Immunotherapy in extensive small cell lung cancer

Nucleic acid-sensing-related gene signature in predicting prognosis and treatment efficiency of small cell lung cancer patients

Introduction

Nucleic acid-sensing (NAS) pathways could induce innate and adaptive immune responses. However, rare evidence exhibited how the core genes of the NAS pathways affected the immune response and prognosis of small cell lung cancer (SCLC) patients.

Methods

We conducted a comprehensive bioinformatic analysis based on the RNA profiles of 114 SCLC patients, including 79 from cBioPortal, 21 from GSE30219, and 14 from our sequencing data. The multiplex immunohistochemistry (mIHC) was used to characterize the role of NAS related genes in the tumor microenvironment (TME) of SCLC.

Results

A prognostic model (7NAS risk model) was constructed based on 7 NAS-related genes which was demonstrated as an independent prognostic index. The low-risk group was identified to have a better prognosis and an immune-activated microenvironment in both the public datasets and our dataset. Intriguingly, mIHC data showed that CD45+ immune cells, CD8+ T lymphocytes, and CD68+ macrophages were prevalently enriched in low-risk SCLC patients and positively correlated with IRF1 expression. Additionally, Patients in the low-risk group might have superior responses to chemotherapy and immunotherapy.

Conclusion

Conclusively, this study created a new risk model based on genes associated with NAS pathways which could predict the prognosis and response of treatment in patients with SCLC.

Single cell and bulk RNA sequencing identifies tumor microenvironment subtypes and chemoresistance-related IGF1+ cancer-associated fibroblast in gastric cancer

BACKGROUND

The tumor microenvironment (TME) significantly influences prognosis and drug resistance in various tumors, yet its heterogeneity and the mechanisms affecting therapeutic response remain unclear in gastric cancer (GC).

METHODS

The heterogenous TME were explored with single-cell RNA-sequencing (scRNA-seq) data of 50 primary GC samples. We then identified four GC TME subtypes with nonnegative matrix factorization (NMF) and constructed a pearson nearest-centroid classifier based on subtype-specific upregulated genes. Genomic features and clinical significance of four subtypes were comprehensively evaluated. We reclustered fibroblasts to identify cancer-associated fibroblast (CAF) subtype associated with poor clinical outcomes. RT-qPCR and double immunofluorescence staining were applied to validate the findings. Cellchat analysis elucidated potential molecular mechanisms of the CAF subtype in GC disease progression and chemotherapy resistance.

FINDINGS

The GC TME exhibited high heterogeneity, influencing chemo-sensitivity. Four TME-based subtypes predicting response to immunotherapy and chemotherapy were identified and validated in 1406 GC patients. Among which, ISG1 subtype displayed higher fibroblasts infiltration and heightened oncogenic pathways, and inferior response to chemotherapy with unfavorable prognosis. Microsatellite instability-high (MSI-H) GCs within four TME subtypes showed immunological heterogeneity. We then reported an IGF1-overexpressing CAF was associated with chemo-resistance and GC recurrence. Cell communication analysis revealed IGF1+ CAF may induce drug-resistant phenotypes in tumor cells through IGF1-α6β4 integrin ligand-receptor binding and activation of EMT biological process.

INTERPRETATION

We identified four TME-based subtypes with different clinical outcomes and IGF1+ CAFs contributing to poor clinical outcomes in GC, which might provide guidance for individualized treatment and facilitate the development of novel therapeutic targets.

Cost-effectiveness analysis of serplulimab combination therapy versus chemotherapy alone for patients with extensive-stage small cell lung cancer

Background

Serplulimab has shown promising results in the treatment of extensive-stage small cell lung cancer (ES-SCLC). This study aimed to evaluate the cost-effectiveness of serplulimab combination therapy compared to chemotherapy alone in patients with ES-SCLC from the Chinese healthcare system perspective.

Methods

A partitioned survival model was developed to simulate the costs and outcomes of patients receiving serplulimab combination therapy or chemotherapy alone over a time horizon of 10 years. Data on overall survival, progression-free survival, and adverse events were obtained from the ASTRUM-005 randomized clinical trial. Costs were estimated from a healthcare system perspective and included drug acquisition, administration, monitoring, and management of adverse events. One-way and probabilistic sensitivity analyses were conducted to assess the impact of uncertainty on the results.

Results

The base-case analysis showed that the combination of serplulimab and chemotherapy has demonstrated a significant increase in QALYs of 0.626 compared to chemotherapy alone. This improved outcome is accompanied by an additional cost of $10893.995. The ICER for incorporating serplulimab into the treatment regimen is $17402.548 per QALY gained. One-way sensitivity analysis confirmed the robustness of the findings. Probabilistic sensitivity analysis demonstrated that serplulimab combination therapy had a 97.40% high probability of being cost-effective compared to chemotherapy alone at the WTP thresholds.

Conclusion

In contrast to chemotherapy as a standalone treatment, the addition of serplulimab to chemotherapy is believed to offer potential cost-effectiveness as a preferred initial therapeutic approach for patients with ES-SCLC in China.

