Baseline plasma levels of soluble PD-1, PD-L1, and BTN3A1 predict response to nivolumab treatment in patients with metastatic renal cell carcinoma: a step toward a biomarker for therapeutic decisions

Liquid biopsy for renal cell carcinoma

Liquid biopsies offer a less invasive alternative to tissue biopsies for diagnosis, prognosis, and determining therapeutic potential in renal cell carcinoma (RCC). Unfortunately, clinical studies using liquid biopsy biomarkers in RCC are limited. Accordingly, we examine RCC biomarkers, derived from urine, plasma, serum and feces of potential impact and clinical outcome in these patients. A PRISMA checklist was used to identify valuable liquid biopsy biomarkers for diagnosis (plasma cfDNA, serum- or urine-derived circulating RNAs, exosomes and proteins), prognosis (plasma cfDNA, plasma- or serum-derived RNAs, and proteins), and therapeutic response (plasma- and serum-derived proteins). Although other analytes have been identified, their application for routine clinical use remains unclear. In general, panels appear more effective than single biomarkers. Important considerations included proof of reproducibility. Unfortunately, many of the examined studies were insufficiently large and lacked multi-center rigor. Cost-effectiveness was also not available. Accordingly, it is clear that more standardized protocols need to be developed before liquid biopsies can be successfully integrated into clinical practice in RCC.

Soluble immune checkpoint molecules in cancer risk, outcomes prediction, and therapeutic applications

Immunotherapy has emerged as a pivotal modality in cancer treatment, with immune checkpoint inhibitors effectively combating malignancies by impeding crucial pathways within the immune system and stimulating patients' immune responses. Soluble forms of immune checkpoints exhibit a remarkable diversity and can be readily tracked in circulation, holding immense potential as biomarkers for cancer treatment. An increasing number of studies focused on soluble immune checkpoints in cancer have emerged thanks to technological advancements. In this systematic review, we comprehensively summarized the recent studies on soluble immune checkpoints in human cancer risk prediction, outcome prediction, therapeutic applications, and potential molecular mechanisms, which demonstrated the promising future of soluble immune checkpoints in clinical applications. The clinical relevance of soluble immune checkpoints has been recognized in multiple cancers, yet the therapeutic applications and mechanisms remain obscure. Interpreting the impacts and mechanisms of soluble immune checkpoints could shed a light on the novel strategies of cancer screening, treatments, and outcome prediction.

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.

High expression of BTN3A1 is associated with clinical and immunological characteristics and predicts a poor prognosis in advanced human gliomas

Introduction

Gliomas represent the most prevalent and aggressive tumors within the central nervous system. Despite the current standard treatments, the median survival time for glioblastoma patients remains dismal, hovering around 14 months. While attempts have been made to inhibit the PD-1/PD-L1 and CTLA-4/CD80-CD86 axes through immunotherapy, the outcomes have yet to demonstrate significant efficacy. The immune checkpoint Butyrophilin 3A1 (BTN3A1) can either be involved in advantageous or detrimental function depending on the cancer type.

Methods

In our study, we utilized a Moroccan cohort to delve into the role of BTN3A1 in gliomas. A transcriptomic analysis was conducted on 34 patients, which was then corroborated through a protein analysis in 27 patients and validated using the TCGA database (n = 667).

Results

Our results revealed an elevated expression of BTN3A1 in glioblastoma (grade 4), as evidenced in both the TCGA database and our cohort of Moroccan glioma patients. Within the TCGA cohort, BTN3A1 expression was notably higher in patients with wild-type IDH. We observed a positive correlation between BTN3A1 expression and immune infiltration of B cells, CD8+ T cells, naive CD4+ T cells, and M2 macrophages. Patients exhibiting increased BTN3A1 expression also presented elevated levels of TGF-β, IL-10, and TIM-3 compared to those with reduced BTN3A1 expression. Notably, patients with high BTN3A1 expression were associated with a poorer prognosis than their counterparts with lower expression.

Conclussion

Our findings suggest that BTN3A1 might promote the establishment of an immunosuppressive microenvironment. Consequently, targeting BTN3A1 could offer novel therapeutic avenues for the management of advanced gliomas.

[The circulating PD-L1: An emerging predictive biomarker for immune checkpoint inhibitors response]

Immune checkpoint inhibitors (ICI) have recently become the standard of care for many metastatic solid tumors, with considerable improvements in patient prognosis. However, a non-negligible proportion of patients does not respond to this type of treatment, making it essential to identify predictive factors of this response in order to better adapt the therapy. Among the biomarkers that have been most extensively studied in recent years, tumor PD-L1 levels come out on top, with controversial results for predicting response to ICI. The determination of circulating PD-L1 (or soluble PD-L1) in peripheral blood seems to be an interesting emerging biomarker. Indeed, several studies have investigated its prognostic value, and/or its potential predictive value of response to immunotherapy, and it would appear that there is a correlation between the level of soluble PD-L1 and the level of tumor aggressiveness and therefore prognosis. Furthermore, the results suggest that higher PD-L1 levels are associated with a poorer response to immunotherapy, although this remains to be confirmed in large-scale studies.

Comprehensive Systematic Review of Biomarkers in Metastatic Renal Cell Carcinoma: Predictors, Prognostics, and Therapeutic Monitoring

BACKGROUND

Challenges remain in determining the most effective treatment strategies and identifying patients who would benefit from adjuvant or neoadjuvant therapy in renal cell carcinoma. The objective of this review is to provide a comprehensive overview of biomarkers in metastatic renal cell carcinoma (mRCC) and their utility in prediction of treatment response, prognosis, and therapeutic monitoring in patients receiving systemic therapy for metastatic disease.

METHODS

A systematic literature search was conducted using the PubMed database for relevant studies published between January 2017 and December 2022. The search focused on biomarkers associated with mRCC and their relationship to immune checkpoint inhibitors, targeted therapy, and VEGF inhibitors in the adjuvant, neoadjuvant, and metastatic settings.

RESULTS

The review identified various biomarkers with predictive, prognostic, and therapeutic monitoring potential in mRCC. The review also discussed the challenges associated with anti-angiogenic and immune-checkpoint monotherapy trials and highlighted the need for personalized therapy based on molecular signatures.

CONCLUSION

This comprehensive review provides valuable insights into the landscape of biomarkers in mRCC and their potential applications in prediction of treatment response, prognosis, and therapeutic monitoring. The findings underscore the importance of incorporating biomarker assessment into clinical practice to guide treatment decisions and improve patient outcomes in mRCC.

