Serum cytokine levels as predictive biomarkers of benefit from ipilimumab in small cell lung cancer

Plasma protein dynamics during ipilimumab treatment in metastatic melanoma: associations with tumor response, adverse events and survival

The immune checkpoint inhibitor ipilimumab provides long term survival in some metastatic melanoma patients, but the majority has no benefit, and may experience serious side effects. Here, we investigated the dynamics of plasma cytokine concentrations and their potential utility for predicting treatment response, adverse events and overall survival (OS) in patients with metastatic melanoma undergoing ipilimumab monotherapy. A cohort of 148 patients was examined, with plasma samples collected prior to treatment initiation and at the end of the first and second treatment cycles. Concentrations of 48 plasma proteins were measured using a multiplex immunoassay. The results revealed a general increase in cytokine levels following the first ipilimumab dose, consistent with immune activation. Patients not responding to treatment exhibited significantly elevated baseline levels of G-CSF, IL-2RA, MIP-1a, and SCF, compared to tumor responders (p < 0.05). Furthermore, high levels of IL-2RA, IFNγ, PDGF-bb and MIG were linked to inferior OS, while high concentrations of MIF and RANTES were associated with improved OS (p < 0.05). A multivariate model containing CRP, LDH, ECOG, IL-2RA and PDGF-bb identified a subgroup of patients with poor OS. Patients who experienced severe immune-related adverse events within three months of treatment initiation had higher baseline concentrations of several cytokines, indicating a potential association between preexisting inflammation and adverse events. These findings indicate that the first dose of ipilimumab induces a systemic response with increased levels of circulating cytokines and suggest candidate biomarkers for clinical response, immune-mediated toxicity and survival. Further studies in independent patient cohorts are required to confirm the findings.

Racial Differences in Systemic Immune Parameters in Individuals With Lung Cancer

Introduction

Racial and ethnic disparities in the presentation and outcomes of lung cancer are widely known. To evaluate potential factors contributing to these observations, we measured systemic immune parameters in Black and White patients with lung cancer.

Methods

Patients scheduled to receive cancer immunotherapy were enrolled in a multi-institutional prospective biospecimen collection registry. Clinical and demographic information were obtained from electronic medical records. Pretreatment peripheral blood samples were collected and analyzed for cytokines using a multiplex panel and for immune cell populations using mass cytometry. Differences between Black and White patients were determined and corrected for multiple comparisons.

Results

A total of 187 patients with NSCLC (Black, 19; White, 168) were included in the analysis. Compared with White patients, Black patients had greater comorbidity (median Charlson Comorbidity Index 5 versus 3; p = 0.04) and were more likely to have received previous chemotherapy (79% versus 47%; p = 0.03). Black patients had significantly lower levels of CCL23 and CCL27 and significantly higher levels of CCL8, CXCL1, CCL26, CCL25, CCL1, IL-1b, CXCL16, and IFN-γ (all p < 0.05, false discovery rate < 0.1). Black patients also exhibited greater populations of nonclassical CD16+ monocytes, NKT-like cells, CD4+ cells, CD38+ monocytes, and CD57+ gamma delta T cells (all p < 0.05).

Conclusions

Black and White patients with lung cancer exhibit several differences in immune parameters, with Black patients exhibiting greater levels of numerous proinflammatory cytokines and cell populations. The etiology and clinical significance of these differences warrant further evaluation.

Predictive biomarkers for immune checkpoint inhibitors therapy in lung cancer

Immune checkpoint inhibitors (ICIs) have changed the treatment mode of lung cancer, extending the survival time of patients unprecedentedly. Once patients respond to ICIs, the median duration of response is usually longer than that achieved with cytotoxic or targeted drugs. Unfortunately, there is still a large proportion of lung cancer patients do not respond to ICI. Effective biomarkers are crucial for identifying lung cancer patients who can benefit from them. The first predictive biomarker is programmed death-ligand 1 (PD-L1), but its predictive value is limited to specific populations. With the development of single-cell sequencing and spatial imaging technologies, as well as the use of deep learning and artificial intelligence, the identification of predictive biomarkers has been greatly expanded. In this review, we will dissect the biomarkers used to predict ICIs efficacy in lung cancer from the tumor-immune microenvironment and host perspectives, and describe cutting-edge technologies to further identify biomarkers.

Advances in biomarkers for immunotherapy in small-cell lung cancer

Small-cell lung cancer (SCLC) is a refractory cancer with rapid growth and high aggressiveness. Extensive-stage SCLC is initially sensitive to chemotherapy; however, drug resistance and recurrence occur rapidly, resulting in a poor survival outcome due to lack of subsequently efficient therapy. The emergence of immune checkpoint inhibitors (ICIs) generated a new landscape of SCLC treatment and significantly prolonged the survival of patients. However, the unselected immunotherapy restrains both beneficiary population and responsive period in SCLC compared to the other tumors. The complex tumor origin, high heterogeneity, and immunosuppressive microenvironment may disturb the value of conventional biomarkers in SCLC including programmed cell death 1 ligand 1 and tumor mutation burden. Transcriptional regulator-based subtypes of SCLC are current research hotspot, revealing that Y (I) subtype can benefit from ICIs. Additionally, molecules related to immune microenvironment, immunogenicity, epigenetics, and SCLC itself also indicated the therapeutic benefits of ICIs, becoming potential predictive biomarkers. In this review, we discussed the advances of biomarkers for prediction and prognosis of immunotherapy, promising directions in the future, and provide reference and options for precision immunotherapy and survival improvement in patients with SCLC.

Advances in predictive biomarkers associated with immunotherapy in extensive-stage small cell lung cancer

Small cell lung cancer (SCLC) is a highly malignant and poor-prognosis cancer, with most cases diagnosed at the extensive stage (ES). Amidst a landscape marked by limited progress in treatment modalities for ES-SCLC over the past few decades, the integration of immune checkpoint inhibitors (ICIs) with platinum-based chemotherapy has provided a milestone approach for improving prognosis, emerging as the new standard for initial therapy in ES-SCLC. However, only a minority of SCLC patients can benefit from ICIs, which frequently come with varying degrees of immune-related adverse events (irAEs). Therefore, it is crucial to investigate predictive biomarkers to screen potential beneficiaries of ICIs, mitigate the risk of side effects, and improve treatment precision. This review summarized potential biomarkers for predicting ICI response in ES-SCLC, with a primary focus on markers sourced from tumor tissue or peripheral blood samples. The former mainly included PD-L1 expression, tumor mutational burden (TMB), along with cellular or molecular components related to the tumor microenvironment (TME) and antigen presentation machinery (APM), molecular subtypes of SCLC, and inflammatory gene expression profiles. Circulating biomarkers predominantly comprised circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), cytokines, plasma autoantibodies, inflammation-related parameters, and blood TMB. We synthesized and analyzed the research progress of these potential markers. Notably, investigations into PD-L1 expression and TMB have been the most extensive, exhibiting preliminary predictive efficacy in salvage immunotherapy; however, consistent conclusions have yet to be reached across studies. Additionally, novel predictive markers developed based on TME composition, APM, transcriptomic and genomic features provide promising tools for precision immunotherapy. Circulating biomarkers offer the advantages of convenience, non-invasiveness, and a comprehensive reflection of tumor molecular characteristics. They may serve as alternative options for predicting immunotherapy efficacy in SCLC. However, there is a scarcity of studies, and the significant heterogeneity in research findings warrants attention.

Efficacy and safety of immune checkpoint inhibitors plus platinum-etoposide vs. platinum-etoposide in the first-line treatment of extensive-stage small cell lung cancer: a systematic review and a meta-analysis

Background

Currently, immune checkpoint inhibitors (ICIs) combined with platinum-etoposide (EP) are gradually becoming the first-line standard treatment for extensive-stage small cell lung cancer (ES-SCLC). This meta-analysis aims to compare the efficacy and safety of ICIs combined with EP vs. EP alone in the first-line treatment of ES-SCLC.

Methods

We searched PubMed, Embase, and Cochrane Library databases for phase II/III randomized controlled trials (RCTs) that met inclusion criteria from January 2016 to November 2023. Outcome measures included progression-free survival (PFS), overall survival (OS), objective response rate (ORR), treatment-related adverse events (TRAEs), treatment-related serious adverse events (TRSAEs), and immune-related adverse events (IRAEs). The effect analysis statistics of the outcome indicators were expressed with hazard ratio (HR) and odds ratio (OR) and their 95% confidence interval (CI).

Results

This study included nine RCTs with a total of 4,711 patients. Compared to EP, ICIs plus EP improved patients' PFS (HR =0.71; 95% CI: 0.64-0.79; P<0.001), OS (HR =0.79; 95% CI: 0.74-0.84; P<0.001), and ORR (OR =1.27; 95% CI: 1.12-1.44; P=0.001), but increased the incidence of adverse events (AEs): TRAEs (OR =1.45; 95% CI: 1.20-1.76; P<0.001), IRAEs (OR =3.97; 95% CI: 2.49-6.32; P<0.001), and grade 3-4 IRAEs (OR =6.17; 95% CI: 2.36-16.15; P<0.001). However, there was no significant difference in the incidence of grade 3-4 TRAEs (OR =1.05; P=0.54), TRSAEs (OR =1.40; P=0.13), and grade 3-4 TRSAEs (OR =1.17; P=0.72). Subgroup analysis found that patients with brain metastasis did not benefit from ICIs combined with EP therapy, and patients with programmed cell death ligand 1 (PD-L1) expression ≥1% had poorer survival benefits compared to patients with PD-L1 expression <1%.

Conclusions

In the first-line treatment of ES-SCLC, compared to EP chemotherapy, ICIs with EP can benefit patients in terms of PFS, OS, and ORR, but it will increase the occurrence of AEs.

