Programmed death ligand-1 and MET co-expression is a poor prognostic factor in gastric cancers after resection

Association of PD-L1 Expression with Clinicopathologic Characters in Gastric Cancer: A Comprehensive Meta-analysis

PURPOSE

The expression level of programmed death ligand-1(PD-L1) in patients with gastric cancer is the key to determining the use of immune drugs. The relationship between PD-L1 expression level and clinical characteristics is worth exploring.

METHODS

By setting the search terms correlated to PD-L1 and gastric cancer, a nearly comprehensive search was carried out in four major databases, and the deadline for searching was September 1, 2022. The retrieved documents were further screened by strict inclusion and exclusion criteria after removing the duplication. Next, the quality of the included studies was evaluated with the Newcastle-Ottawa Scale (NOS) scale. Finally, the STATA15.1 software was used to process data and draw plots, and the odds ratios (ORs) were adopted to assess the pooled effect size.

RESULTS

A total of 85 works of literature were included in this study through screening strictly, and detailed data were extracted after evaluating the quality of the literature. The process of analysis was conducted in the whole population, Asia-Africa population, European and American population, and Asian population with CPS≥1, amd all found that the expression of PD-L1 in gastric cancer was correlated with age, tumor size, EBV infection, Her-2 expression and microsatellite status. However, the subgroup of the region also found some differences in Asian and Western regions, which was interesting and worth studying further. The included research of this study did not have significant publish bias.

CONCLUSION

After careful analysis, this study found that age (>60 years), tumor size (>5cm), EBV infection (+), Her-2 expression (+), microsatellite status (MSI), and mismatch repair status (dMMR) were risk factors for positive expression of PD-L1 in gastric cancer.

Prognostic Implication of EBV Infection in Gastric Carcinomas: A Systematic Review and Meta-Analysis

Background and objectives: This study aims to elucidate the prognostic implications of Epstein-Barr virus (EBV) infection in gastric carcinomas (GCs) through a systematic review and meta-analysis. Materials and Methods: In total, 57 eligible studies and 22,943 patients were included in this meta-analysis. We compared the prognoses of EBV-infected and non-infected GC patients. The subgroup analysis was performed based on the study location, molecular classification, and Lauren's classification. This study was checked according to the PRISMA 2020. The meta-analysis was performed using the Comprehensive Meta-Analysis software package. Results: EBV infection was found in 10.4% (95% confidence interval (CI) 0.082-0.131) of GC patients. The EBV-infected GC patients had a better overall survival compared with the EBV-non-infected GC patients (hazard ratio (HR) 0.890, 95% CI 0.816-0.970). In the subgroup analysis based on molecular classification, no significant differences were found between EBV+ and microsatellite instability and microsatellite stable (MSS)/EBV- subgroups (HR 1.099, 95% CI 0.885-1.364 and HR 0.954, 95% CI 0.872-1.044, respectively). In the diffuse type of Lauren's classification, EBV-infected GCs have a better prognosis compared with the EBV-non-infected GCs (HR 0.400, 95% CI 0.300-0.534). The prognostic impact of EBV infection was found in the Asian and American subgroups but not in the European subgroup (HR 0.880, 95% CI 0.782-0.991, HR 0.840, 95% CI 0.750-0.941, and HR 0.915, 95% CI 0.814-1.028). Conclusions: EBV infection is a favorable survival factor for GCs. However, the prognostic implications of EBV infection in the new molecular classification are not clear.

Estimating the Global Burden of Epstein-Barr Virus-Associated Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Evidence suggests that a fraction of new gastric cancer cases may be etiologically associated with Epstein-Barr virus (EBV), a known carcinogenic agent. We aimed to systematically explore the proportion of EBV-positive gastric cancer.

METHODS

We did a systematic review (PROSPERO CRD42020164473) from January 1990 to August 2021. For each country and geographical region with available data, pooled prevalence and corresponding 95% confidence intervals (CIs) of EBV in gastric tumors were calculated for 3 subtypes of gastric adenocarcinoma (conventional adenocarcinoma, lymphoepithelioma-like gastric carcinoma, and remnant/stump carcinoma). For conventional adenocarcinoma, prevalence ratios (PRs) were presented for sex, Lauren's classification, gastric cancer stage, and anatomical location of the stomach.

