAs in enhancing the diagnosis, prognosis, and treatment of PM in GI cancer, paving the way for more personalized and effective clinical strategies.

Real-World Effectiveness and Safety of Ramucirumab as a Second-Line Treatment for Patients with Unresectable Advanced or Metastatic Gastric/Gastroesophageal Junction Adenocarcinoma in Japan and South Korea: A Systematic Literature Review

INTRODUCTION

Gastric cancer has the highest incidence and mortality in Eastern Asia. The efficacy and safety of ramucirumab (RAM) monotherapy or in combination with paclitaxel (PTX) for patients with unresectable advanced or metastatic gastric/gastroesophageal junction adenocarcinoma (G/GEA) have been established in clinical trials. To assess the effectiveness and safety of RAM or RAM-based therapy as a second-line treatment in real-world clinical practice in Eastern Asia and to pave the way for future research, a systematic literature review (SLR) was conducted.

METHODS

Studies published between January 2014 and December 2021 were identified in PubMed, Embase, Cochrane Library, CNKI, Wanfang, and CBM databases.

RESULTS

This SLR included 23 studies from Japan and South Korea, of which 22 were retrospective and 11 were full-text articles. Most studies investigated RAM + PTX (range of median overall survival [mOS] 7.4-12.2 months; median progression-free survival [mPFS] 3.35-7.0 months). Data were limited for RAM, RAM + albumin-bound paclitaxel, and RAM + taxane. RAM + PTX was associated with longer survival (mOS 9.3-12.2 months vs. 5.2-9.7 months; mPFS 4.1-5.1 months vs. 3.0-4.1 months) than PTX. Patients with prior anti-programmed cell death 1 (anti-PD-1) exposure experienced longer mPFS (4.8 vs. 3.4 months) from RAM + taxane than those without prior anti-PD-1 exposure. Few patients (3.3-6.3%) discontinued RAM or RAM-based therapy because of adverse events (AEs). Hematological toxicities were most frequently occurring AEs and no new safety signals were identified compared to clinical trials.

CONCLUSION

RAM + PTX as a second-line treatment is effective and associated with an acceptable toxicity profile in patients with advanced or metastatic G/GEA in real-world settings of Japan and South Korea. More studies are recommended to further evaluate effectiveness and safety of RAM or RAM-based therapy, especially after anti-PD-1 therapy, in a wider Eastern Asian population.

TRIAL REGISTRATION

INPLASY registration number INPLASY2022120023.

Efficacy and safety of gemcitabine plus raltitrexed or S-1 versus standard third-line therapies in metastatic colorectal cancer: a retrospective cohort study

Background

After the failure of standard first- and second-line treatments, including oxaliplatin, irinotecan, and 5-fluorouracil (5-FU) combined with targeted drugs, the currently recommended third-line regimens for metastatic colorectal cancer (mCRC) include TAS-102, regorafenib, and fruquintinib. However, these regimens have the drawbacks of mediocre efficacy, substantive side effects, and high cost. Therefore, more effective, economical regimens with fewer side effects are needed in clinical practice. In this study, we assessed the efficacy and safety of gemcitabine plus raltitrexed or S-1 as a third- or later-line treatment in comparison to those of standard third-line therapies for patients with mCRC.

Methods

Patients with previous failures of at least two lines of standard therapy with oxaliplatin, 5-FU, irinotecan, or capecitabine combined with targeted drugs were included. The participants received standard third-line therapies (including TAS-102, regorafenib, and fruquintinib) or gemcitabine plus raltitrexed or S-1 until disease progression, death, or intolerable toxicity arose. Imaging follow-up was performed every 3 months during their treatment. Progression-free survival (PFS) and overall survival (OS) were recorded. Cox regression analysis was used to investigate the potential predictors of survival.

Results

From April 2018 to October 2022, 60 patients with mCRC were enrolled in our study. The numbers of patients in the chemotherapy, fruquintinib, regorafenib, and TAS-102 groups were 13, 15, 17, and 15, respectively; the median OS of the four groups was 7.4, 6.1, 8.3, and 6.7 months (P=0.384), respectively; the median PFS was 4.1, 3.4, 4.4, and 2.3 months (P=0.656), respectively; the overall response rate was 7.69%, 6.67%, 0.00%, and 13.33%, respectively; and the disease control rate was 61.54%, 60.00%, 70.59%, and 60.00%, respectively. Additionally, multivariate analysis revealed that primary lesion located in the rectum was adverse independent prognostic factors for OS. A typical case is presented in this article.

Conclusions

The gemcitabine plus raltitrexed or S-1 regimen is a potential regimen with tolerable adverse reactions and low cost for patients with mCRC.

Peritoneal Washing Cytology Positivity in Gastric Cancer: Role of Lymph Node Metastasis as a Risk Factor

PURPOSE

Peritoneal washing cytology (PWC) is a widely used diagnostic tool for detecting peritoneal metastasis of advanced gastric cancer. However, the prognosis of patients with positive PWC remains poor even after gastrectomy, and treatments vary among institutions and eras. In this study, we identified the clinical factors that can help predict cytology-positive (CY(+)) gastric cancer.

MATERIALS AND METHODS

We retrospectively reviewed the national data of patients with gastric cancer from 2019, as provided by the Information Committee of the Korean Gastric Cancer Association. Of the 13,447 patients with gastric cancer, 3,672 underwent PWC. Based on cytology results, we analyzed the clinicopathological characteristics and assessed the possibility of CY(+) outcomes in relation to T and N stages.

RESULTS

Of the 3,270 patients who underwent PWC without preoperative chemotherapy, 325 were CY(+), whereas 2,945 were negative. CY(+) was more commonly observed in patients with Borrmann type IV gastric cancer, an undifferentiated histological type, and advanced pathological stages. Multivariate analysis revealed Borrmann type IV (odds ratio [OR], 1.821), tumor invasion to T3-4 (OR, 2.041), and lymph node metastasis (OR, 3.155) as independent predictors of CY(+). Furthermore, for circular tumor location, the N stage emerged as a significant risk factor for CY(+), particularly when the tumor was located on the posterior wall (PW) side.

CONCLUSIONS

Lymph node metastasis significantly affects CY(+) outcomes, particularly when the tumor is located on the PW side. Therefore, PWC should be considered not only in suspected serosal exposure cases but also in cases of lymph node metastasis.

Construction of an immune-related risk score signature for gastric cancer based on multi-omics data

Early identification of gastric cancer (GC) is associated with a superior survival rate compared to advanced GC. However, the poor specificity and sensitivity of traditional biomarkers suggest the importance of identifying more effective biomarkers. This study aimed to identify novel biomarkers for the prognosis of GC and construct a risk score (RS) signature based on these biomarkers, with to validation of its predictive performance. We used multi-omics data from The Cancer Genome Atlas to analyze the significance of differences in each omics data and combined the data using Fisher's method. Hub genes were subsequently subjected to univariate Cox and LASSO regression analyses and used to construct the RS signature. The RS of each patient was calculated, and the patients were divided into two subgroups according to the RS. The RS signature was validated in two independent datasets from the Gene Expression Omnibus and subsequent analyses were subsequently conducted. Five immune-related genes strongly linked to the prognosis of GC patients were obtained, namely CGB5, SLC10A2, THPO, PDGFRB, and APOD. The results revealed significant differences in overall survival between the two subgroups (p < 0.001) and indicated the high accuracy of the RS signature. When validated in two independent datasets, the results were consistent with those in the training dataset (p = 0.003 and p = 0.001). Subsequent analyses revealed that the RS signature is independent and has broad applicability among various GC subtypes. In conclusion, we used multi-omics data to obtain five immune-related genes comprising the RS signature, which can independently and effectively predict the prognosis of GC patients with high accuracy.

