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

Expression and correlation of PD-L1 and HER2 in oesophageal squamous cell carcinoma

AIMS

In recent years, patients with programmed cell death-Ligand 1 (PD-L1)-positive oesophageal squamous cell carcinoma (OSCC) have been able to benefit from immunotherapy. However, method for improving the treatment efficacy of PD-L1-positive patients is a problem that needs further consideration. Studies on the relationship between human epidermal growth factor receptor 2 (HER2) and PD-L1 expression have recently been reported in certain cancers, but the relationship between PD-L1 and HER2 expression in OSCC is still unclear.

METHODS

A total of 263 patients with OSCC were included in the study. PD-L1 protein expression and HER2 protein expression were analysed by immunohistochemistry (IHC), and fluorescence in situ hybridisation (FISH) was performed to assess HER2 gene amplification. The significance of differences between HER2 status, PD-L1 status and clinicopathological parameters was assessed. The relationship between PD-L1 status and HER2 status was examined.

RESULTS

Of the 263 OSCC cases, the PD-L1-positive expression rates were 39.2% and 77.2% in OSCC for Tumour Proportion Score (TPS) and Combined Positive Score (CPS), respectively, and PD-L1 expression was associated with the degree of tumour differentiation. The HER2 expression was positive in 24% (63/263) of cases based on IHC and FISH. HER2 expression was not significantly associated with clinicopathological characteristics. PD-L1 TPS expression and CPS expression were significantly positively correlated with HER2 expression in OSCC.

CONCLUSIONS

PD-L1 expression was significantly positively correlated with HER2 expression in OSCC. The results provide valuable insight for the future application of HER2-targeted therapy combined with immunotherapy in OSCC.

Prognostic Significance of PD-L1 Expression in Gastric Cancer Patients with Peritoneal Metastasis

BACKGROUND

Recently, many studies have explored the relationship between the expression of programmed death ligand 1 (PD-L1) and prognosis in gastric cancer, but there is still controversy. Additionally, few studies have specifically investigated the expression of PD-L1 in patients with peritoneal metastasis.

METHODS

Immunohistochemistry was used to analyze the expression of PD-L1 in gastric cancer patients with peritoneal metastasis. The combined positive score (CPS) was calculated to evaluate the expression of PD-L1, and the clinicopathological data were analyzed to explore prognostic significance.

RESULTS

In total, 147 gastric cancer patients with peritoneal metastasis were enrolled. The negative PD-L1 expression was defined as a CPS < 1, and high PD-L1 expression was defined as a CPS ≥ 10. PD-L1 expression with CPS ≥ 1 and CPS-negative was detected in 67 (45.58%) and 80 (54.42%) patients, respectively. High PD-L1 expression at PD-L1 CPS ≥ 10 was detected in 21(14.29%) patients. The median overall survival (OS) was 18.53 months in the CPS < 10 group and 27.00 months in the CPS ≥ 10 group; the OS difference between the two groups was significant (p = 0.015). Multivariate analysis demonstrated that a poor Eastern Cooperative Oncology Group performance score (ECOG PS) (p = 0.002) and severe peritoneal metastasis (p = 0.033) were significantly associated with poor survival, while palliative chemotherapy (p = 0.002) and high PD-L1 expression (p = 0.008) were independent and significantly favorable prognostic factors.

CONCLUSIONS

Our study demonstrated that PD-L1 expression was widely presented in gastric cancer patients with peritoneal metastasis, while a CPS no less than 10 predicted better prognosis.

Programmed death-ligand 1 expression and overall survival in Thai patients with gastric cancer

Programmed death-ligand 1 (PD-L1) expression has now been implicated in gastric cancer (GC). This study was conducted to determine the impact of clinicopathological characteristics on PD-L1 expression and its association with survival in GC patients receiving standard-of-care. In total, 268 GC patients receiving upfront surgery were enrolled at Chiang Mai University Hospital. PD-L1 expression was assayed by immunohistochemistry staining using the Dako 22C3 pharmDx. The rates of PD-L1 positivity by combined positive score (CPS) at a cutoff value of 1 and 5 were 22% and 7%. PD-L1 positivity was significantly higher in patients younger than 55 than those older than 55 (32.6% vs. 16.5%, p = 0.003; 11.6% vs. 4.4%, p = 0.027). PD-L1 positivity was observed more frequently in GC with metastases than without (25.2% vs. 17.1%, p = 0.112; 7.2% vs. 6.7%, p = 0.673). Patients with PD-L1 positive had a significantly shorter median overall survival than those with PD-L1 negative (32.7 vs. 41.6 months, p = 0.042, 27.6 vs. 40.8 months, p = 0.038). In conclusion, PD-L1 expression has been associated with young age, short survival, and metastases, although unrelated to the tumor stage. For GC patients, PD-L1 testing is recommended, especially among young patients with metastases.