Isotoosendanin exerts inhibition on triple-negative breast cancer through abrogating TGF-β-induced epithelial-mesenchymal transition via directly targeting TGFβR1

As the most aggressive breast cancer, triple-negative breast cancer (TNBC) is still incurable and very prone to metastasis. The transform growth factor β (TGF-β)-induced epithelial-mesenchymal transition (EMT) is crucially involved in the growth and metastasis of TNBC. This study reported that a natural compound isotoosendanin (ITSN) reduced TNBC metastasis by inhibiting TGF-β-induced EMT and the formation of invadopodia. ITSN can directly interact with TGF-β receptor type-1 (TGFβR1) and abrogated the kinase activity of TGFβR1, thereby blocking the TGF-β-initiated downstream signaling pathway. Moreover, the ITSN-provided inhibition on metastasis obviously disappeared in TGFβR1-overexpressed TNBC cells in vitro as well as in mice bearing TNBC cells overexpressed TGFβR1. Furthermore, Lys232 and Asp351 residues in the kinase domain of TGFβR1 were found to be crucial for the interaction of ITSN with TGFβR1. Additionally, ITSN also improved the inhibitory efficacy of programmed cell death 1 ligand 1 (PD-L1) antibody for TNBC in vivo via inhibiting the TGF-β-mediated EMT in the tumor microenvironment. Our findings not only highlight the key role of TGFβR1 in TNBC metastasis, but also provide a leading compound targeting TGFβR1 for the treatment of TNBC metastasis. Moreover, this study also points out a potential strategy for TNBC treatment by using the combined application of anti-PD-L1 with a TGFβR1 inhibitor.

Heterogeneous distribution pattern of CD3+ tumor-infiltrated lymphocytes (TILs) and high combined positive score (CPS) favored the prognosis of resected early stage small-cell lung cancer

PURPOSE

This study aimed to illustrate the heterogeneity of immune features in small cell lung cancer (SCLC).

METHODS

Immunohistochemistry (IHC) staining of CD3, CD4, CD8 and PD-L1 were performed with 55 SCLC FFPE samples from radical resections. Quantitative assessment of CD3+ tumor-infiltrated lymphocytes (TILs) to present the heterogeneity in the tumor and the stroma areas. Hotspots of TILs were evaluated to illustrate the potential relationship between TIL-density and its immune competence. Programmed death ligand-1 (PD-L1) expressed on both tumor TILs (t-TILs) and stroma TILs (s-TILs) was evaluated and quantitatively described as values of tumor positive score (TPS) and combined positive score (CPS). The clinical value of TPS and CPS were further identified according to their relationship with disease-free survival (DFS).

RESULTS

More abundant CD3+ TILs were observed in the tumor stroma than that within the parenchyma (15.02±2.25% vs. 1.58±0.35%) . The amount of CD3+ s-TILs were positively correlated with DFS. The CD3+/CD4+ subset of the TILs was found more favorable to DFS compared to the CD3+/CD8+ subset. Hotspots of CD3+ TILs were observed in tumor regions and patients with more Hotspots of CD3+ TILs have better outcomes. CPS were more reliable than TPS to describe PD-L1 expression in SCLC and it was found positively correlated with tumor size and DFS.

CONCLUSIONS

The immune microenvironment of SCLC was heterogeneous. Hotspots, the amount of CD3/CD4+ TILs and the CPS value were found valuable in determine the anti-tumor immunity and predicting the clinical outcome of SCLC patients.

Ligand-independent EphA2 contributes to chemoresistance in small-cell lung cancer by enhancing PRMT1-mediated SOX2 methylation

Chemoresistance is the crux of clinical treatment failure of small-cell lung cancer (SCLC). Cancer stem cells play a critical role in therapeutic resistance of malignant tumors. Studies have shown that the role of erythropoietin-producing hepatocellular A2 (EphA2) in tumors is complex. This study aimed to test the hypothesis that ligand-independent activation of EphA2 modulates chemoresistance by enhancing stemness in SCLC. We verified that EphA2 was activated in chemoresistance sublines in a ligand-independent manner rather than a ligand-dependent manner. Ligand-independent EphA2 enhanced the expression of stemness-associated biomarkers (CD44, Myc, and SOX2), accelerated epithelial-mesenchymal transition (EMT) and reinforced self-renewal to drive the chemoresistance of SCLC, while the P817H mutant EphA2 neutralized intrinsic function. Co-immunoprecipitation (co-IP) and GST-pull down experiments were conducted to verify that EphA2 directly interacted with PRMT1. Moreover, EphA2 increased the expression and activity of PRMT1. Whereafter, PRMT1 interacted with and methylated SOX2 to induce stemness and chemoresistance in SCLC. Pharmacological inhibition of EphA2 showed a synergistic anti-tumor effect with chemotherapy in preclinical models, including patient-derived xenograft (PDX) models. These findings highlight, for the first time, that the EphA2/PRMT1/SOX2 pathway induces chemoresistance in SCLC by promoting stemness. EphA2 is a potential therapeutic target in SCLC treatment.

Efficacy of PD-1/PD-L1 plus CTLA-4 inhibitors in solid tumors based on clinical characteristics: a meta-analysis

Aims: To clarify the relationship between the potency of dual blockade of PD-1 or its ligand (PD-L1) plus CTLA-4 and patients with different clinical characteristics with solid tumors, the authors performed this meta-analysis. Patients & methods: 12 randomized clinical trials containing 7056 patients were included after the literature was filtered. Results: Dual blockade substantially enhanced overall survival and progression-free survival compared with standard of care, especially in patients aged <65 years old, those 65-74 years old, those with a smoking history, members of the White population and those with a high tumor mutation burden. Conclusion: Dual blockade therapy significantly improved patient survival outcomes. Age, smoking history, race and tumor mutation burden might be used to predict the potency of dual blockade therapy in solid tumors.

Interpretable deep learning survival predictive tool for small cell lung cancer

Background

Small cell lung cancer (SCLC) is an aggressive and almost universally lethal neoplasm. There is no accurate predictive method for its prognosis. Artificial intelligence deep learning may bring new hope.