Prognostic value of baseline clinicopathological characteristics in first-line chemotherapy ± immunotherapy for extensive-stage small cell lung cancer: a retrospective cohort study

Background

The integration of chemotherapy and immunotherapy as a first-line treatment for extensive-stage small cell lung cancer (ES-SCLC) has been adopted in clinical practice, yet the response to immune checkpoint inhibitors (ICIs) is variable, benefiting only a fraction of patients. The current absence of reliable biomarkers for predicting treatment response and prognosis represents a significant gap in knowledge, hindering the optimization of patient stratification and treatment planning. This retrospective cohort study aims to assess the potential predictive and prognostic significance of clinicopathological baseline features in ES-SCLC patients.

Methods

Our study retrospectively analyzed the data of consecutive patients with ES-SCLC treated with first-line etoposide plus platinum chemotherapy ± immunotherapy at The Affiliated Lihuili Hospital of Ningbo University from April 2017 to April 2023. Data on clinical information, serum laboratory indicators, pathological immunohistochemical markers, and progression-free survival (PFS) times were collected. Univariate and multivariate Cox regression analyses were employed to determine whether these indicators could serve as independent prognostic factors for PFS. Further, potential predictive markers for treatment efficacy were identified using a Cox regression model that incorporated an interaction term between treatment modality and the indicator.

Results

A total of 121 patients with ES-SCLC were enrolled in the study, of whom 62 received chemotherapy alone, and 59 received chemotherapy in combination with immunotherapy. Compared to chemotherapy alone, the addition of immunotherapy to first-line chemotherapy significantly extended the PFS time [P<0.001; hazard ratio (HR) =0.42; 95% confidence interval (CI): 0.28, 0.64] of the ES-SCLC patients. The multivariate analysis revealed that an immunochemotherapy regimen (P<0.001, HR =0.40; 95% CI: 0.24, 0.68), a low-density lipoprotein (LDL) level of >1.8 mmol/L (P=0.02; HR =0.41; 95% CI: 0.20, 0.85) were independent prognostic factors of favorable PFS in the first-line treatment of all ES-SCLC, while a lactate dehydrogenase (LDH) level of >273 U/L (P=0.04; HR =1.78; 95% CI: 1.03, 3.07), a neuron-specific enolase (NSE) concentration of >102.6 ng/mL (P=0.009; HR =6.49; 95% CI: 1.60, 26.32), an apolipoprotein A1 (ApoA1) concentration of >0.9 g/L (P<0.001; HR =4.15; 95% CI: 1.98, 8.71), and an apolipoprotein B (ApoB) concentration of >0.8 g/L (P=0.002; HR =2.24; 95% CI: 1.34, 3.75) were independent prognostic factors of poorer PFS. Further, the interaction effect analysis demonstrated that an LDL level of >1.8 mmol/L and the absence of bone metastasis were potential predictors of an improved response to ICI therapy compared to chemotherapy alone.

Conclusions

This study showed the survival benefit of receiving a chemoimmunotherapy regimen as the first-line treatment in a real-world scenario. It also suggests the prognostic significance of pre-treatment LDL, LDH, NSE, ApoA1, and ApoB with optimal cut-off values in the first-line treatment of all ES-SCLC, and the potential utility of baseline LDL level or the presence of bone metastasis in guiding first-line treatment strategies.

Successful management of pre-existing psoriatic arthritis through targeting the IL-23/IL-17 axis in cancer patients receiving immune checkpoint inhibitor therapy: a case series

BACKGROUND

Immune checkpoint inhibitors (ICIs) have significantly improved outcomes for patients with cancer. However, these therapies are associated with adverse events including de novo immune-related adverse events or flare of pre-exiting autoimmune disorders. Up to 80% of patients with cancer and pre-existing psoriasis (PsO) or psoriatic arthritis (PsA) experience PsO/PsA flare after initiating ICIs. Targeting the interleukin (IL)-17/IL-23 axis is a mainstream of the PsO/PsA treatment. However, whether this treatment can effectively control PsO/PsA with ICI exposure while preserving anti-tumour efficacy remains unknown.

CASE REPORTS

We report three patients with PsA and cancer, who received ICIs for their cancer treatment. All patients were male. Two patients had clear cell renal cell carcinoma, and one had melanoma. Two patients received anti-PD-1 antibody monotherapy, while one patient received combined anti-CTLA-4 and PD-1 antibody therapy. One patient had been receiving anti-IL-17A antibody (secukinumab), while the other two patients started anti-IL-17A antibody (ixekizumab) and anti-IL-23 antibody (guselkumab) after their PsA flared up during ICI treatment. Of note, with the anti-IL-17A or anti-IL-23 antibody treatment, their PsA remained in remission, and they well tolerated the ICI therapy. Importantly, all three patients showed persistent tumour responses to ICI therapy, including two complete remissions and one stable disease, respectively.

CONCLUSIONS

These three cases suggest that targeting the IL-17/23 axis may be an effective and safe approach for patients with cancer and pre-existing PsA being considered for ICI therapy.

Peripheral immune biomarkers for immune checkpoint inhibition of solid tumours

BACKGROUND

With the rapid adoption of immunotherapy for the treatment of cancer comes the pressing need for readily accessible biomarkers to guide immunotherapeutic strategies and offer insights into outcomes with specific treatments. Regular sampling of solid tumour tissues outside of melanoma for immune monitoring is not often feasible; conversely, routine, frequent interrogation of circulating immune biomarkers is entirely possible. As immunotherapies and immune checkpoint inhibitors, in particular, are more widely used in first-line, neoadjuvant, and metastatic settings, the discovery and validation of peripheral immune biomarkers are urgently needed across solid tumour types for improved prediction and prognostication of clinical outcomes in response to immunotherapy, as well as elucidation of mechanistic underpinnings of the intervention. Careful experimental design, encompassing both retrospective and prospective studies, is required in such biomarker identification studies, and concerted efforts are essential for their advancement into clinical settings.

CONCLUSION

In this review, we summarize shared immune features between the tumour microenvironment and systemic circulation, evaluate exploratory peripheral immune biomarker studies, and discuss associations between candidate biomarkers with clinical outcomes. We also consider integration of multiple peripheral immune parameters for better prediction and prognostication and discuss considerations in study design to further evaluate the clinical utility of candidate peripheral immune biomarkers for immunotherapy of solid tumours.

HIGHLIGHTS

Peripheral immune biomarkers are critical for improved prediction and prognostication of clinical outcomes for patients with solid tumours treated with immune checkpoint inhibition. Candidate peripheral biomarkers, such as cytokines, soluble factors, and immune cells, have potential as biomarkers to guide immunotherapy of solid tumours. Multiple peripheral immune parameters may be integrated to improve prediction and prognostication. The potential of peripheral immune biomarkers to guide immunotherapy of solid tumours requires critical work in biomarker discovery, validation, and standardization.

Prognostic impact of Interleukin-8 levels in lung cancer: A meta-analysis and a bioinformatic validation

BACKGROUND

High interleukin-8 (IL-8) levels have been linked to poor prognosis in lung cancer, but conclusive data are lacking.

MATERIALS AND METHODS

A comprehensive search was conducted on April 1st, 2023, from electronic databases, focusing on studies with IL-8 expression evaluations and the availability of hazard ratio (HR) and 95% confidence intervals (CI) for overall survival (OS), progression-free survival (PFS) and disease-free survival (DFS) or adequate data for their estimation. Then, we examined IL-8 and CXCR1 RNA-seq data from The Cancer Genome Atlas (TCGA) dataset, and we correlated these data with OS.

RESULTS

Among 2655 produced records, 10 manuscripts involving both non-small cell lung cancer and small cell lung cancer, were included in the analysis. Two manuscripts and one study included two and three different cohorts, respectively, for a total of 14 cohorts of patients. Overall, 4 cohorts evaluated IL-8 levels in patients treated with chemotherapy, 3 cohorts immunotherapy, 2 cohorts surgical patients and 4 cohorts other treatments; 1 cohort was removed, as the type of treatments was lacking. The 12 cohorts included in the OS analysis revealed that patients with high IL-8 levels have a lower OS probability, as compared to patients with low IL-8 levels (HR=1.75, 95 % CI 1.36-2.26). No significant difference between patients with high and low IL-8 levels was observed in the 8 cohorts available for PFS analysis. Sensitivity analysis according to treatment revealed significant PFS and OS differences for patients treated with chemotherapy or immunotherapy. Analysis of RNA-seq data from TCGA, confirmed the correlation between high IL-8 and CXCR1 expression and worse OS in patients with resected lung cancer.

CONCLUSION

To the best of our knowledge, this study represents the first meta-analysis demonstrating a negative prognostic impact of high IL-8 level in lung cancer, particularly in patients treated with chemotherapy and/or immunotherapy.

Predictive capacity of immune-related adverse events and cytokine profiling in neoadjuvant immune checkpoint inhibitor trials for head and neck squamous cell carcinoma

OBJECTIVES

Certain low-level immune-related adverse events (irAEs) have been associated with survival benefits in patients with various solid tumors on immune checkpoint inhibitors (ICIs). We aimed to investigate the association between irAEs and response to neoadjuvant ICIs in patients with head and neck squamous cell carcinoma (HNSCC) and to identify differences in circulating cytokine levels based on irAE status.

METHODS

This was a retrospective cohort study including three neoadjuvant clinical trials from July 2017 to January 2022: NCT03238365 (nivolumab ± tadalafil), NCT03854032 (nivolumab ± BMS986205), NCT03618654 (durvalumab ± metformin). The presence and type of irAEs, pathologic treatment response, and survival were compared. Canonical linear discriminant analysis (LDA) was performed to identify combinations of circulating cytokines predictive of irAEs using plasma sample multiplex assay.

