Validation of a multiomic model of plasma extracellular vesicle PD-L1 and radiomics for prediction of response to immunotherapy in NSCLC.

BACKGROUND: Immune-checkpoint inhibitors (ICIs) have showed unprecedent efficacy in the treatment of patients with advanced non-small cell lung cancer (NSCLC). However, not all patients manifest clinical benefit due to the lack of reliable predictive biomarkers. We showed preliminary data on the predictive role of the combination of radiomics and plasma extracellular vesicle (EV) PD-L1 to predict durable response to ICIs. MAIN BODY: Here, we validated this model in a prospective cohort of patients receiving ICIs plus chemotherapy and compared it with patients undergoing chemotherapy alone. This multiparametric model showed high sensitivity and specificity at identifying non-responders to ICIs and outperformed tissue PD-L1, being directly correlated with tumor change. SHORT CONCLUSION: These findings indicate that the combination of radiomics and EV PD-L1 dynamics is a minimally invasive and promising biomarker for the stratification of patients to receive ICIs.

The Importance of Biomarker Testing in the Treatment of Advanced Non-Small Cell Lung Cancer: A Podcast.

The identification of actionable biomarkers and development of targeted therapies have revolutionized the field of lung cancer treatment. In patients with advanced non-small cell lung cancer (NSCLC), biomarker testing can inform selection of effective targeted therapies as well as avoid therapies that are less likely to be effective in certain populations. A growing number of actionable targets, including those involving EGFR, ALK, ROS1, BRAF, MET, KRAS, NTRK, RET, HER2, and PD-L1, can be identified with biomarker testing. More than half of patients with advanced NSCLC have tumors that harbor genetic alterations that can be targeted. When these patients are treated with targeted therapy, survival and quality of life may be significantly improved. In addition, broad-based molecular testing may detect alterations identifying patients who are potentially eligible for current or future clinical trials. Comprehensive biomarker testing rates in communities are often low, and turnaround times for results can be unacceptably long. There is an unmet need for widespread, efficient, and routine testing of all biomarkers recommended by clinical guidelines. New testing techniques and technologies can make this an attainable goal. Panel-based sequencing platforms are becoming more accessible, and molecular biomarker analysis of circulating tumor DNA is becoming more common. In this podcast, we discuss the importance of biomarker testing in advanced NSCLC and explore topics such as testing methodologies, effect of biomarker testing on patient outcomes, emerging technologies, and strategies for improving testing rates in the United States. Supplementary file1 (MP4 121301 KB).

Spatial transcriptomics reveals heterogeneity of histological subtypes between lepidic and acinar lung adenocarcinoma.

BACKGROUND: Patients who possess various histological subtypes of early-stage lung adenocarcinoma (LUAD) have considerably diverse prognoses. The simultaneous existence of several histological subtypes reduces the clinical accuracy of the diagnosis and prognosis of early-stage LUAD due to intratumour intricacy. METHODS: We included 11 postoperative LUAD patients pathologically confirmed to be stage IA. Single-cell RNA sequencing (scRNA-seq) was carried out on matched tumour and normal tissue. Three formalin-fixed and paraffin-embedded cases were randomly selected for 10× Genomics Visium analysis, one of which was analysed by digital spatial profiler (DSP). RESULTS: Using DSP and 10× Genomics Visium analysis, signature gene profiles for lepidic and acinar histological subtypes were acquired. The percentage of histological subtypes predicted for the patients from samples of 11 LUAD fresh tissues by scRNA-seq showed a degree of concordance with the clinicopathologic findings assessed by visual examination. DSP proteomics and 10× Genomics Visium transcriptomics analyses revealed that a negative correlation (Spearman correlation analysis: r = -.886; p = .033) between the expression levels of CD8 and the expression trend of programmed cell death 1(PD-L1) on tumour endothelial cells. The percentage of CD8+ T cells in the acinar region was lower than in the lepidic region. CONCLUSIONS: These findings illustrate that assessing patient histological subtypes at the single-cell level is feasible. Additionally, tumour endothelial cells that express PD-L1 in stage IA LUAD suppress immune-responsive CD8+ T cells.

Small cells - big issues: biological implications and preclinical advancements in small cell lung cancer.