Methods

By searching the Surveillance, Epidemiology, and End Results database (SEER), 21,093 patients' clinical data were eventually included. Data were then divided into two groups (train dataset/test dataset). The train dataset (diagnosed in 2010-2014, N = 17,296) was utilized to conduct a deep learning survival model, validated by itself and the test dataset (diagnosed in 2015, N = 3,797) in parallel. According to clinical experience, age, sex, tumor site, T, N, M stage (7th American Joint Committee on Cancer TNM stage), tumor size, surgery, chemotherapy, radiotherapy, and history of malignancy were chosen as predictive clinical features. The C-index was the main indicator to evaluate model performance.

Results

The predictive model had a 0.7181 C-index (95% confidence intervals, CIs, 0.7174-0.7187) in the train dataset and a 0.7208 C-index (95% CIs, 0.7202-0.7215) in the test dataset. These indicated that it had a reliable predictive value on OS for SCLC, so it was then packaged as a Windows software which is free for doctors, researchers, and patients to use.

Conclusion

The interpretable deep learning survival predictive tool for small cell lung cancer developed by this study had a reliable predictive value on their overall survival. More biomarkers may help improve the prognostic predictive performance of small cell lung cancer.

Efficacy and safety of PD-1/PD-L1 plus CTLA-4 antibodies ± other therapies in lung cancer: a systematic review and meta-analysis

PURPOSE

To investigate the efficacy and safety of programmed cell death 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) plus cytotoxic T lymphocyte antigen-4 (CTLA-4) antibodies ± other therapies in patients with advanced lung cancer.

METHODS

In accordance with the retrieval strategy, we searched electronic databases for randomised controlled trials testing PD-1/PD-L1 plus CTLA-4 antibodies in patients with lung cancer; RR (for objective response rate (ORR), overall survival (OS), progression-free survival (PFS), and immune-related adverse events (irAEs)) from individual studies were calculated and pooled by using random-effects models or fixed-effects models; heterogeneity and publication bias analyses were also performed, using Review Manager 5.3 and Stata 15.1 for statistical analysis.

RESULTS

We included six studies. Four different immune checkpoint inhibitors (nivolumab, pembrolizumab, durvalumab, tremelimumab) were used. Dual checkpoint inhibitors ± other therapies for advanced lung cancer showed significant improvements in ORR (RR 1.49, 95% CI 1.11 to 1.98; p=0.007), OS (HR 0.72, 95% CI 0.63 to 0.83; p<0.00001), and PFS (HR 0.72, 95% CI 0.63 to 0.82; p<0.00001). The subgroup analyses were consistent with the pooled results. The PD-L1 ≥1% (HR 0.67, 95% CI 0.54 to 0.82; p<0.0001) subgroup differences indicated a statistically significant subgroup effect, but the PD-L1 <1% subgroup (HR 0.88, 95% CI 0.75 to 1.05; p=0.15) was not statistically significant. The incidence of adverse events (grade ≥3) was lower than that of the control group (RR 0.90, 95% CI 0.80 to 1.02; p=0.09), but was not significant.

CONCLUSIONS

PD-1/PD-L1 inhibitors combined with CTLA-4 inhibitors ± other therapies can improve the ORR, OS and PFS of patients with advanced or metastatic lung cancer, but the incidence of adverse reactions is high although generally tolerable.

PROSPERO REGISTRATION

CRD42020149216.

Investigation of poor predictive factors in extensive stage small cell lung cancer under etoposide-platinum-atezolizumab treatment

BACKGROUND

The phase III trial IMpower133 showed that platinum and etoposide plus atezolizumab was associated with improved overall survival (OS) and progression free-survival (PFS) when compared to the placebo group in treatment-naïve extensive stage (ES) small cell lung cancer (SCLC). Due to superiority in clinical outcomes, combination immunotherapy plus chemotherapy have become mainstay treatment modalities as first-line treatment in ES-SCLC. Nevertheless, real-world data are still lacking and the search for potential biomarkers is essential. This study aimed to evaluate potential predictive biomarkers applicable in ES-SCLC under combination therapy.

METHODS

Patients with ES-SCLC under etoposide-platinum-atezolizumab enrolled from seven university hospitals affiliated to the Catholic University of Korea were evaluated. Pretreatment clinical parameters were evaluated for association with OS and PFS. Adverse events (AEs) during induction and maintenance phases were also evaluated. p-values below 0.05 were considered statistically significant.

RESULTS

A total of 41 patients were evaluated. Six-month survival was 68.6%. As best response to treatment, 26 (63.4%) showed partial response, nine (22.0%) showed stable disease, and four (9.8%) showed progressive disease. During the induction phase, grade I-II AEs occurred in 22 (53.7%) patients, and grade III-IV AEs occurred in 26 (63.4%) patients. During the maintenance phase, nine out of 25 (36.0%) patients experienced any grade AEs. In multivariate analysis for OS, lactate dehydrogenase (LDH), c-reactive protein (CRP), and forced vital capacity (%) were significant factors. In multivariate analysis for PFS, sex, and LDH were significant.

CONCLUSION

In ES-SCLC under etoposide-platinum-atezolizumab, pretreatment CRP, LDH and FVC (%) were independent predictive factors.

Advanced age is not the decisive factor in chemotherapy of small cell lung cancer: a population-based study

OBJECTIVE

There is limited research on the impact of chemotherapy on the prognosis of different age group patients with small cell lung cancer (SCLC). The aim of this study was to explore the impact of chemotherapy on survival prognosis of elderly patients with SCLC.