LncTUG1 promotes hepatocellular carcinoma immune evasion via upregulating PD-L1 expression

HCC is one of the most common malignant tumors worldwide. Although traditional treatment methods have been improved in recent years, the survival rate of HCC patients has not been significantly improved. Immunotherapy has shown extremely high clinical value in a variety of tumors. In this study, we found that TUG1 could regulate the expression of PD-L1 through JAK2/STAT3 to mediate immunosuppression. Here, The expression of TUG1 and PD-L1 in HCC tissues was evaluated through analysis of databases and verified in HCC tissue and HCC cancer cells by qRT-PCR. The effect of TUG1 on tumor immune escape was detected by coculture, and cell viability was detected with a CCK8 assay. The results demonstrated that TUG1 was closely associated with anticancer immunity. TUG1 and PD-L1 were highly expressed in HCC tissues and HCC cancer cells, and high expression of TUG1 and PD-L1 was related to the poor prognosis of HCC patients. In addition, knocking down TUG1 expression could reduce PD-L1 expression and enhance the cancer cell-killing capability of T cells. Downregulating TUG1 expression could also decrease the mRNA and protein expression of JAK2 and STAT3. To sum up, TUG1 and PD-L1 are overexpressed in patients with liver cancer and are related to the poor prognosis of these patients. Silencing TUG1 expression reduced the mRNA and protein expression of PD-L1 by affecting the JAK2/STAT3 pathway.

Network approach in liquidomics landscape

Tissue-based biopsy is the present main tool to explore the molecular landscape of cancer, but it also has many limits to be frequently executed, being too invasive with the risk of side effects. These limits and the ability of cancer to constantly evolve its genomic profile, have recently led to the need of a less invasive and more accurate alternative, such as liquid biopsy. By searching Circulating Tumor Cells and residues of their nucleic acids or other tumor products in body fluids, especially in blood, but also in urine, stools and saliva, liquid biopsy is becoming the future of clinical oncology. Despite the current lack of a standardization for its workflows, that makes it hard to be reproduced, liquid biopsy has already obtained promising results for cancer screening, diagnosis, prognosis, and risk of recurrence.Through a more accessible molecular profiling of tumors, it could become easier to identify biomarkers predictive of response to treatment, such as EGFR mutations in non-small cell lung cancer and KRAS mutations in colorectal cancer, or Microsatellite Instability and Mismatch Repair as predictive markers of pembrolizumab response.By monitoring circulating tumor DNA in longitudinal repeated sampling of blood we could also predict Minimal Residual Disease and the risk of recurrence in already radically resected patients.In this review we will discuss about the current knowledge of limitations and strengths of the different forms of liquid biopsies for its inclusion in normal cancer management, with a brief nod to their newest biomarkers and its future implications.

The components of tumor microenvironment as biomarker for immunotherapy in metastatic renal cell carcinoma

Substantial improvement in prognosis among metastatic renal cell carcinoma (mRCC) patients has been achieved, owing to the rapid development and utilization of immunotherapy. In particular, immune checkpoint inhibitors (ICIs) have been considered the backbone of systemic therapy for patients with mRCC alongside multi-targeted tyrosine kinase inhibitors (TKIs) in the latest clinical practice guidelines. However, controversies and challenges in optimal individualized treatment regarding immunotherapy remains still About 2/3 of the patients presented non-response or acquired resistance to ICIs. Besides, immune-related toxicities, namely immune-related adverse events, are still elusive and life-threatening. Thus, reliable biomarkers to predict immunotherapeutic outcomes for mRCC patients are needed urgently. Tumor microenvironment (TME), consisting of immune cells, vasculature, signaling molecules, and extracellular matrix and regulates tumor immune surveillance and immunological evasion through complex interplay, plays a critical role in tumor immune escape and consequently manipulates the efficacy of immunotherapy. Various studied have identified the different TME components are significantly associated with the outcome of mRCC patients receiving immunotherapy, making them potential valuable biomarkers in therapeutic guidance. The present review aims to summarize the latest evidence on the associations between the components of TME including immune cells, cytokines and extracellular matrix, and the therapeutic responses among mRCC patients with ICI-based treatment. We further discuss the feasibility and limitation of these components as biomarkers.

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.

Low plasma PD-L1 levels, early tumor onset and absence of peritoneal carcinomatosis improve prognosis of women with advanced high-grade serous ovarian cancer

BACKGROUND

The most common subtype of ovarian cancer (OC) showing immunogenic potential is represented by the high-grade serous ovarian cancer (HGSOC), which is characterized by the presence of tumor-infiltrating immune cells able to modulate immune response. Because several studies showed a close correlation between OC patient's clinical outcome and expression of programmed cell death protein-1 or its ligand (PD-1/PD-L1), the aim of our study was to investigate if plasma levels of immunomodulatory proteins may predict prognosis of advanced HGSOC women.

PATIENTS AND METHODS

Through specific ELISA tests, we analyzed plasma concentrations of PD-L1, PD-1, butyrophilin sub-family 3A/CD277 receptor (BTN3A1), pan-BTN3As, butyrophilin sub-family 2 member A1 (BTN2A1), and B- and T-lymphocyte attenuator (BTLA) in one hundred patients affected by advanced HGSOC, before surgery and therapy. The Kaplan-Meier method was used to generate the survival curves, while univariate and multivariate analysis were performed using Cox proportional hazard regression models.

RESULTS

For each analyzed circulating biomarker, advanced HGSOC women were discriminated based on long (≥ 30 months) versus short progression-free survival (PFS < 30 months). The concentration cut-offs, obtained by receiver operating characteristic (ROC) analysis, allowed to observe that poor clinical outcome and median PFS ranging between 6 and 16 months were associated with higher baseline levels of PD-L1 (> 0.42 ng/mL), PD-1 (> 2.48 ng/mL), BTN3A1 (> 4.75 ng/mL), pan-BTN3As (> 13.06 ng/mL), BTN2A1 (> 5.59 ng/mL) and BTLA (> 2.78 ng/mL). Furthermore, a lower median PFS was associated with peritoneal carcinomatosis, age at diagnosis > 60 years or Body Mass Index (BMI) > 25. A multivariate analysis also suggested that plasma concentrations of PD-L1 ≤ 0.42 ng/mL (HR: 2.23; 95% CI: 1.34 to 3.73; p = 0.002), age at diagnosis ≤ 60 years (HR: 1.70; 95% CI: 1.07 to 2.70; p = 0.024) and absence of peritoneal carcinomatosis (HR: 1.87; 95% CI: 1.23 to 2.85; p = 0.003) were significant prognostic marker for a longer PFS in advanced HGSOC patients.

CONCLUSIONS

The identification of high-risk HGSOC women could be improved through determination of the plasma PD-L1, PD-1, BTN3A1, pan-BTN3As, BTN2A1 and BTLA levels.

Butyrophilins: Dynamic Regulators of Protective T Cell Immunity in Cancer

The efficacy of current immunotherapies remains limited in many solid epithelial malignancies. Recent investigations into the biology of butyrophilin (BTN) and butyrophilin-like (BTNL) molecules, however, suggest these molecules are potent immunosuppressors of antigen-specific protective T cell activity in tumor beds. BTN and BTNL molecules also associate with each other dynamically on cellular surfaces in specific contexts, which modulates their biology. At least in the case of BTN3A1, this dynamism drives the immunosuppression of αβ T cells or the activation of Vγ9Vδ2 T cells. Clearly, there is much to learn regarding the biology of BTN and BTNL molecules in the context of cancer, where they may represent intriguing immunotherapeutic targets that could potentially synergize with the current class of immune modulators in cancer. Here, we discuss our current understanding of BTN and BTNL biology, with a particular focus on BTN3A1, and potential therapeutic implications for cancer.