Current treatment guidelines refer to small cell lung cancer (SCLC), one of the deadliest human malignancies, as a homogeneous disease. Accordingly, SCLC therapy comprises chemoradiation with or without immunotherapy. Meanwhile, recent studies have made significant advances in subclassifying SCLC based on the elevated expression of the transcription factors ASCL1, NEUROD1, and POU2F3, as well as on certain inflammatory characteristics. The role of the transcription regulator YAP1 in defining a unique SCLC subset remains to be established. Although preclinical analyses have described numerous subtype-specific characteristics and vulnerabilities, the so far non-existing clinical subtype distinction may be a contributor to negative clinical trial outcomes. This comprehensive review aims to provide a framework for the development of novel personalized therapeutic approaches by compiling the most recent discoveries achieved by preclinical SCLC research. We highlight the challenges faced due to limited access to patient material as well as the advances accomplished by implementing state-of-the-art models and methodologies.

The role of anti-EGFR therapies in EGFR-TKI-resistant advanced non-small cell lung cancer.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are the current recommended option for the first-line treatment of patients with EGFR-mutant non-small cell lung cancer (NSCLC). Resistance to first-generation TKIs led to the development of second- and third-generation TKIs with improved clinical outcomes. However, sequential administration of TKIs has led to the emergence of new EGFR resistance mutations and persistent tumor cell survival. This evidence highlights the potential role of EGFR in transducing growth signals in NSCLC tumor cells. Therefore, dual inhibition of EGFR using combinations of anti-EGFR monoclonal antibodies (mAbs) and EGFR-TKIs may offer a unique treatment strategy to suppress tumor cell growth. Several clinical studies have demonstrated the benefits of dual blockade of EGFR using anti-EGFR mAbs coupled with EGFR-TKIs in overcoming treatment resistance in patients with EGFR-mutated NSCLC. However, a single treatment option may not result in the same clinical benefits in all patients with acquired resistance. Biomarkers, including EGFR overexpression, EGFR gene copy number, EGFR and KRAS mutations, and circulating tumor DNA, have been associated with improved clinical efficacy with anti-EGFR mAbs in patients with NSCLC and acquired resistance. Further investigation of biomarkers may allow patient selection for those who could benefit from anti-EGFR mAbs in combination with EGFR-TKIs. This review summarizes findings of recent studies of anti-EGFR mAbs in combination with EGFR-TKIs for the treatment of patients with EGFR-mutated NSCLC, as well as clinical evidence for potential biomarkers towards personalized targeted medicine.

An IL-4 signalling axis in bone marrow drives pro-tumorigenic myelopoiesis.

Myeloid cells are known to suppress antitumour immunity1. However, the molecular drivers of immunosuppressive myeloid cell states are not well defined. Here we used single-cell RNA sequencing of human and mouse non-small cell lung cancer (NSCLC) lesions, and found that in both species the type 2 cytokine interleukin-4 (IL-4) was predicted to be the primary driver of the tumour-infiltrating monocyte-derived macrophage phenotype. Using a panel of conditional knockout mice, we found that only deletion of the IL-4 receptor IL-4Rα in early myeloid progenitors in bone marrow reduced tumour burden, whereas deletion of IL-4Rα in downstream mature myeloid cells had no effect. Mechanistically, IL-4 derived from bone marrow basophils and eosinophils acted on granulocyte-monocyte progenitors to transcriptionally programme the development of immunosuppressive tumour-promoting myeloid cells. Consequentially, depletion of basophils profoundly reduced tumour burden and normalized myelopoiesis. We subsequently initiated a clinical trial of the IL-4Rα blocking antibody dupilumab2-5 given in conjunction with PD-1/PD-L1 checkpoint blockade in patients with relapsed or refractory NSCLC who had progressed on PD-1/PD-L1 blockade alone (ClinicalTrials.gov identifier NCT05013450 ). Dupilumab supplementation reduced circulating monocytes, expanded tumour-infiltrating CD8 T cells, and in one out of six patients, drove a near-complete clinical response two months after treatment. Our study defines a central role for IL-4 in controlling immunosuppressive myelopoiesis in cancer, identifies a novel combination therapy for immune checkpoint blockade in humans, and highlights cancer as a systemic malady that requires therapeutic strategies beyond the primary disease site.

