Programmed death-ligand 1 is a promising blood marker for predicting tumor progression and prognosis in patients with gastric cancer

Immunohistochemical-Based Molecular Typing of ACRG Combined With Immune-Associated PD-L1 Expression Can Predict the Prognosis of Gastric Cancer

BACKGROUND

Gastric cancer (GC) is a molecularly heterogeneous disease with diverse clinical outcomes. Traditional classifications lack predictive accuracy, necessitating alternative molecular subtyping approaches for effective prognosis prediction. The Asian Cancer Research Group (ACRG) molecular subtypes, combined with immune-associated PD-L1 expression, offer a promising framework to predict patient outcomes and potentially guide treatment strategies in GC.

METHODS

This study retrospectively analyzed 1007 primary GC patients who underwent surgical resection between January 2017 and June 2019 at the Fourth Hospital of Hebei Medical University. Comprehensive immunohistochemical and fluorescent PCR-capillary electrophoresis analyses were conducted to determine ACRG molecular subtypes (microsatellite instability [MSI], microsatellite stability with epithelial-mesenchymal transition [MSS/EMT], MSS/TP53+, and MSS/TP53-) and PD-L1 expression. We assessed the relationship between these classifications and various clinicopathological parameters, including survival outcomes, using Cox regression and Kaplan-Meier analysis.

RESULTS

The ACRG subtypes showed significant associations with clinicopathological features, including tumor invasion depth, Lauren classification, and HER2 status. The MSI subtype (6.7% of cases) was associated with higher PD-L1 positivity and a favorable prognosis, whereas the EMT subtype had the lowest 5-year survival rate (34.55%) and was predominantly linked to diffuse-type histology. PD-L1 positivity correlated with worse survival outcomes, with independent predictive value alongside ACRG subtypes (HR for PD-L1 = 1.759, p = 0.001; HR for ACRG = 5.144, p < 0.001).

CONCLUSION

The combination of ACRG molecular subtyping and PD-L1 expression serves as an effective predictor of GC prognosis, facilitating tailored clinical decision-making. The ACRG-PD-L1 classification system offers a practical, cost-effective approach for routine clinical application, providing critical insight into GC heterogeneity. Further multicenter studies are needed to validate these findings and explore the impact of ACRG subtypes on therapy responses, particularly in immunotherapy settings.

Comparative efficacy of programmed death ligand 1 inhibition and chemotherapy in advanced gastric or gastroesophageal junction cancer with combined positive score - a meta-analysis

Advanced gastric and gastroesophageal junction cancer (G/GEJC) poses significant therapeutic challenges. Immune checkpoint inhibitors, particularly targeting programmed cell death ligand-1 (PD-L1), have emerged as promising agents to enhance patient outcomes. This meta-analysis evaluates the efficacy of PD-L1 inhibitors compared to chemotherapy in patients with advanced G/GEJC characterised by varying combined positive scores (CPS). We systematically searched PubMed, Google Scholar, and Web of science for clinical trial studies comparing PD-L1 inhibitors and chemotherapy in CPS-positive patients, focusing on studies published up to 10 April 2023. Studies were evaluated with risk of bias tools. The primary clinical endpoint analysed in this study was overall survival (OS), and the secondary endpoint was progression-free survival (PFS). This study is registered with Prospero (CRD42023495607). A total of 10 studies comprising 4522 participants were included. Our analysis revealed no statistically significant difference in CPS values between PD-L1 inhibitors and chemotherapy groups (≥ 1 : 1.03 [95% CI: 0.86-1.24], ≤ 1 : 0.92 [95% CI: 0.77-1.11]). However, the pooled hazard ratio for OS favoured PD-L1 inhibitors (hazard ratios - HR, 0.83, [95% CI: 0.78-0.88] and p < 0.00001), while PFS was better after chemotherapy (HR 1.28, [95% CI: 1.04-1.58], p = 0.02). Program death ligand-1 inhibitors improve OS, while chemotherapy enhances PFS in advanced G/GEJC, warranting further investigation into the impact of CPS on treatment outcomes.

Evolving perspectives regarding the role of the PD-1/PD-L1 pathway in gastric cancer immunotherapy

Gastric cancer (GC) is an increasing global health problem and is one of the leading cancers worldwide. Traditional therapies, such as radiation and chemotherapy, have made limited progress in enhancing their efficacy for advanced GC. The development of immunotherapy for advanced GC has considerably improved with a deeper understanding of the tumor microenvironment. Immunotherapy using checkpoint inhibitors is a new therapeutic option that has made substantial advances in the treatment of other malignancies and is increasingly used in other clinical oncology treatments. Particularly, therapeutic antibodies targeting the programmed cell death protein-1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway have been effectively used in the clinical treatment of cancer. Monoclonal antibodies blocking the PD-1/PD-L1 pathway have been developed for cancer immunotherapy to enhance T cell function to restore the immune response and represent a breakthrough in the treatment of GC. This review provides an outline of the progress of PD-1/PD-L1 blockade therapy and its expression characteristics and clinical application in advanced GC.

Prognostic value of PD‑L1 expression and CD68 macrophages in tumor nest of patients with primary gastric cancer