METHODS

Based on the Surveillance, Epidemiology and End Results (SEER) database, 57,460 SCLC patients between 2004 and 2015 were identified and divided into a ≤ 80 years group (n = 50,941) and a >80 years group (n = 6,519). Confounding factors were controlled by propensity score matching (PSM) analysis. Kaplan Meier (KM) analysis was performed to determine the impact of chemotherapy on overall survival (OS) and lung-cancer specific survival (LCSS) of the patients. Other variables that could affect survival of SCLC patients were also examined by COX analysis.

RESULTS

KM analysis showed that both OS and LCSS were improved in chemotherapy group compared to those in non-chemotherapy group (log rank P < 0.001) in both age groups after PSM. Cox analysis demonstrated the survival benefit of chemotherapy in both ≤ 80 years group (OS: HR 0.435; 95% CI 0.424-0.447; LCSS: HR 0.436; 95% CI 0.424-0.448) and >80 years group (OS: HR 0.424; 95% CI 0.397-0.451; LCSS: HR 0.415; 95% CI 0.389-0.444). Additionally, the following parameters had a negative impact on survival of elderly patients: male sex, tumor location in main bronchus, increased stage, bilateral tumor, no surgery or radiation, and lower median household income.

CONCLUSIONS

Elderly patients with SCLC should be encouraged to receive chemotherapy provided their general conditions permit.

19-Hydroxybufalin inhibits non-small cell lung cancer cell proliferation and promotes cell apoptosis via the Wnt/β-catenin pathway

Background

Bufadienolides derived from the skin of toads are often regarded as the main active components with antitumor effects. 19-Hydroxybufalin (19-HB) is a monomer of bufadienolides; however, its effects and underlying molecular mechanisms on tumor growth remain to be ascertained. In this report, we focused on the antitumor effects of 19-HB on non-small cell lung cancer to provide a scientific basis for its further development and utilization.

Methods

The antitumor effects of 19-HB on the human NSCLC cell lines NCI-H1299 and NCI-H838 were examined in vitro. The cells were treated with different concentrations of 19-HB, and the inhibition of cell growth was measured by CCK-8 and colony formation assays. Furthermore, cell apoptosis was analyzed by flow cytometry, TUNEL staining, JC-1 staining, and western blotting. The effects on migration and invasion were evaluated by wound-healing assay, transwell assay, and western blotting. Finally, the antitumor effects of 19-HB were evaluated in vivo using a xenograft mouse model.

Results

19-HB-treated NSCLC cells showed inhibited cell viability and increased apoptosis. The expression levels of cleaved caspase-3, cleaved-PARP, and Bax/Bcl-2 were upregulated, while the mitochondrial membrane potential decreased. In contrast, migration, invasion, as well as the expression of MMP2, MMP7, MMP9, the epithelial–mesenchymal transition-related proteins N-cadherin and Vimentin, and the transcription factors Snail and Slug were inhibited. Furthermore, the expression levels of the key molecules in the Wnt/β-catenin signaling pathway (CyclinD1, c-Myc, and β-catenin) were decreased. In vivo, the growth of xenograft tumors in nude mice was also significantly inhibited by 19-HB, and there were no significant changes in biochemical indicators of hepatic and renal function.

Conclusions

19-HB inhibited the proliferation, migration, and invasion, and promoted the apoptosis of NSCLC cells via the Wnt/β-catenin pathway. In addition, 19-HB inhibited the growth of xenograft tumors in nude mice with little toxicity to the liver and kidney. Thus, 19-HB may be a potential antitumor agent for treating NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40164-021-00243-0.

Combine and conquer: manganese synergizing anti-TGF-β/PD-L1 bispecific antibody YM101 to overcome immunotherapy resistance in non-inflamed cancers

BACKGROUND

Our previous work showed that the anti-TGF-β/PD-L1 bispecific antibody YM101 effectively overcame anti-PD-L1 resistance in immune-excluded tumor models. However, in immune-desert models, the efficacy of YM101 was limited. Bivalent manganese (Mn2+) is identified as a natural stimulator of interferon genes (STING) agonist, which might enhance cancer antigen presentation and improve the therapeutic effect of YM101.

METHODS

The effect of Mn2+ on STING pathway was validated by western blotting and enzyme-linked immunosorbent assay. Dendritic cell (DC) maturation was measured by flow cytometry. The synergistic effect between Mn2+ and YM101 in vitro was determined by one-way mixed lymphocyte reaction, CFSE dilution assay, and cytokine detection. The in vivo antitumor effect of Mn2+ plus YM101 therapy was assessed in CT26, EMT-6, H22, and B16 tumor models. Flow cytometry, RNA-seq, and immunofluorescent staining were adopted to investigate the alterations in the tumor microenvironment.

RESULTS

Mn2+ could activate STING pathway and promote the maturation of human and murine DC. The results of one-way mixed lymphocyte reaction showed that Mn2+ synergized YM101 in T cell activation. Moreover, in multiple syngeneic murine tumor models, Mn2+ plus YM101 therapy exhibited a durable antitumor effect and prolonged the survival of tumor-bearing mice. Relative to YM101 monotherapy and Mn2+ plus anti-PD-L1 therapy, Mn2+ plus YM101 treatment had a more powerful antitumor effect and a broader antitumor spectrum. Mechanistically, Mn2+ plus YM101 strategy simultaneously regulated multiple components in the antitumor immunity and drove the shift from immune-excluded or immune-desert to immune-inflamed tumors. The investigation in the TME indicated Mn2+ plus YM101 strategy activated innate and adaptive immunity, enhanced cancer antigen presentation, and upregulated the density and function of tumor-infiltrating lymphocytes. This normalized TME and reinvigorated antitumor immunity contributed to the superior antitumor effect of the combination therapy.