Prognostic and predictive role of soluble programmed death ligand-1 in head and neck cancer

OBJECTIVES

The aim of the study was to investigate clinical significance of soluble PD-L1 (sPD-L1) serum level in head and neck cancer and to evaluate its role as a possible prognostic and predictive biomarker.

METHODS

A prospective analysis of sPD-L1 levels in 60 patients diagnosed and treated due to malignant and non-malignant lesions in the region of head and neck was performed in peripheral blood by an ELISA test.

RESULTS

The range of sPD-L1 in the study group was 0.16-1.63ng/mL, mean 0.64±0.32. There were no differences in the mean sPD-L1 regarding patients' age, sex, and the localization of the lesion. Statistically significant difference was revealed in the average sPD-L1 level (p= 0.006) depending on the histopathological advancement of the lesions, 0.704 ± 0.349 and 0.512 ± 0.177 respectively in the malignant and benign group. The separate analysis of laryngeal lesions confirmed statistical difference in sPD-L1 (p= 0.002) for the malignant lesions (0.741 ± 0.353) compared with the benign (0.489 ± 0.175). The sPD-L1 level of 0.765 ng/mL or higher, revealed 35% sensitivity and 95.5% specificity for the diagnosis of head and neck malignant lesions (AUC=0.664, 95% CI 0.529‒0.8, p-value=0.039). The 1-year DFS was 83.3% in the group of patients with low sPD-L1 levels (< 0.765ng/mL) and 53.8% in patients with high sPD-L1 (≥0.765ng/mL). The 2-year OS were 68% and 69.2% respectively in both groups. The log-rank test confirmed statistically significant prognostic value of sPD-L1 level for 1-year DFS (p-value=0.035).

CONCLUSIONS

sPD-L1 is a promising prognostic and early recurrence predictive biomarker for head and neck cancers, most significantly for laryngeal lesions.

LEVEL OF EVIDENCE: 3

Liquid biopsy at the frontier in renal cell carcinoma: recent analysis of techniques and clinical application

Renal cell carcinoma (RCC) is a major pathological type of kidney cancer and is one of the most common malignancies worldwide. The unremarkable symptoms of early stages, proneness to postoperative metastasis or recurrence, and low sensitivity to radiotherapy and chemotherapy pose a challenge for the diagnosis and treatment of RCC. Liquid biopsy is an emerging test that measures patient biomarkers, including circulating tumor cells, cell-free DNA/cell-free tumor DNA, cell-free RNA, exosomes, and tumor-derived metabolites and proteins. Owing to its non-invasiveness, liquid biopsy enables continuous and real-time collection of patient information for diagnosis, prognostic assessment, treatment monitoring, and response evaluation. Therefore, the selection of appropriate biomarkers for liquid biopsy is crucial for identifying high-risk patients, developing personalized therapeutic plans, and practicing precision medicine. In recent years, owing to the rapid development and iteration of extraction and analysis technologies, liquid biopsy has emerged as a low cost, high efficiency, and high accuracy clinical detection method. Here, we comprehensively review liquid biopsy components and their clinical applications over the past 5 years. Additionally, we discuss its limitations and predict its future prospects.

Gamma delta T-cell-based immune checkpoint therapy: attractive candidate for antitumor treatment

As a nontraditional T-cell subgroup, γδT cells have gained popularity in the field of immunotherapy in recent years. They have extraordinary antitumor potential and prospects for clinical application. Immune checkpoint inhibitors (ICIs), which are efficacious in tumor patients, have become pioneer drugs in the field of tumor immunotherapy since they were incorporated into clinical practice. In addition, γδT cells that have infiltrated into tumor tissues are found to be in a state of exhaustion or anergy, and there is upregulation of many immune checkpoints (ICs) on their surface, suggesting that γδT cells have a similar ability to respond to ICIs as traditional effector T cells. Studies have shown that targeting ICs can reverse the dysfunctional state of γδT cells in the tumor microenvironment (TME) and exert antitumor effects by improving γδT-cell proliferation and activation and enhancing cytotoxicity. Clarification of the functional state of γδT cells in the TME and the mechanisms underlying their interaction with ICs will solidify ICIs combined with γδT cells as a good treatment option.

Prognostic role of soluble PD-1 and BTN2A1 in overweight melanoma patients treated with nivolumab or pembrolizumab: finding the missing links in the symbiotic immune-metabolic interplay

Individual response to immune checkpoint inhibitors (ICIs) is currently unpredictable in patients with melanoma. Recent findings highlight a striking improvement in the clinical outcomes of overweight/obese patients treated with ICIs, which seems driven, at least in part, by programmed cell death protein 1 (PD-1)-mediated T-cell dysfunction. A putative role of butyrophilins (BTNs) is under investigation as a novel mechanism of cancer immune evasion and obesity-associated inflammation. This study investigates the role of baseline plasma levels of soluble PD-1 (sPD-1), soluble programmed cell death ligand 1 (sPD-L1), BTN2A1 (sBTN2A1), BTN3A1 (sBTN3A1), along with body mass index (BMI), as predictive biomarkers of immunotherapy response in metastatic melanoma patients treated with nivolumab or pembrolizumab as first-line treatment. In all, 41 patients were included in the study. The baseline plasma level of sPD-1 was significantly lower, and the sBTN2A1 was significantly higher, in long-responder patients to nivolumab or pembrolizumab (median sPD-1: 10.3 ng/ml versus 16.6 ng/ml, p = 0.001; median sBTN2A1: 4.4 ng/ml versus 3.77 ng/ml, p = 0.004). Lower levels of sPD-1 and higher levels of sBTN2A1 were also significantly associated with better overall response rate. Notably, when we further stratified the study cohort using BMI along with sPD-1, patients with BMI ⩾ 25 and sPD-1 < 11.24 ng/ml had longer time to treatment failure after PD-1 inhibitor than other subgroups of patients (p < 0.001). Circulating sPD-1 and sBTN2A1 detection, along with BMI, could give more insights into the immune-metabolic interactions underlying the benefit observed in overweight/obese patients, improving the use of dynamic, noninvasive, biomarkers for patient selection.

Exploring the Dynamic Crosstalk between the Immune System and Genetics in Gastrointestinal Stromal Tumors

Gastrointestinal Stromal Tumors (GISTs) represent a paradigmatic model of oncogene addiction. Despite the well-known impact of the mutational status on clinical outcomes, we need to expand our knowledge to other factors that influence behavior heterogeneity in GIST patients. A growing body of studies has revealed that the tumor microenvironment (TME), mostly populated by tumor-associated macrophages (TAMs) and lymphocytes (TILs), and stromal differentiation (SD) have a significant impact on prognosis and response to treatment. Interestingly, even though the current knowledge of the role of immune response in this setting is still limited, recent pre-clinical and clinical data have highlighted the relevance of the TME in GISTs, with possible implications for clinical practice in the near future. Moreover, the expression of immune checkpoints, such as PD-L1, PD-1, and CTLA-4, and their relationship to the clinical phenotype in GIST are emerging as potential prognostic biomarkers. Looking forward, these variables related to the underlying tumoral microenvironment in GIST, though limited to still-ongoing trials, might lead to the potential use of immunotherapy, alone or in combination with targeted therapy, in advanced TKI-refractory GISTs. This review aims to deepen understanding of the potential link between mutational status and the immune microenvironment in GIST.