RESULTS

Of 113 participants meeting inclusion criteria, 32 (28.3%) developed irAEs during treatment or follow-up. Positive p16 status was associated with irAEs (odds ratio [OR] 2.489; 95% CI 1.069-6.119; p = 0.043). irAEs were associated with pathologic treatment response (OR 3.73; 95% CI 1.34-10.35; p = 0.011) and with higher OS in the combined cohort (HR 0.319; 95% CI 0.113-0.906; p = 0.032). Patients with irAEs within the nivolumab cohort had significant elevations of select cytokines pre-treatment. Canonical LDA identified key drivers of irAEs among all trials, which were highly predictive of future irAE status.

CONCLUSIONS

irAEs are associated with response to neoadjuvant ICI therapy in HNSCC and can serve as clinical indicators for improved clinical outcomes. irAEs can be predicted by concentrations of several circulating cytokines prior to treatment.

Alterations in Peripheral Lymphocyte Subsets under Immunochemotherapy in Stage IV SCLC Patients: Th17 Cells as Potential Early Predictive Biomarker for Response

UICC stage IV small-cell lung cancer (SCLC) is a highly aggressive malignancy without curative treatment options. Several randomized trials have demonstrated improved survival rates through the addition of checkpoint inhibitors to first-line platin-based chemotherapy. Consequently, a combination of chemo- and immunotherapy has become standard palliative treatment. However, no reliable predictive biomarkers for treatment response exist. Neither PD-L1 expression nor tumor mutational burden have proven to be effective predictive biomarkers. In this study, we compared the cellular immune statuses of SCLC patients to a healthy control cohort and investigated changes in peripheral blood B, T, and NK lymphocytes, as well as several of their respective subsets, during treatment with immunochemotherapy (ICT) using flow cytometry. Our findings revealed a significant decrease in B cells, while T cells showed a trend to increase throughout ICT. Notably, high levels of exhausted CD4+ and CD8+ cells, alongside NK subsets, increased significantly during treatment. Furthermore, we correlated decreases/increases in subsets after two cycles of ICT with survival. Specifically, a decrease in Th17 cells indicated a better overall survival. Based on these findings, we suggest conducting further investigation into Th17 cells as a potential early predictive biomarkers for response in patients receiving palliative ICT for stage IV SCLC.

Chemotactic signaling pathways in prostate cancer: Implications in the tumor microenvironment and as potential therapeutic targets

Prostate cancer (PCa) stands as a significant global health concern, ranking among the leading causes of cancer deaths in men. While there are several treatment modalities for localized PCa, metastatic castration-resistant PCa (mCRPC) remains incurable. Despite therapeutic advancements showing promise in mCRPC, their impact on overall survival has been limited. This chapter explores the process by which tumors form, reviews our current understanding of PCa progression to mCRPC, and addresses the challenges of boosting anti-tumor immune responses in these tumors. It specifically discusses how chemotactic signaling affects the tumor microenvironment and its role in immune evasion and cancer progression. The chapter further examines the rationale of directly or indirectly targeting these pathways as adjuvant therapies for mCRPC, highlighting recent pre-clinical and clinical studies currently underway. The discussion emphasizes the potential of targeting specific chemokines and chemokine receptors as combination therapies with mainstream treatments for PCa and mCRPC to maximize long-term survival for this deadly disease.

Circulating IL-6 is associated with disease progression in BRAFwt metastatic melanoma patients receiving anti-PD-1 therapy

AIMS

Despite efficacy of anti-PD-1 blockade in treatment of metastatic melanoma (MM), many patients achieve rapid disease progression (DP). Therefore, the aim of this study is to better define biomarkers for DP by analysing levels of circulating cytokines TGF-β, IFN-γ, IL-6, IL-8 and IL-10 in MM patients prior to anti-PD-1 therapy.

METHODS

Cytokine levels were evaluated before therapy with pembrolizumab in peripheral blood of BRAF wild-type (wt) MM patients by ELISA method.

RESULTS

In this study, we give pretherapy levels for circulating TGF-β, IFN-γ, IL-6, IL-8 and IL-10 in BRAFwt MM patients and analyse them according to metastasis stage (M1a+M1 b, M1c, M1d groups), lactate dehydrogenase (LDH) level and occurrence of DP. Increased IL-6 level was found in M1d group (central nervous system metastasis), while LDH+patients (LDH ≥460 IU/L) have increased IL-6 and IL-8 values that correlate with LDH level. Also, IL-6 correlates with C reactive protein values. Furthermore, patients with DP have significantly higher IL-6 level compared with non-DP patients. Conversely, the other analysed cytokines are similar in investigated groups of MM patients. By receiver operating characteristics curve analysis, pretherapy IL-6 level was found to be a biomarker for the occurrence of DP with cut-off value of 3.02 pg/mL. Patients in M1d stage are prevalent in the group with IL-6 ≥3.02 pg/mL that is characterised with reduced progression-free survival and higher pretherapy IL-8 and LDH.

CONCLUSION

The evidence in this study implies that baseline IL-6 could be a biomarker of DP and poor prognosis in BRAFwt MM patients treated with pembrolizumab.

Small-Cell Lung Cancer: Is Liquid Biopsy a New Tool Able to Predict the Efficacy of Immunotherapy?

Small-cell lung cancer (SCLC) cases represent approximately 15% of all lung cancer cases, remaining a recalcitrant malignancy with poor survival and few treatment options. In the last few years, the addition of immunotherapy to chemotherapy improved clinical outcomes compared to chemotherapy alone, resulting in the current standard of care for SCLC. However, the advantage of immunotherapy only applies to a few SCLC patients, and predictive biomarkers selection are lacking for SCLC. In particular, due to some features of SCLC, such as high heterogeneity, elevated cell plasticity, and low-quality tissue samples, SCLC biopsies cannot be used as biomarkers. Therefore, the characterization of the tumor and, subsequently, the selection of an appropriate therapeutic combination may benefit greatly from liquid biopsy. Soluble factors, circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and extracellular vesicles (EVs) are now useful tools in the characterization of SCLC. This review summarizes the most recent data on biomarkers detectable with liquid biopsy, emphasizing their role in supporting tumor detection and their potential role in SCLC treatment choice.

Fever of unknown origin associated with immune checkpoint inhibitors

Since the approval for the treatment of melanoma in 2014, immune checkpoint inhibitors (ICIs) have revolutionized the therapy pattern across various malignancies. Coinciding with their frequent usage, their adverse effects, including fever, cannot be neglected. In the context of cancer diseases and cancer treatments, fever of unknown origin (FUO), which has long posed a challenge for clinicians in terms of diagnosis and management, brings forth new connotation and significance. In this paper review, we present the concept of ICIs-associated FUO, consider activated immune system and elevated cytokines as common mechanisms by which ICIs induce fever and various immune-related adverse events (irAEs), summarize and compare the primary etiologies of ICI-associated FUO, and compare it with conventional types of FUO.

Sex-related differences in serum biomarker levels predict the activity and efficacy of immune checkpoint inhibitors in advanced melanoma and non-small cell lung cancer patients

BACKGROUND

Immune Checkpoint Inhibitors (ICIs) lead to durable response and a significant increase in long-term survival in patients with advanced malignant melanoma (MM) and Non-Small Cell Lung Cancer (NSCLC). The identification of serum cytokines that can predict their activity and efficacy, and their sex interaction, could improve treatment personalization.

METHODS

In this prospective study, we enrolled immunotherapy-naïve patients affected by advanced MM and NSCLC treated with ICIs. The primary endpoint was to dissect the potential sex correlations between serum cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, GM-CSF, MCP-1, TNF-ɑ, IP-10, VEGF, sPD-L1) and the objective response rate (ORR). Secondly, we analyzed biomarker changes during treatment related to ORR, disease control rate (DCR), progression free survival (PFS) and overall survival (OS). Blood samples, collected at baseline and during treatment until disease progression (PD) or up to 2 years, were analyzed using Luminex xMAP or ELLA technologies.

RESULTS

Serum samples from 161 patients (98 males/63 females; 92 MM/69 NSCLC) were analyzed for treatment response. At baseline, IL-6 was significantly lower in females (F) versus males (M); lower levels of IL-4 in F and of IL-6 in both sexes significantly correlated with a better ORR, while higher IL-4 and TNF-ɑ values were predictive of a lower ORR in F versus M. One hundred and sixty-five patients were evaluable for survival analysis: at multiple Cox regression, an increased risk of PD was observed in F with higher baseline values of IL-4, sPD-L1 and IL-10, while higher IL-6 was a negative predictor in males. In males, higher levels of GM-CSF predict a longer survival, whereas higher IL-1β predicts a shorter survival. Regardless of sex, high baseline IL-8 values were associated with an increased risk of both PD and death, and high IL-6 levels only with shorter OS.

CONCLUSIONS

Serum IL-1β, IL-4, IL-6, IL-10, GM-CSF, TNF-ɑ, and sPD-L1 had a significant sex-related predictive impact on ORR, PFS and OS in melanoma and NSCLC patients treated with ICIs. These results will potentially pave the way for new ICI combinations, designed according to baseline and early changes of these cytokines and stratified by sex.

Peripheral B-cell levels predict efficacy and overall survival in advanced melanoma patients under PD-1 immunotherapy

Aims: Programmed death-1 (PD-1) blockade is a vital therapy for solid tumors, but not all patients benefit. Identifying which patients will benefit from immunotherapy is a key focus in oncology research. Patients & Methods: This study analyzed the correlation between the number of peripheral lymphocytes and the efficacy and prognosis of immunotherapy in advanced malignant melanoma. Results: Patients with a partial response had significantly lower peripheral B cell levels, and patients with a lower number of B lymphocytes had a longer survival time. Conclusion: These results suggest that peripheral B cells are correlated with the efficacy of PD-1 antibody and prognosis and are thus potential biomarkers for the efficacy and prognosis of PD-1 antibody immunotherapy in malignant melanoma.