CONCLUSION

Combining Mn2+ with YM101 has a synergistic antitumor effect, effectively controlling tumor growth and prolonging the survival of tumor-bearing mice. This novel cocktail strategy has the potential to be a universal regimen for inflamed and non-inflamed tumors.

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.

Emerging Lab-on-a-Chip Approaches for Liquid Biopsy in Lung Cancer: Status in CTCs and ctDNA Research and Clinical Validation

Simple Summary

Lung cancer (LCa) remains the leading cause of cancer-related mortality worldwide, with late diagnosis and limited therapeutic approaches still constraining patient’s outcome. In recent years, liquid biopsies have significantly improved the disease characterization and brought new insights into LCa diagnosis and management. The integration of microfluidic devices in liquid biopsies have shown promising results regarding circulating biomarkers isolation and analysis and these tools are expected to establish automatized and standardized results for liquid biopsies in the near future. Herein, we review the status of lab-on-a-chip approaches for liquid biopsies in LCa and highlight their current applications for circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) research and clinical validation studies.

Abstract

Despite the intensive efforts dedicated to cancer diagnosis and treatment, lung cancer (LCa) remains the leading cause of cancer-related mortality, worldwide. The poor survival rate among lung cancer patients commonly results from diagnosis at late-stage, limitations in characterizing tumor heterogeneity and the lack of non-invasive tools for detection of residual disease and early recurrence. Henceforth, research on liquid biopsies has been increasingly devoted to overcoming these major limitations and improving management of LCa patients. Liquid biopsy is an emerging field that has evolved significantly in recent years due its minimally invasive nature and potential to assess various disease biomarkers. Several strategies for characterization of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA) have been developed. With the aim of standardizing diagnostic and follow-up practices, microfluidic devices have been introduced to improve biomarkers isolation efficiency and specificity. Nonetheless, implementation of lab-on-a-chip platforms in clinical practice may face some challenges, considering its recent application to liquid biopsies. In this review, recent advances and strategies for the use of liquid biopsies in LCa management are discussed, focusing on high-throughput microfluidic devices applied for CTCs and ctDNA isolation and detection, current clinical validation studies and potential clinical utility.

The construction, expression, and enhanced anti-tumor activity of YM101: a bispecific antibody simultaneously targeting TGF-β and PD-L1

Background

Therapeutic antibodies targeting programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis induce potent and durable anti-tumor responses in multiple types of cancers. However, only a subset of patients benefits from anti-PD-1/PD-L1 therapies. As a negative regulator of anti-tumor immunity, TGF-β impairs the efficacy of anti-PD-1/PD-L1 and induces drug resistance. Developing a novel treatment strategy to simultaneously block PD-1/PD-L1 and TGF-β would be valuable to enhance the effect of anti-PD-1/PD-L1 and relieve drug resistance.

Methods

Based on the Check-BODY™ technology platform, we developed an anti-TGF-β/PD-L1 bispecific antibody YM101. The bioactivity of the anti-TGF-β moiety was determined by Smad-luciferase reporter assay, transwell assay, western blotting, CCK-8, and flow cytometry. The bioactivity of the anti-PD-L1 moiety was measured by T cell activation assays. EMT-6, CT26, and 3LL tumor models were used to investigate the anti-tumor activity of YM101 in vivo. RNA-seq, immunohistochemical staining, and flow cytometry were utilized to analyze the effect of YM101 on the tumor microenvironment.

Results

YM101 could bind to TGF-β and PD-L1 specifically. In vitro experiments showed that YM101 effectively counteracted the biological effects of TGF-β and PD-1/PD-L1 pathway, including activating Smad signaling, inducing epithelial-mesenchymal transition, and immunosuppression. Besides, in vivo experiments indicated the anti-tumor activity of YM101 was superior to anti-TGF-β and anti-PD-L1 monotherapies. Mechanistically, YM101 promoted the formation of ‘hot tumor’: increasing the numbers of tumor infiltrating lymphocytes and dendritic cells, elevating the ratio of M1/M2, and enhancing cytokine production in T cells. This normalized tumor immune microenvironment and enhanced anti-tumor immune response might contribute to the robust anti-tumor effect of YM101.

Conclusion

Our results demonstrated that YM101 could simultaneously block TGF-β and PD-L1 pathways and had a superior anti-tumor effect compared to the monotherapies.

Prolonging Survival: The Role of Immune Checkpoint Inhibitors in the Treatment of Extensive-Stage Small Cell Lung Cancer

BACKGROUND

Small cell lung cancer (SCLC) represents approximately 15% of lung cancers, and approximately 70% are diagnosed as extensive-stage SCLC (ES-SCLC). Although ES-SCLC is highly responsive to chemotherapy, patients typically progress rapidly, and there is an urgent need for new therapies. Immune checkpoint inhibitors (ICIs) have recently been investigated in SCLC, and this review provides guidance on the use of these agents in ES-SCLC based on phase III evidence.

METHODS

Published and presented literature on phase III data addressing use of ICIs in ES-SCLC was identified using the key search terms "small cell lung cancer" AND "checkpoint inhibitors" (OR respective aliases). Directed searches of eligible studies were periodically performed to ensure capture of the most recent data.