Molecular Targeted Therapy in Oncology Focusing on DNA Repair Mechanisms

DNA repair mechanisms are essential for maintaining cellular homeostasis. Malfunction of these repair mechanisms leads to cellular DNA mutations, carcinogenic transformation, and cell death. These same defects also create vulnerabilities that are relatively specific to cancer cells, and which could potentially be exploited to increase the therapeutic index of anticancer treatments and thereby improve patient outcomes. The targeted therapy based on inhibiting the DNA damage response (DDR) opens a new therapeutic landscape for patients with deficient DDR. Currently there are two DNA repair mechanisms that are used as targets for molecular therapies: Mitsmach Repair (MMR) and Homologous Recombination Repair (HRR). These molecular targets allow for immunotherapy treatments based on "checkpoint inhibitors" (ICIs) drugs and "PARP inhibitor" (PARPi) drugs in different solid tumors. In this review we will describe the state of the art of this interesting mechanism and explain the options for treatment based on these alterations. Moreover, many clinical trials are currently underway exploring better treatment options for dMMR and HRD patients with different solid tumours.

Soluble PD-L1 as a Prognostic Factor for Immunotherapy Treatment in Solid Tumors: Systematic Review and Meta-Analysis

Blocking the Programmed Cell Death Protein 1 (PD-1)/programmed death ligand-1 (PD-L1) axis has demonstrated great efficacy in cancer immunotherapy treatment and remains the central modality of immune targeting. To support the rational and tailored use of these drugs, it is important to identify reliable biomarkers related to survival. The role of the soluble form of the PD-L1 (sPD-L1) as a prognostic biomarker related to survival in solid cancer patients treated with immunotherapy has not yet been consistently evaluated. A systematic literature search of original articles in PubMed, MEDLINE and Scopus was conducted. Studies reporting hazard ratios (HRs) with a 95% confidence interval (CI) or Kaplan−Meier curves or individual patient data for overall survival (OS) or progression-free survival (PFS) associated with baseline levels of sPD-L1 in cancer patients undergoing immunotherapy treatment were considered eligible. Twelve studies involving 1076 patients and different tumor types treated with immunotherapy were included in the analysis. High blood levels of sPD-L1 correlated with poorer OS and PFS in cancer patients treated with immunotherapy (HR = 1.49, 95%CI: 1.15, 1.93, p < 0.01, I2 = 77% for OS; HR = 1.59, 95%CI: 1.20, 2.12, p < 0.01, I2 = 82% for PFS). A subgroup analysis highlighted that high levels of sPD-L1 were associated with worse survival in patients affected by NSCLC (HR = 1.81 95%CI: 1.09−3.00, p = 0.02, I2 = 83% for OS; HR = 2.18, 95%CI: 1.27−3.76, p < 0.01, I2 = 88% for PFS). An HR > 1 indicated that patients with low levels of sPD-L1 have the highest rates of OS/PFS. In this meta-analysis, we clarified the role of sPD-L1 in different solid cancers treated exclusively with Immune checkpoint inhibitors (ICIs). sPD-L1 could represent a non-invasive biomarker that is easily dosable in the blood of patients. The pooled data from the selected studies showed that a high circulating concentration of sPD-L1 in cancer patients correlates with worse survival, suggesting that it may be a helpful prognostic biomarker for the selection of cancer patients before immunotherapy, thus improving the efficacy of ICIs and avoiding unnecessary treatment.

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.

Plasma CD27, a Surrogate of the Intratumoral CD27-CD70 Interaction, Correlates with Immunotherapy Resistance in Renal Cell Carcinoma

PURPOSE

CD70 is a costimulatory molecule known to activate CD27-expressing T cells. CD27-CD70 interaction leads to the release of soluble CD27 (sCD27). Clear-cell renal cell carcinoma (ccRCC) expresses the highest levels of CD70 among all solid tumors; however, the clinical consequences of CD70 expression remain unclear.

EXPERIMENTAL DESIGN

Tumor tissue from 25 patients with ccRCC was assessed for the expression of CD27 and CD70 in situ using multiplex immunofluorescence. CD27+ T-cell phenotypes in tumors were analyzed by flow cytometry and their gene expression profile were analyzed by single-cell RNA sequencing then confirmed with public data. Baseline sCD27 was measured in 81 patients with renal cell carcinoma (RCC) treated with immunotherapy (35 for training cohort and 46 for validation cohort).

RESULTS

In the tumor microenvironment, CD27+ T cells interacted with CD70-expressing tumor cells. Compared with CD27- T cells, CD27+ T cells exhibited an apoptotic and dysfunctional signature. In patients with RCC, the intratumoral CD27-CD70 interaction was significantly correlated with the plasma sCD27 concentration. High sCD27 levels predicted poor overall survival in patients with RCC treated with anti-programmed cell death protein 1 in both the training and validation cohorts but not in patients treated with antiangiogenic therapy.

CONCLUSIONS

In conclusion, we demonstrated that sCD27, a surrogate marker of T-cell dysfunction, is a predictive biomarker of resistance to immunotherapy in RCC. Given the frequent expression of CD70 and CD27 in solid tumors, our findings may be extended to other tumors.

BTN3A: A Promising Immune Checkpoint for Cancer Prognosis and Treatment

Butyrophilin-3A (BTN3A) subfamily members are a group of immunoglobulins present on the surface of different cell types, including innate and cancer cells. Due to their high similarity with the B7 family members, different studies have been conducted and revealed the involvement of BTN3A molecules in modulating T cell activity within the tumor microenvironment (TME). However, a great part of this research focused on γδ T cells and how BTN3A contributes to their functions. In this review, we will depict the roles and various aspects of BTN3A molecules in distinct tumor microenvironments and review how BTN3A receptors modulate diverse immune effector functions including those of CD4+ (Th1), cytotoxic CD8+ T cells, and NK cells. We will also highlight the potential of BTN3A molecules as therapeutic targets for effective immunotherapy and successful cancer control, which could represent a bright future for patient treatment.

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.

Can circulating PD-1, PD-L1, BTN3A1, pan-BTN3As, BTN2A1 and BTLA levels enhance prognostic power of CA125 in patients with advanced high-grade serous ovarian cancer?

