High Serum PD-L1 Levels Are Associated with Poor Survival in Urothelial Cancer Patients Treated with Chemotherapy and Immune Checkpoint Inhibitor Therapy

Prognostic and clinicopathological value of soluble programmed cell death ligand-1 (sPD-L1) in patients with peripheral T-cell lymphoma: a meta-analysis

BACKGROUND

Previous studies have explored whether soluble programmed cell death ligand-1 (sPD-L1) can be used to predict the prognosis of patients with peripheral T-cell lymphoma (PTCL); however, no consistent results have been obtained. Consequently, we conducted the present meta-analysis to identify the precise significance of sPD-L1 in predicting the prognosis of PTCL.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library until July 31, 2024. The value of sPD-L1 in predicting PTCL prognosis was examined by combining the hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Seven articles involving 445 patients were included in this study. Based on our pooled findings, increased sPD-L1 was associated with dismal overall survival (OS) (HR = 4.22, 95%CI = 1.89-9.43, p < 0.001) and worse progression-free survival (PFS) (HR = 2.57, 95%CI = 1.35-4.90, p = 0.004) in PTCL. Furthermore, higher sPD-L1 levels were correlated with male sex (OR = 1.80, 95%CI = 1.06-3.03, p = 0.029), International Prognostic Index (IPI) score ≥2 (OR = 4.32, 95%CI = 2.10-8.89, p < 0.001), elevated lactate dehydrogenase (LDH) level (OR = 5.15, 95%CI = 1.94-13.71, p = 0.001), presence of B symptoms (OR = 2.56, 95%CI = 1.45-4.52, p = 0.001), and ECOG PS ≥2 (OR = 7.41, 95%CI = 1.49-36.92, p = 0.015) in PTCL.

CONCLUSION

According to the present meta-analysis, higher sPD-L1 levels were significantly correlated with poor OS and inferior PFS in patients with PTCL. Additionally, high sPD-L1 levels were also associated with clinical features representing the development of PTCL.

High serum levels of soluble PD‑1 and PD‑L1 are associated with advanced clinical stages in patients with cervical cancer

The binding of programmed cell death receptor-ligand 1 (PD-L1) to programmed cell death protein 1 (PD-1) inhibits T-cell activation, playing a negative role in the anticancer immune response. The soluble forms of these proteins, found in blood circulation, have recently received increasing attention and their function in the cancer immune response remains unclear. The present study evaluated the serum levels of soluble (s)PD-1 and sPD-L1 in patients with cervical cancer and healthy controls, and their associations with clinicopathological characteristics and clinical outcomes. The serum concentrations of both soluble proteins were determined via ELISA. The concentrations of sPD-1 and sPD-L1 were higher in patients with cervical cancer and advanced clinical stages. The evaluation of sPD-1 and clinical outcome revealed higher levels in deceased patients than in total remission patients. sPD-1 and sPD-L1 concentrations were moderately positively correlated; however, in patients with clinical stage IV disease, a very strong correlation was observed. sPD-1 and sPD-L1 could be used as potential diagnostic biomarkers for patients with cervical cancer. Considering the higher levels in advanced clinical stages, their role in cervical cancer progression or treatment response must be explored.

Assessing the Clinical Relevance of Soluble PD-1 and PD-L1: A Multi-Cohort Study Across Diverse Tumor Types and Prognostic Implications

Background/Objectives: Immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway have revolutionized cancer immunotherapy, however the clinical relevance of their soluble forms (sPD-1 and sPD-L1) remains less studied. Soluble PD-1 and PD-L1 have been implicated in tumor progression, prognosis, and treatment response across various malignancies. This study aims to provide a comprehensive analysis of sPD-1 and sPD-L1 levels in serum across diverse tumor types, including rare malignancies, and to evaluate their associations with clinicopathological characteristics and prognostic significance. Methods: In this study we analyzed sPD-1 and sPD-L1 levels in serum samples from 675 cancer patients representing a range of malignancies, including ovarian cancer, breast cancer, gastric cancer, colorectal cancer, renal cell carcinoma, and bone tumors. sPD-1 and sPD-L1 concentrations were measured using ELISA. Statistical analyses were performed to evaluate associations between soluble marker concentrations and clinicopathological factors, including tumor stage, size, histological subtype, and survival outcomes. Results: Elevated sPD-L1 levels were observed in several tumor types, including ovarian cancer, renal cell carcinoma, and gastric cancer, where they were associated with features of advanced disease, such as tumor size, stage, and metastases. In contrast, sPD-1 levels showed limited associations, with significant findings solely in gastric cancer and bone tumors, where levels correlated with histological subtype and differentiation. Prognostic analyses identified sPD-L1 as a marker of poor survival outcomes in ovarian cancer and bone tumors, while sPD-1 displayed no consistent prognostic significance. Conclusions: This study identifies the potential of sPD-L1 as a biomarker for tumor progression and prognosis across multiple malignancies. In contrast, sPD-1 showed limited clinical relevance, suggesting the importance of further investigation. These findings contribute to our understanding of soluble immune checkpoint proteins and their integration into personalized oncology strategies.