The programmed death receptor 1/programmed death receptor ligand 1 axis (PD-1/PD-L1) is involved in tumor immune escape and is a potential prognostic biomarker and anti-tumor immunotherapy target in patients with gastric cancer (GC). However, the results of studies obtained in recent years have been inconsistent. The present study aimed to determine the possible predictive significance of PD-L1 in conjunction with three proteins linked with PD-L1 regulation in patients with primary GC. In the present study, the PD-L1, human epidermal growth factor receptor 2 (HER2), cluster of differentiation (CD)133 and microphage-associated CD68 expression levels were identified by multiplexed immunohistochemistry and assessed by automated pathological analysis system in 93 GC tumors and neighboring normal tissues arrayed on the same tissue microarray. All four proteins were statistically analyzed in relation to the clinicopathological characteristics. The expression levels of HER2, CD133 and CD68 were considerably higher in cancer tissues compared with neighboring normal tissues (P<0.05), however, the reverse trend was detected for PD-L1 expression (P=0.0577), particularly in tumor nest (TN; P<0.05). There was no significant correlation between the HER2 and CD133 expression levels and clinicopathological factors. However, significant relationships were found between PD-L1 expression and the TNM stage, pathological differentiation and survival status of patients (P<0.05). Moreover, survival time was prolonged in individuals with elevated PD-L1 expression in TN and GC tissues, but no significant correlation was identified (P=0.0881). The CD68 expression level in tumor stroma, but not in TN, was significantly correlated with poor pathological differentiation in patients with GC (P<0.05). However, PD-L1+CD68+ macrophages were strongly related to lower tumor size (diameter <5 cm), early TNM stage (stage I+II), good pathological differentiation and overall survival in TN (P<0.05). In conclusion, PD-L1+CD68+ macrophage infiltration in TN might be a potential indicator of prognosis in patients with primary GC and merits further investigation.

Efficacy and safety of PD‑1/PD‑L1 inhibitors combined with chemotherapy in patients with advanced gastric or gastro‑esophageal junction cancer: A systematic review and meta‑analysis

Although the efficacy and safety of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitor combined with chemotherapy vs. chemotherapy alone has been analyzed, there have been no in-depth studies on the outcomes of patients with PD-L1 positive advanced gastric or gastro-esophageal junction cancer patients (GC/GEJC). This systematic review and meta-analysis focused on comparing the efficacy and safety of PD-1/PD-L1 inhibitors vs. PD-1/PD-L1 inhibitors combined with chemotherapy vs. chemotherapy in PD-L1 positive advanced GC/GEJC patients, aiming to provide more precise guidance for the clinical treatment of GC/GEJC. In this meta-analysis, PubMed, Embase, and Cochrane Library were searched from the establishment of the database till June 2022. Randomized controlled trials (RCTs) in which control patients underwent chemotherapy and experimental group patients underwent PD-1/PD-L1 inhibitors or PD-1/PD-L1 inhibitors combined with chemotherapy were included in this investigation. Investigations without complete information, studies from which information could not be extracted, duplicate articles, animal studies, review articles, and systematic reviews were excluded. The pooled results suggested that chemotherapy combined with immunotherapy prolonged overall survival (OS) in patients with advanced GC/GEJC, while progression free-survival (PFS) with PD-1/PD-L1 inhibitors alone or in combination with chemotherapy were all improved compared with chemotherapy alone. However, PD-1/PD-L1 inhibitors did not significantly increase objective response rates (ORR) in PD-L1-positive patients compared with chemotherapy, but in combination with chemotherapy, they did improve ORR. The pooled results also showed that patients treated with PD-1/PD-L1 inhibitors had higher stable disease (SD) and progressive disease (PD) rates compared to chemotherapy in PD-L1-positive patients. Additionally, in PD-L1-positive patients, PD-1/PD-L1 inhibitors alone or combined with chemotherapy increased OS compared with chemotherapy alone. However, PD-1/PD-L1 inhibitors only prolonged PFS compared with chemotherapy alone in patients with a combined positive score (CPS; 100% of cells were required to be positively stained) for PD-L1, but when combined with chemotherapy, OS and PFS were prolonged in all PD-L1-positive patients compared with chemotherapy alone. Finally, the pooled results showed that the incidence of adverse events of PD-1/PD-L1 inhibitors in PD-L1-zpositive patients was significantly lower than that in patients treated with chemotherapy alone. In conclusion, single agent of PD-1/PD-L1 inhibitor alone or combined with chemotherapy significantly prolongs the survival of patients compared with chemotherapy alone, with fewer adverse effects. However, the degree of CPS may affect efficacy, thus further investigation is required.

Impact of Programmed Death-Ligand 1 Expression on Mismatch Repair Deficiency and Epstein-Barr Virus Status on Survival Outcomes in Patients with Stage II/III Gastric Cancer After Surgery

BACKGROUND

The aim of this study was to investigate the prognostic impact of mismatch repair (MMR) status, programmed death-ligand 1 (PD-L1) expression, and Epstein-Barr virus (EBV) status in stage II/III gastric cancer after surgery.

METHODS

This study included 679 patients diagnosed with pathological stage II/III gastric cancer who underwent curative gastrectomy followed by adjuvant chemotherapy (AC) or observation between 2007 and 2015. Clinical outcomes were retrospectively reviewed and compared with stratification by AC and other clinicopathological factors.

RESULTS

Patients were divided into AC (n = 484) or surgery alone (SA; n = 195) groups and were further stratified by MMR and EBV status: MMR-deficient (DMMR) and MMR-proficient (PMMR) groups. Comparing the AC-DMMR group versus the AC-PMMR group, 5-year overall survival was 92.0% versus 74.0% (log-rank p < 0.01), and comparing the SA-DMMR group versus the SA-PMMR group, 5-year overall survival was 71.1% versus 73.7% (log-rank p = 0.89). DMMR (hazard ratio 0.25, 95% confidence interval 0.07-0.81) was identified as an independent prognostic factor in the AC group but not in the SA group. In the subgroup analysis, PD-L1-negative patients among the EBV-positive patients or in the DMMR group had a poor prognosis in both the AC and SA groups. The prognosis of the PMMR and EBV-negative patients was similar regardless of PD-L1 expression.

CONCLUSIONS

DMMR was associated with a favorable prognosis in stage II/III gastric cancer after surgery and adjuvant therapy. PD-L1 expression may affect the prognosis of DMMR and EBV-positive gastric cancer.