The most common subtype of ovarian cancer (OC) is the high-grade serous ovarian carcinoma (HGSOC), accounting for 70%–80% of all OC deaths. Although HGSOC is a potentially immunogenic tumor, clinical studies assessing the effectiveness of inhibitors of programmed death protein and its ligand (PD-1/PD-L1) in OC patients so far showed only response rates &lt;15%. However, recent studies revealed an interesting prognostic role of plasma PD-1/PD-L1 and other circulating immunoregulatory molecules, such as the B- and T-lymphocyte attenuator (BTLA), butyrophilin sub-family 3A/CD277 receptors (BTN3A), and butyrophilin sub-family 2 member A1 (BTN2A1), in several solid tumors. Since evidence showed the prognostic relevance of pretreatment serum CA125 levels in OC, the aim of our study was to investigate if soluble forms of inhibitory immune checkpoints can enhance prognostic power of CA125 in advanced HGSOC women. Using specific ELISA tests, we examined the circulating PD-1, PD-L1, pan-BTN3As, BTN3A1, BTN2A1, and BTLA levels in 100 advanced HGSOC patients before treatment, correlating them with baseline serum CA125, age at diagnosis, body mass index (BMI), and peritoneal carcinomatosis. A multivariate analysis revealed that plasma BTN3A1 ≤4.75 ng/ml (HR, 1.94; 95% CI, 1.23–3.07; p=0.004), age at diagnosis ≤60 years (HR, 1.65; 95% CI, 1.05–2.59; p=0.03) and absence of peritoneal carcinomatosis (HR, 2.65; 95% CI, 1.66–4.22; p&lt;0.0001) were independent prognostic factors for a longer progression-free survival (PFS) (≥30 months) in advanced HGSOC women. However, further two-factor multivariate analyses highlighted that baseline serum CA125 levels &gt;401 U/ml and each soluble protein above respective concentration cutoff were covariates associated with shorter PFS (&lt;30 months) and unfavorable clinical outcome, suggesting that contemporary measurement of both biomarkers than CA125 only could strengthen prognostic power of serum CA125 in predicting PFS of advanced HGSOC women. Plasma PD-L1, PD-1, BTN3A1, pan-sBTN3As, BTN2A1, or BTLA levels could be helpful biomarkers to increase prognostic value of CA125.

Comprehensive analyses of a tumor-infiltrating lymphocytes-related gene signature regarding the prognosis and immunologic features for immunotherapy in bladder cancer on the basis of WGCNA

Tumor-infiltrating lymphocyte (TIL) is a class of cells with important immune functions and plays a crucial role in bladder cancer (BCa). Several studies have shown the clinical significance of TIL in predicting the prognosis and immunotherapy efficacy. TIL-related gene module was screened utilizing weighted gene coexpression network analysis. We screened eight TIL-related genes utilizing univariate Cox regression analysis, least absolute shrinkage and selection operator (LASSO) Cox regression analysis, and multivariate Cox regression analysis. Then, we established a TIL-related signature model containing the eight selected genes and subsequently classified all patients into two groups, that is, the high-risk as well as low-risk groups. Gene mutation status, prognosis, immune cell infiltration, immune subtypes, TME, clinical features, and immunotherapy response were assessed among different risk subgroups. The results affirmed that the TIL-related signature model was a reliable predictor of overall survival (OS) for BCa and was determined as an independent risk factor for BCa patients in two cohorts. Moreover, the risk score was substantially linked to age, tumor staging, TNM stage, and pathological grade. And there were different mutational profiles, biological pathways, immune scores, stromal scores, and immune cell infiltration in the tumor microenvironment (TME) between the two risk groups. In particular, immune checkpoint genes’ expression was remarkably different between the two risk groups, with patients belonging to the low-risk group responding better to immune checkpoint inhibition (ICI) therapy. In conclusion, our study demonstrates that the TIL-related model was a reliable signature in anticipating prognosis, immune status, and immunotherapy response, which can help in screening patients who respond to immunotherapy.

Comprehensive Analysis of the Prognostic Value and Immune Infiltration of Butyrophilin Subfamily 2/3 (BTN2/3) Members in Pan-Glioma

The BTN2/3 subfamilies are overexpressed in many cancers, including pan-glioma (low- and high-grade gliomas). However, the expression and prognosis of BTN2/3 subfamilies and tumor-infiltrating lymphocytes in pan-glioma remain unknown. In the present study, we systematically explored and validated the expression and prognostic value of BTN2/3 subfamily members in pan-glioma [The Cancer Genome Atlas–glioblastoma and low-grade glioma (TCGA-GBMLGG) merge cohort] using multiple public databases. We used clinical specimens for high-throughput verification and cell lines for qRT-PCR verification, which confirmed the expression profiles of BTN2/3 subfamilies. In addition, the function of the BTN2/3 subfamily members and the correlations between BTN2/3 subfamily expression and pan-glioma immune infiltration levels were investigated. We found that BTN2/3 subfamily members were rarely mutated. BTN2/3 subfamilies were overexpressed in pan-glioma; high expression of BTN2/3 subfamily members was correlated with poor prognosis. In addition, BTN2/3 subfamilies might positively regulate proliferation, and the overexpression of BTN2/3 subfamilies influenced cell cycle, differentiation, and glioma stemness. In terms of immune infiltrating levels, BTN2/3 subfamily expression was positively associated with CD4+ T-cell, B-cell, neutrophil, macrophage, and dendritic cell infiltrating levels. These findings suggest that BTN2/3 subfamily expression is correlated with prognosis and immune infiltration levels in glioma. Therefore, the BTN2/3 subfamilies can be used as biomarkers for pan-glioma and prognostic biomarkers for determining the prognosis and immune infiltration levels in pan-glioma.

MiRNAs in renal cell carcinoma

MicroRNAs (miRNAs) are small RNA sequences that act as post-transcriptional regulatory genes to control many cellular processes through pairing bases with a complementary messenger RNA (mRNA). A single miRNA molecule can regulate more than 200 different transcripts and the same mRNA can be regulated by multiple miRNAs. In this review, we highlight the importance of miRNAs and collect the existing evidence on their relationship with kidney cancer.

Co-Inhibitory Molecules – Their Role in Health and Autoimmunity; Highlighted by Immune Related Adverse Events

Immune checkpoint receptors are key players in regulating the immune response. They are responsible for both generating an immune response sufficient to kill invading pathogens, balancing the same response, and protecting against tissue destruction or the development of autoimmune events. The central role of the co-inhibitory receptors also referred to as inhibitory immune checkpoints, including PD-1 and CTLA-4 has become especially evident with the cancer treatments targeting these receptors. Blocking these pathways enhances the immune activity, resulting in both an increased chance of cancer clearance, at the same time induction of immune-related adverse events (irAE). Some of these irAE progress into actual autoimmune diseases with autoantibodies and symptoms, undistinguished from the naturally occurring diseases. This review will take advantage of the lessons learned from immune checkpoint blockade and relate this knowledge to our understanding of the same pathways in naturally occurring autoimmune diseases, mainly focusing on rheumatic diseases.