Tissue and circulating biomarkers of benefit to immunotherapy in extensive-stage small cell lung cancer patients

Extensive stage-Small-Cell Lung Cancer (ES-SCLC) is an aggressive cancer with dismal prognosis. The addition of immune-checkpoint inhibitors (ICIs) to platinum-based chemotherapy have been consistently demonstrated to improve outcomes and survival, becoming the new standard in first - line treatment of ES-SCLC patients. However, despite positive results reported in the pivotal trials, longer benefit appears evident only for a selected group of patients. Several predictive biomarkers have been studied so far but the prospective identification of patients more likely to experience better outcome seems to be challenging in SCLC. Indeed, classical immune predictive biomarkers as PD-L1 and tumor mutational burden (TMB) seem not to correlate with outcomes. Recently, a new molecular classification of SCLC based on differential expression of genes associated with specific clinical behaviors and therapeutic vulnerability have been presented suggesting a new field to be investigated. Despite the achievements, these studies focused mainly on inter-tumoral heterogeneity, limiting the exploration of intra-tumoral heterogeneity and cell to cell interactions. New analysis methods are ongoing in order to explore subtypes plasticity. Analysis on single biopsies cannot catch the whole genomic profile and dynamic change of disease over time and during treatment. Moreover, the availability of tissue for translational research is limited due to the low proportion of patients undergoing surgery. In this context, liquid biopsy is a promising tool to detect reliable predictive biomarkers. Here, we reviewed the current available data on predictive role of tissue and liquid biomarkers in ES-SCLC patients receiving ICIs. We assessed latest results in terms of predictive and prognostic value of gene expression profiling in SCLC. Finally, we explored the role of liquid biopsy as a tool to monitor SCLC patients over time.

New perspectives in cancer immunotherapy: targeting IL-6 cytokine family

Chronic inflammation has been recognized as a canonical cancer hallmark. It is orchestrated by cytokines, which are master regulators of the tumor microenvironment (TME) as they represent the main communication bridge between cancer cells, the tumor stroma, and the immune system. Interleukin (IL)-6 represents a keystone cytokine in the link between inflammation and cancer. Many cytokines from the IL-6 family, which includes IL-6, oncostatin M, leukemia inhibitory factor, IL-11, IL-27, IL-31, ciliary neurotrophic factor, cardiotrophin 1, and cardiotrophin-like cytokine factor 1, have been shown to elicit tumor-promoting roles by modulating the TME, making them attractive therapeutic targets for cancer treatment.The development of immune checkpoint blockade (ICB) immunotherapies has radically changed the outcome of some cancers including melanoma, lung, and renal, although not without hurdles. However, ICB shows limited efficacy in other solid tumors. Recent reports support that chronic inflammation and IL-6 cytokine signaling are involved in resistance to immunotherapy. This review summarizes the available preclinical and clinical data regarding the implication of IL-6-related cytokines in regulating the immune TME and the response to ICB. Moreover, the potential clinical benefit of combining ICB with therapies targeting IL-6 cytokine members for cancer treatment is discussed.

Plasma levels of 12 different cytokines correlate to PD-1 inhibitor combined chemotherapy responses in advanced non-small-cell lung cancer patient

BACKGROUND

Targeted anti-programmed death receptor 1 (PD-1) monoclonal antibodies, when combined with chemotherapy, have shown improved outcomes in non-small cell lung cancer (NSCLC). However, it is important to note that not all patients benefit from this treatment, and there is a pressing need for more reliable efficacy measures and potential predictors of outcome. Cytokines, which are important molecules in the immune system, have been considered as potential biomarkers in clinical settings, but their precise clinical use remains unclear. In this study, our objective was to assess whether the levels of cytokines in the patient's blood sample are associated with tumor response to anti-PD-1 monoclonal antibodies combined with chemotherapy as well as the survival of patients with advanced non-small cell lung cancer.

MATERIALS AND METHODS

A total of 12 plasma cytokines were measured in advanced NSCLC patients (n = 35) and healthy individuals (n = 26) using multi-microsphere flow immunofluorescence. The relationship between cytokine levels and clinical response was analyzed using nonparametric Wilcoxon matched-pair ranked tests. Progression-free survival (PFS) time was recorded for all patients through radiographic outcome assessment and telephone follow-up. Survival curves were generated using the Kaplan-Meier and log-rank tests, and the thresholds for cytokines were determined using receiver operating characteristic analysis (ROC).

RESULTS

The expression levels of interleukin IL-6, IL-1 β, IFN-γ, IL-12p70, and TNF-α were significantly lower in the control group than those in the NSCLC group (p = 0.001, p = 0.0028, p = 0.019, p = 0.0001, p = 0.0021). High IL-10 levels at baseline and after 4 cycles of treatment conferred a worse prognosis; in addition, high TNF-α levels in patients after two cycles of immunochemotherapy suggested drug resistance. High levels of IL-6 and IFN-γ in patients undergoing four cycles of immunochemotherapy were associated with worse PFS.

CONCLUSIONS

Our study suggests that cytokines can serve as detection indicators for predicting efficacy in non-small cell lung cancer patients undergoing anti-PD-1 combined with chemotherapy treatment. Elevated levels of IL-10, TNF-α, IL-6, and IFN-γ in the plasma may indicate a higher likelihood of experiencing a worse clinical outcome.

Role of cytokine in malignant T-cell metabolism and subsequent alternation in T-cell tumor microenvironment

T cells are an important component of adaptive immunity and T-cell-derived lymphomas are very complex due to many functional sub-types and functional elasticity of T-cells. As with other tumors, tissues specific factors are crucial in the development of T-cell lymphomas. In addition to neoplastic cells, T- cell lymphomas consist of a tumor micro-environment composed of normal cells and stroma. Numerous studies established the qualitative and quantitative differences between the tumor microenvironment and normal cell surroundings. Interaction between the various component of the tumor microenvironment is crucial since tumor cells can change the microenvironment and vice versa. In normal T-cell development, T-cells must respond to various stimulants deferentially and during these courses of adaptation. T-cells undergo various metabolic alterations. From the stage of quiescence to attention of fully active form T-cells undergoes various stage in terms of metabolic activity. Predominantly quiescent T-cells have ATP-generating metabolism while during the proliferative stage, their metabolism tilted towards the growth-promoting pathways. In addition to this, a functionally different subset of T-cells requires to activate the different metabolic pathways, and consequently, this regulation of the metabolic pathway control activation and function of T-cells. So, it is obvious that dynamic, and well-regulated metabolic pathways are important for the normal functioning of T-cells and their interaction with the microenvironment. There are various cell signaling mechanisms of metabolism are involved in this regulation and more and more studies have suggested the involvement of additional signaling in the development of the overall metabolic phenotype of T cells. These important signaling mediators include cytokines and hormones. The impact and role of these mediators especially the cytokines on the interplay between T-cell metabolism and the interaction of T-cells with their micro-environments in the context of T-cells lymphomas are discussed in this review article.

Prognostic role of IL-8 in cancer patients treated with immune checkpoint inhibitors: a system review and meta-analysis

Background

Immune checkpoint inhibitors (ICIs) have been proven to be an effective treatment strategy for a variety of malignant tumors. However, only a subset of patients can benefit from ICIs due to factors such as drug resistance. Therefore, it is crucial to identify biomarkers that can accurately predict the efficacy of ICIs and provide a basis for individualized immunotherapy. In this study, we conducted a systematic review and meta-analysis to explore whether the chemokine interleukin 8 (IL-8) can be used as a biomarker to evaluate the efficacy of ICIs treatment.

Methods

We conducted a comprehensive search of several databases, including PubMed, Embase, Web of Science, and Cochrane, to identify relevant articles published up to June 08, 2023. Our inclusion criteria were limited to cohort studies and clinical trials that reported hazard ratios (HR) and 95% confidence intervals (CI) for overall survival (OS) and/or progression-free survival (PFS), as well as the objective response rate (ORR), in cancer patients with high and low IL-8 expression. For data analysis, we used Revman to generate forest plots, subgroup analysis, and assess publication bias. Additionally, Stata was utilized for sensitivity analysis and further examination of publication bias.

Results

A total of 24 datasets, involving 3190 participants, were selected from 14 studies. The meta-analysis revealed a reduction in ORR, OS, and/or PFS in the high IL-8 group after treatment with ICIs compared to the low IL-8 group.

Conclusion

IL-8 can serve as a biomarker for predicting the efficacy of ICIs. Patients with lower expression of IL-8 may benefit from ICIs treatment.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=383188, identifier CRD42022383188.

Detection of sFas, sCD137, and IL-27 Cytokines as Potential Biomarkers for Hepatocellular Carcinoma Diagnosis

Purpose

Hepatocellular carcinoma (HCC), a prevalent type of liver cancer, is mainly diagnosed in the advanced stage, leading to a high mortality rate. Recent advances have identified peripheral cytokines as a potential tool to predict disease outcomes and inform therapeutic decisions. Hence, in this study, we aim to build a predictive model for HCC based on serum levels of different cytokines.

Patients and Methods

We used immunoassay to quantify the concentrations of IL-27, MIP-1β, Perforin, sCD137, sFas, and TNF-α in the serum of 38 HCC patients and 15 healthy controls. Logistic regression was then used to construct classification models detecting HCC based on these cytokines. A nomogram of the best-performing model was generated to visualize HCC prediction.

Results

sFas and MIP-1β were found to be significantly higher in HCC patients compared to controls. Predictive models based on cytokine levels combining sFas, sCD137, and IL-27 performed the best in distinguishing HCC patients from healthy controls. This model has a bias-corrected area under the receiver operating characteristic (ROC) curve (AUC) of 0.948, a sensitivity of 92.11%, a specificity of 93.33%, and an accuracy of 0.925.

Conclusion

Our findings suggest that serum cytokines have the potential to be utilized in HCC screening to improve detection rates.