Plasma sPD-L1 and VEGF levels are associated with the prognosis of NSCLC patients treated with combination immunotherapy

The clinical significance of plasma soluble programmed cell death ligand 1 (sPD-L1) and vascular endothelial growth factor (VEGF) for non-small cell lung cancer (NSCLC) treated with the combination of anti-angiogenic therapy and anti-PD-L1 antibody (Ab) remain unknown. This study aimed to explore the association between plasma sPD-L1 and VEGF levels and the prognosis of NSCLC patients treated with the combination of Envafolimab and Endostar. Peripheral blood samples were collected from 24 NSCLC patients at baseline and after 6 weeks of treatment and were detected for sPD-L1 and VEGF levels. Both baseline and posttreatment sPD-L1 were significantly higher in progressive disease (PD) group than in controlled disease (CD) group (median: 77.5 pg/ml vs. 64.6 pg/ml, P  = 0.036, median: 8451 pg/ml vs. 5563 pg/ml, P  = 0.012). In multivariate analysis, lower baseline sPD-L1 levels were significantly associated with longer progression-free survival (PFS) (HR = 6.834, 95% CI: 1.350-34.592, P  = 0.020). There were significantly higher posttreatment VEGF levels in PD group compared with CD group (median: 323.7 pg/ml vs. 178.5 pg/ml, P  = 0.009). Higher posttreatment VEGF levels were significantly associated with shorter PFS in multivariate analysis (HR = 5.911, 95% CI: 1.391-25.122, P  = 0.016). Plasma sPD-L1 and VEGF levels are associated with the clinical response and prognosis of NSCLC patients treated with the combination of PD-L1 inhibitors and anti-angiogenetic therapy.

Soluble immune checkpoints: implications for cancer prognosis and response to immune checkpoint therapy and conventional therapies

Longitudinal sampling of tumor tissue from patients with solid cancers, aside from melanoma and a few other cases, is often unfeasible, and thus may not capture the plasticity of interactions between the tumor and immune system under selective pressure of a given therapy. Peripheral blood analyses provide salient information about the human peripheral immunome while offering technical and practical advantages over traditional tumor biopsies, and should be utilized where possible alongside interrogation of the tumor. Some common blood-based biomarkers used to study the immune response include immune cell subsets, circulating tumor DNA, and protein analytes such as cytokines. With the recent explosion of immune checkpoint inhibitors (ICI) as a modality of treatment in multiple cancer types, soluble immune checkpoints have become a relevant area of investigation for peripheral immune-based biomarkers. However, the exact functions of soluble immune checkpoints and their roles in cancer for the most part remain unclear. This review discusses current literature on the production, function, and expression of nine soluble immune checkpoints - sPD-L1, sPD-1, sCTLA4, sCD80, sTIM3, sLAG3, sB7-H3, sBTLA, and sHVEM - in patients with solid tumors, and explores their role as biomarkers of response to ICI as well as to conventional therapies (chemotherapy, radiotherapy, targeted therapy, and surgery) in cancer patients.

Novel ultrasensitive automated kinetic exclusion assay for measurement of plasma levels of soluble PD-L1, the predictive and prognostic biomarker in cancer patients treated with immune checkpoint inhibitors