RESULTS

In 220 eligible studies including over 68,000 cases of conventional gastric adenocarcinoma, EBV prevalence in tumor cells was 7.5% (95% CI, 6.9%-8.1%) and was higher in men compared with women (PR, 2.1; 95% CI, 1.9-2.4), in diffuse type compared with intestinal type (PR, 1.3; 95% CI, 1.1-1.5), and in the proximal region compared with the distal region (PR, 2.5; 95% CI, 2.0-3.1). There was no difference in EBV prevalence by gastric cancer stage. EBV prevalence was 75.9% (95% CI, 62.8%-85.5%) among lymphoepithelioma-like gastric carcinoma and 26.3% (95% CI, 22.2%-32.0%) among remnant or stump carcinoma.

CONCLUSIONS

Assuming a causal association between EBV and gastric cancer, our findings, when applied to the GLOBOCAN 2020 gastric cancer incidence, suggest that primary prevention such as the development of an effective EBV vaccine might prevent 81,000 EBV-associated gastric cancer cases worldwide annually.

PD-L1 expression in EBV associated gastric cancer: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis is to the summarize the evidence on programmed cell death protein ligand 1 (PD-L1) in Epstein-Barr virus associated gastric cancer (EBVaGC) and to estimate the expression rate of PD-L1 among this subtype of Gastric Cancer (GC).

MATERIALS AND METHODS

For this study, PubMed^®, EMBASE^® and Web of Science^® databases were searched for articles published until 1st November 2021. A total of 43 eligible publications with a total of 11,327 patients were included analysis based on inclusion and exclusion criteria. A total of 41 publications present data for proportion estimation and 33 for comparison of PD-L1 between EBV positive and negative GC. DerSimonian-Laird random-effects model was used for meta-analysis.

RESULTS

The analysis showed that in EBVaGC the pooled positivity rate for PD-L1 was 54.6% (p < 0.001), with a high heterogeneity between the included studies, which was associated with variation on positivity criteria for PD-L1 expression. Overall, the study reveals an increased association between PD-L1 and EBVaGC (OR = 6.36, 95% CI 3.91-10.3, p < 0.001). Furthermore, the study revealed that GC with lymphoid stroma (GCLS) is highly associated with EBV (OR = 17.4, 95% CI 6.83-44.1, p < 0.001), with a pooled EBV positivity rate of 52.9% (p < 0.001).

CONCLUSIONS

Patients with EBVaGC tend to show higher PD-L1 expression, which enhances EBV positivity as a promising marker for patient selection for immunotherapy targeted agents. A uniform criteria for PD-L1 positivity in tumor cells is needed, as well as further prospective studies to validate our findings and their prognostic significance.

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).

Clinicopathological and prognostic significance of programmed death ligant-1 expression in gastric cancer: a meta-analysis

Background

Gastric cancer (GC) is a common malignant tumor with a high incidence in China. The use of immune checkpoint inhibitors has become the focus of tumor immunotherapy in recent years. This study was to investigate the clinicopathological and prognostic significance of programmed death ligant-1 (PD-L1) expression in GC.

Methods

We searched the PubMed, ScienceNet, EMbase, CNKI, and Wanfang databases for retrospective cohort studies on the clinicopathology and prognosis of PD-L1 expression in GC published between January 2010 and April 2020. The literature was first selected to extract data according to the inclusion and exclusion criteria, then a meta-analysis performed using Stata15.0 software. Publication bias and sensitivity analysis were carried out for the included studies.

Results

A total of 3,218 patients in 15 studies were included in the meta-analysis. The positive expression of PD-L1 was related to a decrease in the 3-year survival rate (HR =1.32, 95% CI: 1.02-1.49, P=0.028) and 5-year survival rate (HR =1.39, 95% CI: 1.14-1.69, P=0.001). The difference in PD-L1 expression was related to lymph node metastasis (OR =1.73, 95% CI: 1.18-2.54, P<0.001), but not to tumor stage (OR =1.28, 95% CI: 0.81-2.02, P=0.292).

Conclusions

The results show that PD-L1 is related to the prognosis of GC. Its high expression decreases the 3- and 5-year survival rates and promotes lymph node metastasis, but does not reflect tumor stage. The results may provide a theoretical basis for the choice of clinical immunotherapy in GC patients.