High serum IL-6 correlates with reduced clinical benefit of atezolizumab and bevacizumab in unresectable hepatocellular carcinoma

Background & Aims

We elucidated the clinical and immunologic implications of serum IL-6 levels in patients with unresectable hepatocellular carcinoma (HCC) treated with atezolizumab and bevacizumab (Ate/Bev).

Methods

We prospectively enrolled 165 patients with unresectable HCC (discovery cohort: 84 patients from three centres; validation cohort: 81 patients from one centre). Baseline blood samples were analysed using a flow cytometric bead array. The tumour immune microenvironment was analysed using RNA sequencing.

Results

In the discovery cohort, clinical benefit 6 months (CB6m) was defined as complete or partial response, or stable disease for ≥6 months. Among various blood-based biomarkers, serum IL-6 levels were significantly higher in participants without CB6m than in those with CB6m (mean 11.56 vs. 5.05 pg/ml, p = 0.02). Using maximally selected rank statistics, the optimal cut-off value for high IL-6 was determined as 18.49 pg/ml, and 15.2% of participants were found to have high IL-6 levels at baseline. In both the discovery and validation cohorts, participants with high baseline IL-6 levels had a reduced response rate and worse progression-free and overall survival after Ate/Bev treatment compared with those with low baseline IL-6 levels. In multivariable Cox regression analysis, the clinical implications of high IL-6 levels persisted, even after adjusting for various confounding factors. Participants with high IL-6 levels showed reduced interferon-γ and tumour necrosis factor-α secretion from CD8+ T cells. Moreover, excess IL-6 suppressed cytokine production and proliferation of CD8+ T cells. Finally, participants with high IL-6 levels exhibited a non-T-cell-inflamed immunosuppressive tumour microenvironment.

Conclusions

High baseline IL-6 levels can be associated with poor clinical outcomes and impaired T-cell function in patients with unresectable HCC after Ate/Bev treatment.

Impact and implications

Although patients with hepatocellular carcinoma who respond to treatment with atezolizumab and bevacizumab exhibit favourable clinical outcomes, a fraction of these still experience primary resistance. We found that high baseline serum levels of IL-6 correlate with poor clinical outcomes and impaired T-cell response in patients with hepatocellular carcinoma treated with atezolizumab and bevacizumab.

Development of a nomogram based on serum cytokine-related riskscore in breast cancer

Background

Cytokines are involved in many inflammatory diseases and thus play an important role in tumor immune regulation. In recent years, researchers have found that breast cancer is not only related to genetic and environmental factors, but also to the chronic inflammation and immunity. However, the correlation between serum cytokines and blood tests indicators remain unclear.

Methods

A total of 84 serum samples and clinicopathological data of breast cancer patients from Tianjin Cancer Institute &amp; Hospital, Tianjin Medical University, Tianjin, P. R. China were collected. The expression levels of the 12 cytokines were detected by immunofluorescence method. Blood tests results were obtained from medical records. By stepwise Cox regression analysis, a cytokine-related gene signature was generated. Univariate and multivariate Cox regression were used to analyze the influence on the prognosis of patients. A nomogram was constructed to illustrate the cytokine-related riskscore predicting 5-year OS, which was further evaluated and validated by C-index and ROC curve. The correlation between the expression of cytokines in serum and other blood indicators was studied by using Spearman’s test.

Results

The riskscore was calculated as IL-4×0.99069 + TNF-α×0.03683. Patients were divided into high and low risk groups according to the median riskscore, with the high-risk group has a shorter survival time by log-rank test (training set, P=0.017; validation set, P=0.013). Combined with the clinical characteristics, the riskscore was found to be an independent factor for predicting the OS of breast cancer patients in both training cohort (HR=1.2, P&lt;0.01) and validation cohort (HR=1.6, P=0.023). The 5-year C-index and AUC of the nomogram were 0.78 and 0.68, respectively. IL-4 was further found to be negatively correlated with ALB.

Conclusion

In summary, we have developed a nomogram based on two cytokines including IL-4 and TNF-α to predict OS of breast cancer and investigated their correlation with blood test indicators.

New biomarkers exploration and nomogram construction of prognostic and immune-related adverse events of advanced non-small cell lung cancer patients receiving immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are regarded as the most promising treatment for advanced-stage non-small cell lung cancer (aNSCLC). Unfortunately, there has been no unified accuracy biomarkers and systematic model specifically identified for prognostic and severe immune-related adverse events (irAEs). Our goal was to discover new biomarkers and develop a publicly accessible method of identifying patients who may maximize benefit from ICIs.

METHODS

This retrospective study enrolled 138 aNSCLC patients receiving ICIs treatment. Progression-free survival (PFS) and severe irAEs were end-points. Data of demographic features, severe irAEs, and peripheral blood inflammatory-nutritional and immune indices before and after 1 or 2 cycles of ICIs were collected. Independent factors were selected by least absolute shrinkage and selection operator (LASSO) combined with multivariate analysis, and incorporated into nomogram construction. Internal validation was performed by applying area under curve (AUC), calibration plots, and decision curve.

RESULTS

Three nomograms with great predictive accuracy and discriminatory power were constructed in this study. Among them, two nomograms based on combined inflammatory-nutritional biomarkers were constructed for PFS (1 year-PFS and 2 year-PFS) and severe irAEs respectively, and one nomogram was constructed for 1 year-PFS based on immune indices. ESCLL nomogram (based on ECOG PS, preSII, changeCAR, changeLYM and postLDH) was constructed to assess PFS (1-, 2-year-AUC = 0.893 [95% CI 0.837-0.950], 0.828 [95% CI 0.721-0.935]). AdNLA nomogram (based on age, change-dNLR, changeLMR and postALI) was constructed to predict the risk of severe irAEs (AUC = 0.762 [95% CI 0.670-0.854]). NKT-B nomogram (based on change-CD3+CD56+CD16+NKT-like cells and change-B cells) was constructed to assess PFS (1-year-AUC = 0.872 [95% CI 0.764-0.965]). Although immune indices could not be modeled for severe irAEs prediction due to limited data, we were the first to find CD3+CD56+CD16+NKT-like cells were not only correlated with PFS but also associated with severe irAEs, which have not been reported in the study of aNSCLC-ICIs. Furthermore, our study also discovered higher change-CD4+/CD8+ ratio was significantly associated with severe irAEs.

CONCLUSIONS

These three new nomograms proceeded from non-invasive and straightforward peripheral blood data may be useful for decisions-making. CD3+CD56+CD16+NKT-like cells were first discovered to be an important biomarker for treatment and severe irAEs, and play a vital role in distinguishing the therapy response and serious toxicity of ICIs.

Serum cytokine levels and other associated factors as possible immunotherapeutic targets and prognostic indicators for lung cancer

Lung cancer is one of the most prevalent cancer types and the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for 80-85% of all cancer incidences. Lung cancer therapy and prognosis largely depend on the disease's degree at the diagnosis time. Cytokines are soluble polypeptides that contribute to cell-to-cell communication, acting paracrine or autocrine on neighboring or distant cells. Cytokines are essential for developing neoplastic growth, but they are also known to operate as biological inducers following cancer therapy. Early indications are that inflammatory cytokines such as IL-6 and IL-8 play a predictive role in lung cancer. Nevertheless, the biological significance of cytokine levels in lung cancer has not yet been investigated. This review aimed to assess the existing literature on serum cytokine levels and additional factors as potential immunotherapeutic targets and lung cancer prognostic indicators. Changes in serum cytokine levels have been identified as immunological biomarkers for lung cancer and predict the effectiveness of targeted immunotherapy.

Association between serum levels of 12 different cytokines and short-term efficacy of anti-PD-1 monoclonal antibody combined with chemotherapy in advanced gastric cancer

BACKGROUND

Gastric cancer (GC) is characterized by aggressive tumor growth and poor prognosis. The benefits of targeted anti-programmed death receptor 1 (PD-1) monoclonal antibody combined with chemotherapy have not yet been characterized. The tumor microenvironment and circulating factors have garnered interest as possible predictors of response and prognosis. The aim of this study was to evaluate whether cytokine levels in the serum of patients were related to tumor response to anti-PD-1 monoclonal antibody combined with chemotherapy and survival in advanced GC.

MATERIALS AND METHODS

Preoperative serum samples were collected from patients with GC (n = 52) and healthy individuals (n = 31). The levels of 12 different cytokines were measured using a multiple microsphere flow immunofluorescence assay. The association between cytokine levels and clinical response was analyzed using nonparametric Wilcoxon matched-pair ranked tests. Progression-free survival (PFS) time for all patients was recorded via evaluation of imaging results and follow-up via telephone. Kaplan-Meier and log-rank tests were used to plot survival curves.

RESULTS

The levels of interleukin (IL)-6, IL-1β, interferon (IFN)-γ, IL-17, and IL-12p70 in the control group were significantly lower than those in the GC group (p = 0.0002, p = 0.0065, p = 0.0003, p = 0.0303, and p = 0.0295, respectively). The level of IL-4 was significantly higher in healthy individuals than that in patients with GC (p = 0.0201). The cytokine levels in the good responder group were higher than those in the poor responder group before therapy. Patients treated with immunochemotherapy showed an overall reduction in all cytokine levels after treatment initiation. A high baseline level of IFN-γ was associated with a better prognosis. However, high IL-6 levels in patients after two cycles of immunochemotherapy indicated resistance. High IL-4 levels in patients treated with four cycles of immunochemotherapy were associated with better PFS.

CONCLUSIONS

Our study suggests that low levels of IFN-γ before immune checkpoint inhibitor treatment may be useful for the detection of a poor immunological status. Hence, a reduction in IL-6 levels is predictive of a longer PFS, and increased IL-4 levels are predictive of a good response. IL-4 and IL-6 may, therefore, serve as promising circulating predictive biomarkers for patients who can benefit from anti-PD-1 monoclonal antibodies administered in combination with chemotherapy.