Gastric cancer peritoneal metastasis related signature predicts prognosis and sensitivity to immunotherapy in gastric cancer

Gastric cancer peritoneal metastases (GCPM) is a leading cause of GC-related death. Early detection of GCPM is critical for improving the prognosis of advanced GC. Differentially expressed genes (DEGs) were identified in the GSE62254 database to distinguish between GCPM and non-GCPM. The gastric cancer peritoneal metastases signature (GCPMs) was developed using DEGs. We analysed the effectiveness of GCPMs as indicators for prognosis, chemotherapy, and immune therapy response in GC patients. Subsequently, we analysed the correlation between GCPMs and immune microenvironment as well as immune escape in GC patients. Random forest model and immunohistochemistry was utilized to identify the crucial genes that can aid in the diagnosis of GCPM. We identified five DEGs and utilized their expression to construct GCPMs. Patients with high GCPMs had a higher likelihood of a poor prognosis, while those with low GCPMs appeared to potentially benefit more from chemotherapy. GCPMs were a dependable marker for predicting the response to immunotherapy. Additionally, GCPMs was found to be significantly linked to stromal score and cancer-associated fibroblasts. SYNPO2 has been identified as the gene with the highest significance in the diagnosis of GCPM. Immunohistochemistry suggests that SYNPO2-positive expression in tumour cells, fibroblasts, inflammatory cell may be associated with promoting peritoneal metastasis in GC. GCPMs have shown to be a promising biomarker for predicting the prognosis and response of GC patients to chemotherapy and immunotherapy. The use of GCPMs for individual tumour evaluation may pave the way for personalized treatment for GC patients in the future.

Systematic review of diagnostic tools for peritoneal metastasis in gastric cancer-staging laparoscopy and its alternatives

BACKGROUND

Gastric cancer is one of the leading causes of cancer burden and mortality, often resulting in peritoneal metastasis in advanced stages with negative survival outcomes. Staging laparoscopy has become standard practice for suspected cases before a definitive gastrectomy or palliation. This systematic review aims to compare the efficacy of other diagnostic modalities instead of staging laparoscopy as the alternatives are able to reduce cost and invasive staging procedures. Recently, a radiomic model based on computed tomography and positron emission tomography (PET) has also emerged as another method to predict peritoneal metastasis.

AIM

To determine if the efficacy of computed tomography, magnetic resonance imaging and PET is comparable with staging laparoscopy.

METHODS

Articles comparing computed tomography, PET, magnetic resonance imaging, and radiomic models based on computed tomography and PET to staging laparoscopies were filtered out from the Cochrane Library, EMBASE, PubMed, Web of Science, and Reference Citations Analysis (https://www.referencecitationanalysis.com/). In the search for studies comparing computed tomography (CT) to staging laparoscopy, five retrospective studies and three prospective studies were found. Similarly, five retrospective studies and two prospective studies were also included for papers comparing CT to PET scans. Only one retrospective study and one prospective study were found to be suitable for papers comparing CT to magnetic resonance imaging scans.

RESULTS

Staging laparoscopy outperformed computed tomography in all measured aspects, namely sensitivity, specificity, positive predictive value and negative predictive value. Magnetic resonance imaging and PET produced mixed results, with the former shown to be only marginally better than computed tomography. CT performed slightly better than PET in most measured domains, except in specificity and true negative rates. We speculate that this may be due to the limited F-fluorodeoxyglucose uptake in small peritoneal metastases and in linitis plastica. Radiomic modelling, in its current state, shows promise as an alternative for predicting peritoneal metastases. With further research, deep learning and radiomic modelling can be refined and potentially applied as a preoperative diagnostic tool to reduce the need for invasive staging laparoscopy.

CONCLUSION

Staging laparoscopy was superior in all measured aspects. However, associated risks and costs must be considered. Refinements in radiomic modelling are necessary to establish it as a reliable screening technique.

The Shorr Versus Modified Ultrafast Papanicolaou Method for Intraoperative Diagnosis of Peritoneal Washing Cytology in Advanced Gastric Cancer: A Phase II Study

PURPOSE

According to the American Joint Committee on Cancer cancer staging system, positive peritoneal washing cytology (PWC) indicates stage IV gastric cancer. However, rapid intraoperative diagnosis of PWC has no established reliable method. This study evaluated and compared the diagnostic accuracy of the Shorr and the modified ultrafast Papanicolaou (MUFP) methods for intraoperative PWC.

MATERIALS AND METHODS

This study included patients with gastric cancer who were clinically diagnosed with stage cT3 or higher. The Shorr and MUFP methods were performed on all PWC specimens, and the results were compared with those of conventional Papanicolaou (PAP) staining with carcinoembryonic antigen immunohistochemistry. Sensitivity, specificity, and partial likelihood tests were used to compare the 2 methods.

RESULTS

Forty patients underwent intraoperative PWC between November 2019 and August 2021. The average time between specimen reception and slide preparation using Shorr and MUFP methods was 44.4±4.5 minutes, and the average time between specimen reception and pathologic diagnosis was 53.9±8.9 minutes. Eight patients (20.0%) had positive cytology in PAP staining. The Shorr method had a sensitivity of 75.0% and specificity of 93.8%; the MUFP method had 62.5% sensitivity and 100.0% specificity. The area under the curve was 0.844 for Shorr and 0.813 for MUFP. In comparing the C-indices of each method with overall survival, no difference was found among the Shorr, MUFP, and conventional PAP methods.

CONCLUSIONS

The Shorr and MUFP methods are acceptable for the intraoperative diagnosis of PWC in advanced gastric cancer.

Malignant ascites supernatant enhances the proliferation of gastric cancer cells partially via the upregulation of asparagine synthetase

Malignant ascites (MA) is a common manifestation of advanced gastric cancer (GC) with peritoneal metastasis (PM), which usually indicates a poor prognosis. The present study aimed to explore the effects of MA, a unique microenvironment of PM, on the proliferation of cancer cells and investigate the underlying mechanisms. Ex vivo experiments demonstrated that GC cells treated with MA exhibited enhanced proliferation. RNA sequencing indicated that asparagine synthetase (ASNS) was one of the differentially expressed genes in GC cells following incubation with MAs. Furthermore, the present study suggested that MA induced an upregulation of ASNS expression and the stimulatory effect of MA on cancer cell proliferation was alleviated upon ASNS downregulation. Activating transcription factor 4 (ATF4), a pivotal transcription factor regulating ASNS, was upregulated when cells were treated with MA supernatant. After ATF4 knockdown, the proliferation of MA-treated GC cells and the expression of ASNS decreased. In addition, the decline in the proliferation of the ATF4-downregulated AGS GC cell line was rescued by ASNS upregulation. The findings indicated that MA could promote the proliferation of GC cells via activation of the ATF4-ASNS axis. Hence, it may be a potential target for treating GC with PM and MA.

Discovery of CDK signature and CDK5 as potential biomarkers for predicting prognosis and immunotherapeutic response in gastric cancer peritoneal metastases

Gastric cancer peritoneal metastases (GCPM) are a leading cause of death in gastric cancer patients. In this study, we focused on the expression of cyclin-dependent protein kinases (CDK), essential regulators of transcription, metabolism, and cell differentiation, in GCPM. Utilizing the GSE62254 cohort, we established a CDK signature (CDKS) model comprising ten CDK gene family members. Analysis of both the GSE62254 and TCGA cohorts revealed that patients with low CDKS had a worse prognosis compared to those with high CDKS. Furthermore, patients with high CDKS demonstrated positive responses from immunotherapy, as observed in the KIM cohort. We investigated the association between CDKS and the tumor microenvironment, including immune escape mechanisms. Immunohistochemistry analysis revealed a positive correlation between CDK5 and PD-L1 expression in gastric cancer. Furthermore, we found that CDK5 knockdown led to the inhibition of PD-L1 expression in gastric cancer cells. Our findings highlight the potential of CDKS as a prognostic biomarker and an indicator of immunotherapy response in gastric cancer patients. Moreover, our study suggests that targeting CDK5 could provide a new pathway for exploring immunotherapeutic research.

Role of N6-methyladenosine RNA modification in gastric cancer

N6-methyladenosine (m6A) RNA methylation is the most prevalent internal modification of mammalian messenger RNA. The m6A modification affects multiple aspects of RNA metabolism, including processing, splicing, export, stability, and translation through the reversible regulation of methyltransferases (Writers), demethylases (Erasers), and recognition binding proteins (Readers). Accumulating evidence indicates that altered m6A levels are associated with a variety of human cancers. Recently, dysregulation of m6A methylation was shown to be involved in the occurrence and development of gastric cancer (GC) through various pathways. Thus, elucidating the relationship between m6A and the pathogenesis of GC has important clinical implications for the diagnosis, treatment, and prognosis of GC patients. In this review, we evaluate the potential role and clinical significance of m6A-related proteins which function in GC in an m6A-dependent manner. We discuss current issues regarding m6A-targeted inhibition of GC, explore new methods for GC diagnosis and prognosis, consider new targets for GC treatment, and provide a reasonable outlook for the future of GC research.