LncRNA NCK1-AS1-mediated regulatory functions in human diseases

Disease development requires the activation of complex multi-factor processes involving numerous long noncoding RNAs (lncRNAs), which describe non-protein-coding RNAs longer than 200 nucleotides. Emerging evidence indicates that lncRNAs act as essential regulators that perform pivotal roles in the pathogenesis and progression of human diseases. The mechanisms underlying lncRNA involvement in diverse diseases have been extensively explored, and lncRNAs are considered powerful biomarkers for clinical practice. The lncRNA noncatalytic region of tyrosine kinase adaptor protein 1 (NCK1) antisense 1 (NCK1-AS1), also known as NCK1 divergent transcript (NCK1-DT), is encoded on human chromosome 3q22.3 and produces a 27,274-base-long transcript. NCK1-AS1 has increasingly been characterized as a causative agent for multiple diseases. The abnormal expression and involvement of NCK1-AS1 in various biological processes have been associated with several diseases. Further exploration of the mechanisms through which NCK1-AS1 contributes to disease development and progression will provide a foundation for potential clinical applications of NCK1-AS1 in the diagnosis and treatment of various diseases. This review summarizes the current understanding of the various functions and mechanisms through which NCK1-AS1 contributes to various diseases and the clinical application prospects for NCK1-AS1.

DCE-MRI radiomics models predicting the expression of radioresistant-related factors of LRP-1 and survivin in locally advanced rectal cancer

Objective

Low-density lipoprotein receptor-related protein-1 (LRP-1) and survivin are associated with radiotherapy resistance in patients with locally advanced rectal cancer (LARC). This study aimed to evaluate the value of a radiomics model based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the preoperative assessment of LRP-1 and survivin expressions in these patients.

Methods

One hundred patients with pathologically confirmed LARC who underwent DCE-MRI before surgery between February 2017 and September 2021 were included in this retrospective study. DCE-MRI perfusion histogram parameters were calculated for the entire lesion using post-processing software (Omni Kinetics, G.E. Healthcare, China), with three quantitative parameter maps. LRP-1 and survivin expressions were assessed by immunohistochemical methods and patients were classified into low- and high-expression groups.

Results

Four radiomics features were selected to construct the LRP-1 discrimination model. The LRP-1 predictive model achieved excellent diagnostic performance, with areas under the receiver operating curve (AUCs) of 0.853 and 0.747 in the training and validation cohorts, respectively. The other four radiomics characteristics were screened to construct the survivin predictive model, with AUCs of 0.780 and 0.800 in the training and validation cohorts, respectively. Decision curve analysis confirmed the clinical usefulness of the radiomics models.

Conclusion

DCE-MRI radiomics models are particularly useful for evaluating LRP-1 and survivin expressions in patients with LARC. Our model has significant potential for the preoperative identification of patients with radiotherapy resistance and can serve as an essential reference for treatment planning.

Development of Tumor Mutation Burden-Related Prognostic Model and Novel Biomarker Identification in Stomach Adenocarcinoma

Background: Stomach adenocarcinoma (STAD) is one of the most common tumors. Tumor mutation burden (TMB) has been linked to immunotherapy response. We wanted to see if there was any link between TMB and cancer prognosis.

Methods: The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases were used to obtain mutation data, gene expression profiles, and clinical data. We looked at the differences in gene expression and immune markers between low and high TMB groups, built an immune prognostic model, and created a dynamic nomograph App that may be used in the clinic. Simultaneously, We ran the immunotherapy prediction and model comparison at the same time. Finally, model gene mutation and copy number variation (CNV) were displayed. The cellular functional experiments were used to investigate the potential role of GLP2R in gastric cancer.

Results: Firstly, basic mutation information and differences in immune infiltration in STAD are revealed. Secondly, the prognostic model developed by us has good accuracy, and the corresponding dynamic nomograph Apps online and immunotherapy prediction facilitate clinical transformation. Furthermore, GLP2R knockdown significantly inhibited the proliferation, migration of gastric cancer cells in vitro.

Conclusion: Our findings imply that TMB plays a significant role in the prognosis of STAD patients from a biological perspective. GLP2R may serve as a potential target for gastric cancer.

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis

BACKGROUND

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors.

METHODS

We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification.

RESULTS

One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70).

CONCLUSIONS

High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

Prediction of Two Molecular Subtypes of Gastric Cancer Based on Immune Signature

Gastric cancer is the fifth most common type of human cancer and the third leading cause of cancer-related death. The purpose of this study is to investigate the immune infiltration signatures of gastric cancer and their relation to prognosis. We identified two distinct subtypes of gastric cancer (C1/C2) characterized by different immune infiltration signatures. C1 is featured by immune resting, epithelial–mesenchymal transition, and angiogenesis pathways, while C2 is featured by enrichment of the MYC target, oxidative phosphorylation, and E2F target pathways. The C2 subtype has a better prognosis than the C1 subtype (HR = 0.61, 95% CI: 0.44–0.85; log-rank test, p = 0.0029). The association of C1/C2 with prognosis remained statistically significant (HR = 0.62, 95% CI: 0.44–0.87; p = 0.006) after controlling for age, gender, and stage. The prognosis prediction of C1/C2 was verified in four independent cohorts (including an internal cohort). In summary, our study is helpful for better understanding of the association between immune infiltration and the prognosis of gastric cancer.

PD-L1 Expression Is a Favorable Prognostic Marker in Gastric Carcinoma

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related mortality worldwide. Although multidisciplinary therapeutic strategies have improved treatment outcomes, the overall prognosis for patients with GC remains poor. Recently, immunotherapeutic agents targeting immunosuppressive proteins such as anti-programmed death-1 receptor and anti-programmed death ligand-1 (PD-L1) have emerged as effective treatment options for various cancers, including GC. In addition to their therapeutic role, the expression of PD-L1 has been used as a predictive biomarker for programmed death-1/PD-L1 treatment response and has been shown to have a prognostic role in certain cancers. This study aims to evaluate the expression of PD-L1 in GC samples from Jordanian patients and assess its prognostic role as well as its correlation with clinicopathologic variables. Gastrectomy samples from 96 patients diagnosed with gastric adenocarcinoma were included in the study. Immunohistochemistry assay was employed for PD-L1 testing, and the scoring was based on a combined positive score (CPS). It was found that 66.7% of the study samples were positive for PD-L1 (CPS≥1). The expression of PD-L1 was not significantly associated with any of the assessed clinicopathologic variables; however, it was found to be an independent favorable prognostic factor for overall survival (hazard ratio: 0.481; 95% confidence interval: 0.231-1.001; P=0.050).