Effect of CD274 (PD-L1) overexpression on survival outcomes in 10 specific cancers: a systematic review and meta-analysis

AIM

The prognostic role of CD274 (programmed cell death ligand 1 (PD-L1)) overexpression has been examined in many studies. However, the results are controversial and conflicting. The present study aims to investigate the potential role of CD274 (PD-L1) immunohistochemical overexpression as a prognostic marker in malignant tumours.

METHODS

We searched PubMed, Embase and Web of Science from inception to December 2021 to identify potentially eligible studies. The pooled HRs with 95% CIs were calculated to identify the association between CD274 (PD-L1) overexpression and overall survival (OS), cancer-specific survival, disease-free survival, recurrence-free survival and progression-free survival in 10 lethal malignant tumours. Heterogeneity and publication bias were also analysed.

RESULTS

The study included 57 322 patients from 250 eligible studies (241 articles). The meta-analysis by tumour type using multivariate HR revealed worse OS in non-small cell lung cancer (HR 1.41, 95% CI 1.19 to 1.68), hepatocellular carcinoma (HR 1.75, 95% CI 1.11 to 2.74), pancreatic cancer (HR 1.84, 95% CI 1.12 to 3.02), renal cell carcinoma (HR 1.55, 95% CI 1.12 to 2.14) and colorectal cancer (HR 1.46, 95% CI 1.14 to 1.88). Estimated HRs showed associations between CD274 (PD-L1) overexpression and worse prognosis across different types of tumours in various survival endpoints, but no inverse correlation was identified. The heterogeneity for most of the pooled results was high.

CONCLUSIONS

This large meta-analysis suggests that CD274 (PD-L1) overexpression is a potential biomarker for multiple types of cancers. However, further studies are needed to reduce high heterogeneity.

PROSPERO REGISTRATION NUMBER

CRD42022296801.

Helicobacter pylori infection and PD-L1 expression in gastric cancer: A meta-analysis

BACKGROUND

High expression of programmed death ligand-1 (PD-L1) has been related to good response to immunotherapy patients with gastric cancer (GC). However, the influence of Helicobacter pylori (HP) infection on PD-L1 expression in GC remains unknown. A meta-analysis was performed to evaluate the association between HP infection and PD-L1 expression in GC.

METHODS

Observational studies that investigated the relationship between HP infection and PD-L1 expression in patients with GC were obtained by search electronic databases, including PubMed, Embase, Cochrane's Library and Web of Science. A random-effect model incorporating the possible influence of between-study heterogeneity was used to pool the results.

RESULTS

Ten studies with 1870 patients with GC contributed to the meta-analysis. Pooled results showed that HP infection was significantly associated with the tumour expression of PD-L1 (odds ratio [OR]: 1.90, 95% confidence interval: 1.33-2.72, p < .001; I²  = 53%). Subgroup analyses showed that the association between HP infection and PD-L1 expression in GC was not significantly affected by sample size, methods for PD-L1 evaluation and quality score (p for subgroup analyses all >.05). However, a stronger association was observed in studies with higher prevalence of HP infection (≥35%, OR: 2.58) as compared with those with lower prevalence (<35%, OR: 1.45, p for subgroup difference = .04).

CONCLUSION

Helicobacter pylori infection in GC patients is associated with tumour expression of PD-L1, suggesting HP infection may be a predictor of good response to immunotherapy in GC.