Soluble factors in malignant ascites promote the metastatic adhesion of gastric adenocarcinoma cells

BACKGROUND

Adenocarcinoma of the proximal stomach is the fastest rising malignancy in North America. It is commonly associated with peritoneal accumulation of malignant ascites (MA), a fluid containing cancer and inflammatory cells and soluble proteins. Peritoneal metastasis (PM) is the most common site of gastric cancer (GC) progression after curative-intent surgery and is the leading cause of death among GC patients.

METHODS/RESULTS

Using a panel of gastric adenocarcinoma cell lines (human: MKN 45, SNU-5; murine: NCC-S1M), we demonstrate that prior incubation of GC cells with MA results in a significant (> 1.7-fold) increase in the number of cells capable of adhering to human peritoneal mesothelial cells (HPMC) (p < 0.05). We then corroborate these findings using an ex vivo PM model and show that MA also significantly enhances the ability of GC cells to adhere to strips of human peritoneum (p < 0.05). Using a multiplex ELISA, we identify MIF and VEGF as consistently elevated across MA samples from GC patients (p < 0.05). We demonstrate that agents that block the effects of MIF or VEGF abrogate the ability of MA to stimulate the adhesion of GC cells to adhere to human peritoneum and promote both ex vivo and in vivo metastases.

CONCLUSION

Agents targeting MIF or VEGF may be relevant to the treatment or prevention of PM in GC patients.

Evaluation of second-line apatinib plus irinotecan as a treatment for advanced gastric adenocarcinoma or gastroesophageal conjunction adenocarcinoma: a prospective, multicenter phase II trial

Objective

Apatinib and irinotecan are used as systematic therapies for advanced gastric adenocarcinoma (GAC) and gastroesophageal junction adenocarcinoma (GEJA), while the evidence for their combination as second-line therapy in these patients is limited. This study aimed to evaluate the efficacy and safety of second-line apatinib plus irinotecan for the treatment of GAC and GEJA.

Methods

In this prospective, multicenter phase II clinical study, 28 patients with advanced GAC or GEJA who received second-line apatinib plus irinotecan were recruited.

Results

In total, 1 (3.6%) patient achieved complete response, 7 (25.0%) patients achieved partial response, 13 (46.4%) patients had stable disease, and 4 (14.3%) patients showed progressive disease, while clinical response was not evaluable or not assessed in 3 (10.7%) patients. The objective response rate and disease control rate were 28.6% and 75.0%, respectively. Meanwhile, the median (95% confidence interval (CI)) progression-free survival (PFS) was 4.5 (3.9-5.1) months, and the median (95% CI) overall survival (OS) was 11.3 (7.4-15.1) months. By multivariate Cox regression analysis, male sex, liver metastasis, and peritoneal metastasis were independently associated with worse PFS or OS, while treatment duration ≥5 months was independently associated with better OS. In terms of the safety profile, 89.3% of patients experienced treatment-emergent adverse events of any grade, among which 82.1% of patients had grade 1-2 adverse events and 64.3% of patients had grade 3-4 adverse events.

Conclusion

Apatinib plus irinotecan as second-line therapy achieves a good treatment response and satisfactory survival with tolerable safety in patients with advanced GAC or GEJA.

Effects of Tegafur, Gimeracil and Oteracil Potassium Capsules combined with Calf Spleen Extractive Injection on serum VEGF and MMP-9 in patients with advanced gastric cancer

OBJECTIVE

To explore the effects of Tegafur, Gimeracil and Oteracil Potassium Capsules (TGOPC) combined with Calf Spleen Extractive Injection (CSEI) on vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) in patients with advanced gastric cancer.

METHODS

A retrospective analysis was conducted on data of 118 patients with advanced gastric cancer treated in Anyang Tumor Hospital from January 2016 to September 2018. The patients were divided into two groups according to treatment modalities, with control group receiving Oxaliplatin and TGOPC and observation group receiving Oxaliplatin, TGOPC and CSEI. Clinical efficacy, changes of serum VEGF and MMP-9 before and after chemotherapy, survival rate and incidence of adverse reactions were compared between the two groups.

RESULTS

The number of responded patients was 36 (61.02%) in the observation group and was 18 (30.51%) in the control group (P<0.05). The levels of serum VEGF and MMP-9, and incidence of nausea and vomiting in the observation group were lower than those in the control group (P<0.05). The 1-year and 2-year survival rates in the observation group were higher than those in the control group (P<0.05).

CONCLUSION

The use of CSEI on the basis of Oxaliplatin combined with TGOPC chemotherapy for the treatment of advanced gastric cancer could further improve the clinical efficacy and survival rate, and reduce the incidence of adverse reactions.

Incidental findings on prostate MRI: a close look at the field of view in this anatomical region

Magnetic resonance imaging (MRI) has been widely used as an advanced imaging modality to detect prostate cancer and indicate suspicious areas to guide biopsy procedures. The increasing number of prostate examinations with MRI has provided an opportunity to detect incidental lesions, and some might be very significant to elucidate patient symptoms or occult neoplastic process in the early stages. These incidental lesions might be located in the prostate gland, adjacent tissues, or organs around the prostate gland or out of the genitourinary system. The field of view of prostate MRI includes not only the prostate gland but also other critical pelvic organs in this specific anatomical region. Some of these incidental lesions might cause the same symptoms as prostate cancer and might explain the symptoms of the patient, and some might indicate early cancer stages located outside the prostate. Reporting these lesions might be life-saving by initiating early disease treatment. Awareness of the predicted locations of congenital anomalies would also be beneficial for the radiologists to mention these incidental findings.

Modification of erythrocytes by internalizing Arg-Gly-Asp (iRGD) in boosting the curative effect of radiotherapy for gastric carcinoma

BACKGROUND

Radiation resistance remains the leading cause of radiotherapy (RT) failure. The development of tumor-specific targeted sensitizers is key to overcoming radiation resistance. Our early data showed that cancer cell penetration was simulated by internalizing arginine-glycine-aspartic acid (iRGD), and the irradiation efficacy was improved. The present study aims to design and fabricate iRGD-modified red blood cell (RBCs) for tumor targeting and RT enhancement, and to evaluate its safety and efficacy in vivo.

METHODS

1,2-Distearoyl-sn-glycero-3-phosphoethanolamine-poly ethylene glycol-iRGD (DSPE-PEG-iRGD) was used to modify RBCs by a lipid-insertion method without direct chemical bioconjugation. Fluorescent dyes were used to trace the functional RBCs through confocal microscopy examination. In vitro stability evaluation was performed using cell culture medium incubation for 48 h followed by fluorescence decay assay. Furthermore, a subcutaneous cancer cell mouse model was constructed with MKN-45 cells for target efficacy and RT enhancement evaluation with DSPE-PEG-iRGD-modified RBCs (RBC-iRGD).

RESULTS

Successful construction of RBC-iRGD was verified by the presence of the yellow fluorescence, and an approximately 10⁸ iRGD molecules were labeled on a single RBC. The final RBC-iRGD showed good stability without any hemolytic effects in the cell culture medium. Moreover, higher fluorescence intensity and decreased liver and spleen accumulation could be observed in RBC-iRGD compared to RBC + iRGD in vivo. The RBC-iRGD exerted enhanced radiosensitivity in subcutaneous gastric tumor mice.

CONCLUSIONS

The RBC-iRGD exerted good tumor-targeting efficacy and favorable effects for RT enhancement in vivo.

Hsa_circ_0001020 Serves as a Potential Biomarker for Gastric Cancer Screening and Prognosis

Circular RNAs (circRNAs) are an intriguing class of RNAs with covalently closed-loop structures. With characteristics of high stability and disease-specific expression, circRNAs are emerging as ideal targets for cancer therapy. However, the screening utility and clinical value of circRNAs in gastric cancer (GC) remain largely elusive. We detected levels of hsa_circ_0001020 in cell lines and tissue and plasma samples and investigated its clinicopathological correlations. Kaplan-Meier survival curves and regression analyses were used to analyze its prognostic value. Receiver operating characteristic curves and biomarker combinations were examined to verify its screening value. Bioinformatics analysis was also performed to predict potential biological functions. Our tests found that hsa_circ_0001020 was significantly upregulated in GC cell lines, GC tissue samples, and even in plasma. High hsa_circ_0001020 expression levels in GC tissues were significantly associated with distal metastasis and blood carbohydrate antigen 19-9 (CA19-9). GC patients with high hsa_circ_0001020 had a lower overall survival and disease-free survival time than the low levels. Regression analysis suggested that the level of hsa_circ_0001020 expression was an independent prognostic factor for survival time. As a biomarker for GC, hsa_circ_0001020 showed a superior AUC, sensitivity, and specificity than carcinoembryonic antigen and CA19-9, and was suitable for combination with clinical tumor biomarkers. Bioinformatics analysis provided valuable clues for the possible oncogenic pathways of GC, such as the FoxO and p53 signaling pathways. In conclusion, our study found that hsa_circ_0001020 in GC could be a reliable biomarker to screen for GC and predict prognosis.