Recently, the blood plasma or serum levels of soluble programmed death protein 1 (PD-L1), but not tissue PD-L1 expression level, have been proposed as an effective predictive and prognostic biomarker in patients treated with immune checkpoint inhibitors for different types of cancers. The quantification of soluble PD-L1 in blood will provide a quick evaluation of patients' immune status; however, the available assays have limitations in their sensitivity, reproducibility, and accuracy for use in clinical settings. To overcome these problems, this study was dedicated to developing an ultrasensitive automated flow-based kinetic exclusion assay (KinExA) for the accurate and precise measurement of soluble PD-L1 in plasma. The assay was developed with the assistance of KinExA™ 3200 biosensor. In this assay, PD-L1 in its calibrator or plasma sample solution was pre-equilibrated with anti-PD-L1 monoclonal antibody. The equilibrated mixture solution was then passed rapidly over PD-L1 protein that has been coated onto polymethylmethacrylate beads consolidated as a microcolumn in the observation cell of the KinExA™ biosensor. The free anti- PD-L1 antibody was bound to the immobilized PD-L1, however, the unbound molecules were removed from the beads microcolumn by flushing the system with phosphate-buffered saline. Fluorescein-labeled secondary antibody was passed rapidly over the beads, and the fluorescence signals were monitored during the flow of the labeled antibody through the beads. The calibration curve was generated by plotting the binding percentages as a function of PD-L1 concentrations in its sample solution. The working range of the assay with very a good correlation coefficient on a 4-parameter equation (r = 0.9992) was 0.5 - 100 pg mL─1. The assay limit of detection and quantitation were 0.15 and 0.5 pg mL─1, respectively. The recovery values of plasma-spiked PD-L1 were in the range of 96.4-104.3 % (±3.7-6.2 %). The precision of the assay was satisfactory; the values of the coefficient of variations did not exceed 6.2 % for both intra- and inter-day precision. The automated analysis by the proposed KinExA facilitates the processing of many specimens in clinical settings. The overall performance of the proposed KinExA is superior to the available assays for plasma levels of soluble PD-L1. The proposed assay is anticipated to have a great value in the measurement of PD-L1 where a more confident result is needed.

Unraveling the genetic associations between PD-1/PD-L1 and 13 circulating biomarkers linked to physiological and pathological processes

BACKGROUND

Evidence of the genetic interconnectedness between PD-1/PD-L1 and circulating biomarkers related to physiological and pathological processes is largely unclear. Understanding these genetic links is crucial for gaining insights into the underlying mechanisms and potential implications in cancer immunotherapy.

METHODS

To shed light on potential roles of 90 circulating biomarkers in PD-1/PD-L1, we conducted a comprehensive Mendelian randomization (MR) analysis, leveraging genetic data from large-scale genome-wide association studies.

RESULTS

Our results revealed negative associations between EN-RAGE and TRAIL-R2 with PD-1 levels. Additionally, we observed that PD-1 levels were positively associated with TRAIL, VEGF, and ANPEP, indicating their potential role in PD-1 upregulation. Furthermore, our analysis revealed causal associations between several circulating proteins and PD-L1 levels. Thrombomodulin, PSGL-1, TNFSF14, renin, follistatin, β-NGF, KLK6, and MMP-7 demonstrated significant effects on PD-L1 regulation, suggesting their potential inhibitory role in immune checkpoint regulation. Eventually, we confirmed the potential roles of key genes involved in above circulating proteins in influencing the response to immunotherapy.

CONCLUSIONS

Our findings provide valuable evidence of the genetic interconnectedness between PD-1/PD-L1 and circulating proteins related to physiological and pathological processes, shedding light on their potential roles in disease progression and therapeutic interventions.

Soluble programmed death ligand 1 as prognostic biomarker in non-small cell lung cancer patients receiving nivolumab, pembrolizumab or atezolizumab therapy

Many studies have focused on the prognostic role of soluble programmed death ligand 1 (sPD-L1) in non-small cell lung cancer (NSCLC), but outcomes are ambiguous and further investigations are needed. We addressed the matter by studying sPD-L1 in baseline samples and in longitudinal samples taken prior to three subsequent cycles of anti-PD-1/anti-PD-L1 treatments. Eighty patients with NSCLC were enrolled. Median sPD-L1 level at baseline was 52 pg/mL [95% confidence interval (CI) 49-57]. In patients treated with pembrolizumab and nivolumab, the concentration of sPD-L1 remained rather stable throughout treatment. In contrast, sPD-L1 rose by 50-fold following the first cycle of atezolizumab therapy. We found the baseline level of sPD-L1 to be related to overall survival (OS) after two years of follow-up in simple Cox analysis (p = 0.006) and multiple Cox Regression, hazard ratio 1.02 (95% CI 1.00-1.03) (p = 0.033). There was no association between sPD-L1 and tissue PD-L1 expression, overall response rate, or progression free survival. In conclusion, sPD-L1 measured in baseline serum samples may be associated with OS in NSCLC patients receiving anti-PD1/anti-PD-L1 treatment. Importantly, the results signify that further research is warranted to explore the clinical utility of sPD-L1 in patients treated with anti-PD-L1.

Meta-analysis of the prognostic value of soluble programmed death ligand-1 (sPD-L1) in cancers

BACKGROUND

The soluble programmed death ligand-1 (sPD-L1) and its prognostic role in cancers have been investigated in numerous studies. However, due to the inconsistency on some findings, this meta-analysis was performed to assess the prognostic value of sPD-L1 in patients with cancer.