The Correlation of Ten Immune Checkpoint Gene Expressions and Their Association with Gastric Cancer Development

In the immunotherapy based on immune checkpoint inhibition (IC), additional ICs are being studied to increase its effectiveness. An almost unstudied feature is the possible co-expression of ICs, which can determine the therapeutic efficacy of their inhibition. For the selection of promising ICs, information on the association of their expression with cancer development may be essential. We have obtained data on the expression correlation of ADAM17, PVR, TDO2, CD274, CD276, CEACAM1, IDO1, LGALS3, LGALS9, and HHLA2 genes in gastric cancer (GC). All but one, TDO2, have other IC genes with co-expression at some stage. At the metastatic stage, the expression of the IDO1 does not correlate with any other gene. The correlations are positive, but the expressions of the CD276 and CEACAM1 genes are negatively correlated. The expression of TDO2 and LGALS3 is associated with GC metastasis. The expression of TDO2 four-fold higher in metastatic tumors than in non-metastatic tumors, but LGALS3 was two-fold lower. The differentiation is associated with IDO1. The revealed features of TDO2, with a significant increase in expression at the metastatic stage and the absence of other IC genes with correlated expression indicates that the prospect of inhibiting TDO2 in metastatic GC. IDO1 may be considered for inhibition in low-differentiated tumors.

CD3D Is an Independent Prognostic Factor and Correlates With Immune Infiltration in Gastric Cancer

The protein encoded by CD3D is part of the T-cell receptor/CD3 complex (TCR/CD3 complex) and is involved in T-cell development and signal transduction. Previous studies have shown that CD3D is associated with prognosis and treatment response in breast, colorectal, and liver cancer. However, the expression and clinical significance of CD3D in gastric cancer are not clear. In this study, we collected 488 gastric cancer tissues and 430 paired adjacent tissues to perform tissue microarrays (TMAs). Then, immunohistochemical staining of CD3D, CD3, CD4, CD8 and PD-L1 was conducted to investigate the expression of CD3D in gastric cancer and the correlation between the expression of CD3D and tumor infiltrating lymphocytes (TILs) and PD-L1. The results showed that CD3D was highly expressed in gastric cancer tissues compared with paracancerous tissues (P<0.000). Univariate and multivariate analyses showed that CD3D was an independent good prognostic factor for gastric cancer (P=0.004, HR=0.677, 95%CI: 0.510-0.898 for univariate analyses; P=0.046, HR=0.687, 95%CI: 0.474-0.994 for multivariate analyses). In addition, CD3D was negatively correlated with the tumor location, Borrmann type and distant metastasis (P=0.012 for tumor location; P=0.007 for Borrmann type; P=0.027 for distant metastasis). In addition, the expression of CD3D was highly positively correlated with the expression of CD3, CD4, CD8, and PD-L1, and the combination of CD3D with CD3, CD4, CD8 and PD-L1 predicted the best prognosis (P=0.043). In summary, CD3D may play an important regulatory role in the tumor immune microenvironment of gastric cancer and may serve as a potential indicator of prognosis and immunotherapy response.

Programmed Death-Ligand 1 (PD-L1) Positivity and Factors Associated with Poor Prognosis in Patients with Gastric Cancer: An Umbrella Meta-Analysis

Gastric cancer (GC) is one of the most common malignancies throughout the world with late diagnosis and poor prognosis. The expression of programmed death-ligand 1 (PD-L1) in GC is attributed to immune evasion and tumor progression. PD-L1 positivity has both predictive and prognostic biomarker potential. Aiming to summarize a large amount of research and to provide a definitive conclusion to the conflicting results on the prognostic significance of PD-L1 expression in GC, we performed an umbrella review based on existing meta-analyses which were published recently (2016-2021) and indexed in the PubMed database. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used in August 2021 to screen articles, and data extraction with quality assessment was performed on the selected meta-analyses. Review Manager (RevMan) 5.3 software was used to analyze the HR and OR with a 95% confidence interval (CI) among PD-L1 positive GC patients. We also assessed the between-study heterogeneity (I ²). Forest and Funnel plots were obtained, and a P-value of <0.05 was considered statistically significant. A total of 567 articles were screened, and we selected three meta-analyses with a total of 40 studies conducted over a period of 14 years. In our umbrella review, a total of 8,419 GC patients with an average PD-L1 positivity of 39% were analyzed. We found that PD-L1 positivity in GC patients is associated with poor prognosis (pooled HR =1.44, 95% CI: 1.24-1.68, P<0.00001) having higher mortality reducing the chances of overall survival (OS). However, there are no significant differences in PD-L1 expression among different lymph node (LN) metastases (OR=1.31, 95% CI: 0.98-1.74, P=0.07) and tumor, node, and metastasis (TNM) stages (OR=1.13, 95% CI: 0.80-1.58, P=0.50). Early identification of PD-L1 expression may help tailor cost-effective and targeted immunotherapy among GC patients. More research is needed to further understand how PD-L1 affects LN metastasis and tumor invasion.