Genomic profiling of tissue and blood predicts survival outcomes in patients with resected pleural mesothelioma.

PURPOSE: Pleural mesothelioma (PM) is an aggressive tumor still considered incurable, in part due to the lack of predictive biomarkers. Little is known about the clinical implications of molecular alterations in resectable PM tissues and blood. Here, we characterized genetic alterations to identify prognostic and predictive biomarkers in patients with resected PM. EXPERIMENTAL DESIGN: Targeted next-generation sequencing was performed in retrospective pleural tumor tissue and paired plasma samples from stage IB-IIIB resected PM. Association between prognosis and presence of specific mutations was validated in silico. RESULTS: Thirty PM tissues and paired blood samples from 12 patients were analyzed. High tissue tumor mutational burden (TMB) (>10 mutations/Mb), tissue median minor allele frequency (MAF) (>9 mutations/Mb), and blood TMB (>6 mutations/Mb), tissue KMT2C, PBRM1, PKHD1,EPHB1 and blood LIFR mutations correlated with longer disease-free survival and/or overall survival. High concordance (>80%) between tissue and blood was found for some mutations. CONCLUSIONS: Tissue TMB and MAF, blood TMB, and specific mutations correlated with outcomes in patients with resected PM and should be further studied to validate their role as prognostic biomarkers and potentially predictive factors for combinations with immune-checkpoint inhibitors. This suggest that molecular profiling could identify longer survivors in patients with resected PM.

Artificial Intelligence-Powered Assessment of Pathologic Response to Neoadjuvant Atezolizumab in Patients With NSCLC: Results From the LCMC3 Study.

INTRODUCTION: Pathologic response (PathR) by histopathologic assessment of resected specimens may be an early clinical end point associated with long-term outcomes with neoadjuvant therapy. Digital pathology may improve the efficiency and precision of PathR assessment. LCMC3 (NCT02927301) evaluated neoadjuvant atezolizumab in patients with resectable NSCLC and reported a 20% major PathR rate. METHODS: We determined PathR in primary tumor resection specimens using guidelines-based visual techniques and developed a convolutional neural network model using the same criteria to digitally measure the percent viable tumor on whole-slide images. Concordance was evaluated between visual determination of percent viable tumor (n = 151) performed by one of the 47 local pathologists and three central pathologists. RESULTS: For concordance among visual determination of percent viable tumor, the interclass correlation coefficient was 0.87 (95% confidence interval [CI]: 0.84-0.90). Agreement for visually assessed 10% or less viable tumor (major PathR [MPR]) in the primary tumor was 92.1% (Fleiss kappa = 0.83). Digitally assessed percent viable tumor (n = 136) correlated with visual assessment (Pearson r = 0.73; digital/visual slope = 0.28). Digitally assessed MPR predicted visually assessed MPR with outstanding discrimination (area under receiver operating characteristic curve, 0.98) and was associated with longer disease-free survival (hazard ratio [HR] = 0.30; 95% CI: 0.09-0.97, p = 0.033) and overall survival (HR = 0.14, 95% CI: 0.02-1.06, p = 0.027) versus no MPR. Digitally assessed PathR strongly correlated with visual measurements. CONCLUSIONS: Artificial intelligence-powered digital pathology exhibits promise in assisting pathologic assessments in neoadjuvant NSCLC clinical trials. The development of artificial intelligence-powered approaches in clinical settings may aid pathologists in clinical operations, including routine PathR assessments, and subsequently support improved patient care and long-term outcomes.

Disparities in outcomes between Black and White patients in North America with thoracic malignancies and COVID-19 infection (TERAVOLT).