Case Report: Squamous Cell Carcinoma of Pancreas With High PD-L1 Expression: A Rare Presentation

Primary pancreatic squamous cell carcinoma is sporadic. The diagnosis is usually made following surgery or needle biopsy and requires a thorough workup to exclude metastatic squamous cell carcinoma. Squamous cell carcinoma of the pancreas often has a very poor prognosis. There is no treatment guideline for this type of cancer, and to date, no therapeutic regimen has been proven effective. Here, we report the effectiveness of immunotherapy in combination with chemotherapy against locally advanced squamous cell carcinoma of the pancreas with high programmed cell death ligand 1 (PD-L1) expression. Regional intra-arterial infusion chemotherapy consisting of nab-Paclitaxel followed by gemcitabine infused via gastroduodenal artery every three weeks for two cycles. This therapy resulted in the depletion of carcinoma, and the patient continues to lead a high-quality life with no symptoms for more than 16 months.

Protective role of astragaloside IV in gastric cancer through regulation of microRNA-195-5p-mediated PD-L1

AIM

Astragaloside IV (AS-IV) was reported to exert anti-cancer function in many cancers, but its actions in gastric cancer (GC) remain unclear. In the present study, we tried to elaborate the underlying mechanism by which AS-IV regulated the epithelial-mesenchymal transition (EMT) and angiogenesis of GC cells.

METHODS

The expressions of hsa-miR-15b-5p, hsa-miR-15a-5p, hsa-miR-195-5p, hsa-miR-424-5p and hsa-miR-497-5p in GC tissues and adjacent normal tissues were predicted by TCGA database. SGC7901 or MGC803 cells were treated with AS-IV, or transfected with miR-195-5p inhibitor/mimic or pcDNA3.1-PD-L1 followed by detection of cell proliferation, EMT and angiogenesis. The target relation between miR-195-5p and PD-L1 was confirmed by dual luciferase reporter gene assay.

RESULTS

Elevated hsa-miR-15b-5p, hsa-miR-15a-5p and hsa-miR-424-5p expressions were found in GC tissues, while decreased hsa-miR-195-5p and hsa-miR-497-5p expressions were observed in GC tissues. AS-IV inhibits EMT and angiogenesis in GC. PD-L1 was a potential target of miR-195-5p. Down-regulation of miR-195-5p or elevated PD-L1 expression reverses the inhibitory effect of AS-IV on EMT and angiogenesis of GC cells.

CONCLUSION

The present study demonstrated that AS-IV inhibited EMT and angiogenesis in GC through upregulation of miR-195-5p, highlighting the potential therapeutic effect of AS-IV on GC via miR-195-5p-regulated PD-L1.

Programmed cell death 1 as prognostic marker and therapeutic target in upper gastrointestinal cancers

Gastrointestinal (GIs) cancers are among the most common causes of cancer related death, and hence the importance for the identification of novel prognostic/predictive biomarkers for detection of patients at an early stage, and for using these to identify novel targeted therapies to improve the efficacy of existing chemotherapeutic regimens. Programmed cell death 1 has been reported as a potential target in several malignancies, and targeting agents are being developed, some already approved by FDA, such as: pembrolizumab, Atezolizumab, Nivolumab. Pembrolizumab that have been approved for the treatment of metastatic non-small cell lung cancer. Here we provide an overview of the mechanism of action PD-1/PD-L1, prognostic value and current progress in clinical trials using PD-1/PD-L1 inhibitors, and the resistant mechanisms at underlie the inhibitory effect of these agents in the treatment of gastrointestinal cancers.

miR-502-5p affects gastric cancer progression by targeting PD-L1

Background

Studies have shown that miR-502-5p functions as a tumor suppressor and is associated with tumor growth and metastasis. This study intends to uncover the potential mechanism of miR-502-5p functioning as a tumor suppressor in gastric cancer.

Methods

Expression levels of miR-502-5p and PD-L1 were measured by using qRT-PCR. Cell proliferation abilities were examined by EDU incorporation assay. Cell migration, invasion and cell cycle analysis of cells were determined by transwell assay, transwell-matrigel assay and flow cytometry, respectively. The relationship between miR-502-5p expression and the overall survival of xenograft tumor mice was statistically analyzed. Bioinformatics analysis and luciferase reporter assays were applied to analyze the relationship between miR-502-5p and CD40, STAT3 or PD-L1. Expressions of CD40, STAT3 and PD-L1 at protein level were detected by western blot.

Results

The results showed that miR-502-5p was significantly downregulated in gastric cancer tumor tissues compared with adjacent normal tissues. Overexpression of miR-502-5p significantly attenuated the proliferation, migration/invasion and induced the G1 phase arrest of gastric cancer cells. Consistently, miR-502-5p suppressed tumor growth and metastasis in vivo. Mechanically, we demonstrated that miR-502-5p had inhibited the malignant behaviour of gastric cancer by down-regulating PD-L1 expression at transcriptional level and post-transcriptional levels.

Conclusions

These findings suggest that miR-502-5p acts as a tumor suppressor in gastric cancer (GC). MiR-502-5p/PD-L1 may be a novel therapeutic target in GC treatment.

Research progress of PD-1/PD-L1 immunotherapy in gastrointestinal tumors

Gastrointestinal tumor (GIT) is a common malignant tumor of the digestive system, which seriously threatens people's health and life. With the deepening of the study on the mechanism of tumor immune escape, programmed death receptor ligand 1 (PD-L1) has been proved to interact with the tumor microenvironment to mediate tumor immune escape. PD-L1 inhibitor is a hot spot in tumor immunotherapy in recent years, which can restore the activity of T cells, enhance the body's ability of immune response, and ultimately enable the immune system to effectively identify and kill gastric cancer cells, then achieve long-term tumor remission in patients with GITs. At present, variety of PD-L1 inhibitors such as pembrolizumab, nivolumab and avelumab have been approved for the market, and they have achieved good results in clinical studies on the GIT. This paper reviews the progress of PD-1/PD-L1 immunotherapy in GITs which include gastric cancer, colon cancer and rectal cancer.