Challenges and the Evolving Landscape of Assessing Blood-Based PD-L1 Expression as a Biomarker for Anti-PD-(L)1 Immunotherapy

While promising, PD-L1 expression on tumor tissues as assessed by immunohistochemistry has been shown to be an imperfect biomarker that only applies to a limited number of cancers, whereas many patients with PD-L1-negative tumors still respond to anti-PD-(L)1 immunotherapy. Recent studies using patient blood samples to assess immunotherapeutic responsiveness suggests a promising approach to the identification of novel and/or improved biomarkers for anti-PD-(L)1 immunotherapy. In this review, we discuss the advances in our evolving understanding of the regulation and function of PD-L1 expression, which is the foundation for developing blood-based PD-L1 as a biomarker for anti-PD-(L)1 immunotherapy. We further discuss current knowledge and clinical study results for biomarker identification using PD-L1 expression on tumor and immune cells, exosomes, and soluble forms of PD-L1 in the peripheral blood. Finally, we discuss key challenges for the successful development of the potential use of blood-based PD-L1 as a biomarker for anti-PD-(L)1 immunotherapy.

Can the tumor-agnostic evaluation of MSI/MMR status be the common denominator for the immunotherapy treatment of patients with several solid tumors?

Alterations in short-repetitive DNA sequences, known as microsatellite instability (MSI), can reflect deficiencies in Mismatch Repair (MMR) system which represents a major player in DNA integrity maintenance. The incidence of MSI-H/dMMR has been shown to be variable depending on the tumor type. Several studies confirmed that dMMR/MSI status, although less frequent than PD-L1 expression, may better predict response to immune-checkpoint inhibitors (ICIs) in patients with solid tumors. In October 2016, the FDA granted pembrolizumab as breakthrough therapy for the treatment of non-CRC, MSI-H/dMMR tumors, providing, for the first time, a tumor-agnostic indication. In the next future, the tissue-agnostic evaluation of MSI-H/dMMR could become the common denominator for the immunotherapy treatment of patients with different advanced solid tumors, in order to select patient subgroups which may benefit from this therapy. In this Review we provided an overview of the main clinical studies describing the association between MSI-H/dMMR tumors and immunotherapy response.

The Role of Circulating Biomarkers in the Oncological Management of Metastatic Renal Cell Carcinoma: Where Do We Stand Now?

Renal cell carcinoma (RCC) is an increasingly common malignancy that can progress to metastatic renal cell carcinoma (mRCC) in approximately one-third of RCC patients. The 5-year survival rate for mRCC is abysmally low, and, at the present time, there are sparingly few if any effective treatments. Current surgical and pharmacological treatments can have a long-lasting impact on renal function, as well. Thus, there is a compelling unmet need to discover novel biomarkers and surveillance methods to improve patient outcomes with more targeted therapies earlier in the course of the disease. Circulating biomarkers, such as circulating tumor DNA, noncoding RNA, proteins, extracellular vesicles, or cancer cells themselves potentially represent a minimally invasive tool to fill this gap and accelerate both diagnosis and treatment. Here, we discuss the clinical relevance of different circulating biomarkers in metastatic renal cell carcinoma by clarifying their potential role as novel biomarkers of response or resistance to treatments but also by guiding clinicians in novel therapeutic approaches.

Soluble PD-L1 as a predictive biomarker in lung cancer: a systematic review and meta-analysis

Background: We performed a meta-analysis to evaluate the association between soluble PD-L1 (sPD-L1) and survival outcomes and treatment response in lung cancer. Methods & methods: Eligible studies were obtained by searching PubMed, EMBASE and Web of Science. Pooled effect estimates were calculated for overall survival (OS), progression-free survival (PFS) and objective response rate (ORR). Results: Twelve eligible studies with 1188 lung cancer patients were included. High sPD-L1 was significantly associated with worse OS (hazard ratio [HR] = 2.20; 95% CI: 1.59-3.05; p < 0.001) and PFS (HR = 2.42; 95% CI: 1.72-3.42; p < 0.001) in patients treated with immune checkpoint inhibitors (ICIs). Meanwhile, high sPD-L1 predicted worse OS (HR = 1.60; 95% CI: 1.31-1.96; p < 0.001) and lower ORR (odds ratio = 0.52; 95% CI: 0.35-0.80; p = 0.002) in patients treated with non-ICI therapies. Conclusion: sPD-L1 is a potential predictive biomarker of lung cancer.

Potential Biomarkers for the Efficacy of PD-1-PD-L Blockade in Cancer

A decade ago, immune checkpoint blockade emerged as a major breakthrough in oncology, proposing a novel approach by which immune brakes could be released to enhance antitumor responses. Despite apparently modest improvement of the median duration of response, a spectacular doubling of long-term responses as compared to the available standard of care was seen, for instance, in metastatic melanoma. It soon became obvious that the percentage of patients responding to these novel approaches is relatively small, and the importance of an accurate prediction of responders became more and more clear. Strong predictive markers would allow for the administration of immune checkpoint blocker therapy to the patients most likely to benefit from it, and sparing the potential non-responders of a treatment which is far from innocuous, being associated with significant side-effects and, not least, an important price tag. A number of potential response predictors have already been investigated and partly validated, but they do not cover the major unmet need encountered in the current clinical setting. Here, we review biomarkers for immune checkpoint blockade efficacy, either clinically validated and currently in use, or which have been proposed as candidates and are currently under investigation.

Utility of Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Systemic Immune Inflammation Index as Prognostic, Predictive Biomarkers in Patients with Metastatic Renal Cell Carcinoma Treated with Nivolumab and Ipilimumab

The aim of this study was to assess the utility of neutrophil-to-lymphocyte ratio (NLR), plate-let-to-lymphocyte ratio (PLR), and systemic immune inflammation index (SII) as predictive biomarkers with oncological outcomes for metastatic renal cell carcinoma (mRCC) patients treated with nivolumab and ipilimumab (NIVO + IPI). We conducted a retrospective multicenter cohort study assessing patients with mRCC treated with NIVO + IPI at eight institutions in Japan. In this study, the follow-up period was median 14 months. The 1-year overall- and progression-free survival (PFS) rates were 89.1% and 63.1, respectively. The objective response rate (ORR) and disease control rate (DCR) were 41.9% and 81.4%, respectively. The 1-year PFS rates were 85.7% and 49.1% for NLR ≤ 2.8 and >2.8, respectively (p = 0.005), and 75.5% and 49.7% for PLR ≤ 215.6 and >215.6, respectively (p = 0.034). Regarding SII, the 1-year PFS rates were 90.0% and 54.8% when SII was ≤561.7 and >561.7, respectively (p = 0.023). Therefore, NLR, PLR, and SII levels in mRCC patients treated with NIVO + IPI may be useful in predicting oncological outcomes.

Nivolumab Reduces PD1 Expression and Alters Density and Proliferation of Tumor Infiltrating Immune Cells in a Tissue Slice Culture Model of Renal Cell Carcinoma

Simple Summary

Immune checkpoint inhibitors (ICIs) have become a first-choice therapy option in the treatment of clear cell renal cell carcinoma (ccRCC). A predictive biomarker is urgently needed since not all patients respond and adverse events occur. Therefore, an ex vivo tissue slice culture (TSC) model was tested to investigate the effects of nivolumab on tumor infiltrating immune cells (TIIC). A decrease in programmed death receptor 1 expression, as well as effects on density and proliferation of TIIC, were observed. Thus, the TSC model could serve as a test platform for response prediction to ICIs.