Efficacy and Safety of Conversion Therapy by Intraperitoneal and Intravenous Paclitaxel Plus Oral S-1 in Gastric Cancer Patients With Peritoneal Metastasis: A Prospective Phase II Study

BACKGROUND

Neoadjuvant intraperitoneal and systemic chemotherapy (NIPS) has shown promising results in gastric cancer (GC) with peritoneal metastasis. However, clinical practice experience of NIPS is still lacking in China. In this study, we investigate the efficacy and safety of NIPS in Chinese patients.

METHODS

Eligible patients received NIPS every 3 weeks. Gastrectomy was performed for patients who met the criteria of conversion surgery. The primary end point was 1-year overall survival (OS) rate. Secondary end points were the response rate, toxic effects, conversion surgery outcomes and median survival time (MST).

RESULTS

Sixty-seven patients were enrolled. The primary endpoint was achieved with 1-year OS rate reached 67.2% (95% CI, 56.8%-79.4%). Conversion surgery was performed in 42 patients (62.9%), and R0 resection was achieved in 23 patients (54.8%) with the MST of 31.3 months (95% CI, 24.3-38.3). And the MST was 19.3 months (95% CI, 16.4-22.2) for all patients. Toxicity and surgical complications were well-tolerated. Moreover, sex, R0 resection, pathological nodal stage and tumor regression grade (TRG) were independent prognostic factors for patients who underwent conversion surgery.

CONCLUSION

The NIPS is effective and safe in treating GC patients with peritoneal metastasis. Male patients, patients who underwent R0 resection, patients with ypN0-1 or TRG 1 after conversion surgery are more likely to benefit from the NIPS.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/, identifier https://clinicaltrials.gov/ ().

Differences in glucose concentration shows new perspectives in gastric cancer metabolism

Gastric cancer (GC) is among the deadliest cancers worldwide despite available therapies, highlighting the need for novel therapies and pharmacological agents. Metabolic deregulation is a potential study area for new anticancer targets, but the in vitro metabolic studies are controversial, as different ranges of glucose used in the culture medium can influence results. In this study, we evaluated cellular viability, glucose uptake, and LDH activity in gastric cell lines when exposed to different glucose concentrations: high (HG, 25 mM), low (LG, 5.5 mM), and free (FG, 0 mM) glucose mediums. Moreover, we evaluated how glucose variations may influence cellular phenotype and the expression of genes related to epithelial-mesenchymal transition (EMT), metabolism, and cancer development in metastatic GC cells (AGP-01). Results showed that in the FG metastatic cells evidenced higher viability when compared with other cell lines and that when exposed to either LG or HG mediums most of the phenotypic assays did not differ. However, cells exposed to LG increased colony formation and mRNA levels of metabolic-related genes when compared to HG medium. Our results recommend LG medium to metabolic studies once glucose concentration is closer to physiological levels. These findings are important to point out new relevant targets in metabolic reprogramming that can be alternatives to current chemotherapies in patients with metastatic GC.

Impact of Selected Serum Factors on Metastatic Potential of Gastric Cancer Cells

(1) Background: stromal-derived factor-1 (SDF-1/CXCL12), hepatocyte and vascular-endothelial growth factors (HGF and VEGF) have been shown to facilitate cell motility, proliferation and promote local tumor progression and metastatic spread. Recent research shows the important role of these cytokines in gastric cancer (GC) progression. (2) Methods: 21 gastric cancer patients and 19 healthy controls were included in the study. SDF-1, HGF and VEGF levels were evaluated in sera by ELISA. Patients and control sera were used to stimulate CRL-1739 GC cell line, and chemotaxis, adhesion and proliferation potential were assessed. (3) Results: Concentrations of SDF-1, HGF and VEGF were significantly higher in patients than in controls. Chemotaxis and adhesion assays revealed a significant response of GC cells to patients’ serum. Furthermore, significant relationships were seen between chemotactic/adhesion response and tumor stage. Serum from intestinal early GC patients produced significantly stronger chemotactic response when compared to patients with metastatic spread. In turn, serum from patients with distal metastases significantly increased the adhesion of GC cells when compared to sera from the patients with no distal metastases. We also observed that HGF strongly stimulated the proliferation of CRL-1739 cells. (4) Conclusions: We observed that the sera from GC patients, but also SDF-1, HGF and VEGF used alone, have a strong pro-metastatic effect on CRL-1739 cells. We also demonstrated that the concentration of these cytokines is specifically elevated in the sera of patients in an early stage of malignancy. Our results indicate that SDF-1, HGF and VEGF are very important molecules involved in gastric cancer progression.

Oncolytic Virotherapy in Peritoneal Metastasis Gastric Cancer: The Challenges and Achievements

Gastric cancer (GC) is the fourth most common cancer and the second leading cause of cancer death globally. Although the mortality rate in some parts of the world, such as East Asia, is still high, new treatments and lifestyle changes have effectively reduced deaths from this type of cancer. One of the main challenges of this type of cancer is its late diagnosis and poor prognosis. GC patients are usually diagnosed in the advanced stages of the disease, which is often associated with peritoneal metastasis (PM) and significantly reduces survival. This type of metastasis in patients with GC poses a serious challenge due to limitations in common therapies such as surgery and tumor resection, as well as failure to respond to systemic chemotherapy. To solve this problem, researchers have used virotherapy such as reovirus-based anticancer therapy in patients with GC along with PM who are resistant to current chemotherapies because this therapeutic approach is able to overcome immune suppression by activating dendritic cells (DCs) and eventually lead to the intrinsic activity of antitumor effector T cells. This review summarizes the immunopathogenesis of peritoneal metastasis of gastric cancer (PMGC) and the details for using virotherapy as an effective anticancer treatment approach, as well as its challenges and opportunities.

Multi-omic profiling of peritoneal metastases in gastric cancer identifies molecular subtypes and therapeutic vulnerabilities

Peritoneal metastasis, a hallmark of incurable advanced gastric cancer (GC), presently has no curative therapy and its molecular features have not been examined extensively. Here we present a comprehensive multi-omic analysis of malignant ascitic fluid samples and their corresponding tumor cell lines from 98 patients, including whole-genome sequencing, RNA sequencing, DNA methylation and enhancer landscape. We identify a higher frequency of receptor tyrosine kinase and mitogen-activated protein kinase pathway alterations compared to primary GC; moreover, approximately half of the gene alterations are potentially treatable with targeted therapy. Our analyses also stratify ascites-disseminated GC into two distinct molecular subtypes: one displaying active super enhancers (SEs) at the ELF3, KLF5 and EHF loci, and a second subtype bearing transforming growth factor-β (TGF-β) pathway activation through SMAD3 SE activation and high expression of transcriptional enhancer factor TEF-1 (TEAD1). In the TGF-β subtype, inhibition of the TEAD pathway circumvents therapy resistance, suggesting a potential molecular-guided therapeutic strategy for this subtype of intractable GC.

Noncoding RNAs and hyperthermic intraperitoneal chemotherapy in advanced gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors globally. About 20-30% of patients with gastric cancer show peritoneal implantation metastasis at the first diagnosis. Peritoneal metastasis is responsible for 70% of deaths of patients with advanced gastric cancer. Although there are many ways to treat advanced gastric cancer, the prognosis of patients with recurrence is unsatisfactory. An auxiliary treatment with hyperthermic intraperitoneal chemotherapy (HIPEC), is an internationally recognized recommended treatment for advanced gastric cancer. A series of clinical trials have shown that HIPEC significantly improves the overall survival of patients with cancer. Compared with the cytoreductive surgery (CRS) alone, HIPEC combined with CRS markedly reduced the rate of peritoneal metastasis in patients with ovarian cancer and colorectal cancer. It has been demonstrated that HIPEC alters transcription of many genes by affecting non-coding RNAs, which may contribute to the suppressive effect of HIPEC on the synthesis of nucleic acids and proteins in cancer cells. This paper reviews the recent advances in understanding the role of non-coding RNAs in tumor invasion and metastasis of advanced gastric cancer. We also consider changes in noncoding RNA levels and other molecules in advanced gastric cancer cases treated with HIPEC. We hope that our review will provide a reference for future research on molecular epidemiology and etiology of advanced gastric cancer and promote precise treatment of this malignancy using HIPEC.