METHODS

We searched the PubMed, Web of Science, MEDLINE, Wiley Online Library and ScienceDirect, and screened the studies for eligibility. Recurrence-free survival (RFS), progression-free survival (PFS) and disease-free survival (DFS) were for short term survival. The overall survival (OS) was for long term survival.

RESULTS

Forty studies with 4441 patients were included in this meta-analysis. Elevated sPD-L1 was associated with short OS [HR = 2.44 (2.03-2.94), p = 0.000]. Moreover, a high sPD-L1 was predictive of worse DFS/RFS/PFS [HR = 2.52 (1.83-3.44), p = 0.000]. In addition, high sPD-L1 was consistently correlated with poor OS in irrespective of study type, univariate and multivariate analysis, ethnicity, cut-off value of sPD-L1, sample and treatment. In the subgroup analysis, high sPD-L1 was correlated with poor OS in gastrointestinal cancer, lung cancer, hepatic cancer, oesophageal cancer and clear cell renal cell carcinoma.

CONCLUSIONS

The present meta-analysis showed that a high level of sPD-L1 was associated with worse prognosis in some types of cancer.

Clinical roles of soluble PD-1 and PD-L1 in plasma of NSCLC patients treated with immune checkpoint inhibitors

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have significantly improved the prognosis of non-small cell lung cancer (NSCLC). However, only a limited proportion of patients can benefit from this therapy, and clinically useful predictive biomarkers remain to be elucidated.

METHODS

Blood was collected from 189 patients with NSCLC before and six weeks after the initiation of ICI treatment (anti-PD-1 or anti-PD-L1 antibody). Soluble PD-1 (sPD-1) and PD-L1 (sPD-L1) in plasma before and after treatment were analyzed to evaluate their clinical significance.

RESULTS

Cox regression analysis demonstrated that higher sPD-L1 levels before treatment significantly predicted unfavorable progression-free survival (PFS; HR 15.4, 95% CI 1.10-86.7, P = 0.009) and overall survival (OS; HR 11.4, 95% CI 1.19-52.3, P = 0.007) in NSCLC patients treated with ICI monotherapy (n = 122) but not in those treated with ICIs combined with chemotherapy (n = 67: P = 0.729 and P = 0.155, respectively). In addition, higher sPD-1 levels after treatment were significantly associated with better OS (HR 0.24, 95% CI 0.06-0.91, P = 0.037) in patients treated with anti-PD-1 monotherapy, whereas higher sPD-L1 levels after treatment were significantly associated with worse PFS (HR 6.09, 95% CI 1.42-21.0, P = 0.008) and OS (HR 42.6, 95% CI 6.83-226, P < 0.001). The levels of sPD-L1 at baseline closely correlated with those of other soluble factors, such as sCD30, IL-2Ra, sTNF-R1, and sTNF-R2, which are known to be released from the cell surface by zinc-binding proteases ADAM10/17.

CONCLUSIONS

These findings suggest the clinical significance of pretreatment sPD-L1 as well as posttreatment sPD-1 and sPD-L1 in NSCLC patients treated with ICI monotherapy.

Urine PD-L1 is a tumor tissue candidate substitute and is associated with poor survival in muscle-invasive bladder cancer patients

Programmed death molecule ligand 1 (PD-L1) expression in urothelial carcinoma is a predictive marker used to guide immunotherapy. As expression of PD-L1 may be heterogeneous in the tumor tissue space, it cannot be accurately determined by immunohistochemical analysis. In this study, we examined PD-L1 protein levels in preoperative urine samples from bladder cancer patients, evaluated the prevalence of PD-L1 in urine, examined the usefulness of urine as a surrogate for PD-L1 expression in tumors, and compared PD-L1 expression in postoperative pathological sections. We found that PD-L1 in urine and tumor tissue correlated well and that it may be able to some extent serve as a surrogate for tissues in bladder cancer and thus predict risk of recurrence in muscle-invasive bladder cancer (MIBC) patients. Our findings reveal the clinical relevance of urine PD-L1 as a noninvasive prognostic indicator for immunotherapy and offer clinical translational suggestions for eventual development of a prognostic model for immunotherapy for bladder cancer.