RESULTS

Six phase III trials were identified, with four assessing the benefits of ICIs plus chemotherapy first-line, one evaluating ICIs as first-line therapy maintenance, and one assessing ICI monotherapy after progression on platinum-based chemotherapy. The addition of ipilimumab or tremelimumab to first-line treatment or as first-line maintenance did not improve survival. Two out of three studies combining PD-1/PD-L1 inhibitors with first-line platinum-based chemotherapy demonstrated significant long-lasting survival benefits and improved quality of life with no unexpected safety concerns. PD-1/PD-L1 inhibitors as first-line maintenance or in later lines of therapy did not improve survival. Biomarker research is ongoing as well as research into the role of ICIs in combination with radiation therapy in limited-stage SCLC.

CONCLUSION

The addition of atezolizumab or durvalumab to first-line platinum-based chemotherapy for ES-SCLC prolongs survival and improves quality of life.

IMPLICATIONS FOR PRACTICE

Platinum-based chemotherapy has been standard of care for extensive-stage small cell lung cancer (ES-SCLC) for more than a decade. Six recent phase III trials investigating immune checkpoint inhibitors (ICIs) have clarified the role of these agents in this setting. Although ICIs were assessed first-line, as first-line maintenance, and in later lines of therapy, the additions of atezolizumab or durvalumab to first-line platinum-based chemotherapy were the only interventions that significantly improved overall survival and increased quality of life. These combinations should therefore be considered standard therapy for first-line ES-SCLC. Biomarker research and investigations into the role of ICIs for limited-stage disease are ongoing.

Interferon-Induced Transmembrane Protein 1 (IFITM1) Promotes Distant Metastasis of Small Cell Lung Cancer

Small cell lung cancer (SCLC) is a severe malignancy associated with early and widespread metastasis. To study SCLC metastasis, we previously developed an orthotopic transplantation model using the human SCLC cell line DMS273. In the model, metastatic foci were found in distant tissues such as bone and the adrenal gland, similarly as observed in patients with SCLC. In this study, we evaluated the differentially expressed genes between orthotopic and metastatic tumors in the model. We isolated tumor cells from orthotopic and metastatic sites, and the tumor cell RNA was analyzed using DNA microarray analysis. We found that 19 genes in metastatic tumors were upregulated by more than 4-fold compared with their expression in orthotopic tumors. One of these genes encodes a transmembrane protein, interferon (IFN)-induced transmembrane protein 1 (IFITM1), and immunohistochemical analysis confirmed the higher expression of the protein in metastatic sites than in orthotopic sites. IFITM1 was also detected in some SCLC cell lines and lung tumors from patients with SCLC. The overexpression of IFITM1 in DMS273 cells increased their metastatic formation in the orthotopic model and in an experimental metastasis model. Conversely, the silencing of IFITM1 suppressed metastatic formation by DMS273 cells. We also found that IFITM1 overexpression promoted the metastatic formation of NCI-H69 human SCLC cells. These results demonstrate that IFITM1 promotes distant metastasis in xenograft models of human SCLC.

Prognostic and Clinicopathological Value of Programmed Cell Death Ligand1 Expression in Patients With Small Cell Lung Cancer: A Meta-Analysis

Background: Programmed death-ligand 1 (PD-L1) is an immune checkpoint molecule expressed by cancer cells. Previous studies have demonstrated the prognostic role of PD-L1 expression in patients with small cell lung cancer (SCLC), where the results were inconsistent. Therefore, we conducted a meta-analysis to identify the prognostic impact of PD-L1 on SCLC.

Methods: We searched the PubMed, Embase, ISI Web of Science, and Cochrane Library databases for articles published before and on March 2nd, 2020. Data of PD-L1 expression in tumor cells detected using immunohistochemistry methods were extracted for analysis. Pooled hazard ratios (HRs) with confidence intervals (CIs) and odds ratios (ORs) with 95% CIs were calculated to assess the correlations among PD-L1, overall survival (OS), and clinicopathological factors.

Results: Nine studies of 921 patients published between 2015 and 2019 were included in this meta-analysis. The pooled data (HR = 0.91, 95% CI = 0.46–1.80, p = 0.787) indicated that PD-L1 expression is not a significant predictor of poor OS. Moreover, the results also revealed that PD-L1 expression is not significantly associated with gender (OR = 1.12, 95% CI = 0.73–1.74, p = 0.601), age (OR = 1.15, 95% CI = 0.58–2.30, p = 0.683), pN stage (OR = 0.65, 95% CI = 0.24–1.72, p = 0.381), pT stage (OR = 1.16, 95% CI = 0.26–5.23, p = 0.847), serum lactate dehydrogenase level (OR = 1.06, 95% CI = 0.13–8.43, p = 0.958), or performance status (OR = 0.69, 95% CI = 0.24–1.95, p = 0.479). No significant publication bias was detected in this meta-analysis.

Conclusions: This meta-analysis suggests that PD-L1 expression is not a significant prognostic factor of poor survival in SCLC. Because of significant variations, high-quality studies are needed to validate our results.

Metastatic Mixed Adenoneuroendocrine Carcinoma of the Colon with Response to Immunotherapy with Pembrolizumab: A Case Report

Mixed adenoneuroendocrine carcinoma (MANEC) is a rare, aggressive tumor arising from different localizations along the gastrointestinal tract with generally poor prognosis. We present the case of a 51-year-old female patient with histopathologically confirmed diagnosis of a MANEC of the descending colon. At presentation, the tumor had already spread to the liver causing extensive hepatic metastases. Immunohistochemical examination showed 5%-10% of tumor cells to express the programmed cell death receptor ligand 1 and FoundationOne testing revealed a high mutational tumor burden with 149 Muts/Mb. The patient responded very well clinically and radiologically to anti-programmed death 1 receptor monoclonal antibody pembrolizumab therapy after having undergone 3 previous systemic treatment regimens as well as selective internal radiation therapy of her hepatic metastases. Clinical improvement was evident after the first infusion already and is ongoing for 10 months so far with very little side effects including initial and short lived skin irritation as well as muscle pain. To our knowledge, this is the first published case where a MANEC was successfully treated with immunotherapy targeting the programmed death 1 receptor.