Abstract

Background: In the treatment of clear cell renal cell carcinoma (ccRCC), nivolumab is an established component of the first-line therapy with a favorable impact on progression free survival and overall survival. However, treatment-related adverse effects occur and, to date, there is no approved predictive biomarker for patient stratification. Thus, the aim of this study was to establish an ex vivo tissue slice culture model of ccRCC and to elucidate the impact of nivolumab on tumor infiltrating immune cells. Methods: Fresh tumor tissue of ccRCC was treated with the immune checkpoint inhibitor nivolumab using ex vivo tissue slice culture (TSC). After cultivation, tissue slices were formalin-fixed, immunohistochemically stained and analyzed via digital image analysis. Results: The TSC model was shown to be suitable for ex vivo pharmacological experiments on intratumoral immune cells in ccRCC. PD1 expression on tumor infiltrating immune cells was dose-dependently reduced after nivolumab treatment (p < 0.01), whereas density and proliferation of tumor infiltrating T-cells and cytotoxic T-cells were inter-individually altered with a remarkable variability. Tumor cell proliferation was not affected by nivolumab. Conclusions: This study could demonstrate nivolumab-dependent effects on PD1 expression and tumor infiltrating T-cells in TSC of ccRCC. This is in line with results from other scientific studies about changes in immune cell proliferation in peripheral blood in response to nivolumab. Thus, TSC of ccRCC could be a further step to personalized medicine in terms of testing the response of individual patients to nivolumab.

Plasma Proteomic Analysis in Non-Small Cell Lung Cancer Patients Treated with PD-1/PD-L1 Blockade

Simple Summary

Immunotherapy leads to highly variable responses in lung cancer patients. We assessed the value of a blood-based test to predict which patients would benefit from this new treatment modality. We determined that some patients have higher and lower levels of immune markers in their blood samples, and that this is related to better survival without tumor growth. The blood test has the potential to help select the optimal therapy for lung cancer patients.

Abstract

Checkpoint inhibitors have been approved for the treatment of non-small cell lung cancer (NSCLC). However, only a minority of patients demonstrate a durable clinical response. PD-L1 scoring is currently the only biomarker measure routinely used to select patients for immunotherapy, but its predictive accuracy is modest. The aim of our study was to evaluate a proteomic assay for the analysis of patient plasma in the context of immunotherapy. Pretreatment plasma samples from 43 NSCLC patients who received anti-PD-(L)1 therapy were analyzed using a proximity extension assay (PEA) to quantify 92 different immune oncology-related proteins. The plasma protein levels were associated with clinical and histopathological parameters, as well as therapy response and survival. Unsupervised hierarchical cluster analysis revealed two patient groups with distinct protein profiles associated with high and low immune protein levels, designated as “hot” and “cold”. Further supervised cluster analysis based on T-cell activation markers showed that higher levels of T-cell activation markers were associated with longer progression-free survival (PFS) (p < 0.01). The analysis of single proteins revealed that high plasma levels of CXCL9 and CXCL10 and low ADA levels were associated with better response and prolonged PFS (p < 0.05). Moreover, in an explorative response prediction model, the combination of protein markers (CXCL9, CXCL10, IL-15, CASP8, and ADA) resulted in higher accuracy in predicting response than tumor PD-L1 expression or each protein assayed individually. Our findings demonstrate a proof of concept for the use of multiplex plasma protein levels as a tool for anti-PD-(L)1 response prediction in NSCLC. Additionally, we identified protein signatures that could predict the response to anti-PD-(L)1 therapy.

Challenges and advances for the treatment of renal cancer patients with brain metastases: From immunological background to upcoming clinical evidence on immune-checkpoint inhibitors

The introduction of checkpoint inhibitors (ICIs) in renal cell carcinoma (RCC) treatment landscape, resulted in improvements in overall survival (OS) in metastatic patients. Brain metastases (BMs) are a specific metastatic site of interest representing a predictive factor of poor prognosis. Patients with BMs were usually excluded from prospective clinical trials in the past. Despite recent evidence suggest the efficacy and safety of ICIs, the BMs treatment remains a challenge; the immunotherapy responsiveness seems to be multifactorial and dependent on several factors, such as the genetic intratumor heterogeneity and the immunosuppressive role of the brain tumor microenvironment. This review, starting from the immunological background in RCC BMs, provide an overview of the upcoming evidence from clinical trials, address the issues related to the neuroradiological immunotherapy response evaluation and, with a look to the future, describes how the epigenetic modulation of immune evasion could represent a background for new therapeutic strategies.

The molecular profiling of solid tumors by liquid biopsy: a position paper of the AIOM-SIAPEC-IAP-SIBioC-SIC-SIF Italian Scientific Societies

The term liquid biopsy (LB) refers to the use of various biological fluids as a surrogate for neoplastic tissue to achieve information for diagnostic, prognostic and predictive purposes. In the current clinical practice, LB is used for the identification of driver mutations in circulating tumor DNA derived from both tumor tissue and circulating neoplastic cells. As suggested by a growing body of evidence, however, there are several clinical settings where biological samples other than tissue could be used in the routine practice to identify potentially predictive biomarkers of either response or resistance to targeted treatments. New applications are emerging as useful clinical tools, and other blood derivatives, such as circulating tumor cells, circulating tumor RNA, microRNAs, platelets, extracellular vesicles, as well as other biofluids such as urine and cerebrospinal fluid, may be adopted in the near future. Despite the evident advantages compared with tissue biopsy, LB still presents some limitations due to both biological and technological issues. In this context, the absence of harmonized procedures corresponds to an unmet clinical need, ultimately affecting the rapid implementation of LB in clinical practice. In this position paper, based on experts’ opinions, the AIOM–SIAPEC-IAP–SIBIOC–SIF Italian Scientific Societies critically discuss the most relevant technical issues of LB, the current and emerging evidences, with the aim to optimizing the applications of LB in the clinical setting.

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In the current clinical practice LB is used for the identification of driver mutations in circulating tumor DNA (ctDNA).

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New applications in tumors other than non-small-cell lung cancer (NSCLC) are emerging as useful clinical tools.

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Other blood derivatives, together with other biofluids, are an active field of research and may be adopted in the near future.

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Despite the evident advantages, liquid biopsy still presents limitations due to both biological and technological issues.

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Standardization of the procedures needs to be addressed to ensure widespread implementation in clinical practice.