Utilizing MALDI-TOF MS and LC-MS/MS to access serum peptidome-based biomarkers in canine oral tumors

Tumors frequently found in dogs include canine oral tumors, either cancerous or noncancerous. The bloodstream is an important route for tumor metastasis, particularly for late-stage oral melanoma (LOM) and late-stage oral squamous cell carcinoma (LOSCC). The present study aimed to investigate serum peptidome-based biomarkers of dogs with early-stage oral melanoma, LOM, LOSCC, benign oral tumors, chronic periodontitis and healthy controls, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and liquid chromatography tandem mass spectrometry. A principal component analysis plot showed distinct clusters among all groups. Four peptides were identified, including peptidyl-prolyl cis-trans isomerase FKBP4 isoform X2 (FKBP4), steroid hormone receptor ERR1 (ESRRA or ERRA), immunoglobulin superfamily member 10 (IGSF10) and ATP-binding cassette subfamily B member 5 (ABCB5). FKBP4, ESRRA and ABCB5 were found to be overexpressed in both LOM and LOSCC, whereas IGSF10 expression was markedly increased in LOSCC only. These four proteins also played a crucial role in numerous pathways of cancer metastasis and showed a strong relationship with chemotherapy drugs. In conclusion, this study showed rapid screening of canine oral tumors using serum and MALDI-TOF MS. In addition, potential serum peptidome-based biomarker candidates for LOM and LOSCC were identified.

Emerging role of chemokines in small cell lung cancer: Road signs for metastasis, heterogeneity, and immune response

Small cell lung cancer (SCLC) is a recalcitrant, relatively immune-cold, and deadly subtype of lung cancer. SCLC has been viewed as a single or homogenous disease that includes deletion or inactivation of the two major tumor suppressor genes (TP53 and RB1) as a key hallmark. However, recent sightings suggest the complexity of SCLC tumors that comprises highly dynamic multiple subtypes contributing to high intratumor heterogeneity. Furthermore, the absence of targeted therapies, the understudied tumor immune microenvironment (TIME), and subtype plasticity are also responsible for therapy resistance. Secretory chemokines play a crucial role in immunomodulation by trafficking immune cells to the tumors. Chemokines and cytokines modulate the anti-tumor immune response and wield a pro-/anti-tumorigenic effect on SCLC cells after binding to cognate receptors. In this review, we summarize and highlight recent findings that establish the role of chemokines in SCLC growth and metastasis, and sophisticated intratumor heterogeneity. We also discuss the chemokine networks that are putative targets or modulators for augmenting the anti-tumor immune responses in targeted or chemo-/immuno-therapeutic strategies, and how these combinations may be utilized to conquer SCLC.

Dissecting Immunotherapy Strategies for Small Cell Lung Cancer: Antibodies, Ionizing Radiation and CAR-T

Small cell lung cancer (SCLC) is a highly aggressive malignancy that accounts for about 14% of all lung cancers. Platinum-based chemotherapy has been the only available treatment for a long time, until the introduction of immune checkpoint inhibitors (ICIs) recently changed first-line standard of care and shed light on the pivotal role of the immune system. Despite improved survival in a subset of patients, a lot of them still do not benefit from first-line chemo-immunotherapy, and several studies are investigating whether different combination strategies (with both systemic and local treatments, such as radiotherapy) may improve patient outcomes. Moreover, research of biomarkers that may be used to predict patients' outcomes is ongoing. In addition to ICIs, immunotherapy offers other different strategies, including naked monoclonal antibodies targeting tumor associated antigens, conjugated antibody, bispecific antibodies and cellular therapies. In this review, we summarize the main evidence available about the use of immunotherapy in SCLC, the rationale behind combination strategies and the studies that are currently ongoing in this setting, in order to give the reader a clear and complete view of this rapidly expanding topic.

Peripheral cytokine levels as novel predictors of survival in cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis

Background

Early identification of patients who will benefit from immune checkpoint inhibitors (ICIs) has recently become a hot issue in cancer immunotherapy. Peripheral cytokines are key regulators in the immune system that can induce the expression of immune checkpoint molecules; however, the association between peripheral cytokines and the efficiency of ICIs remains unclear.

Methods

A systematic review was conducted in several public databases from inception through 3 February 2022 to identify studies investigating the association between peripheral cytokines (i.e., IL-1β, IL-2, IL-2RA, IL-2R, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-15, IL-17, TNF-α, IFN-γ, and TGF-β) and ICI treatment. Survival data, including overall survival (OS) and/or progression-free survival (PFS), were extracted, and meta-analyses were performed.

Results

Twenty-four studies were included in this analysis. The pooled results demonstrated that the pretreatment peripheral levels of IL-6 (univariate analysis: HR = 2.53, 95% CI = 2.21–2.89, p < 0.00001; multivariate analysis: HR = 2.21, 95% CI = 1.67–2.93, p < 0.00001) and IL-8 (univariate analysis: HR = 2.17, 95% CI = 1.98–2.38, p < 0.00001; multivariate analysis: HR = 1.88, 95% CI= 1.70–2.07, p < 0.00001) were significantly associated with worse OS of cancer patients receiving ICI treatment in both univariate and multivariate analysis. However, high heterogeneity was found for IL-6, which might be attributed to region, cancer type, treatment method, sample source, and detection method.

Conclusion

The peripheral level of IL-8 may be used as a prognostic marker to identify patients with inferior response to ICIs. More high-quality prospective studies are warranted to assess the predictive value of peripheral cytokines for ICI treatment.

Changes of Tumor Markers in Patients with Lung Cancer after Immunotherapy and Their Link with Inflammation in the Body

Purpose

To figure out tumor markers changes in lung cancer (LC) patients after immunotherapy and their link with inflammation in the body.

Methods

From May 2017 to January 2021, taking 97 LC patients with elevated Programmed Cell Death Protein 1 and Programmed Cell Death Protein-ligand 1 was as the research objects. They were all given immunotherapy and assigned into the remission and the nonremission groups on the grounds of the tumor remission after 6 months of treatment, after comparison of tumor markers [carcinoembryonic antigen (CEA), squamous cell carcinoma-associated antigen (SCC-Ag), cytokeratin 19 fragment (CYFRA12-1), and neuron-specific enolase (NSE)] and inflammation indicators [interleukin-10 (IL-10), interleukin (IL-6), and tumor necrosis factor-α (TNF-α)] in the two.

Results

Tumor markers, IL-10, IL-6, and TNF-α in the remission after treatment were reduced vs. the nonremission (P < 0.05); SCC-Ag was positively linked with IL-10, IL-6, and TNF-α in the patients after treatment (P < 0.05); the AUC of the combined detection to assess the efficacy of LC immunotherapy was greater vs. the individual detection of indicators (P < 0.05).

Conclusion

Tumor markers and the inflammation state of the body in LC patients are memorably reduced after immunotherapy, and a correlation is presented between the two, which manifests evaluating value of the efficacy of immunotherapy.

Exploration of serum biomarkers in dogs with malignant melanoma receiving anti-PD-L1 therapy and potential of COX-2 inhibition for combination therapy

Immune checkpoint inhibitors (ICIs) such as anti-PD-L1 antibodies are widely used to treat human cancers, and growing evidence suggests that ICIs are promising treatments for canine malignancies. However, only some canine oral malignant melanoma (OMM) cases respond to ICIs. To explore biomarkers predictive of survival in dogs with pulmonary metastatic OMM receiving the anti-PD-L1 antibody c4G12 (n = 27), serum concentrations of prostaglandin E2 (PGE2), cytokines, chemokines, and growth factors were measured prior to treatment initiation. Among 12 factors tested, PGE2, interleukin (IL)-12p40, IL-8, monocyte chemotactic protein-1 (MCP-1), and stem cell factor (SCF) were higher in OMM dogs compared to healthy dogs (n = 8). Further, lower baseline serum PGE2, MCP-1, and vascular endothelial growth factor (VEGF)-A concentrations as well as higher IL-2, IL-12, and SCF concentrations predicted prolonged overall survival. These observations suggest that PGE2 confers resistance against anti-PD-L1 therapy through immunosuppression and thus is a candidate target for combination therapy. Indeed, PGE2 suppressed IL-2 and interferon (IFN)-γ production by stimulated canine peripheral blood mononuclear cells (PBMCs), while inhibition of PGE2 biosynthesis using the COX-2 inhibitor meloxicam in combination with c4G12 enhanced Th1 cytokine production by PBMCs. Thus, serum PGE2 may be predictive of c4G12 treatment response, and concomitant use of COX-2 inhibitors may enhance ICI antitumor efficacy.

Intravenous Oncolytic Vaccinia Virus Therapy Results in a Differential Immune Response between Cancer Patients

Simple Summary

Oncolytic viruses (OVs) have been extensively studied as an immunotherapeutic agent against a variety of cancers with some successes. Immunotherapeutic strategies, such as OVs, aim to transform an immunologically ‘cold’ tumour microenvironment into a more favourable inflammatory ‘hot’ tumour. However, it is evident that not all patients have a favourable response to treatment. Furthermore, reliable biomarkers able to predict a patient’s response to therapy have not yet been elucidated. We show evidence of a distinct immunologically exhausted profile in patients who do not respond to OV, which may pave the way for the development of predictive biomarkers leading to a more personalised approach to cancer treatment using combination therapies.