PD-L1 Expression in Small Cell and Large Cell Neuroendocrine Carcinomas of Lung: an Immunohistochemical Study with Review of Literature

High-grade neuroendocrine tumors (HGNET) have distinctive tumor biology/behaviour. Newer modalities of treatment (immunotherapy) for them have been included in recent NCCN guidelines. Detection of programmed death receptor-ligand 1 (PD-L1) expression by immunohistochemistry have made easy identification of patients eligible for immunotherapy. We aimed to ascertain expression of PD-L1 on small cell and large cell neuroendocrine carcinomas of lung and review existing literature. Eighty-five cases of HGNET lung (primary/metastatic), were retrieved and reviewed. Immunostaining for PD-L1 using clone SP263 was done. Any amount/intensity of membranous staining of > = 1% tumor cells was cut-off for positivity. Previously published studies using Google and/Pubmed search engines were reviewed. Of 85 cases, 70 were small-cell lung cancer (SCLC), 11 large-cell neuroendocrine carcinoma (LCNEC) and 4 combined SCLC. Median age was 46.5 years with male preponderance. No PD-L1 expression was seen in 91.6% cases. The 7 positive cases were 4 LCNEC, 2 SCLC and 1 combined SCLC. The percentage positivity varied from 1-100%; lower percentage positivity was seen in SCLC. PD-L1 expression on immune cells was seen in 31.3% cases. Sixteen studies evaluating 1992 NET were found; E1L3N PD-L1 clone was commonly used clone. PD-L1 positivity was associated with better prognosis in most studies. There are only a few studies available in literature related to PDL1 expression in high grade neuroendocrine carcinomas of lung. In general, PD-L1 positivity is highly variable and seen in lower percentage of these tumors. With the recent approval of immunotherapy, biomarkers other than PD-L1 should also be investigated in these tumors.

Overexpressed immunoglobulin-like transcript (ILT) 4 in lung adenocarcinoma is correlated with immunosuppressive T cell subset infiltration and poor patient outcomes

Background

The poor response to current PD-1/PD-L1 inhibitors in lung cancer patients requires development of novel immunotargets. Immunoglobulin-like transcript (ILT)4 is an immunosuppressive molecule mainly expressed in myeloid innate cells. Recent studies showed that ILT4 was highly expressed in multiple malignant cells and regulated tumor biologies including proliferation, invasion and metastasis. However, the immunomodulatory role of tumor cell-derived ILT4 is unclear. Here we aimed to analyze the correlation of tumor cell ILT4 expression with T cell infiltration and subset distribution, illustrate ILT4-regulated immunosuppressive microenvironment, and raise tumor cell-derived ILT4 as a novel immunotherapeutic target and prognostic biomarker for lung adenocarcinoma (LUAD) patients.

Methods

We collected the tissue samples and corresponding clinicopathological data from 216 primary LUAD patients. Using immunohistochemical staining and public database analyses we investigated the relationship between ILT4 expression and different T cell subset density as well as patient outcomes.

Results

Enriched ILT4 expression in tumor cells of LUAD tissues indicated reduced T cell infiltration in the tumor microenvironment (TME), advanced diseases and poor patient overall survival (OS). Further T cell subset analyses revealed that ILT4 expression was correlated with decreased CD8⁺T cell and increased Treg frequency in both cancer nest and stroma, but not with altered CD4⁺T cell frequency. High ILT4 level combined with low CD8⁺T cell/high Treg density predicted markedly poorer clinical outcomes compared with any of these biomarkers alone.

Conclusions

Tumor cell-derived ILT4 is correlated with immunosuppressive T cell subset infiltration and poor clinical outcomes, and might be a potential immunotherapeutic target and prognostic biomarker for LUAD patients. Combined ILT4 expression and CD8⁺ T cell/Treg frequency in tumor infiltrating lymphocytes (TILs) are stronger predictors for patient outcomes.

Chemotherapy treatments, costs of care, and survival for patients diagnosed with small cell lung cancer: A SEER-Medicare study

OBJECTIVES

The effectiveness and costs of new treatments should be assessed in relation to existing practice. We describe treatments, survival and costs for advanced or metastatic small cell lung cancer (SCLC) patients receiving systemic therapy in the period preceding the introduction of immunotherapies.

MATERIALS AND METHODS

This was a retrospective cohort study of patients aged ≥65 years, identified using linked Surveillance, Epidemiology, and End Results and Medicare databases. Individuals with a new primary diagnosis of SCLC between January 2007 and December 2013 were followed until December 2014. Chemotherapy treatments, health care visits and costs (in 2016 USD), and survival were determined by line of therapy.

RESULTS

A total of 11 812 patients were identified with SCLC. First-line (1L) chemotherapy was received by 6509 (55.1%) patients, most (93.2%) with carboplatin- (71.0%) or cisplatin- (22.2%) based therapies, typically combined with etoposide (79.2%). Second- (2L) and third- (3L) line chemotherapies were received by 2238 (18.9%) and 679 (5.7%) patients, of which 48.4% and 30.9%, respectively, were platinum-based. The median durations of 1L, 2L, and 3L carboplatin-based therapies were 5.9, 4.8, and 5.4 months, respectively, and the corresponding durations of cisplatin-based therapies were 5.3, 4.2, and 5.3 months. During 1L, 2L, and 3L chemotherapies, patients averaged 8.2, 7.4, and 7.3 health care visits per month, respectively, and incurred total mean health care costs of $60 223, $42 636, and $35 903 per patient, respectively. Median survival from the start of 1L, 2L, and 3L chemotherapy was 9.2, 6.0, and 5.7 months, respectively.