A Review of Recent Research on the Role of MicroRNAs in Renal Cancer

Renal cell carcinoma (RCC) is a most common type of urologic neoplasms; it accounts for 3% of malignant tumors, with high rates of relapse and mortality. The most common types of renal cancer are clear cell carcinoma (ccRCC), papillary renal cell carcinoma (pRCC), and chromophobe renal carcinoma (chRCC), which account for 90%, 6–15%, and 2–5%, respectively, of all renal malignancies. Although surgical resection, chemotherapy, and radiotherapy are the most common treatment method for those diseases, their effects remain dissatisfactory. Furthermore, recent research shows that the treatment efficacy of checkpoint inhibitors in advanced RCC patients is widely variable. Hence, patients urgently need a new molecular biomarker for early diagnosis and evaluating the prognosis of RCC. MicroRNAs (miRNAs) belong to a family of short, non-coding RNAs that are highly conserved, have long half-life evolution, and post-transcriptionally regulate gene expression; they have been predicted to play crucial roles in tumor metastasis, invasion, angiogenesis, proliferation, apoptosis, epithelial-mesenchymal transition, differentiation, metabolism, cancer occurrence, and treatment resistance. Although some previous papers demonstrated that miRNAs play vital roles in renal cancer, such as pathogenesis, diagnosis, and prognosis, the roles of miRNAs in kidney cancer are still unclear. Therefore, we reviewed studies indexed in PubMed from 2017 to 2020, and found several studies suggesting that there are more than 82 miRNAs involved in renal cancers. The present review describes the current status of miRNAs in RCC and their roles in progression, diagnosis, therapy targeting, and prognosis of RCC.

Prognostic Role of Plasma PD-1, PD-L1, pan-BTN3As and BTN3A1 in Patients Affected by Metastatic Gastrointestinal Stromal Tumors: Can Immune Checkpoints Act as a Sentinel for Short-Term Survival?

Gastrointestinal stromal tumors (GISTs) represent 1% of all primary gastrointestinal tumors. Immune surveillance is often overcome by cancer cells due to the activation of immunoregulatory molecules such as programmed death protein (PD-1) and its ligand PD-L1, and butyrophilin sub-family 3A/CD277 receptors (BTN3A). Because several studies demonstrated that tumor PD-1 and PD-L1 expression may have a prominent prognostic function, this investigation aimed to discover if soluble forms of these molecules may be useful in predicting survival of metastatic GIST (mGIST) patients. Through specific ad hoc developed ELISA assays not yet available on the market, the circulating PD-1, PD-L1, BTN3A1, and pan-BTN3As levels were examined in 30 c-KIT exon 11-mutated mGIST patients, prior to imatinib therapy. Using specific thresholds derived by ROC analysis, we found that high baseline levels of sPD-1 (>8.1 ng/mL), sPD-L1 (>0.7 ng/mL), sBTN3A1 (>7.0 ng/mL), and pan-BTN3As (>5.0 ng/mL) were correlated with shorter progression-free survival (PFS) and poor prognosis. Contrariwise, subjects with lower plasma concentrations exhibited a median PFS about 20 months longer than to the earlier. Finally, an additional multivariate analysis revealed that circulating levels of sPD-L1 ≤ 0.7 ng/mL and pan-sBTN3As ≤ 5.0 ng/mL, and the absence of KIT exon 11 deletions or delins at codons 557 and/or 558 were associated with a longer PFS in mGIST patients. Our investigation, for the first time, revealed that evaluating the plasma concentration of some immune checkpoints may help prognosticate survival in mGIST patients, suggesting their potential use as prognostic biomarkers beyond the presence of KIT exon 11 Del or Delins at codons 557/558.

Soluble BTN2A1 Is a Potential Prognosis Biomarker in Pre-Treated Advanced Renal Cell Carcinoma

The development of immune checkpoint inhibitors (ICI) has dramatically changed the landscape of therapies for metastatic renal cell carcinoma. However, many patients do not benefit from such therapy and prognostic or predictive validated biomarker validated for ICI are still needed to better select and treat patient. Plasmatic soluble immune checkpoints have been described as potential immune biomarkers in hematological malignancies and solids tumors, then, we would like to explore the prognostic value of different soluble immune checkpoints in patients with mRCC treated with nivolumab after TKI. We prospectively collected plasma samples before nivolumab infusion from 38 patients previously treated for mRCC with TKI at Paoli-Calmettes Institute, from the NIVOREN GETUG-AFU 26 study (NCT03013335). Enzyme-linked immunosorbent assays (ELISA) were performed for soluble forms of PD-1, PD-L1, global BTN3, BTLA, BTN3A1 and BTN2A1. Among the different soluble checkpoints analyzed, only high baseline plasmatic level of BTN2A1 was significantly associated with shorter PFS: median PFS was 3.95 months for sBTN2A1high vs 14.30 months for sBTN2A1low (sBTN2A1 cut-off: 6.7ng/mL; HR = 2.26, 95%CI [0.68 - 4.60], p = 0.0307). There was no statistical difference in OS between sBTN2A1high and sBTN2A1^low. Our results suggest that the baseline level of plasmatic BTN2A1 could be an independent prognosis factor of PFS after nivolumab for pre-treated patient with mRCC. However, these results need to be validated in a larger prospective cohort and the biological role of BTN subfamily and γδ T cell immunity in mRCC must be elucidated.

A "Lymphocyte MicroRNA Signature" as Predictive Biomarker of Immunotherapy Response and Plasma PD-1/PD-L1 Expression Levels in Patients with Metastatic Renal Cell Carcinoma: Pointing towards Epigenetic Reprogramming

Simple Summary

MicroRNAs are small molecules of non-coding RNAs which regulate gene expression at the post-transcriptional level. Normal miRNA expression and function can be deregulated in cancer. The comprehensive molecular characterization of Renal Cell Carcinoma shows several genes silenced and signaling pathways deregulated by epigenetic modifications, such as the abnormal expression of miRNAs. They can be secreted from malignant cells in whole-blood, plasma, serum, and urine samples, making miRNAs potential non-invasive tumor biomarkers. However, if a single miRNA can show low discriminatory power, the combination of miRNAs in a “miRNA signature”, identified in the peripheral lymphocytes of patients, could function better with much higher probability to predict the response to immunotherapy and to discriminate responders from non-responders patients already at therapy baseline.

Abstract

Introduction of checkpoint inhibitors resulted in durable responses and improvements in overall survival in advanced RCC patients, but the treatment efficacy is widely variable, and a considerable number of patients are resistant to PD-1/PD-L1 inhibition. This variability of clinical response makes necessary the discovery of predictive biomarkers for patient selection. Previous findings showed that the epigenetic modifications, including an extensive microRNA-mediated regulation of tumor suppressor genes, are key features of RCC. Based on this biological background, we hypothesized that a miRNA expression profile directly identified in the peripheral lymphocytes of the patients before and after the nivolumab administration could represent a step toward a real-time monitoring of the dynamic changes during cancer evolution and treatment. Interestingly, we found a specific subset of miRNAs, called “lymphocyte miRNA signature”, specifically induced in long-responder patients (CR, PR, or SD to nivolumab >18 months). Focusing on the clinical translational potential of miRNAs in controlling the expression of immune checkpoints, we identified the association between the plasma levels of soluble PD-1/PD-L1 and expression of some lymphocyte miRNAs. These findings could help the development of novel dynamic predictive biomarkers urgently needed to predict the potential response to immunotherapy and to guide clinical decision-making in RCC patients.