HIPEC-Induced Acute Kidney Injury: A Retrospective Clinical Study and Preclinical Model

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) combined with cytoreductive surgery (CRS) is the treatment of choice for selected patients with peritoneal malignancies. HIPEC is accompanied by moderate-to-high patient morbidity, including acute kidney injury. The significance of nephrotoxic agents such as cisplatin versus hyperthermia in HIPEC-induced nephrotoxicity has not been defined yet.

PATIENTS AND METHODS

A total of 153 patients treated with HIPEC were divided into groups with (AKI+) and without (AKI-) kidney injury. Laboratory parameters and data concerning patient demographics, underlying disease, surgery, complications, and HIPEC were gathered to evaluate risk factors for HIPEC-induced AKI. A preclinical mouse model was applied to assess the significance of cisplatin and hyperthermia in HIPEC-induced AKI, as well as protective effects of the cytoprotective agent amifostine.

RESULTS

AKI occurred in 31.8% of patients undergoing HIPEC. Treatment with cisplatin-containing HIPEC regimens represented a major risk factor for HIPEC-related AKI (p < 0.001). Besides, angiotensin receptor blockers and increased preoperative creatinine and urea levels were independent risk factors for AKI after HIPEC. In a preclinical mouse model, intraperitoneal perfusion with cisplatin induced AKI, whereas hyperthermia alone, or in combination with cisplatin, did not induce or enhance renal injury. Amifostine failed to confer nephroprotective effects in a miniaturized HIPEC model.

CONCLUSIONS

AKI is a frequent complication after HIPEC. The risk of renal injury is particularly high in patients treated with cisplatin-containing HIPEC regimens. Hyperthermic perfusion of the abdomen by itself does not seem to induce or aggravate HIPEC-induced renal injury.

Clinical Complete Remission of An Advanced Gastric Adenocarcinoma After Camrelizumab Plus Chemotherapy Followed by Camrelizumab Plus Capecitabine: A Case Report

We report a rare case of PDL1-negative advanced gastric adenocarcinoma that improved significantly after camrelizumab plus chemotherapy followed by camrelizumab plus capecitabine as first-line therapy. A 65-year-old woman was diagnosed with a gastric adenocarcinoma in 2017 via contrast-enhanced computed tomography (CT) and endoscopic biopsy. She stabilised after preoperative neoadjuvant chemotherapy, surgery, and postoperative adjuvant chemotherapy. In September 2019, positron emission tomography (PET)/CT re-examination suggested a peritoneal metastasis and multiple lymph node metastases. She then received six cycles of camrelizumab plus chemotherapy. PET/CT indicated that the metastatic foci had disappeared and that she had achieved a clinical complete response(CCR). She was followed-up with camrelizumab plus capecitabine (maintenance therapy). At the time of writing, her progression-free survival is more than 14 months and her quality of life is good. Thus, camrelizumab plus chemotherapy is a useful first-line treatment for HER2- and PD-L1-negative advanced gastric adenocarcinoma.

Oxaliplatin plus S-1 with intraperitoneal paclitaxel for the treatment of Chinese advanced gastric cancer with peritoneal metastases

BACKGROUND

In this study, we tried to access the efficacy and safety of oxaliplatin plus S-1 with intraperitoneal paclitaxel (PTX) for the treatment of Chinese advanced gastric cancer with peritoneal metastases.

PATIENTS AND METHODS

Thirty patients diagnosed with advanced gastric cancer underwent laparoscopic exploration and were enrolled when macroscopic disseminated metastases (P1) were confirmed. PTX was diluted in 1 l of normal saline and IP administered through peritoneal port at an initial dose of 40 mg/m2 over 1 h on day1,8, respectively. Oxaliplatin was administered intravenously at an initial dose of 100 mg/m2 on day1, and S-1 was administered orally at an initial dose of 80 mg/m2 for 14 days followed by 7 days rest, repeated by every 3 weeks.

RESULTS

Of all these 30 patients, the median number of cycles was 6 (range 2-16) due to the limitation of hematotoxicity and peripheral neuropathy by oxaliplatin. There were 11 (36.7%) patients received conversion surgery. The median progression free survival (PFS) was 6.6 months (95% CI = 4.7-8.5 months) and the median overall survival (OS) was 15.1 months (95% CI = 12.4-17.8 months). The grade 3-4 hematological toxicities were leucopenia (23.3%), neutropenia (23.3%), anemia (16.7%), and thrombocytopenia (20%), respectively. The grade 3-4 non-hematological toxicities were tolerated, most of which were peripheral sensory neuropathy (40%) due to oxaliplatin, diarrhea (20%), nausea and vomiting (26.7%).

CONCLUSIONS

SOX+ip PTX regimen was effective in advanced gastric cancer with peritoneal metastasis. Survival time was significantly prolonged by conversion surgery. Grade 3-4 toxicities were uncommon. Large scale clinical trial is necessary to get more evidence to identify its efficacy.

TRAIL REGISTRATION

ChiCTR, ChiCTR-IIR-16009802 . Registered 9 November 2016.

Development and Validation of a Radiomics Model Based on 18F-FDG PET of Primary Gastric Cancer for Predicting Peritoneal Metastasis

Objectives

The aim of this study was to develop a preoperative positron emission tomography (PET)-based radiomics model for predicting peritoneal metastasis (PM) of gastric cancer (GC).

Methods

In this study, a total of 355 patients (109PM+, 246PM-) who underwent preoperative fluorine-18-fludeoxyglucose (¹⁸F-FDG) PET images were retrospectively analyzed. According to a 7:3 ratio, patients were randomly divided into a training set and a validation set. Radiomics features and metabolic parameters data were extracted from PET images. The radiomics features were selected by logistic regression after using maximum relevance and minimum redundancy (mRMR) and the least shrinkage and selection operator (LASSO) method. The radiomics models were based on the rest of these features. The performance of the models was determined by their discrimination, calibration, and clinical usefulness in the training and validation sets.

Results

After dimensionality reduction, 12 radiomics feature parameters were obtained to construct radiomics signatures. According to the results of the multivariate logistic regression analysis, only carbohydrate antigen 125 (CA125), maximum standardized uptake value (SUVmax), and the radiomics signature showed statistically significant differences between patients (P<0.05). A radiomics model was developed based on the logistic analyses with an AUC of 0.86 in the training cohort and 0.87 in the validation cohort. The clinical prediction model based on CA125 and SUVmax was 0.76 in the training set and 0.69 in the validation set. The comprehensive model, which contained a rad-score and the clinical factor (CA125) as well as the metabolic parameter (SUVmax), showed promising performance with an AUC of 0.90 in the training cohort and 0.88 in the validation cohort, respectively. The calibration curve showed the actual rate of the nomogram-predicted probability of peritoneal metastasis. Decision curve analysis (DCA) also demonstrated the good clinical utility of the radiomics nomogram.

Conclusions

The comprehensive model based on the rad-score and other factors (SUVmax, CA125) can provide a novel tool for predicting peritoneal metastasis of gastric cancer patients preoperatively.

Identification of novel prognostic biomarkers by integrating multi-omics data in gastric cancer

BACKGROUND

Gastric cancer is a fatal gastrointestinal cancer with high morbidity and poor prognosis. The dismal 5-year survival rate warrants reliable biomarkers to assess and improve the prognosis of gastric cancer. Distinguishing driver mutations that are required for the cancer phenotype from passenger mutations poses a formidable challenge for cancer genomics.

METHODS

We integrated the multi-omics data of 293 primary gastric cancer patients from The Cancer Genome Atlas (TCGA) to identify key driver genes by establishing a prognostic model of the patients. Analyzing both copy number alteration and somatic mutation data helped us to comprehensively reveal molecular markers of genomic variation. Integrating the transcription level of genes provided a unique perspective for us to discover dysregulated factors in transcriptional regulation.

RESULTS

We comprehensively identified 31 molecular markers of genomic variation. For instance, the copy number alteration of WASHC5 (also known as KIAA0196) frequently occurred in gastric cancer patients, which cannot be discovered using traditional methods based on significant mutations. Furthermore, we revealed that several dysregulation factors played a hub regulatory role in the process of biological metabolism based on dysregulation networks. Cancer hallmark and functional enrichment analysis showed that these key driver (KD) genes played a vital role in regulating programmed cell death. The drug response patterns and transcriptional signatures of KD genes reflected their clinical application value.