Pre-treatment soluble PD-L1 as a predictor of overall survival for immune checkpoint inhibitor therapy: a systematic review and meta-analysis

Introduction

Immune checkpoint inhibitors (ICI) such as anti-PD-L1 and anti-PD-1 agents have been proven to be effective in various cancers. However, the rate of non-responders is still high in all cancer entities. Therefore, the identification of biomarkers that could help to optimize therapeutic decision-making is of great clinical importance. Soluble PD-L1 (sPD-L1) and PD-1 (sPD-1) are emerging blood-based biomarkers and were previously shown to be prognostic in various clinical studies.

Objective

We aimed to evaluate the prognostic relevance of sPD-L1 and sPD-1 in patients with different tumor entities who underwent ICI therapy.

Methods

We searched for articles in PubMed via Medline, Embase, Scopus, and Cochrane databases. The primary outcome was overall survival (OS) and progression-free survival (PFS); furthermore, we analyzed on-treatment serum level changes of sPD-L1 and sPD-1 during ICI therapy.

Results

We synthesized the data of 1,054 patients with different cancer types from 15 articles. Pooled univariate analysis showed that elevated levels of sPD-L1 were significantly associated with inferior OS (HR = 1.67; CI:1.26–2.23, I2 = 79%, p < 0.001). The strongest association was found in non-small cell lung cancer, whereas weaker or no association was observed in melanoma as well as in renal cell and esophageal cancers. Pooled multivariate analysis also showed that elevated levels of sPD-L1 correlated with worse OS (HR = 1.62; CI: 1.00–2.62, I2 = 84%, p = 0.05) and PFS (HR = 1.71; CI:1.00–2.94, I2 = 82%, p = 0.051). Furthermore, we observed that one or three months of anti-PD-L1 treatment caused a strong (27.67-fold) elevation of sPD-L1 levels in malignant mesothelioma and urothelial cancer.

Conclusions

We found significantly inferior OS in ICI-treated cancer patients with elevated pre-treatment sPD-L1 levels, but this association seems to be tumor type dependent. In addition, sPD-L1 increases during anti-PD-L1 therapy seems to be therapy specific.

High Pretreatment Serum PD-L1 Levels Are Associated with Muscle Invasion and Shorter Survival in Upper Tract Urothelial Carcinoma

Programmed death ligand-1 (PD-L1) is an immune checkpoint molecule and a widely used therapeutic target in urothelial cancer. Its circulating, soluble levels (sPD-L1) were recently suggested to be associated with the presence and prognosis of various malignancies but have not yet been investigated in upper tract urothelial carcinoma (UTUC). In this study, we assessed sPD-L1 levels in 97 prospectively collected serum samples from 61 UTUC patients who underwent radical nephroureterectomy (RNU), chemotherapy (CTX), or immune checkpoint inhibitor (ICI) therapy. In addition to pretreatment samples, postoperative and on-treatment sPD-L1 levels were determined in some patients by using ELISA. In the RNU group, elevated preoperative sPD-L1 was associated with a higher tumor grade (p = 0.019), stage (p < 0.001) and the presence of metastasis (p = 0.002). High sPD-L1 levels were significantly associated with worse survival in both the RNU and CTX cohorts. sPD-L1 levels were significantly elevated in postoperative samples (p = 0.011), while they remained unchanged during CTX. Interestingly, ICI treatment caused a strong, 25-fold increase in sPD-L1 (p < 0.001). Our results suggest that elevated preoperative sPD-L1 level is a predictor of higher pathological tumor stage and worse survival in UTUC, which therefore may help to optimize therapeutic decision-making. The observed characteristic sPD-L1 flare during immune checkpoint inhibitor therapy may have clinical significance.

Programmed Cell Death-Ligand-1 expression in Bladder Schistosomal Squamous Cell Carcinoma – There’s room for Immune Checkpoint Blockage?