Profiles of PD-1, PD-L1, PD-L2 in Gastric Cancer and Their Relation with Mutation, Immune Infiltration, and Survival

Background

Although multiple types of cancers demonstrated favorable outcome after immunotherapy of PD-1/PD-L1 blockade, the specific regulatory mechanism of PD genes in gastric cancer (GC) remains largely unknown.

Materials and Methods

Expression of RNA, copy number variants, and clinical parameters of GC individuals from TCGA were analyzed. Coexpressed genes for PD-1, PD-L1, and PD-L2 were selected by correlation analysis and confirmed by STRING. Gene Ontology and KEGG pathway analyses were performed by clusterProfiler. The influence of PD-1/PD-L1/PD-L2 on immune cell infiltration was investigated by MCP-counter.

Results

PD-L2 demonstrated significant relation with clinical stage of GC (P = 0.043). Survival analysis showed that PD-1 expression was correlated with better prognosis of GC patients (HR = 0.70, P = 0.031), but PD-L2 expression was related with worse survival (HR = 1.42, P = 0.032). Mutation of PIK3CA could alter the level of PD-1, PD-L1, and PD-L2 (P < 0.001), and TP53 mutation demonstrated significant correlation with PD-L1 (P = 0.015) and PD-L2 (P = 0.014) expression. Enrichment analysis of PD-1/PD-L1/PD-L2 coexpressed genes indicated a biological process of mononuclear cell proliferation, leukocyte cell-cell adhesion, and lymphocyte activation as well as KEGG pathways including cell differentiation of Th1 and Th2, cell differentiation of Th17, and hematopoietic cell landscape. As for immune infiltration analysis, PD-1 was mainly related with cytotoxic lymphocytes and endothelial cells; PD-L1 were associated with monocytic lineage; PD-L2 showed significant correlation with myeloid dendritic cells.

Conclusion

PD-1 expression showed association with better prognosis of GC, and PD-L2 expression was related with worse survival. Mutations of PIK3CA and TP53 significantly correlated with PD-1/PD-L1/PD-L2 axis. PD-1/PD-L1/PD-L2 coexpressed genes demonstrated enrichment in mononuclear cell proliferation, leukocyte cell-cell adhesion, and lymphocyte activation as well as KEGG pathways including cell differentiation of Th1, Th2, and Th17.

A Multichannel Data Fusion Method Based on Multiple Deep Belief Networks for Intelligent Fault Diagnosis of Main Reducer

Aiming at the problems of poor efficiency of the intelligent fault diagnosis method of the main reducer and the poor effectiveness of multichannel data fusion, this paper proposes a multichannel data fusion method based on deep belief networks and random forest fusion for fault diagnosis. Multiple deep belief networks (MDBNs) are constructed to obtain deep representative features from multiple modalities of multichannel data. Random forest can fuse deep representative features achieved from MDBNs to construct the model of multiple deep belief networks fusion (MDBNF). The proposed method is applied to fault diagnosis of the main reducer and evaluation of the performance. Multiple deep belief network model fusions (MD BN F) are constructed to improve the multichannel data fusion effect. Single sensory data, multichannel data, and two intelligent models based on support vector machine and deep belief networks are used as comparison in the experiments. The results indicate that the classification accuracy of the test set collected by sensor 1 and sensor 2 is 88.35% and 88.73%, respectively. The comparison results show that the method has good convergence. The data fusion of the proposed diagnostic model can effectively improve the correlation between the collected vibration signals and the failure mode, thereby improving the diagnostic performance by nearly 8%, representing improved diagnostic accuracy.

Oncological outcomes of addition of anti-PD1/PD-L1 to chemotherapy in the therapy of patients with advanced gastric or gastro-oesophageal junction cancer: A meta-analysis

BACKGROUND

Patients with advanced gastric or gastro-oesophageal junction cancer (GC/GEJC) that fail to respond to prior chemotherapy have poor clinical prognosis. Lately, many trials have paid much attention on the oncological outcomes of immune checkpoint inhibitors (ICI). A new therapy based on programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors has recognized as promising prospects for advanced GC/GEJC. We assessed efficacy and safety of PD-L1 antibody versus chemotherapy alone in previously treated non-small cell lung cancer.

METHODS

Computerized literature search was done on the published trials in: Pubmed, Embase, Cochrane library updated on June 2019. Randomized controlled trials were selected investigating chemotherapy plus PD-1/PD-L1 versus chemotherapy alone.

RESULTS

Three randomized controlled trails were included. The pooled analysis of overall survival (OS) was longer with anti-PD1/PD-L1 than with chemotherapy alone in the OS (OR = 0.66, 95%CI = 0.47-0.92, P = .02) and sub-group OS of GEJC (OR = 0.73, 95%CI = 0.58-0.93, P = .01). Whereas, there is no significant difference in progression-free survival (OR = 0.93, 95%CI = 0.62-1.39, P = .72). The pooling adverse events (AE) data did not achieve advantage in the PD-1/PD-L1 targeted agents (OR = 0.53, 95%CI = 0.13-2.10, P = .36), the same as the treatment-related AE of grade 3 to 5 (OR = 0.53, 95%CI = 0.16-1.74, P = .30).

CONCLUSIONS

Treatment of patients with advanced GC/GEJC with PD-1/PD-L1 targeted did result in an improvement in some but not all survival endpoints. Moreover, it had a comparable toxicity profile as compared with chemotherapy alone. More well designed studies are needed to develop a database of all anti-PD1/PD-L1 sub-groups and their individual impact on the differing anti-PD1/PD-L1 treatments.