Significance of druggable targets (PD-L1, KRAS, BRAF, PIK3CA, MSI, and HPV) on curatively resected esophageal squamous cell carcinoma

Background

Esophageal squamous cell carcinoma (ESCC) still remains intractable disease with few therapeutic options. Programmed death-ligand 1 (PD-L1), which is essential for immune evasion, is involved in the pathogenesis of ESCC and thus is a potential therapeutic target. PIK3CA, KRAS, and BRAF mutations, microsatellite instability (MSI) caused by deficient mismatch repair (dMMR), and human papillomavirus (HPV) can potentially upregulate PD-L1 expression, which might contribute to the clinical outcome of patients with ESCC.

Methods

We investigated the significance of the present druggable markers [PD-L1, PIK3CA, KRAS, and BRAF mutations, MSI caused by deficient dMMR, and HPV] in 64 curatively resected ESCCs, using immunohistochemistry (PD-L1 and MMR protein expression), direct sequencing (KRAS, BRAF, and PIK3CA mutations), real-time PCR (HPV infection), and MSI using quasi-monomorphic markers.

Results

PD-L1 expression, PIK3CA mutation, and MSI/dMMR were detected in 35.9, 12.5, and 17.2% of ESCCs, respectively. HPV was rarely detected (1.6%) (high-risk HPV68), whereas KRAS and BRAF mutations were not detected in ESCCs. PD-L1-positive tumors were not correlated with PIK3CA mutation or MSI/dMMR (all P > 0.05). PD-L1, PIK3CA mutation, and MSI/dMMR characterized the patients associated with light smoking, female and younger age, and younger age and well-differentiated tumors, respectively (all P < 0.05). In multivariate analysis, only PD-L1-positivity was an independent favorable prognostic factor for overall survival (OS) and disease-free survival (DFS) (P = 0.023, P = 0.014). In the PD-L1-negative ESCCs, PIK3CA mutation had a poor prognostic impact on both OS and DFS (P = 0.006, P = 0.002).

Conclusions

PIK3CA mutation may be an alternative prognostic biomarker in PD-L1-negative curatively resected ESCCs that can be optional to identify high-risk patients with worse clinical outcome who require more intensive therapy and follow-up.

Clinicopathological Significance of EBV-Infected Gastric Carcinomas: A Meta-Analysis

Background and objectives: The present study aims to elucidate the clinicopathologic significance of Epstein-Barr virus (EBV) infection in gastric carcinomas (GCs) through a meta-analysis. Materials and Methods: Sixty-one eligible studies were included in the present meta-analysis. The included patients, with and without EBV infection, were 2063 and 17,684, respectively. We investigated the clinicopathologic characteristics and various biomarkers, including programmed death-ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs). Results: The estimated EBV-infected rate of GCs was 0.113 (95% confidence interval (CI): 0.088-0.143). The EBV infection rates in GC cells were 0.138 (95% CI: 0.096-0.194), 0.103 (95% CI: 0.077-0.137), 0.080 (95% CI: 0.061-0.106), and 0.042 (95% CI: 0.016-0.106) in the population of Asia, America, Europe, and Africa, respectively. There was a significant difference between EBV-infected and noninfected GCs in the male: female ratio, but not other clinicopathological characteristics. EBV infection rates were higher in GC with lymphoid stroma (0.573, 95% CI: 0.428-0.706) than other histologic types of GCs. There were significant differences in high AT-rich interactive domain-containing protein 1A (ARID1A) and PD-L1 expressions, and high CD8+ TILs between EBV-infected and noninfected GCs. Conclusions: Our results showed that EBV infection of GCs was frequently found in male patients and GCs with lymphoid stroma. EBV infection was significantly correlated with ARID1A and PD-L1 expressions and CD8+ TILs in GCs.

Human papillomavirus as a driver of head and neck cancers

The human papillomavirus (HPV) family includes more than 170 different types of virus that infect stratified epithelium. High-risk HPV is well established as the primary cause of cervical cancer, but in recent years, a clear role for this virus in other malignancies is also emerging. Indeed, HPV plays a pathogenic role in a subset of head and neck cancers-mostly cancers of the oropharynx-with distinct epidemiological, clinical and molecular characteristics compared with head and neck cancers not caused by HPV. This review summarises our current understanding of HPV in these cancers, specifically detailing HPV infection in head and neck cancers within different racial/ethnic subpopulations, and the differences in various aspects of these diseases between women and men. Finally, we provide an outlook for this disease, in terms of clinical management, and consider the issues of 'diagnostic biomarkers' and targeted therapies.