Abstract

Pexa-Vec is an engineered Wyeth-strain vaccinia oncolytic virus (OV), which has been tested extensively in clinical trials, demonstrating enhanced cytotoxic T cell infiltration into tumours following treatment. Favourable immune consequences to Pexa-Vec include the induction of an interferon (IFN) response, followed by inflammatory cytokine/chemokine secretion. This promotes tumour immune infiltration, innate and adaptive immune cell activation and T cell priming, culminating in targeted tumour cell killing, i.e., an immunologically ‘cold’ tumour microenvironment is transformed into a ‘hot’ tumour. However, as with all immunotherapies, not all patients respond in a uniformly favourable manner. Our study herein, shows a differential immune response by patients to intravenous Pexa-Vec therapy, whereby some patients responded to the virus in a typical and expected manner, demonstrating a significant IFN induction and subsequent peripheral immune activation. However, other patients experienced a markedly subdued immune response and appeared to exhibit an exhausted phenotype at baseline, characterised by higher baseline immune checkpoint expression and regulatory T cell (Treg) levels. This differential baseline immunological profile accurately predicted the subsequent response to Pexa-Vec and may, therefore, enable the development of predictive biomarkers for Pexa-Vec and OV therapies more widely. If confirmed in larger clinical trials, these immunological biomarkers may enable a personalised approach, whereby patients with an exhausted baseline immune profile are treated with immune checkpoint blockade, with the aim of reversing immune exhaustion, prior to or alongside OV therapy.

Small-Cell Lung Cancer Long-Term Survivor Patients: How to Find a Needle in a Haystack?

Small-cell lung cancer (SCLC) is an aggressive malignancy characterized by a rapid progression and a high resistance to treatments. Unlike other solid tumors, there has been a scarce improvement in emerging treatments and survival during the last years. A better understanding of SCLC biology has allowed for the establishment of a molecular classification based on four transcription factors, and certain therapeutic vulnerabilities have been proposed. The universal inactivation of TP53 and RB1, along with the absence of mutations in known targetable oncogenes, has hampered the development of targeted therapies. On the other hand, the immunosuppressive microenvironment makes the success of immune checkpoint inhibitors (ICIs), which have achieved a modest improvement in overall survival in patients with extensive disease, difficult. Currently, atezolizumab or durvalumab, in combination with platinum–etoposide chemotherapy, is the standard of care in first-line setting. However, the magnitude of the benefit is scarce and no predictive biomarkers of response have yet been established. In this review, we describe SCLC biology and molecular classification, examine the SCLC tumor microenvironment and the challenges of predictive biomarkers of response to new treatments, and, finally, assess clinical and molecular characteristics of long-term survivor patients in order to identify possible prognostic factors and treatment vulnerabilities.

PIV and PILE Score at Baseline Predict Clinical Outcome of Anti-PD-1/PD-L1 Inhibitor Combined With Chemotherapy in Extensive-Stage Small Cell Lung Cancer Patients

Objectives

The objective of this study is to evaluate whether PIV (Pan-Immune-Inflammation Value) and PILE [a score derived from PIV, lactate dehydrogenase (LDH), and Eastern Cooperative Oncology Group Performance Status (ECOG PS)] can predict clinical outcome of anti-PD-1/PD-L1 inhibitor combined with chemotherapy in patients with extensive-stage (ES) small cell lung cancer (SCLC).

Methods

A total of 53 patients with ES-SCLC in the control group of clinical trial (NCT03041311) were included in this study. PIV was calculated as follows: (neutrophil count × platelet count × monocyte count)/lymphocyte count. The PILE scores were composited based on PIV, LDH levels, and ECOG PS. The Kaplan–Meier method and Cox hazards regression models were used for survival analyses. Moreover, the predictive ability of PIV and PILE was validated in an independent real-world group consisting of 84 patients.

Results

Patients in the low PIV group (PIV < median) had longer progression-free survival (PFS) and overall survival (OS) than those in the high PIV group (PIV ≥ median), along with the HR, which was 2.157 and 2.359, respectively (PFS HR 95% CI: 1.181–3.940, p = 0.012; OS HR 95% CI: 1.168–4.762, p = 0.020). High PILE score was observed relating to worse treatment efficacy (disease control rate (DCR): 84.21% vs. 100%, p = 0.047; durable clinical benefit (DCB) rate: 10% vs. 48.5%, p = 0.060) and poor clinical outcome (median PFS: 4.75 vs. 5.53 m, p = 0.043; median OS: 7.13 vs. 15.93 m, p = 0.002). Similar results were obtained about the predictive and prognostic abilities of PIV and PILE scores in the validation group.

Conclusions

High PIV and high PILE were correlated with worse clinical outcomes in ES-SCLC patients treated with anti-PD-1/PD-L1 inhibitor combined with chemotherapy, reflecting that PIV and PILE might be useful to identify patients unlikely to benefit from anti-PD-1/PD-L1 therapy.

Collagen Fragments Produced in Cancer Mediate T Cell Suppression Through Leukocyte-Associated Immunoglobulin-Like Receptor 1

The tumor microenvironment (TME) is a complex structure comprised of tumor, immune and stromal cells, vasculature, and extracellular matrix (ECM). During tumor development, ECM homeostasis is dysregulated. Collagen remodeling by matrix metalloproteinases (MMPs) generates specific collagen fragments, that can be detected in the circulation of cancer patients and correlate with poor disease outcome. Leukocyte-Associated Immunoglobulin-like Receptor-1 (LAIR-1) is an inhibitory collagen receptor expressed on immune cells in the TME and in the circulation. We hypothesized that in addition to ECM collagen, collagen fragments produced in cancer can mediate T cell immunosuppression through LAIR-1. Our analyses of TCGA datasets show that cancer patients with high tumor mRNA expression of MMPs, collagen I and LAIR-1 have worse overall survival. We show that in vitro generated MMP1 or MMP9 collagen I fragments bind to and trigger LAIR-1. Importantly, LAIR-1 triggering by collagen I fragments inhibits CD3 signaling and IFN-γ secretion in a T cell line. LAIR-2 is a soluble homologue of LAIR-1 with higher affinity for collagen and thereby acts as a decoy receptor. Fc fusion proteins of LAIR-2 have potential as cancer immunotherapeutic agents and are currently being tested in clinical trials. We demonstrate that collagen fragment-induced inhibition of T cell function could be reversed by LAIR-2 fusion proteins. Overall, we show that collagen fragments produced in cancer can mediate T cell suppression through LAIR-1, potentially contributing to systemic immune suppression. Blocking the interaction of LAIR-1 with collagen fragments could be an added benefit of LAIR-1-directed immunotherapy.

What Are the Biomarkers for Immunotherapy in SCLC?

Small-cell lung cancer (SCLC) is an aggressive malignancy that exhibits a rapid doubling time, a high growth fraction, and the early development of widespread metastases. The addition of immune checkpoint inhibitors to first-line chemotherapy represents the first significant improvement of systemic therapy in several decades. However, in contrast to its effects on non-SCLC, the advantageous effects of immunotherapy addition are modest in SCLC. In particular, only a small number of SCLC patients benefit from immune checkpoint inhibitors. Additionally, biomarkers selection is lacking for SCLC, with clinical trials largely focusing on unselected populations. Here, we review the data concerning the major biomarkers for immunotherapy, namely, programmed death ligand 1 expression and tumour mutational burden. Furthermore, we explore other potential biomarkers, including the role of the immune microenvironment in SCLC, the role of genetic alterations, and the potential links between neurological paraneoplastic syndromes, serum anti-neuronal nuclear antibodies, and outcomes in SCLC patients treated with immunotherapy.

The Role of Cytokines in Predicting the Response and Adverse Events Related to Immune Checkpoint Inhibitors

Recently, the overall survival (OS) and progression-free survival (PFS) of patients with advanced cancer has been significantly improved due to the application of immune checkpoint inhibitors (ICIs). Low response rate and high occurrence of immune-related adverse events (irAEs) make urgently need for ideal predictive biomarkers to identity efficient population and guide treatment strategies. Cytokines are small soluble proteins with a wide range of biological activity that are secreted by activated immune cells or tumor cells and act as a bridge between innate immunity, infection, inflammation and cancer. Cytokines can be detected in peripheral blood and suitable for dynamic detection. During the era of ICIs, many studies investigated the role of cytokines in prediction of the efficiency and toxicity of ICIs. Herein, we review the relevant studies on TNF-α, IFN-γ, IL-6, IL-8, TGF-β and other cytokines as biomarkers for predicting ICI-related reactions and adverse events, and explore the immunomodulatory mechanisms. Finally, the most important purpose of this review is to help identify predictors of ICI to screen patients who are most likely to benefit from immunotherapy.

Systemic immunity in cancer

Immunotherapy has revolutionized cancer treatment, but efficacy remains limited in most clinical settings. Cancer is a systemic disease that induces many functional and compositional changes to the immune system as a whole. Immunity is regulated by interactions of diverse cell lineages across tissues. Therefore, an improved understanding of tumour immunology must assess the systemic immune landscape beyond the tumour microenvironment (TME). Importantly, the peripheral immune system is required to drive effective natural and therapeutically induced antitumour immune responses. In fact, emerging evidence suggests that immunotherapy drives new immune responses rather than the reinvigoration of pre-existing immune responses. However, new immune responses in individuals burdened with tumours are compromised even beyond the TME. Herein, we aim to comprehensively outline the current knowledge of systemic immunity in cancer.

A narrative review of current and potential prognostic biomarkers for immunotherapy in small-cell lung cancer

Small-cell lung cancer (SCLC) is a highly invasive and rapidly proliferating pathologic subtype that accounts for 13-15% of all lung cancer cases. Recently in extensive-stage SCLC, treatments that combine immunotherapy and chemotherapy showed increased efficacy compared to chemotherapy alone in several trials. However, the combination of immunotherapy and conventional chemotherapy regimens was introduced only recently for extensive-stage SCLC, with relatively little real-world data. The demand for reliable biomarkers that can predict the efficacy of immunotherapy in SCLC is high. Several studies evaluated various parameters including programmed cell death ligand-1 (PD-L1) expression, tumor mutation burden (TMB), gene expression profiling, autoantibody, and blood cytokines for predictive value for response to immunotherapy in SCLC. Despite some observed correlations, there is a lack of concrete support for the use of PD-L1 expression levels for readily available biomarker. High TMB in combination with smoking history is predictive of a better response to immunotherapy, but validation of cutoffs and testing methods is necessary before it can be widely applied in clinical settings. Other candidate biomarkers such as immune cell distribution among tumor microenvironment, and systemic inflammatory markers can also be evaluated, after an accumulation of real-life data from SCLC patients under immunotherapy.