The Clinical Significance of Soluble Programmed Cell Death-Ligand 1 (sPD-L1) in Patients With Gliomas

Background: Soluble PD-L1 (sPD-L1) in the circulation has been documented to activate global immunosuppression and is considered a predictor of negative clinical outcomes in several malignances. However, the clinical significance of sPD-L1 in the peripheral blood and cerebrospinal fluid (CSF) of patients with glioma remains unclear.

Objective: The aim of this study was to detect the correlations of sPD-L1 with clinical features in brain tumors and assess the diagnostic value of this protein in gliomas.

Methods: Serum samples were obtained from 73 patients with glioma, 20 patients with meningioma, and 49 healthy controls (HCs) in this study. In total, 31 CSF samples were collected from the matched glioma patients, and seven samples were collected from the matched meningioma patients. The expression of serum sPD-L1 in the glioma cohort was followed for 20 days after surgery to examine the kinetics in the circulation. Inflammatory markers were evaluated based on preoperative blood parameters. The sPD-L1 levels in the serum and CSF were determined by enzyme-linked immunosorbent assay (ELISA). The logistic regression model was used to assess the independent associations of sPD-L1 with gliomas, including high-grade gliomas.

Results: Serum and CSF levels of sPD-L1 were significantly elevated in patients with gliomas compared to those with meningiomas and HCs. Additionally, increased levels of sPD-L1 were observed in relatively advanced tumors. sPD-L1 overexpression in the CSF appears to be more representative of aggressive tumor features than overexpression in the serum. For glioma diagnosis, both serum and CSF sPD-L1 showed significant value in the diagnosis and stratification of glioma, and the best diagnostic performance was obtained with serum sPD-L1 rather than blood-based inflammatory markers. In addition, a descending trend in the level of serum sPD-L1 was observed in postoperative patients.

Conclusion: In gliomas, elevated circulating and CSF sPD-L1 levels are associated with aggressive biological activities. The results of the current study suggest that sPD-L1 is a promising biomarker for gliomas that can be used in clinical practice.

Soluble programmed death-1 (sPD-1) and programmed death ligand 1 (sPD-L1) as potential biomarkers for the diagnosis and prognosis of glioma patients

Background

This study aimed at investigating the feasibility of testing for soluble programmed death-1 (sPD-1) and soluble programmed death ligand 1 (sPD-L1) in serum samples of glioma patients and to evaluate the diagnostic and prognostic value of these two soluble molecules.

Methods

Serum samples collected from 70 glioma patients before surgery were designated as the pre-operative (Pre) group, samples obtained from 90 post-surgery glioblastoma patients were designated as the Post group, and samples from 20 healthy volunteers were used as controls. Peripheral blood sPD-1 and sPD-L1 levels were detected by using ELISA kits and compared among the groups. The associations of these soluble molecule levels with clinicopathological variables and tumour progression were investigated.

Results

Among the three groups, the Pre group had the highest sPD-1 levels, whereas the median sPD-L1 level was significantly lower in the Post group than in the other two groups. The area under the curve (AUC) of sPD-1 (0.762) for diagnosis was similar to that of sPD-L1 (0.718). Higher serum levels of sPD-1 and sPD-L1 were present in samples of patients with more advanced brain tumours. Kaplan-Meier analysis showed that higher serum levels of sPD-1 (>11.14 pg/mL) and sPD-L1 (>63.03 pg/mL) might predict shorter progression-free survival times of glioma patients.

Conclusions

This study showed that sPD-1 and sPD-L1 might be promising predictive biomarkers for the diagnosis and prognosis of glioma patients.

High PD-L1 Expression Predicts for Worse Outcome of Leukemia Patients with Concomitant NPM1 and FLT3 Mutations

Compared to solid tumors, the role of PD-L1 in hematological malignancies is less explored, and the knowledge in this area is mostly limited to lymphomas. However, several studies indicated that PD-L1 is also overexpressed in myeloid malignancies. Successful treatment of the acute myeloid leukemia (AML) is likely associated with elimination of the residual disease by the immune system, and possible involvement of PD-L1 in this process remains to be elucidated. We analyzed PD-L1 expression on AML primary cells by flow cytometry and, in parallel, transcript levels were determined for the transcription variants v1 and v2. The ratio of v1/v2 cDNA correlated with the surface protein amount, and high v1/v2 levels were associated with worse overall survival (p = 0.0045). The prognostic impact of PD-L1 was limited to AML with mutated nucleophosmin and concomitant internal tandem duplications in the FLT3 gene (p less than 0.0001 for this particular AML subgroup).

PD-L1 Expression in Systemic Immune Cell Populations as a Potential Predictive Biomarker of Responses to PD-L1/PD-1 Blockade Therapy in Lung Cancer

PD-L1 tumor expression is a widely used biomarker for patient stratification in PD-L1/PD-1 blockade anticancer therapies, particularly for lung cancer. However, the reliability of this marker is still under debate. Moreover, PD-L1 is widely expressed by many immune cell types, and little is known on the relevance of systemic PD-L1⁺ cells for responses to immune checkpoint blockade. We present two clinical cases of patients with non-small cell lung cancer (NSCLC) and PD-L1-negative tumors treated with atezolizumab that showed either objective responses or progression. These patients showed major differences in the distribution of PD-L1 expression within systemic immune cells. Based on these results, an exploratory study was carried out with 32 cases of NSCLC patients undergoing PD-L1/PD-1 blockade therapies, to compare PD-L1 expression profiles and their relationships with clinical outcomes. Significant differences in the percentage of PD-L1⁺ CD11b⁺ myeloid cell populations were found between objective responders and non-responders. Patients with percentages of PD-L1⁺ CD11b⁺ cells above 30% before the start of immunotherapy showed response rates of 50%, and 70% when combined with memory CD4 T cell profiling. These findings indicate that quantification of systemic PD-L1⁺ myeloid cell subsets could provide a simple biomarker for patient stratification, even if biopsies are scored as PD-L1 null.