CONCLUSION

First-line chemotherapy was primarily platinum-based, and a plethora of different regimens was used for 2L and 3L chemotherapies. Median survival from the start of 1L chemotherapy was 9 months, with an associated health care cost of $60 000. These data highlight an unmet medical need among SCLC patients receiving systemic therapy.

YAP1 promotes multidrug resistance of small cell lung cancer by CD74-related signaling pathways

BACKGROUND

Our previous research found that YAP1 may have a role in multidrug resistance (MDR) in small cell lung cancer (SCLC). However, its underlying mechanism is unknown.

METHODS

In this study, we investigated the expression of YAP1 using immunohistochemical staining and assessed the relationship between the expression of YAP1 and overall survival in patients with SCLC. We established H69 stable cell lines that overexpressed constitutively active YAP1 and H446 stable cell lines that dominate negative YAP1. We conducted CCK-8, flow cytometric analysis, and in vivo chemosensitivity experiments to evaluate the function of YAP1 in drug sensitivity apoptosis in vitro and in vivo.

RESULTS

The results indicated that patients with high YAP1 expression have shorter survival rates and more advanced disease stage than those with low YAP1 expression. YAP1 may induce MDR by inhibiting the apoptosis of SCLC. YAP1 induced MDR when YAP1 was hyperactivated, and drug sensitivity increased when YAP1 was inhibited in vitro and in vivo. CD74 was significantly correlated with YAP1 in SCLC samples. Inhibition of CD74 using ISO-1 increased drug sensitivity significantly.

CONCLUSIONS

The expression of YAP1 is significantly correlated with overall survival and disease stage in patients with SCLC. YAP1 may play an important role in these patients. We were the first to report that YAP1 can induce MDR in SCLC in vitro and in vivo. CD74 may be involved in YAP1-induced MDR.

The Role of Immunotherapy in Extensive Stage Small-Cell Lung Cancer: A Review of the Literature

Lung cancer is the second most common cancer in both sexes worldwide. Small-cell lung cancer (SCLC) is a form of neuroendocrine tumor, which is classified into limited and extensive-stage disease and shows excellent initial response to chemotherapy; however, almost all patients relapse later. During the past few years, several clinical trials have evaluated the effect of addition of immunotherapy to conventional chemotherapy in patients with extensive SCLC. Checkpoint inhibitors are currently under investigation, especially the CTLA-4 and PD-1/PD-L1 inhibitors. Nowadays, evidence show a statistically significant survival benefit of adding atezolizumab, an IgG1 monoclonal antibody targeting against PD-L1, to platinum-based chemotherapy plus etoposide in patients who have not received any previous systemic therapy. Furthermore, the role of nivolumab, an IgG4 anti-PD-1 monoclonal antibody, is significant for the treatment of relapsed SCLC cases. Recently, pembrolizumab was the first immunotherapeutic agent to be approved by the FDA for patients with metastatic SCLC with disease progression on or after platinum-based chemotherapy and at least one other prior line of chemotherapy. Nevertheless, prognostic biomarkers to immunotherapy response remain to be discovered.

Immunotherapy in Small Cell Lung Cancer

Small-cell lung cancer (SCLC) is extremely sensitive to standard treatments, including conventional cytotoxic chemotherapies and radiotherapy, and has poor prognosis and short survival. Standard therapies have reached a plateau of effectiveness and new therapeutic strategies are needed to improve SCLC patient outcomes going forward. Immunotherapy has revolutionised the treatment of solid malignancies, offering a novel way to harness the host immune system to target malignant cells in patients whose disease may no longer respond to cytotoxic therapy. This review describes the available data for the checkpoint inhibitors, such as anti-cytotoxic T-lymphocyte antigen-4 protein (CTLA-4), anti-programmed cell death-1 protein receptor (PD-1), and ligands (PD-L1 and PD-L2) alone or in combination with first-line chemotherapy or in relapsed SCLC. Several trials investigating immunotherapy in SCLC patients are ongoing and the results are awaited soon. Moreover, further immune checkpoint inhibitors directed against other targets, such as the killer-cell immunoglobulin-like receptor and lymphocyte-activation gene-3, are in clinical development. Overall, the high expectations from the oncology community are that the drugs under development will offer new and improved treatment options for SCLC patients.

Emerging therapies for small cell lung cancer

Currently, chemotherapy remains the standard treatment for first- and second-line management of small cell lung cancer (SCLC). Immunotherapy has made progress in the treatment of SCLC, and nivolumab, pembrolizumab, atezolizumab, and durvalumab have led to significant improvements in clinical outcomes of SCLC. Regarding options in other classes of therapy, the cytotoxic drug lurbinectedin was granted orphan drug status based on a remarkable objective response rate of 39.3%. In addition, an increase in progression-free survival (PFS) was achieved in a phase II study of anlotinib (ALTER 1202). Future prospects for even better outcomes in SCLC lie in novel ways to integrate immunotherapy and small-molecule TKI drugs. Innovative clinical trial designs are needed to efficiently explore the increasing number of options with new drugs and new combinations thereof for SCLC.