Expression of mucins (MUC1, MUC2, MUC5AC and MUC6) in ALK-positive lung cancer: Comparison with EGFR-mutated lung cancer

ALK-positive (ALK+) lung adenocarcinoma usually shows a more advanced-staged disease with frequent nodal metastasis and highly aggressive outcomes compared with EGFR-mutated lung cancers. The aim of this study was to investigate the expression profiles of several mucins in ALK + lung cancers to gain insight into the relationship between the more aggressive biological nature of ALK + lung cancers and the role of mucins. We examined the immunohistochemical profiles of mucins MUC1, MUC2, MUC5AC, and MUC6 in 19 ALK + lung cancers compared with 42 EGFR-mutated lung cancers. ALK + cancers were found to occur in younger patients and were characterized by a solid-predominant histologic subtype with frequent signet ring cells and peritumoral muciphages. By contrast, EGFR-mutated cancers lacked ALK-specific histological patterns. Although all MUC1 and MUC5AC were expressed in both subtypes, MUC1 expression in ALK + cancers was visualized exclusively through cytoplasmic staining, whereas those in EGFR-mutated cancers were predominantly membranous staining in apical area (92.9%) and focally in cytoplasmic staining (7.1%). MUC5AC expression in ALK + cancers was exclusively visualized through cytoplasmic staining (100%), whereas EGFR-mutated cancers showed predominantly perinuclear dot-like patterns (90.5%) and focal cytoplasmic staining (9.5%). MUC2 and MUC6 expression was not detected in either type of lung cancer. CONCLUSIONS: The high frequency of both MUC1 and MUC5AC cytoplasmic expression, coupled with a lack of MUC2 and MUC6 expression in ALK + lung cancer may contribute to the biologically aggressive behavior of ALK + cancer. Inhibitors to these types of mucins may thus act as a barrier to cancerous extension reducing their aggressive behavior.

MET is overexpressed in microsatellite instability-high gastric carcinoma

BACKGROUND

MET is a tyrosine kinase receptor for the hepatocyte growth factor, and its overexpression is a poor prognostic factor in gastric carcinomas. Programmed death-ligand 1 (PD-L1) is an important biomarker of immunotherapy and is frequently positive in microsatellite instability-high (MSI-H) gastric carcinomas. In lung cancers, MET activation up-regulates PD-L1 expression. In this study, we investigated expression of MET and PD-L1 in MSI-H gastric carcinoma and the effects on prognosis.

METHODS

MET and PD-L1 (SP142) immunohistochemistry was performed in 73 gastric carcinomas with MSI-H. In cases with MET overexpression, we performed fluorescent in situ hybridization (FISH). PD-L1 expression was calculated from both tumor cells (2+ and 3+ in > 10% of tumor cells was defined as PD-L1^TC+) and immune cells (positive in >5% immune cells was PD-L1^IC+), and also used a combined positive score (CPS; number of PD-L1 staining cells relative to all viable tumor cells; > 1 was PD-L1⁺).

RESULTS

In 73 MSI-H gastric carcinomas, MET overexpression was observed in 11 cases (15.1%). In all 11 cases with MET overexpression,MET amplification was not found. MET overexpression was not related to any of clinico-pathological variables and PD-L1 expression. However, the PD-L1 CPS tended to be higher in tumors that were MET positive. Although MET overexpression alone was not a prognostic indicator, combined MET overexpression/PD-L1 predictive models showed that patients with MET⁺/PD-L1⁺ showed the best prognosis for overall survival as compared to other groups.

CONCLUSION

MET overexpression was observed in 15% of MSI-H gastric carcinomas and was associated with high level expression of PD-L1.

Immunohistochemistry Biomarkers Predict Survival in Stage II/III Gastric Cancer Patients: From a Prospective Clinical Trial

Purpose

Identification of biomarkers to predict recurrence risk is essential to improve adjuvant treatment strategies in stage II/III gastric cancer patients. This study evaluated biomarkers for predicting survival after surgical resection.

Materials and Methods

This post-hoc analysis evaluated patients from the CLASSIC trial who underwent D2 gastrectomywith orwithout adjuvant chemotherapy (capecitabine plus oxaliplatin) at the Yonsei Cancer Center. Tumor expressions of thymidylate synthase (TS), excision repair cross-complementation group 1 (ERCC1), and programmed death-ligand 1 (PD-L1) were evaluated by immunohistochemical (IHC) staining to determine their predictive values.