Schistosoma haematobium, the causative agent of urogenital schistosomiasis, is a carcinogen type 1 since 1994. It is strongly associated with bladder squamous-cell carcinoma in endemic regions, where it accounts for 53-69% of bladder-carcinoma cases. This histological subtype is associated with chronic inflammation being more aggressive and resistant to conventional chemo and radiotherapy. Immune-Checkpoint-Blockage (ICB) therapies targeting the Programmed-Cell-Death-Protein-1(PD-1)/Programmed-Cell-Death-Ligand-1(PD-L1) axis showed considerable success in treating advanced bladder urothelial carcinoma. PD-L1 is induced by inflammatory stimuli and expressed in immune and tumor cells. The binding of PD-L1 with PD-1 modulates immune response leading to T-cell exhaustion. PD-L1 presents in several isoforms and its expression is dynamic and can serve as a companion marker for patients’ eligibility, allowing the identification of positive tumors that are more likely to respond to ICB therapy. The high PD-L1 expression in bladder-urothelial-carcinoma and squamous-cell carcinoma may affect further ICB-therapy application and outcomes. In general, divergent histologies are ineligible for therapy. These treatments are expensive and prone to auto-immune side effects and resistance. Thus, biomarkers capable of predicting therapy response are needed. Also, the PD-L1 expression assessment still needs refinement. Studies focused on squamous cell differentiation associated with S. haematobium remain scarce. Furthermore, in low and middle-income-regions, where schistosomiasis is endemic, SCC biomarkers are needed. This mini-review provides an overview of the current literature regarding PD-L1 expression in bladder-squamous-cell-carcinoma and schistosomiasis. It aims to pinpoint future directions, controversies, challenges, and the importance of PD-L1 as a biomarker for diagnosis, disease aggressiveness, and ICB-therapy prognosis in bladder-schistosomal-squamous-cell carcinoma.

Does Elevated Pre-Treatment Plasma PD-L1 Level Indicate an Increased Tumor Burden and Worse Prognosis in Metastatic Colorectal Cancer?

Background: Programmed death-ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) have been reported as possibly favorable prognostic factors in colorectal cancer (CRC). However, their longitudinal effect is unknown. Methods: A pilot study was performed to investigate whether baseline PD-1/PD-L1 levels are associated with further laboratory changes and/or shorter survival. Results: A total of 506 laboratory measurements from 37 metastatic CRC patients were analyzed. The baseline plasma PD-1 and PD-L1 levels were 27.73 ± 1.20 pg/mL and 16.01 ± 1.09 pg/mL, respectively. Disease progression (p = 0.0443) and baseline high-sensitivity C-reactive protein (p = 0.0011), aspartate transaminase (p = 0.0253), alanine transaminase (p = 0.0386), and gamma-glutamyl transferase (p = 0.0103) were associated with higher PD-L1 levels. Based on the baseline PD-1/PD-L1 levels, low and high PD-1/PD-L1 groups were created. Constant, pathological levels of complete blood count values, high-sensitivity C-reactive protein, serum albumin, high-density lipoprotein cholesterol, and lactate dehydrogenase were characteristic for patients with high baseline PD-L1. High PD-L1 levels were significantly associated with increased tumor burden. Disease-specific survival and progression-free survival were significantly shorter in patients with high PD-L1. Conclusions: Abnormal levels of laboratory parameters and intensified tumor burden can be expected if elevated baseline plasma PD-1/PD-L1 levels are found.

Prognostic value of soluble programmed cell death ligand-1 in patients with non-small-cell lung cancer: a meta-analysis

Background: Previously published data was collected and a meta-analysis was conducted to precisely identify the prognostic and clinicopathological significance of soluble programmed cell death ligand-1 (sPD-L1) in patients with non-small-cell lung cancer (NSCLC). Materials & methods: Combined hazard ratios (HRs), odds ratios and 95% confidence intervals were used to assess the correlation between sPD-L1 expression and prognosis in patients with NSCLC. Results: A total of 11 studies with 976 patients were included in this meta-analysis. High levels of sPD-L1 were associated with poor overall and progression-free survival (HR: 2.65, 95% CI: 2.32-3.02; p < 0.001 vs HR: 2.02, 95% CI: 1.24-3.29; p = 0.005). sPD-L1 level was not significantly correlated with sex, smoking status, age, Eastern Cooperative Oncology Group performance status, subtype or EGFR mutation. Conclusion: High levels of sPD-L1 are a prognostic marker for poor survival in patients with NSCLC.

Prognostic value and potential biological functions of ferroptosis‑related gene signature in bladder cancer

Bladder cancer (BC), as a genitourinary system tumor, is a highly prevalent tumor type. Ferroptosis is an iron-dependent oxidative cell death mechanism that is becoming increasingly recognized as a promising avenue for cancer therapy. However, further determination of the prospective prognostic value of ferroptosis for BC and investigation of the underlying mechanisms is required. The mRNA expression profiles and associated clinical data were downloaded from public databases such as The Cancer Genome Atlas, Gene Expression Omnibus and the IMvigor210 database. To construct a predictive formula, the least absolute shrinkage and selection operator Cox regression algorithm was used. In addition, a prognostic multigene signature was constructed using previously selected ferroptosis-related genes (FRGs). A total of 28 FRGs were differentially expressed between tumor and normal samples with |log2 fold change| >1 and adjusted P<0.05. A prognostic model was then established and it was validated in the GEO cohort using six genes: Glutamate-cysteine ligase modifier subunit, crystallin α-B, transferrin receptor, zinc finger E-box binding homeobox 1, squalene epoxidase and glucose-6-phosphate dehydrogenase (G6PD). Numerous important pathways involved in the development of the immune system and cancer were indicated to be significantly different between the two risk groups. In addition, it was discovered that G6PD expression subgroups that were associated with immunotherapy response in patients with BC had similar prognostic features to risk score subgroups. In the present study, a gene signature with a prognostic value for ferroptosis in BC was successfully developed and the potential value of G6PD was identified for future research.