CONCLUSIONS

These findings indicated that KD genes could serve as novel prognostic biomarkers for further research on the pathogenesis of gastric cancers. Our study elucidated a multidimensional and comprehensive genomic landscape and highlighted the molecular complexity of GC.

METTL3-mediated m6A methylation of SPHK2 promotes gastric cancer progression by targeting KLF2

N6-methyladenosine (m⁶A) RNA methylation is profoundly involved in epigenetic regulation, especially for carcinogenesis and tumor progression. Mounting evidence suggests that methyltransferase METTL3 regulates malignant behaviors of gastric cancer (GC). However, the clinical significance and biological implication of SPHK2 and its related m⁶A modification in GC remain unclear. In this study, quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry were utilized to detect the expression profiles and prognostic significance of SPHK2 in GC. Here, we showed that increased SPHK2 was signified a poor prognosis of GC patients. Phosphorylation and ubiquitination assays were used to investigate the possible mechanisms of SPHK2-mediated KLF2 expression. SPHK2 can promote the phosphorylation of KLF2, which triggers the ubiquitination and degradation of KLF2 protein in GC. Methylated RNA immunoprecipitation (MeRIP) was performed to uncover the m⁶A modification of SPHK2 mRNA. METTL3 promotes translation of SPHK2 mRNA via an m⁶A-YTHDF1-dependent manner. Functionally, SPHK2 facilitates GC cell proliferation, migration and invasion by inhibiting KLF2 expression. SPHK2/KLF2 regulates the cell proliferation, migration, and invasion induced by METTL3 in GC. Overall, our findings reveal that METTL3-mediated m⁶A modification of SPHK2 contributes to GC progression, which extends the understanding of the importance m⁶A methylation in GC and represents a potential target for GC therapy.

Intraperitoneal Administration of Paclitaxel Combined with S-1 Plus Oxaliplatin as Induction Therapy for Patients with Advanced Gastric Cancer with Peritoneal Metastases

Background

Intraperitoneal (IP) administration of paclitaxel (PTX) has a great pharmacokinetic advantage to control peritoneal lesions and can be combined with various systemic chemotherapies. In this study, we evaluate the efficacy and tolerability of a combination of IP-PTX and systemic S-1/oxaliplatin (SOX) for induction chemotherapy for patients with peritoneal metastases (PM) from gastric cancer (GC).

Patients and Methods

Patients with GC who were diagnosed as macroscopic PM (P1) or positive peritoneal cytology (CY1) by staging laparoscopy between 2016 and 2019 were enrolled. PTX was IP administered at 40 mg/m² on days 1 and 8. Oxaliplatin was IV administered at 100 mg/m² on day 1, and S-1 was administered at 80 mg/m²/day for 14 consecutive days, repeated every 21 days. Survival time and toxicities were retrospectively explored.

Results

Forty-four patients received SOX + IP-PTX with a median (range) of 16 (1–48) courses, although oxaliplatin was suspended due to the hematotoxicity or intolerable peripheral neuropathy in many patients. The 1-year overall survival (OS) rate was 79.5% (95% CI 64.4–88.8%) with median survival time of 25.8 months. Gastrectomy was performed in 20 (45%) patients who showed macroscopic shrinkage of PM with a 1-year OS rate of 100% (95% CI 69.5–100%). Grade 2 and 3 histological responses was achieved in four (20%) and one (5%) patients. Grade 3/4 toxicities included neutropenia (11%), leukopenia (39%), and anemia (14%). There were no treatment-related deaths.

Conclusions

Combination chemotherapy using SOX + IP-PTX regimen is highly effective and recommended as induction chemotherapy for patients with PM from GC.

Second-line chemotherapy using taxane in patients with advanced gastric cancer who presented with severe peritoneal metastasis: a multicenter retrospective study

BACKGROUND

Individuals with advanced gastric cancer (AGC) who present with severe peritoneal metastasis (SPM) have poor prognosis. This study aimed to evaluate efficacy and safety of second-line treatment for patients with such condition.

METHODS

This retrospective study included patients receiving taxane-based second-line chemotherapy at three Japanese institutions between 2010 and 2016. Patients with AGC who present with SPM were included if they had massive ascites and/or inadequate oral intake requiring intravenous nutritional support.

RESULTS

In this study, 43 (40%) of 108 patients had an Eastern Cooperative Oncology Group Performance Status score ≥ 2, and the median serum albumin level of the patients was 3.3 g/dL. Ramucirumab was used in combination with paclitaxel in 21 patients. The median overall survival (OS) and progression-free survival (PFS) were 5.1 and 2.8 months, respectively. Inadequate oral intake was considered a negative prognostic factor of both OS and PFS in the multivariate analysis. Three treatment-related deaths were observed, which include those attributed to febrile neutropenia, gastrointestinal perforation, and pneumonitis. Common grade ≥ 3 adverse events were neutropenia (35%), leukopenia (30%), anemia (24%), and anorexia (16%). We observed febrile neutropenia in 8% and gastrointestinal perforation in 4% of patients, and such conditions were dominantly observed in patients with inadequate oral intake.

CONCLUSION

Taxane-based second-line chemotherapy was effective and safe for patients with AGC who present with SPM. Attention must be provided when treating patients with inadequate oral intake as they are likely to have short prognosis and serious toxicities.

Chimeric Antigen Receptor T Cell Therapy Targeting ICAM-1 in Gastric Cancer

Cancer therapy utilizing adoptive transfer of chimeric antigen receptor (CAR) T cells has demonstrated remarkable clinical outcomes in hematologic malignancies. However, CAR T cell application to solid tumors has had limited success, partly due to the lack of tumor-specific antigens and an immune-suppressive tumor microenvironment. From the tumor tissues of gastric cancer patients, we found that intercellular adhesion molecule 1 (ICAM-1) expression is significantly associated with advanced stage and shorter survival. In this study, we report a proof-of-concept study using ICAM-1-targeting CAR T cells against gastric cancer. The efficacy of ICAM-1 CAR T cells showed a significant correlation with the level of ICAM-1 expression in target cells in vitro. In animal models of human gastric cancer, ICAM-1-targeting CAR T cells potently eliminated tumors that developed in the lungs, while their efficacy was more limited against the tumors in the peritoneum. To augment CAR T cell activity against intraperitoneal tumors, combinations with paclitaxel or CAR activation-dependent interleukin (IL)-12 release were explored and found to significantly increase anti-tumor activity and survival benefit. Collectively, ICAM-1-targeting CAR T cells alone or in combination with chemotherapy represent a promising strategy to treat patients with ICAM-1+ advanced gastric cancer.

Rapid Detection of Free Cancer Cells in Intraoperative Peritoneal Lavage Using One-Step Nucleic Acid Amplification (OSNA) in Gastric Cancer Patients

Cytokeratin-19 (CK19) has been proven to be commonly expressed by cancer cells in a variety of solid tumors and may serve as a suitable marker of metastases in gastric cancer (GC). Since objective assessment of peritoneal lavage or fluid for free cancer cells (FCC) is essential for clinical decision making in patients with GC, it is important to develop a quantitative and reproducible method for such evaluation. We assessed the possible application of One-Step Nucleic Acid amplification (OSNA) assay as a rapid method for FCC detection in intraoperative peritoneal lavage or fluid of GC patients. Seventy-eight intraoperative peritoneal lavage or fluid samples were eligible for the analysis by conventional cytology and OSNA examination. The concentration of CK19 mRNA in intraoperative peritoneal lavage and fluid was compared with the conventional cytological assessment. CK19 mRNA concentration was detected by OSNA assay. For peritoneal lavage samples, sensitivity and specificity were 83.3% and 87.8%, respectively. In peritoneal fluid, significantly higher CK19 values were observed in patients with serosal infiltration (medians: 100 copies/µL vs. 415.7 copies/µL; p = 0.0335) and lymph node metastases (medians: 2.48 copies/µL vs. 334.8 copies/µL). OSNA assay turns out to be an objective, fast, and reproducible quantitative method of FCC assessment.