PD-1/PD-L1 antagonists in gastric cancer: Current studies and perspectives

Immune checkpoints release suppressive signals for T cells, which enable the tumors to escape from immune destruction and provide a new concept that uses the capabilities of the immune system as a therapeutic target for tumors. At present, programmed death receptor 1 (PD-1)/programmed death ligand-1 (PD-L1) has become the most promising therapeutic target. PD-1/PD-L1 blockades exhibit long-lasting antitumor efficacy and safety in patients with various cancers, such as melanoma and non-small-cell lung cancer. Moreover, PD-L1 is highly expressed in the peripheral blood and tumor specimens of patients with cancer, and the expression of PD-L1 is positively correlated with various pathological features and may serve as a predictor of poor prognosis or a diagnostic tool. Clinical trials have verified that PD-1/PD-L1 blockade therapy benefits patients with advanced gastric cancer or gastroesophageal junction cancer. Furthermore, there are many molecules involved in the regulation of PD-1/PD-L1 expression, and the modification of these molecules via drugs and combinations with PD-1/PD-L1 inhibitors may further improve the efficacy of immunotherapy for gastric cancer. In this review, the efficacy, safety, and possible combination treatment options of PD-1/PD-L1 in gastric cancer are reviewed in experimental and clinical settings.

Potential Utility of Liquid Biopsy as a Diagnostic and Prognostic Tool for the Assessment of Solid Tumors: Implications in the Precision Oncology

Liquid biopsy is a technique that utilizes circulating biomarkers in the body fluids of cancer patients to provide information regarding the genetic landscape of the cancer. It is emerging as an alternative and complementary diagnostic and prognostic tool to surgical biopsy in oncology. Liquid biopsy focuses on the detection and isolation of circulating tumor cells, circulating tumor DNA and exosomes, as a source of genomic and proteomic information in cancer patients. Liquid biopsy is expected to provide the necessary acceleratory force for the implementation of precision oncology in clinical settings by contributing an enhanced understanding of tumor heterogeneity and permitting the dynamic monitoring of treatment responses and genomic variations. However, widespread implementation of liquid biopsy based biomarker-driven therapy in the clinical practice is still in its infancy. Technological advancements have resolved many of the hurdles faced in the liquid biopsy methodologies but sufficient clinical and technical validation for specificity and sensitivity has not yet been attained for routine clinical implementation. This article provides a comprehensive review of the clinical utility of liquid biopsy and its effectiveness as an important diagnostic and prognostic tool in colorectal, breast, hepatocellular, gastric and lung carcinomas which were the five leading cancer related mortalities in 2018.

Soluble PD-L1 Expression in Circulation as a Predictive Marker for Recurrence and Prognosis in Gastric Cancer: Direct Comparison of the Clinical Burden Between Tissue and Serum PD-L1 Expression

BACKGROUND

This study assessed programmed cell death ligand 1 (PD-L1) expression in primary tissues and soluble PD-L1 (sPD-L1) concentration in matched preoperative serum in gastric cancer (GC) patients to perform direct comparison between tissue and serum PD-L1 expression and to clarify the prognostic implication in GC.

METHODS

The study enrolled 180 GC patients who underwent surgery for GC at the authors' institution. The study evaluated tissue PD-L1 expression using immunohistochemistry and quantified sPD-L1 concentration in preoperative serum using enzyme-linked immunosorbent assay in GC patients.

RESULTS

The findings showed that PD-L1 was overexpressed in GC tissues compared with normal mucosa. Tissue PD-L1 expression was significantly higher in the GC patients with advanced T stage, presence of lympho-vascular invasion, lymph node metastasis, and peritoneal metastasis. Furthermore, elevated tissue PD-L1 expression was significantly associated with poor prognosis for overall survival (OS) and disease-free survival (DFS). Serum sPD-L1 was significantly higher in the GC patients than in the healthy volunteers. Although serum sPD-L1 was not correlated with any clinicopathologic factors, the patients with high serum sPD-L1 showed poorer OS and DFS than those with low sPD-L1. Multivariate analyses showed that both elevated tissue PD-L1 and serum sPD-L1 were independent prognostic factors for poor OS [tissue PD-L1: hazard ratio (HR), 4.28; 95% confidence interval (CI), 1.43-12.8; P = 0.0094 vs. serum sPD-L1: HR, 11.2; 95% CI, 3.44-36.7; P = 0.0001] and poor DFS (tissue PD-L1: HR, 6.96; 95% CI, 2.48-19.6; P = 0.0002 vs. serum sPD-L1: HR, 8.7; 95% CI, 3.16-23.9; P < 0.0001) for the GC patients. Furthermore, infiltrative CD8- and Foxp3-positive T cells were significantly increased in the GC patients with elevated tissue PD-L1 expression.

CONCLUSION

Both serum sPD-L1 and tissue PD-L1 expression may serve as predictive biomarkers for recurrence and prognosis in GC patients.

PD-L1 expression in pancreatic adenosquamous carcinoma: PD-L1 expression is limited to the squamous component

AIM

We examined the programmed death-ligand 1 (PD-L1) expression in surgically resected pancreatic adenosquamous carcinoma (PASC) samples. Furthermore, the detection rate was also assessed using biopsy cases obtained from endoscopic ultrasound-guided fine needle aspiration (EUS-FNA).

METHODS

Fifteen cases of PASC (six resected and nine EUS-FNA biopsied) from the Kurume University Hospital between 2009 and 2016 were used for the evaluation of PD-L1 expression. As a control group, 34 cases of pancreatic ductal adenocarcinomas (PDACs) were selected. To compare　the positivity and intensity of PD-L1, two types of clones (SP263, E1L3N) were examined for immunostaining. Only the membrane expression of PD-L1 was regarded as positive. The PD-L1 expressions in the squamous cell carcinoma component (SCc), adenocarcinoma component (ACc), and immune cells were assessed separately. The ratio of PD-L1 expression was calculated by counting the positive tumor cells, and tumor proportion score (TPS) was applied (TPS; Null < 1%, low expression; 1 ≤ TPS ≤ 49% and high expression; ≥ 50%).