Biological Characteristics and Clinical Significance of Soluble PD-1/PD-L1 and Exosomal PD-L1 in Cancer

The immune checkpoint pathway consisting of the cell membrane-bound molecule programmed death protein 1 (PD-1) and its ligand PD-L1 has been found to mediate negative regulatory signals that effectively inhibit T-cell proliferation and function and impair antitumor immune responses. Considerable evidence suggests that the PD-1/PD-L1 pathway is responsible for tumor immune tolerance and immune escape. Blockage of this pathway has been found to reverse T lymphocyte depletion and restore antitumor immunity. Antagonists targeting this pathway have shown significant clinical activity in specific cancer types. Although originally identified as membrane-type molecules, several other forms of PD-1/PD-L1 have been detected in the blood of cancer patients, including soluble PD-1/PD-L1 (sPD-1/sPD-L1) and exosomal PD-L1 (exoPD-L1), increasing the composition and functional complications of the PD-1/PD-L1 signaling pathway. For example, sPD-1 has been shown to block the PD-1/PD-L immunosuppressive pathway by binding to PD-L1 and PD-L2, whereas the role of sPD-L1 and its mechanism of action in cancer remain unclear. In addition, many studies have investigated the roles of exoPD-L1 in immunosuppression, as a biomarker for tumor progression and as a predictive biomarker for response to immunotherapy. This review describes the molecular mechanisms underlying the generation of sPD-1/sPD-L1 and exoPD-L1, along with their biological activities and methods of detection. In addition, this review discusses the clinical importance of sPD-1/sPD-L1 and exoPD-L1 in cancer, including their predictive and prognostic roles and the effects of treatments that target these molecules.

Elevated Pre-Treatment Serum MMP-7 Levels Are Associated with the Presence of Metastasis and Poor Survival in Upper Tract Urothelial Carcinoma

Upper tract urothelial carcinoma (UTUC) is a rare cancer with a barely predictable clinical behaviour. Serum MMP-7 is a validated prognostic marker in urothelial bladder cancer, a tumour entity with large clinical, histological, and molecular similarity to UTUC. The serum MMP-7 levels have not yet been investigated in UTUC. In the present study, we determined MMP-7 concentrations in an overall number of 103 serum samples from 57 UTUC patients who underwent surgical or systemic (platinum or immune checkpoint inhibitor) therapy by using the ELISA method. In addition to pre-treatment samples, the serum samples collected at predefined time points after or during therapy were also investigated. Serum MMP-7 concentrations were correlated with clinicopathological and follow-up data. Our results revealed significantly, two-fold elevated pre-treatment serum MMP-7 levels in metastatic cases of UTUC in both the radical surgery- and the chemotherapy-treated cohorts (p = 0.045 and p = 0.040, respectively). In addition, high serum MMP-7 levels significantly decreased after radical surgery, and high pre-treatment MMP-7 concentrations were associated with shorter survival both in the surgery- and chemotherapy-treated cohorts (p = 0.029 and p = 0.001, respectively). Our results revealed pre-treatment serum MMP-7 as a prognostic marker for UTUC, which may help to improve preoperative risk-stratification and thereby improve therapeutic decision-making.

Soluble PD-L1 in Serum and Urine in Urinary Bladder Cancer Patients

Simple Summary

Non-invasive diagnostic and prognostic biomarkers for urinary bladder cancer (BC) are eagerly awaited, since these could improve patient’s quality of life and reduce resources and costs for the health care system. The PD-1/PD-L1 axis is an important immune escape mechanism for tumors, and both high tissue expression and soluble levels of PD-L1 have been shown to be associated with worse prognosis for patients with various tumor. The knowledge about soluble PD-L1 in body fluids such as serum and urine in patients with BC is sparse, and more studies are needed to investigate its role as a biomarker for the disease. In the present study, we show that high serum PD-L1 levels are associated with aggressive disease and development of metastatic disease in BC patients.