Biomimetic construction of peritoneum to imitate peritoneal metastasis using digital micromirror device-based optical projection lithography

Currently, the mechanisms underlying the peritoneal metastasis of gastric cancer cells and the function of mesothelial cells during this process are unclear, primarily due to the absence of an effective in vitro peritoneal model. In this study, we constructed a biomimetic peritoneal model using a digital micromirror device-based optical projection lithography system. This model enabled the simulation of a damaged peritoneum, which allowed for a comparison of the characteristics of an undamaged peritoneum, such as porosity, mechanical properties, and surface morphology, with those of a damaged peritoneum. Biological inertness and removability of the polyethylene glycol dimethacrylate hydrogel were exploited to fabricate an arrayed heterogeneous interface that imitated a damaged human peritoneum. The porous structure of the peritoneum was achieved by adjusting the ratio of collagen I to gelatin methacryloyl; this structure of the peritoneum might contribute to its shock absorption property. Atomic force microscopy characterization showed that the outermost layers of the model peritoneum and real peritoneum were similar in surface morphology and mechanical properties. Furthermore, we reproduced the process of peritoneal metastasis in vitro. The numbers of gastric cancer cells that adhered to the heterogeneous interface were different, and mesothelial cells played an essential role in peritoneal metastasis. Our findings indicate that this model can be utilized in preclinical drug screening and personalized therapy.

Molecular mediators of peritoneal metastasis in pancreatic cancer

Pancreatic cancer is the third leading cause of cancer death in the USA, and pancreatic ductal adenocarcinoma (PDA) constitutes 85% of pancreatic cancer diagnoses. PDA frequently metastasizes to the peritoneum, but effective treatment of peritoneal metastasis remains a clinical challenge. Despite this unmet need, understanding of the biological mechanisms that contribute to development and progression of PDA peritoneal metastasis is sparse. By contrast, a vast number of studies have investigated mechanisms of peritoneal metastasis in ovarian and gastric cancers. Here, we contrast similarities and differences between peritoneal metastasis in PDA as compared with those in gastric and ovarian cancer by outlining molecular mediators involved in each step of the peritoneal metastasis cascade. This review aims to provide mechanistic insights that could be translated into effective targeted therapies for patients with peritoneal metastasis from PDA.

Lobaplatin in Prophylactic Hyperthermic Intraperitoneal Chemotherapy for Advanced Gastric Cancer: Safety and Efficacy Profiles

OBJECTIVE

This study aims to evaluate the safety and efficacy of lobaplatin in prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) for advanced gastric cancer.

METHODS

Advanced gastric cancer patients who underwent radical gastric resection and/or prophylactic HIPEC were systematically reviewed in our department from January 2016 to June 2017. All enrolled patients were grouped in either HIPEC or non-HIPEC groups. Clinical data were collected and analyzed.

RESULTS

A total of 129 patients were enrolled with 61 cases in the HIPEC group and 68 in the non-HIPEC group. The two groups were well balanced in terms of clinical characteristics. In patients of the HIPEC group, three suffered leakage from the duodenal stump or anastomosis, one suffered abnormal bleeding and two were found to have abnormal routine blood tests; no significant difference in adverse events between groups, however, was noted (p > 0.05) and most patients recovered uneventfully. During follow-up, peritoneal recurrence was significantly less among HIPEC patients (p = 0.029), with only three suffering peritoneal recurrence, as compared to 12 non-HIPEC patients. In addition, the estimated illness-specific 3-year disease-free survival rate was significantly higher in the HIPEC group as compared to the non-HIPEC group (89.4% vs.73.9%; p = 0.031).

CONCLUSION

Lobaplatin in prophylactic HIPEC is safe for advanced gastric cancer patients after treatment by radical resection and can effectively improve illness-specific 3-year disease-free survival.

Luteolin Suppresses the Proliferation of Gastric Cancer Cells and Acts in Synergy with Oxaliplatin

Objective. Gastric cancer, one of the most common malignant tumors worldwide, arises from the gastric mucosal epithelium and severely affects patient health and quality of life. Luteolin (LUT) is a flavonoid found in vegetables and fruits with diverse functions. A large number of studies have confirmed that LUT has an antitumor effect. Therefore, this study is aimed at verifying whether LUT can exert antitumor effects in synergy with oxaliplatin (OXA). As such, we examined the effects of LUT, OXA, and their coadministration in a gastric adenocarcinoma cell line (SGC-7901). We used the MTT assay to quantify the proliferation of SGC-7901 cells, flow cytometry to detect the cell cycle and apoptosis, ELISA to detect the expression of cell-cycle-related proteins, and western blot to detect the expression of related apoptotic factors. The results of this study show that the combination of LUT and OXA inhibited SGC-7901 cell proliferation and induced apoptosis by altering cell-cycle proportions. In addition, the combination also activated Cyt c/caspase signaling in SGC-7901 cells. In summary, LUT synergy with OXA inhibited the proliferation of gastric cancer cells in vitro. The present study also elucidated the mechanism by which LUT potentiated the sensitivity of SGC-7901 cells to OXA through the Cyt c/caspase pathway.

The Impact of Ramucirumab Treatment on Survival and Quality of Life in Patients with Gastric Cancer

Gastric cancer is the sixth most common cancer and is known to be the fifth-leading cause of cancer-related deaths globally in 2018. Systemic therapy remains the only curative option in advanced gastric carcinoma with the primary goal of improving the Health-related Quality of Life (HRQoL) (including palliation of symptoms such as dysphagia) and prolonging overall survival. Recently, ramucirumab is approved by the United States Food and Drug Administration (US-FDA) as a second-line agent either as monotherapy or in combination with paclitaxel in advanced or metastatic gastric and gastro-esophageal junction adenocarcinoma patients who have progressed on prior treatment with fluoropyrimidine or platinum containing chemotherapy. HRQoL is a subjective term that typically constitutes four components - psychological, social, occupational and physical well being. This has been evaluated as secondary endpoint in the pivotal Phase III trials with ramucirumab. HRQoL measurement can potentially provide additional information for clinical decision making beyond that of traditional medical outcomes. The present work is primarily focused on discussing HRQoL in gastric cancer patients and the impact of ramucirumab on the HRQoL in the patients with advanced gastric cancer. We also summarized the studies that evaluated the benefits of systemic therapies on HRQoL in advanced gastric cancer.

Issues on peritoneal metastasis of gastric cancer: an update

BACKGROUND

Peritoneal metastasis (PM) is one of the most common forms of metastasis with a very poor prognosis in patients with gastric cancer (GC). The mechanisms, diagnosis, and management of PM remain controversial.

MAIN BODY

Stephen Paget's "seed-and-soil" hypothesis gives us an illustration of the mechanisms of PM. Recently, hematogenous metastasis and exosomes from GC are identified as novel mechanisms for PM. Diagnostic accuracy of conventional imaging modalities for PM is not satisfactory, but texture analysis may be a useful adjunct for the prediction of PM. Biological markers in peritoneal washings are helpful in identifying patients at high risk of PM, but many limitations remain to be overcome. Response of PM from systemic chemotherapy alone is very limited. However, conversion therapy is confirmed to be safe and able to prolong the survival of GC patients with PM. As an important part of conversion therapy, intraperitoneal chemotherapy with taxanes has become an ideal approach with several advantages. Additionally, gastrectomy should be considered in patients who would tolerate surgery if a remarkable response to chemotherapy was observed.

CONCLUSION

Texture analysis is a reliable adjunct for the prediction of PM, and conversion therapy provides a new choice for GC patients with PM. The underlying mechanisms and new biological markers for GC patients with PM should be the direction of future studies. Furthermore, significant aspects of conversion therapy, such as timing and method of the operation, and the indications remain to be clarified.

Surgical management of metastatic gastric cancer: moving beyond the guidelines

Despite decreasing incidence, gastric cancer remains a major health problem worldwide and is associated with poor survival. The poor survival is mainly attributed to delayed presentation which may cause local or systemic metastases. The standard of care for patients with metastatic gastric cancer (MGC) is palliative chemotherapy with best supportive care. Although the survival has improved owing to advances in chemotherapeutic agents, it is still unsatisfactory, and some perspective changes are needed in the management of MGC to improve the outcomes. Therefore, various alternative treatment strategies for MGC have formed the most important research topics. Liver-directed treatment (LDT) options such as liver resection, radiofrequency ablation (RFA), microwave ablation (MWA), and hepatic artery infusion chemotherapy (HAIC) have been studied in the management of liver metastasis from gastric cancer (LMGC). Intraperitoneal chemotherapy (IPC) in addition to cytoreductive surgery (CRS) aiming to remove all macroscopic tumor focus resulting from peritoneal dissemination is the treatment option for peritoneal metastasis, while para-aortic lymph node dissection is the treatment option for para-aortic lymph node metastasis which is considered to be M1 disease. Conversion surgery is a novel concept aiming at R0 resection for originally unresectable or marginally resectable tumors after a remarkably good response to the chemotherapy. Large amounts of data in the literature have demonstrated the benefits of individualized approaches such as the combination of systemic and local treatment options in selected patient groups. In this review, we aimed to explore the current and future treatment options by reviewing the literature on this controversial topic.