RESULTS

PD-L1 expression was observed in five surgical PASC samples (83%). This shows that SCc presented a high expression in these cases. However, the overall TPS indicated a low expression. In contrast, only one case (3%) was positive for PD-L1 in PDACs, and the TPS indicated a low expression. No differences in PD-L1 expression were observed between the two clones, SP263 and E1L3N. High PD-L1 expression in the EUS-FNA sample was found in only one case (11%).

DISCUSSION

Although assessment using the tumor cells of PASC samples obtained from EUS-FNA was difficult, this study suggests the selective expression of PD-L1 in the SCc of PASC. Furthermore, it was considered that immune checkpoint inhibitors could provide therapeutic effects selectively on the SCc for the entire range of TPSs, though the PD-L1 expression was low.

Phase III, randomised trial of avelumab versus physician's choice of chemotherapy as third-line treatment of patients with advanced gastric or gastro-oesophageal junction cancer: primary analysis of JAVELIN Gastric 300

BACKGROUND

There currently are no internationally recognised treatment guidelines for patients with advanced gastric cancer/gastro-oesophageal junction cancer (GC/GEJC) in whom two prior lines of therapy have failed. The randomised, phase III JAVELIN Gastric 300 trial compared avelumab versus physician's choice of chemotherapy as third-line therapy in patients with advanced GC/GEJC.

PATIENTS AND METHODS

Patients with unresectable, recurrent, locally advanced, or metastatic GC/GEJC were recruited at 147 sites globally. All patients were randomised to receive either avelumab 10 mg/kg by intravenous infusion every 2 weeks or physician's choice of chemotherapy (paclitaxel 80 mg/m2 on days 1, 8, and 15 or irinotecan 150 mg/m2 on days 1 and 15, each of a 4-week treatment cycle); patients ineligible for chemotherapy received best supportive care. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety.

RESULTS

A total of 371 patients were randomised. The trial did not meet its primary end point of improving OS {median, 4.6 versus 5.0 months; hazard ratio (HR)=1.1 [95% confidence interval (CI) 0.9-1.4]; P = 0.81} or the secondary end points of PFS [median, 1.4 versus 2.7 months; HR=1.73 (95% CI 1.4-2.2); P > 0.99] or ORR (2.2% versus 4.3%) in the avelumab versus chemotherapy arms, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 90 patients (48.9%) and 131 patients (74.0%) in the avelumab and chemotherapy arms, respectively. Grade ≥3 TRAEs occurred in 17 patients (9.2%) in the avelumab arm and in 56 patients (31.6%) in the chemotherapy arm.

CONCLUSIONS

Treatment of patients with GC/GEJC with single-agent avelumab in the third-line setting did not result in an improvement in OS or PFS compared with chemotherapy. Avelumab showed a more manageable safety profile than chemotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02625623.

Is high serum programmed death ligand 1 level a risk factor for poor survival in patients with gastric cancer?

BACKGROUND AND AIM

Although the clinicopathological significance of the expression of programmed death ligand 1(PD-L1) in various cancer tissues has been reported, serum PD-L1 level has not been evaluated in patients with surgically treated gastric cancer. Therefore, we evaluated the clinicopathological characteristics and prognostic significance of preoperative serum PD-L1 levels in patients with gastric cancer.

PATIENTS AND METHODS

Serum samples were obtained before surgery from 152 patients with gastric cancer, including 75 patients with stage I, 31 with stage II, 23 with stage III, and 23 with stage IV gastric cancer. The samples were analyzed using enzyme-linked immunosorbent assay to detect soluble PD-L1. Using the median serum PD-L1 level of 50 pg/mL, patients were divided into two groups, namely high serum and low serum PD-L1 level groups. Clinicopathological characteristics and prognosis were compared between these two groups using univariate and multivariate analysis.

RESULTS

Serum PD-L1 level was significantly associated with older age, positive cancer antigen 19-9 (CA19-9), C-reactive protein levels, and albumin levels but not with tumor stage. Patients in the high serum PD-L1 group showed significantly worse overall survival and recurrence-free survival than those in the low serum PD-L1 group (P < .05). Multivariate analysis showed that high serum PD-L1 level was an independent risk factor for poor overall survival (P = .02).

CONCLUSION

High serum PD-L1 level was a prognostic factor for reduced overall survival in patients with surgically treated gastric cancer.

Programmed death-ligand 1 is a promising blood marker for predicting tumor progression and prognosis in patients with gastric cancer

Immune checkpoint inhibitor therapy has been clinically introduced for several malignancies, and its effectiveness has been confirmed by clinical trials. In particular, programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) are widely known as important immune checkpoint molecules associated with the mechanisms of immune escape by malignant tumor cells. In addition, liquid biopsy of blood specimens has the clinical benefit of providing a simple, repeatable sampling tool. Non-invasive liquid biopsy has recently been spotlighted as a promising approach to predicting tumor progression and prognosis. This study assessed the clinical significance of PD-L1 mRNA expression in blood specimens obtained from patients with gastric cancer. Peripheral blood specimens were collected before treatment from 124 patients with gastric cancer. The PD-L1 mRNA expression was evaluated by quantitative RT-PCR. Programmed death-ligand 1 mRNA expression was significantly higher in patients with advanced gastric cancer than in patients with early gastric cancer (P = .002). Moreover, PD-L1 expression correlated significantly with depth of tumor invasion, distant metastasis, and stage (P = .001, P < .001, and P < .001, respectively). Patients with high PD-L1 expression showed significantly poorer prognosis than those with low PD-L1 expression (P < .0001). Multivariate analysis indicated PD-L1 expression as an independent prognostic factor. Expression of PD-L1 in peripheral blood may offer an immunological predictor of tumor progression and disease outcome in patients with gastric cancer.