BACKGROUND: Patients with thoracic malignancies who develop COVID-19 infection have a higher hospitalization rate compared to the general population and to those with other cancer types, but how this outcome differs by race and ethnicity is relatively understudied. METHODS: The TERAVOLT database is an international, multi-center repository of cross-sectional and longitudinal data studying the impact of COVID-19 on individuals with thoracic malignancies. Patients from North America with thoracic malignancies and confirmed COVID-19 infection were included for this analysis of racial and ethnic disparities. Patients with missing race data or races and ethnicities with fewer than 50 patients were excluded from analysis. Multivariable analyses for endpoints of hospitalization and death were performed on these 471 patients. RESULTS: Of the 471 patients, 73% were White and 27% were Black. The majority (90%) were non-Hispanic ethnicity, 5% were Hispanic, and 4% were missing ethnicity data. Black patients were more likely to have an Eastern Cooperative Oncology Group (ECOG) Performance Status ≥ 2 (p-value = 0.04). On multivariable analysis, Black patients were more likely than White patients to require hospitalization (Odds Ratio (OR): 1.69, 95% CI: 1.01-2.83, p-value = 0.044). These differences remained across different waves of the pandemic. However, no statistically significant difference in mortality was found between Black and White patients (OR 1.29, 95% CI: 0.69-2.40, p-value = 0.408). CONCLUSIONS: Black patients with thoracic malignancies who acquire COVID-19 infection are at a significantly higher risk of hospitalization compared to White patients, but there is no significant difference in mortality. The underlying drivers of racial disparity among patients with thoracic malignancies and COVID-19 infection require ongoing investigation.

Longitudinal nucleocapsid antibody testing reveals undocumented SARS-CoV-2 infections in patients with lung cancer.

Patients diagnosed with lung cancer (LC) exhibit increased susceptibility to SARS-CoV-2 infection. Rodilla et al. monitor the levels of plasma anti-nucleocapsid antibodies within a cohort of fully vaccinated LC patients and reveal that the actual infection rate is nearly twice the documented rate, indicating a significant prevalence of unreported cases.

Unfolding the secrets of small cell lung cancer progression: Novel approaches and insights through rapid autopsies.

The understanding of small cell lung cancer (SCLC) biology has increased dramatically in recent years, but the processes that allow SCLC to progress rapidly remain poorly understood. Here, we advocate the integration of rapid autopsies and preclinical models into SCLC research as a comprehensive strategy with the potential to revolutionize current treatment paradigms.

Clinical insights into small cell lung cancer: Tumor heterogeneity, diagnosis, therapy, and future directions.

Small cell lung cancer (SCLC) is characterized by rapid growth and high metastatic capacity. It has strong epidemiologic and biologic links to tobacco carcinogens. Although the majority of SCLCs exhibit neuroendocrine features, an important subset of tumors lacks these properties. Genomic profiling of SCLC reveals genetic instability, almost universal inactivation of the tumor suppressor genes TP53 and RB1, and a high mutation burden. Because of early metastasis, only a small fraction of patients are amenable to curative-intent lung resection, and these individuals require adjuvant platinum-etoposide chemotherapy. Therefore, the vast majority of patients are currently being treated with chemoradiation with or without immunotherapy. In patients with disease confined to the chest, standard therapy includes thoracic radiotherapy and concurrent platinum-etoposide chemotherapy. Patients with metastatic (extensive-stage) disease are treated with a combination of platinum-etoposide chemotherapy plus immunotherapy with an anti-programmed death-ligand 1 monoclonal antibody. Although SCLC is initially very responsive to platinum-based chemotherapy, these responses are transient because of the development of drug resistance. In recent years, the authors have witnessed an accelerating pace of biologic insights into the disease, leading to the redefinition of the SCLC classification scheme. This emerging knowledge of SCLC molecular subtypes has the potential to define unique therapeutic vulnerabilities. Synthesizing these new discoveries with the current knowledge of SCLC biology and clinical management may lead to unprecedented advances in SCLC patient care. Here, the authors present an overview of multimodal clinical approaches in SCLC, with a special focus on illuminating how recent advancements in SCLC research could accelerate clinical development.

The presence of circulating genetically abnormal cells in blood predicts risk of lung cancer in individuals with indeterminate pulmonary nodules.