Results

Among 139 patients, IHC analysis revealed high tumor expression of TS (n=22, 15.8%), ERCC1 (n=23, 16.5%), and PD-L1 (n=42, 30.2%) in the subset of patients. Among all patients, high TS expression tended to predict poor disease-free survival (DFS; hazard ratio [HR], 1.80; p=0.053), whereas PD-L1 positivity was associated with favorable DFS (HR, 0.33; p=0.001) and overall survival (OS; HR, 0.38; p=0.009) in multivariate Cox analysis. In the subgroup analysis, poor DFS was independently predicted by high TS expression (HR, 2.51; p=0.022) in the adjuvant chemotherapy subgroup (n=66). High PD-L1 expression was associated with favorable DFS (HR, 0.25; p=0.011) and OS (HR, 0.22; p=0.015) only in the surgery-alone subgroup (n=73). The prognostic impact of high ERCC1 expression was not significant in the multivariate Cox analysis.

Conclusion

This study shows that high TS expression is a predictive factor for worse outcomes on capecitabine plus oxaliplatin adjuvant chemotherapy, whereas PD-L1 expression is a favorable prognostic factor in locally advanced gastric cancer patients.

A gene expression-based risk model reveals prognosis of gastric cancer

Background

The prognosis of gastric cancer is difficult to determine, although clinical indicators provide valuable evidence.

Methods

In this study, using screened biomarkers of gastric cancer in combination with random forest variable hunting and multivariable Cox regression, a risk score model was developed to predict the survival of gastric cancer. Survival difference between high/low-risk groups were compared. The relationship between risk score and other clinicopathological indicators was evaluated. Gene set enrichment analysis (GSEA) was used to identify pathways associated with risk scores.

Results

The patients with high risk scores (median overall survival: 20.2 months, 95% CI [16.9–26.0] months) tend to exhibit early events compared with those with low risk scores (median survival: 70.0 months, 95% CI [46.9–101] months, p = 1.80e–5). Further validation was implemented in another three independent datasets (GSE15459, GSE26253, GSE62254). Correlation analyses between clinical observations and risk scores were performed, and the results indicated that the risk score was not significantly associated with gender, age and primary tumor size but was significantly associated with grade and tumor stage. In addition, the risk score was also not influenced by radiation therapy. Cox multivariate regression and three-year survival nomogram suggest that the risk score is an important indicator of gastric cancer prognosis. GSEA was used to identified KEGG pathways significantly associated with risk score, and signaling pathways involved in focal adhesion and the TGF-beta signaling pathway were identified.

Conclusion

The risk score model successfully predicted the survival of 1,294 gastric cancer samples from four independent datasets and is among the most important indicators in clinical clinicopathological information for the prognosis of gastric cancer. To our knowledge, it is the first report to predict the survival of gastric cancer using optimized expression panel.

The prognostic value of programmed cell death ligand 1 expression in non-Hodgkin lymphoma: a meta-analysis

Objective:

Although the prognostic value of programmed cell death-ligand 1 (PD-L1) expression in non-Hodgkin lymphoma (NHL) has been evaluated in many studies, the results remain controversial. To investigate the prognostic role of PD-L1 expression and the association between PD-L1 expression and clinicopathological features of NHL, we performed a meta-analysis.

Methods:

The PubMed, EMBASE, and Cochrane Library databases were searched up to November 30, 2017. The hazard ratio (HR), 95% confidence interval (CI), and odds ratios (OR) with 95% CIs were combined to evaluate the association of PD-L1 expression with overall survival (OS) and clinicopathological features. Review manager 5.3 and STATA 12.0 were used in this meta-analysis.

Results:

A total of 2,005 patients across nine studies were enrolled in our meta-analysis, and the pooled results showed that high PD-L1 expression was associated with a poor prognosis (HR=2.04, 95% CI: 1.18–3.54, P=0.01). In the subgroup analysis according to histology types, pooled results demonstrated that an increased PD-L1 expression was an unfavorable prognostic factor for diffuse large B-cell lymphoma (HR=1.92, 95% CI: 1.06–3.48, P=0.03) but not for natural killer/T-cell lymphoma (HR=2.41, 95% CI: 0.47–12.22, P=0.29). Pooled ORs indicated that PD-L1 expression was higher in NHL with international prognostic indices of ≥3. However, PD-L1 expression had no correlation with gender, age, disease stage, lactate dehydrogenase level, B symptoms, and germinal center B-cell-like lymphoma.

Conclusions:

High PD-L1 expression was a poor prognostic biomarker in patients with NHL. Because of our limited sample size, high-quality studies with larger sample sizes are needed to validate our results.