Inhibition of STAT3 augments antitumor efficacy of anti-CTLA-4 treatment against prostate cancer

There is an urgent need for new treatment options in metastatic drug-resistant prostate cancer. Combining immunotherapy with other targeted therapies may be an effective strategy for advanced prostate cancer. In the present study, we sought to investigate to enhance the efficacy of anti-CTLA-4 therapy against prostate cancer by the combination with STAT3 inhibition.

Male C57BL6 mice were subcutaneously inoculated with the murine prostate cancer cell line RM-1. Tumor progression was monitored following treatment with vehicle, the small molecule STAT3 inhibitor GPB730, anti-CTLA-4 or GPB730 + anti-CTLA-4. Treatment with anti-CTLA-4 or anti-CTLA-4 + GPB730 significantly inhibited tumor growth and enhanced survival compared to vehicle. Combining anti-CTLA-4 treatment with GPB730 resulted in a significantly prolonged survival compared to anti-CTLA-4 alone. GPB730 significantly increased infiltration of CD45 + cells in tumors of anti-CTLA-4-treated mice compared to anti-CTLA-4 alone. The levels of tumor-infiltrating Tregs were significantly decreased and the CD8:Treg ratio significantly increased by GPB730 treatment in combination with anti-CTLA-4 compared to anti-CTLA-4 alone. Immunohistochemical analysis showed a significant increase in CD45-positive cells in anti-CTLA-4 and anti-CTLA-4 + GPB730-treated tumors compared to vehicle or GPB730 monotherapy. Plasma levels of IL10 were significantly increased by anti-CTLA-4 compared to vehicle but no increase was observed when combining anti-CTLA-4 with GPB730.

In conclusion, STAT3 inhibition by GPB730 enhances the antitumoral activity of anti-CTLA-4 and decreases the intratumoral Treg frequency in a prostate cancer mouse model. These results support the combination of STAT3 inhibition with anti-CTLA-4 therapy to increase clinical responses in patients with prostate cancer.

Progress and Challenges of Predictive Biomarkers for Immune Checkpoint Blockade

Over the past decade, immune checkpoint blockade (ICB) therapy has revolutionized the outlook for oncology with significant and sustained improvement in the overall patient survival. Unlike traditional cancer therapies, which target the cancer cells directly, ICB acts on the immune system to enhance anti-tumoral immunity. However, the response rate is still far from satisfactory and most patients are refractory to such treatment. Unfortunately, the mechanisms underlying such heterogeneous responses between patients to ICB therapy remain unclear. In addition, escalating costs of cancer care and unnecessary immune-related adverse events also are pertinent considerations with applications of ICB. Given these issues, identifying explicit predictive biomarkers for patient selection is an urgent unmet need to increase the efficacy of ICB therapy. The markers can be classified as tumor related and non-tumor-related biomarkers. Although substantial efforts have been put into investigating various biomarkers, none of them has been found to be sufficient for effectively stratifying patients who may benefit from immunotherapy. The present write up is an attempt to review the various emerging clinically relevant biomarkers affecting the efficacy of immune checkpoint inhibitors, as well as the limitations associated with their clinical application.

Identification of immune checkpoint and cytokine signatures associated with the response to immune checkpoint blockade in gastrointestinal cancers

Immune checkpoint blockade (ICB) of the programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) immune checkpoint pathway has led to unprecedented advances in cancer therapy. However, the overall response rate of anti-PD-1/PD-L1 monotherapy is still unpromising, underscoring the need for predictive biomarkers. In this retrospective study, we collected pretreatment plasma samples from two independent cohorts of patients receiving ICB. To determine whether a signature of plasma cytokines could be associated with therapeutic efficacy, we systemically profiled cytokine clusters and functional groups in the discovery and validation datasets by using 59 multiplexed bead immunoassays and bioinformatics analysis. We first attempted to functionally classify the 59 immunological factors according to their biological classification or functional roles in the cancer-immunity cycle. Surprisingly, we observed that two signatures, the "checkpoint signature" and "trafficking of T-cell signature", were higher in the response subgroup than in the nonresponse subgroup in both the discovery and validation cohorts. Moreover, enrichment of the "checkpoint signature" was correlated with improved overall survival and progression-free survival in both datasets. In addition, we demonstrated that increased baseline levels of three checkpoint molecules (PD-L1, T-cell immunoglobulin mucin receptor 3 and T-cell-specific surface glycoprotein CD28) were common peripheral responsive correlates in both cohorts, thus rendering this "refined checkpoint signature" an ideal candidate for future verification. In the peripheral blood system, the "refined checkpoint signature" may function as a potential biomarker for anti-PD-1/PD-L1 monotherapy in gastrointestinal (GI) cancers.

Downregulating testosterone levels enhance immunotherapy efficiency

Low response rates to certain tumor types remain a major challenge for immune checkpoint blockade therapy. In this study, we first conducted an integrated biomarker evaluation of bladder cancer patients from confirmatory cohorts (IMvigor210) and found that no significant differences exist between sexes before acceptance of anti-PD-L1 treatment, whereas male patients showed a better response. Thus, we then focused on sex-related changes post anti-PD-L1 treatment and found no obvious impact on the gut microbiota in male mice but a significant decrease in the sex hormone levels. Further, castration dramatically enhanced the antitumor efficacy against murine colon adenocarcinoma in male mice. Moreover, a narrow-spectrum antibiotic, colistin was innovatively used for deregulation of testosterone levels to enhance the immunotherapy efficiency in male mice. These findings indicate that the impact on the sex hormone levels in males may contribute to the sexual dimorphism in response and provide a promising way to enhance immunotherapy efficiency.

Integrating Circulating Biomarkers in the Immune Checkpoint Inhibitor Treatment in Lung Cancer

Simple Summary

Immune checkpoint inhibitors (ICI) are now a cornerstone of treatment for non-small cell lung cancer (NSCLC). Despite reporting tremendous results for some patients, ICI efficacy remains reserved to a subgroup that is not yet fully characterized. Tissue based assays, such as Programmed cell death protein 1 (PD-L1) expression may enrich the responder population, but this biomarker is not always available or reliable, as responses have been observed in patients with negative PD-L1. Blood markers are hoped to be easier to access and follow, and to give an insight on patient’s immune status and tumor as well. To date, several papers have been looking for circulating biomarkers that are focused on tumor cells or host specific or general immunity in NSCLC treated with ICI. In this article, we review these circulating biomarkers in peculiar circulating immune cell, tumor related cell and soluble systemic marker. We describe the available data and comment on the technical requirements and limits of these promising techniques.

Abstract

Immune checkpoint inhibitors are now a cornerstone of treatment for non-small cell lung cancer (NSCLC). Tissue-based assays, such as Programmed cell death protein 1 (PD-L1) expression or mismatch repair deficiency/microsatellite instability (MMRD/MSI) status, are approved as treatment drivers in various settings, and represent the main field of research in biomarkers for immunotherapy. Nonetheless, responses have been observed in patients with negative PD-L1 or low tumor mutational burden. Some aspects of biomarker use remain poorly understood and sub-optimal, in particular tumoral heterogeneity, time-evolving sampling, and the ability to detect patients who are unlikely to respond. Moreover, tumor biopsies offer little insight into the host’s immune status. Circulating biomarkers offer an alternative non-invasive solution to address these pitfalls. Here, we summarize current knowledge on circulating biomarkers while using liquid biopsies in patients with lung cancer who receive treatment with immune checkpoint inhibitors, in terms of their potential as being predictive of outcome as well as their role in monitoring ongoing treatment. We address host biomarkers, notably circulating immune cells and soluble systemic immune and inflammatory markers, and also review tumor markers, including blood-based tumor mutational burden, circulating tumor cells, and circulating tumor DNA. Technical requirements are discussed along with the current limitations that are associated with these promising biomarkers.

Peripheral cytokine levels as predictive biomarkers of benefit from immune checkpoint inhibitors in cancer therapy

Currently, only a small subset of cancer patients can benefit from anti-PD-1/PD-L1 monotherapy, indicating that further predictive biomarkers are needed. In the retrospective study, plasma samples were collected before anti-PD-L1/PD-L1 treatment in two subsets of patients. A total of 59 immunological factors, including cytokines, chemokines, and soluble immune checkpoints, were measured by using a multiplex immunoassay kit. Moreover, multiplex immunohistochemistry (mIHC) was performed in a subgroup of patients. In the discovery cohort, multiplex immunoassay profiling data revealed that both soluble PD-L1 and C-C motif chemokine 5 (CCL5/RANTES) showed rising trends across the three subgroups PD, SD and CR/PR. Further investigation demonstrated the predictive and prognostic value of the pre-treatment levels of PD-L1, CCL5/RANTES, and their combinatorial signature the "2-cytokine signature". As expected, the signature-high patients displayed a remarkably increased disease control rate (DCR) and prolonged survival versus that of the lower subgroup. More importantly, the relevance between the three signatures and the efficiency of immunotherapy was confirmed in the pan-cancer validation cohort. Notably, the significant association between the "2-cytokine signature" and longer survival was validated. Further quantitative analyses of the tumor microenvironment composition suggested a link between the "2-cytokine signature" and NK cell infiltration. In conclusion, a combined peripheral signature comprising CCL5/RANTES and soluble PD-L1 appears to be an effective biomarker to predict benefit from anti-PD-1/PD-L1 monotherapy. Our study underscores that peripheral immunological features may play an essential role in guiding patient selection and are worthy of future prospective investigations.