PURPOSE: Computed tomography is the standard method by which pulmonary nodules are detected. Greater than 40% of pulmonary biopsies are not lung cancer and therefore not necessary, suggesting that improved diagnostic tools are needed. The LungLB™ blood test was developed to aid the clinical assessment of indeterminate nodules suspicious for lung cancer. LungLB™ identifies circulating genetically abnormal cells (CGACs) that are present early in lung cancer pathogenesis. METHODS: LungLB™ is a 4-color fluorescence in-situ hybridization assay for detecting CGACs from peripheral blood. A prospective correlational study was performed on 151 participants scheduled for a pulmonary nodule biopsy. Mann-Whitney, Fisher's Exact and Chi-Square tests were used to assess participant demographics and correlation of LungLB™ with biopsy results, and sensitivity and specificity were also evaluated. RESULTS: Participants from Mount Sinai Hospital (n = 83) and MD Anderson (n = 68), scheduled for a pulmonary biopsy were enrolled to have a LungLB™ test. Additional clinical variables including smoking history, previous cancer, lesion size, and nodule appearance were also collected. LungLB™ achieved 77% sensitivity and 72% specificity with an AUC of 0.78 for predicting lung cancer in the associated needle biopsy. Multivariate analysis found that clinical and radiological factors commonly used in malignancy prediction models did not impact the test performance. High test performance was observed across all participant characteristics, including clinical categories where other tests perform poorly (Mayo Clinic Model, AUC = 0.52). CONCLUSION: Early clinical performance of the LungLB™ test supports a role in the discrimination of benign from malignant pulmonary nodules. Extended studies are underway.

Radiotherapy and Immunotherapy in Lung Cancer.

The emergence of immune checkpoint inhibitors (ICIs) as a pillar of cancer treatment has emphasized the immune system's integral role in tumor control and progression through cancer immune surveillance. ICIs are being investigated and incorporated into the treatment paradigm for lung cancers across stages and histology. To date, definitive concurrent chemoradiotherapy followed by consolidative durvalumab is the only National Comprehensive Cancer Network's recommended treatment paradigm including radiotherapy with ICI in lung cancers, although there are other recommendations for ICI with chemotherapy and/or surgery. This narrative review provides an overall view of the evolving integration and synergistic role of immunotherapy and radiotherapy and outlines the use of immunotherapy with radiotherapy for the management of small cell lung cancer and non-small cell lung cancer. It also reviews selected, practice-changing clinical trials that led to the current standard of care for lung cancers.

Serological Response to SARS-CoV-2 after COVID-19 Vaccination in Lung Cancer Patients: Short Review.

In comparison to the general population, lung cancer patients are more likely to suffer from severe Coronavirus disease (COVID-19) and associated mortality. Considering this increased risk, and in order to prevent symptoms and severe disease, patients with lung cancer have been prioritized for COVID-19 vaccination primary and booster doses. Despite this, the pivotal clinical trials did not include these patients, which leaves open questions regarding vaccine efficacy and humoral immune response. This review outlines the findings of recent investigations into the humoral responses of lung cancer patients to COVID-19 vaccination, particularly the primary doses and first boost.

Predictive Capability of PD-L1 Protein Expression for Patients With Advanced NSCLC: Any Differences Based on Histology?

Lung cancer is responsible for 1.8 million annual deaths. Non-small cell lung cancers (NSCLC) represent 85% of lung cancer tumors. While surgery is an effective early-stage treatment, the majority of newly identified US lung cancer cases are stage III/IV. Immunotherapy, using programmed death-ligand 1 (PD-L1) or programmed death 1 (PD-1) receptor antibody therapeutics, has increased survival for patients with NSCLC. PD-L1 protein expression is widely used as a predictive biomarker informing treatment decisions. However, only a minority of patients (27%-39%) respond to PD-L1/PD-1 treatment. PD-L1 protein expression by immunohistochemistry assay has deficiencies in identifying responding and refractory patients. Given the different characteristics of squamous and nonsquamous NSCLC, the predictability of PD-L1 levels in determining which patients would benefit from immunotherapy could vary between the 2 histologies. We analyzed 17 phase-III clinical studies and a retrospective study to determine if the predictive capability of PD-L1 expression varies between squamous and nonsquamous NSCLC. For patients with NSCLC treated with mono or dual-immune checkpoint inhibitors (ICI), PD-L1 expression was more predictive of benefit for patients with nonsquamous NSCLC than squamous NSCLC. Patients with nonsquamous histology and PD-L1 high tumor proportion scores (TPS) survived 2.0x longer compared to those with low TPS, when treated with monotherapy ICI. Among patients with squamous NSCLC, that difference was 1.2 to 1.3x. For patients treated with ICIs and chemotherapy, there was no clear difference in the predictive value of PD-L1 levels between histologies. We encourage future researchers to analyze the predictability of PD-L1 biomarker expression separately for squamous and nonsquamous NSCLC.