Abstract

Soluble PD-L1 (sPD-L1) levels have been identified as a potential biomarker for various cancers, but its diagnostic and prognostic value in urinary bladder cancer (BC) remains to be fully elucidated. In this study, we investigated sPD-L1 levels in serum and urine samples from 132 patients with BC and compared them to 51 patients with hematuria (controls). The levels of sPD-L1 in serum and urine were determined using ELISA. Soluble PD-L1 could be detected in 99.5% of the serum samples and 34.4% of the urine samples. Patients diagnosed with BC had significantly higher urinary levels of sPD-L1, compared to controls, however no difference were found in serum sPD-L1 levels (p = 0.038 and p = 0.61, respectively). Significantly higher serum sPD-L1 levels were found in patients with muscle invasive disease and metastatic disease, compared to patients with non-muscle invasive BC and non-metastatic disease (p < 0.05). There was also a trend for higher urine sPD-L1 levels in patients with metastatic disease, compared to patients with non-metastatic disease (p = 0.05). The results from this study suggest that sPD-L1 in serum, but not in urine, could be a potential prognostic biomarker for patients with BC.

A novel signature constructed by ferroptosis-associated genes (FAGs) for the prediction of prognosis in bladder urothelial carcinoma (BLCA) and associated with immune infiltration

Background

Ferroptosis, a novel form of regulated cell death, has been implicated in the pathogenesis of cancers. Nevertheless, the potential function and prognostic values of ferroptosis in bladder urothelial carcinoma (BLCA) are complex and remain to be clarified. Therefore, we proposed to systematically examine the roles of ferroptosis-associated genes (FAGs) in BLCA.

Methods

According to The Cancer Genome Atlas (TCGA) database, differently expressed FAGs (DEFAGs) and differently expressed transcription factors (DETFs) were identified in BLCA. Next, the network between DEFAGs and DETFs, GO annotations and KEGG pathway analyses were performed. Then, through univariate, LASSO and multivariate regression analyses, a novel signature based on FAGs was constructed. Moreover, survival analysis, PCA analysis, t-SNE analysis, ROC analysis, independent prognostic analysis, clinicopathological and immune correlation analysis, and experimental validation were utilized to evaluate the signature.

Results

Twenty-eight DEFAGs were identified, and four FAGs (CRYAB, TFRC, SQLE and G6PD) were finally utilized to establish the FAGs based signature in the TCGA cohort, which was subsequently validated in the GEO database. Moreover, we found that immune cell infiltration, immunotherapy-related biomarkers and immune-related pathways were significantly different between two risk groups. Besides, nine molecule drugs with the potential to treat bladder cancer were identified by the connectivity map database analysis. Finally, the expression levels of crucial FAGs were verified by the experiment, which were consistent with our bioinformatics analysis, and knockdown of TFRC could inhibit cell proliferation and colony formation in BLCA cell lines in vitro.

Conclusions

Our study identified prognostic ferroptosis-associated genes and established a novel FAGs signature, which could accurately predict prognosis in BLCA patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02096-3.

Levels of Circulating PD-L1 Are Decreased in Patients with Resectable Cholangiocarcinoma

Tumor resection represents the only curative treatment option for patients with biliary tract cancers (BTCs), including intrahepatic cholangiocarcinoma (CCA), perihilar and extrahepatic CCA and gallbladder cancer. However, many patients develop early tumor recurrence and are unlikely to benefit from surgery. Therefore, markers to identify ideal surgical candidates are urgently needed. Circulating programmed cell death 1 ligand 1 (PD-L1) has recently been associated with different malignancies, including pancreatic cancer which closely resembles BTC in terms of patients’ prognosis and tumor biology. Here, we aim at evaluating a potential role of circulating PD-L1 as a novel biomarker for resectable BTC. Methods: Serum levels of PD-L1 were analyzed by ELISA in 73 BTC patients and 42 healthy controls. Results: Circulating levels of preoperative PD-L1 were significantly lower in patients with BTC compared to controls. Patients with low PD-L1 levels displayed a strong trend towards an impaired prognosis, and circulating PD-L1 was negatively correlated with experimental markers of promalignant tumor characteristics such as CCL1, CCL21, CCL25 and CCL26. For 37 out of 73 patients, postoperative PD-L1 levels were available. Interestingly, after tumor resection, circulating PD-L1 raised to almost normal levels. Notably, patients with further decreasing PD-L1 concentrations after surgery showed a trend towards an impaired postoperative outcome. Conclusion: Circulating PD-L1 levels were decreased in patients with resectable BTC. Lack of normalization of PD-L1 levels after surgery might identify patients at high risk for tumor recurrence or adverse outcome.