Recent insights into the use of immune checkpoint inhibitors in gastric cancer

Gastric cancer (GC) is the fifth most incident and the fourth deadliest cancer worldwide. GC is a heterogeneous disease from the histological and molecular standpoints. This malignancy is mostly diagnosed at advanced stages of the disease, where the available therapeutic interventions are not effective. The emergence of immunotherapy has transformed the landscape of cancer treatment, including GC, and currently immune checkpoint inhibitors have been approved for the treatment of patients with recurrent/metastatic GC. This review summarizes the main clinical trials evaluating the use of immune checkpoint inhibitors in GC. It also highlights the potential of biomarkers for patient selection for GC immune checkpoint inhibition therapy, including programmed cell death ligand 1 expression and tumor mutational burden, and characteristics of the GC molecular classification, such as microsatellite instability status and Epstein-Barr virus infection, as predictors of response to blockade of the programmed cell death 1/programmed cell death ligand 1 axis.

Expression of Immune Checkpoints in Malignant Tumors: Therapy Targets and Biomarkers for the Gastric Cancer Prognosis

To increase the effectiveness of anticancer therapy based on immune checkpoint (IC) inhibition, some ICs are being investigated in addition to those used in clinic. We reviewed data on the relationship between PD-L1, B7-H3, B7-H4, IDO1, Galectin-3 and -9, CEACAM1, CD155, Siglec-15 and ADAM17 expression with cancer development in complex with the results of clinical trials on their inhibition. Increased expression of the most studied ICs—PD-L1, B7-H3, and B7-H4—is associated with poor survival; their inhibition is clinically significant. Expression of IDO1, CD155, and ADAM17 is also associated with poor survival, including gastric cancer (GC). The available data indicate that CD155 and ADAM17 are promising targets for immune therapy. However, the clinical trials of anti-IDO1 antibodies have been unsatisfactory. Expression of Galectin-3 and -9, CEACAM1 and Siglec-15 demonstrates a contradictory relationship with patient survival. The lack of satisfactory results of these IC inhibitor clinical trials additionally indicates the complex nature of their functioning. In conclusion, in many cases it is important to analyze the expression of other participants of the immune response besides target IC. The PD-L1, B7-H3, B7-H4, IDO1 and ADAM17 may be considered as candidates for prognosis markers for GC patient survival.

Prognostic Function of Programmed Cell Death-Ligand 1 in Esophageal Squamous Cell Carcinoma Patients Without Preoperative Therapy: A Systematic Review and Meta-Analysis

Background

Studies investigating the correlation between the expression of programmed cell death-ligand 1 (PD-L1) and prognosis in patients with esophageal squamous cell carcinoma (ESCC) not receiving preoperative therapy have increased significantly, but conclusions remain inconclusive. Therefore, this study aimed to determine the association between clinical outcomes and expression of PD-L1 in ESCC patients without preoperative therapy.

Methods

We conducted a comprehensive literature search using four databases up to May 2020. Quality assessment was carried out according to the Newcastle-Ottawa Quality Assessment Scale (NOS). Hazard ratios (HRs) were used to analyze the association between PD-L1 expression with prognosis. Furthermore, we evaluated the correlation between PD-L1 and clinicopathological characteristics using odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Twenty studies (19 publications) comprising 3,677 patients were included in this meta-analysis. We found that the expression of PD-L1 was not related to overall survival (OS, HR: 1.16, 95% CI: 0.94-1.42, p = 0.16) or disease-free survival (DFS, HR: 0.85, 95% CI: 0.66-1.10, p = 0.21) in ESCC. Furthermore, although PD-L1 expression was not significantly associated with sex, degree of differentiation, TNM stage, T stage, lymph node status, smoking, or alcohol use, the merged OR demonstrated that the expression of PD-L1 was higher in older patients compared to younger patients (OR: 1.40, 95% CI: 1.07-1.83, p = 0.01). No obvious publication bias was observed.

Conclusions

Our present study illustrated that PD-L1 expression was not related to poor prognosis of ESCC patients not receiving preoperative therapy, albeit the association only showed a tendency for statistical significance. Notably, PD-L1 expression showed a significant association with age. This meta-analysis had several limitations; therefore, our results need to be verified through further large-scale and prospective studies.