Role of Lactate in the Regulation of Transcriptional Activity of Breast Cancer-Related Genes and Epithelial-to-Mesenchymal Transition Proteins: A Compassion of MCF7 and MDA-MB-231 Cancer Cell Lines.

The Warburg Effect is characterized by accelerated glycolytic metabolism and lactate production and under fully aerobic conditions is a hallmark of cancer cells. Recently, we have demonstrated the role of endogenous, glucose-derived lactate as an oncometabolite which regulates gene expression in the estrogen receptor positive (ER+) MCF7 cell line cultivated in glucose media. Presently, with the addition of a triple negative breast cancer (TNBC) cell line, MDA-MB-231, we further confirm the effect of lactate on gene expression patterns and extend results to include lactate effects on protein expression. As well, we report effects of lactate on the expression of E-cadherin and vimentin, proteins associated with epithelial-to-mesenchymal transition (EMT). Endogenous lactate regulates the expression of multiple genes involved in carcinogenesis. In MCF7 cells, lactate increased the expression of EGFR, VEGF, HIF-1a, KRAS, MIF, mTOR, PIK3CA, TP53, and CDK4 as well as decreased the expression of ATM, BRCA1, BRCA2, E2F1, MET, MYC, and RAF mainly after 48h of exposure. On the other hand, in the MDA-MB-231 cell line, lactate increased the expressions of PIK3CA, VEGF, EGFR, mTOR, HIF-1α, ATM, E2F1, TP53 and decreased the expressions of BRCA1, BRCA2, CDK4, CDK6, MET, MIF, MYC, and RAF after 48h of exposure. In response to endogenous lactate, changes in protein expression of representative genes corroborated changes in mRNA expressions. Finally, lactate exposure decreased E-cadherin protein expression in MCF7 cells and increased vimentin expression in MDA-MB-231 cells. Furthermore, by genetically silencing LDHA in MCF7 cells, we show suppression of protein expression of EGFR and HIF-1α, while full protein expression occurred under glucose and glucose + exogenous lactate exposure. Hence, endogenous, glucose-derived lactate, and not glucose, elicited changes in gene and protein expression levels. In this study, we demonstrate that endogenous lactate produced under aerobic conditions (Warburg Effect) elicits important changes in gene and protein expression in both ER+ and TNBC cell lines. The widespread regulation of multiple genes by lactate and involves those involved in carcinogenesis including DNA repair, cell growth, proliferation, angiogenesis, and metastasis. Furthermore, lactate affected the expression of two relevant EMT biomarkers, E-cadherin and vimentin, which could contribute to the complex process of EMT and a shift towards a more mesenchymal phenotype in the two cancer cell lines studied.

Tumor Treating Fields (TTFields) Therapy Concomitant with Taxanes for Cancer Treatment.

Non-small cell lung cancer, ovarian cancer, and pancreatic cancer all present with high morbidity and mortality. Systemic chemotherapies have historically been the cornerstone of standard of care (SOC) regimens for many cancers, but are associated with systemic toxicity. Multimodal treatment combinations can help improve patient outcomes; however, implementation is limited by additive toxicities and potential drug-drug interactions. As such, there is a high unmet need to develop additional therapies to enhance the efficacy of SOC treatments without increasing toxicity. Tumor Treating Fields (TTFields) are electric fields that exert physical forces to disrupt cellular processes critical for cancer cell viability and tumor progression. The therapy is locoregional and is delivered noninvasively to the tumor site via a portable medical device that consists of field generator and arrays that are placed on the patient's skin. As a noninvasive treatment modality, TTFields therapy-related adverse events mainly consist of localized skin reactions, which are manageable with effective acute and prophylactic treatments. TTFields selectively target cancer cells through a multi-mechanistic approach without affecting healthy cells and tissues. Therefore, the application of TTFields therapy concomitant with other cancer treatments may lead to enhanced efficacy, with low risk of further systemic toxicity. In this review, we explore TTFields therapy concomitant with taxanes in both preclinical and clinical settings. The summarized data suggest that TTFields therapy concomitant with taxanes may be beneficial in the treatment of certain cancers.