Fluoropyrimidine with or without platinum as first-line chemotherapy in patients with advanced gastric cancer and severe peritoneal metastasis: a multicenter retrospective study

BACKGROUND

There is no standard first-line chemotherapy for advanced gastric cancer with severe peritoneal metastasis. Although fluoropyrimidine is often used, its efficacy is limited, and it remains unclear whether combination therapy with platinum improves clinical outcomes.

METHODS

This retrospective study involved patients at six Japanese academic hospitals between 2010 and 2016. Patients with advanced gastric cancer and severe peritoneal metastasis were included if they had massive ascites and/or inadequate oral intake requiring intravenous nutritional support. We then compared the efficacy and safety of fluoropyrimidine monotherapy with those of fluoropyrimidine/platinum combination therapy.

RESULTS

Compared with the combination therapy group (n = 64), the monotherapy group (n = 65) had worse general health (more patients with elderly age, performance status > 2, and having both massive ascites and inadequate oral intake). Both overall survival (9.0 vs 5.0 months, p < 0.01) and progression-free survival (4.3 vs 2.3 months, p < 0.01) were significantly longer in the combination group, and the significance remained after adjusting for prognostic variables (hazard ratios of 0.47 and 0.41, respectively; p < 0.01). Improvements in ascites and oral intake were also greater in the combination group. Although neutropenia (grade ≥ 3) occurred more frequently with combination therapy, both treatments in this study were tolerable.

CONCLUSIONS

Combination therapy with fluoropyrimidine and platinum might be more effective than monotherapy with fluoropyrimidine and was tolerable for patients with advanced gastric cancer and severe peritoneal metastasis.

iRGD synergizes with PD-1 knockout immunotherapy by enhancing lymphocyte infiltration in gastric cancer

Poor infiltration of activated lymphocytes into tumors represents a fundamental factor limiting the therapeutic effect of adoptive cell immunotherapy. A tumor-penetrating peptide, iRGD, has been widely used to deliver drugs into tumor tissues. In this study, we demonstrate for the first time that iRGD could also facilitate the infiltration of lymphocytes in both 3D tumor spheroids and several xenograft mouse models. In addition, combining iRGD modification with PD-1 knockout lymphocytes reveals a superior anti-tumor efficiency. Mechanistic studies demonstrate that the binding of iRGD to neuropilin-1 results in tyrosine phosphorylation of the endothelial barrier regulator VE-cadherin, which plays a role in the opening of endothelial cell contacts and the promotion of transendothelial lymphocyte migration. In summary, these results demonstrate that iRGD modification could promote tumor-specific lymphocyte infiltration, and thereby overcome the bottleneck associated with adoptive immune cell therapy in solid tumors.

The therapeutic efficacy of adoptive T cell transfer is limited by their ability to infiltrate solid tumours. Here, the authors show that loading the tumor penetrating cyclic peptide iRGD on the cell surface of T cells enhances their ability to penetrate the tumour, resulting in enhanced efficacy in a mouse model of gastric cancer.

Co-operative groups in the development of chemotherapy for gastric cancer

In the multimodality treatment strategy for gastric cancer, chemotherapy has an important role in conferring survival benefit. For the last three decades, great progress has been achieved in adjuvant and palliative chemotherapy. Powerful combination regimens using doublet or triplet cytotoxic agents have been developed and new molecular targeted drugs, including trastuzumab and ramucirumab, have been introduced in clinical practice. These advances have resulted from the accumulation of many clinical trials. A well-designed phase III trial can change standard treatment; however, such a trial is hard to complete due to its huge cost and need to recruit many patients. Some co-operative groups have actively made efforts at fundraising and patient recruitment, which can make implementation of high-quality and large-scale phase III trials possible. This review summarizes the development of chemotherapy for gastric cancer with focus on co-operative groups around the world, considering effective treatment developments in gastric cancer. We studied 11 active co-operative groups, including six in Europe, two in the United States, and three in Japan, that have completed one or more phase III trials cited in the major guidelines. Each co-operative group had its own characteristics and contributed to the establishment of standard treatment in each region. International collaboration in the development of gastric cancer treatment may be difficult due to regional differences in standards of care, particularly for resectable gastric cancer. Whereas, intergroup collaboration within each region is a reasonable method to effectively develop treatments for resectable and advanced gastric cancer.

Regulatory network analysis of high expressed long non-coding RNA LINC00941 in gastric cancer

Accumulating evidence suggests that the aberrant expression of long non-coding RNAs is closely related to the carcinogenesis and progression of gastric cancer (GC), which is a type of prevalent tumor with a high incidence and mortality rate. However, it is still a challenge to find reliable biomarkers and to understand their molecular mechanisms in GC. In this study, we first confirmed that LINC00941was up-regulated in GC tumor tissues compared with adjacent normal tissues by RT-PCR, and found that the expression level of LINC00941 was correlated with invasion depth, lymphatic metastasis, and the TNM stage of patients with GC. Furthermore, by performing enrichment analysis based on the co-expression network and regulatory network, we found that LINC00941 was associated with cancer related biological processes such as cell cycle, cell communication, cell migration, cell division, as well as processes associated with the immune system. Our results suggested that LINC00941 may be a potential novel biomarker for therapeutic or diagnostic of GC.

TMEM119 silencing inhibits cell viability and causes the apoptosis of gastric cancer SGC-7901 cells

Gastric cancer is the second major cause of death associated with cancer and ranks among the top four cancers diagnosed worldwide. Previous findings identified the association of transmembrane proteins (TMEMs) with tumorigenesis of various types of cancer, including breast, liver and kidney cancer. However, the expression and the biological function of TMEMs, especially TMEM119, and its possible molecular mechanism in gastric cancer remain less understood. CCK-8 and flow cytometric analysis was employed to examine the viability and apoptosis of gastric adenocarcinoma SGC-7901 and AGS cells, gastric carcinoma MKN45 cells, as well as gastric epithelial cell lines GES-1 after transfection with TMEM119-siRNA (siTMEM119), respectively. Quantitative PCR, western blot analysis and immunohistochemistry was performed to detect the expression levels of TMEM119, Bax, Bcl-2 and caspase-3. The results showed that, TMEM119 was elevated with the highest expression detected in SGC-7901 cells compared to AGS cells, MKN45 cells, as well as GES-1. TMEM119 silencing in the gastric cancer cell line, SGC-7901, significantly inhibited cell viability and induced apoptosis. The downregulation of TMEM119 exhibited reduced levels of Bcl-2 and higher levels of Bax and caspase-3 in SGC-7901 cells. These results suggest that TMEM119 is useful in the treatment of gastric cancer.

Follow-up after curative resection for gastric cancer: Is it time to tailor it?

There is still no consensus on the follow-up frequency and regimen after curative resection for gastric cancer. Moreover, controversy exists regarding the utility of follow-up in improving survival, and the recommendations of experts and societies vary considerably. The main reason to establish surveillance programs is to diagnose tumor recurrence or metachronous cancers early and to thereby provide prompt treatment and prolong survival. In the setting of gastric malignancies, other reasons have been put forth: (1) the detection of adverse effects of a previous surgery, such as malnutrition or digestive sequelae; (2) the collection of data; and (3) the identification of psychological and/or social problems and provision of appropriate support to the patients. No randomized controlled trials on the role of follow-up after curative resection of gastric carcinoma have been published. Herein, the primary retrospective series and systematic reviews on this subject are analyzed and discussed. Furthermore, the guidelines from international and national scientific societies are discussed. Follow-up is recommended by the majority of institutions; however, there is no real evidence that follow-up can improve long-term survival rates. Several studies have demonstrated that it is possible to stratify patients submitted to curative gastrectomy into different classes according to the risk of recurrence. Furthermore, promising studies have identified several molecular markers that are related to the risk of relapse and to prognosis. Based on these premises, a promising strategy will be to tailor follow-up in relation to the patient and tumor characteristics, molecular marker status, and individual risk of recurrence.