Baseline extracellular vesicle TGF-ß is a predictive biomarker for response to immune checkpoint inhibitors and survival in non-small cell lung cancer.

BACKGROUND: Immune-checkpoint inhibitors (ICIs) are an effective therapeutic strategy, improving the survival of patients with lung cancer compared with conventional treatments. However, novel predictive biomarkers are needed to stratify which patients derive clinical benefit because the currently used and highly heterogenic histological PD-L1 has shown low accuracy. Liquid biopsy is the analysis of biomarkers in body fluids and represents a minimally invasive tool that can be used to monitor tumor evolution and treatment effects, potentially reducing biases associated with tumor heterogeneity associated with tissue biopsies. In this context, cytokines, such as transforming growth factor-ß (TGF-ß), can be found free in circulation in the blood and packaged into extracellular vesicles (EVs), which have a specific delivery tropism and can affect in tumor/immune system interaction. TGF-ß is an immunosuppressive cytokine that plays a crucial role in tumor immune escape, treatment resistance, and metastasis. Thus, we aimed to evaluate the predictive value of circulating and EV TGF-ß in patients with non-small-cell lung cancer receiving ICIs. METHODS: Plasma samples were collected in 33 patients with advanced non-small-cell lung cancer before and during treatment with ICIs. EV were isolated from plasma by serial ultracentrifugation methods and circulating and EV TGF-ß expression levels were evaluated by enzyme-linked immunosorbent assay. RESULTS: Baseline high expression of TGF-ß in EVs was associated with nonresponse to ICIs as well as shorter progression-free survival and overall survival, outperforming circulating TGF-ß levels and tissue PD-L1 as a predictive biomarker. CONCLUSION: If validated, EV TGF-ß could be used to improve patient stratification, increasing the effectiveness of treatment with ICIs and potentially informing combinatory treatments with TGF-ß blockade. PLAIN LANGUAGE SUMMARY: Treatment with immune-checkpoint inhibitors (ICIs) has improved the survival of some patients with lung cancer. However, the majority of patients do not benefit from this treatment, making it essential to develop more reliable biomarkers to identify patients most likely to benefit. In this pilot study, the expression of transforming growth factor-ß (TGF-ß) in blood circulation and in extracellular vesicles was analyzed. The levels of extracellular vesicle TGF-ß before treatment were able to determine which patients would benefit from treatment with ICIs and have a longer survival with higher accuracy than circulating TGF-ß and tissue PD-L1, which is the currently used biomarker in clinical practice.

Protein Expression of immune checkpoints STING and MHCII in small cell lung cancer.

BACKGROUND: SCLC is an aggressive malignancy where immunotherapies show limited efficacy. We aimed to characterize the SCLC microenvironment according to the expression patterns of SCLC subtype markers and novel immune checkpoints to identify therapeutic vulnerabilities. METHODS: We included SCLC tissue samples from 219 surgically resected, limited-stage patients in this cross-sectional study. We performed immunohistochemistry for STING and MHCII, as well as for the novel subtype markers (ASCL1, NEUROD1, POU2F3, YAP1). Moreover, we assessed CD45 + , CD8 + and CD68 + immune cell infiltration. RESULTS: 36% of SCLC tumors showed significant stromal or intraepithelial CD45 + immune cell infiltration. These patients exhibited significantly increased overall survival (OS) (vs. patients with immune-deserted tumors). High CD8 expression was associated with increased median OS. We found STING expression on cancer-associated fibroblasts in the stroma and on T-cells and macrophages in both tumorous and stromal compartments. STING expression positively correlated with immune cell infiltration. Increased STING-positivity in tumor nests was an independent favorable prognosticator for OS. ASCL1 was the most frequently expressed subtype-specific protein. Concomitant expression of three or four subtype-defining markers was seen in 13.8% of the included samples, whereas 24.1% of the cases were classified as quadruple negative tumors. YAP1 expression was associated with increased immune infiltrates. Tumor cell MHCII expression positively correlated with immune cell infiltration and with STING- and YAP1 expressions. CONCLUSIONS: STING and MHCII are expressed in SCLC. The majority of immune-infiltrated SCLCs exhibit increased STING expression. Immune infiltration and STING expression are prognostic in limited-stage SCLC, making STING a potential therapeutic target.