Image Analysis-based Assessment of PD-L1 and Tumor-Associated Immune Cells Density Supports Distinct Intratumoral Microenvironment Groups in Non-small Cell Lung Carcinoma Patients

Identification of distinct immune landscapes using an automated nine-color multiplex immunofluorescence staining panel and image analysis in paraffin tumor tissues

Immune profiling is becoming a vital tool for identifying predictive and prognostic markers for translational studies. The study of the tumor microenvironment (TME) in paraffin tumor tissues such as malignant pleural mesothelioma (MPM) could yield insights to actionable targets to improve patient outcome. Here, we optimized and tested a new immune-profiling method to characterize immune cell phenotypes in paraffin tissues and explore the co-localization and spatial distribution between the immune cells within the TME and the stromal or tumor compartments. Tonsil tissues and tissue microarray (TMA) were used to optimize an automated nine-color multiplex immunofluorescence (mIF) panel to study the TME using eight antibodies: PD-L1, PD-1, CD3, CD8, Foxp3, CD68, KI67, and pancytokeratin. To explore the potential role of the cells into the TME with this mIF panel we applied this panel in twelve MPM cases to assess the multiple cell phenotypes obtained from the image analysis and well as their spatial distribution in this cohort. We successful optimized and applied an automated nine-color mIF panel to explore a small set of MPM cases. Image analysis showed a high degree of cell phenotype diversity with immunosuppression patterns in the TME of the MPM cases. Mapping the geographic cell phenotype distribution in the TME, we were able to identify two distinct, complex immune landscapes characterized by specific patterns of cellular distribution as well as cell phenotype interactions with malignant cells. Successful we showed the optimization and reproducibility of our mIF panel and their incorporation for comprehensive TME immune profiling into translational studies that could refine our ability to correlate immunologic phenotypes with specific patterns of cells distribution and distance analysis. Overall, this will improve our ability to understand the behavior of cells within the TME and predict new treatment strategies to improve patient outcome.

Tumor infiltrated immune cell types support distinct immune checkpoint inhibitor outcomes in patients with advanced non-small cell lung cancer

The evaluation of PD‐L1 expression alone has limitations in predicting clinical outcome in immune‐checkpoint inhibitors (ICI). This study aimed to evaluate the predictive and prognostic effects of the presence of various immune cells in pretreatment tissue samples and to identify determinants associated with response in patients with advanced non‐small cell lung cancer (NSCLC) treated with PD‐1 blockade. Immune cell distribution was heterogeneous and the most dominant immune cell type was T cells. Patients with durable clinical benefit (DCB) showed significantly higher PD‐L1 expression. The ratio of tumor/stroma region of T cell, B cell, and macrophage was significantly higher in patient with DCB. High intratumoral T‐ and B‐cell density (≥median) was associated with DCB in the low PD‐L1 expression (<50%) group. In univariate analyses, the overall survival (OS) benefit was shown according to intratumoral B‐cell density (p = 0.0337). The incidence of hyperprogressive disease (HPD) was 13.0%. The Chi‐square test revealed that HPD was significantly associated with intratumoral B‐cell density but not T‐cell or macrophage density. Our results demonstrate different predictive and prognostic values for infiltrating immune cells in tumor tissue, which may help in selecting patients for ICI.

Digital Immunophenotyping Predicts Disease Free and Overall Survival in Early Stage Melanoma Patients

Background: the prognostic significance of tumor infiltrating lymphocytes (TILs) in intermediate/thick primary cutaneous melanoma (PCM) remains controversial, partially because conventional evaluation is not reliable, due to inter-observer variability and diverse scoring methods. We aimed to assess the prognostic impact of the density and spatial distribution of immune cells in early stage intermediate/thick PCM. Materials and Methods: digital image acquisition and quantitative analysis of tissue immune biomarkers (CD3, CD4, CD8, CD68, PD-L1, CD163, FOX-P3, and PD-1) was carried out in a training cohort, which included patients with primary PCM ≥ 2 mm diagnosed, treated, and followed-up prospectively in three Italian centers. Results were validated in an independent Italian cohort. Results: in the training cohort, 100 Stage II–III melanoma patients were valuable. At multivariable analysis, a longer disease free survival (DFS) was statistically associated with higher levels of CD4⁺ intratumoral T-cells (aHR [100 cell/mm² increase] 0.98, 95%CI 0.95–1.00, p = 0.041) and CD163⁺ inner peritumoral (aHR [high vs. low] 0.56, 95%CI 0.32–0.99, p = 0.047). A statistically significant longer DFS (aHR [high-high vs. low-low] 0.52, 95%CI 0.28–0.99, p = 0.047) and overall survival (OS) (aHR [high-high vs. low-low] 0.39, 95%CI 0.18–0.85, p = 0.018) was found in patients with a high density of both intratumoral CD8⁺ T-cells and CD68⁺ macrophages as compared to those with low density of both intratumoral CD8⁺ T-cells and CD68⁺ macrophages. Consistently, in the validation cohort, patients with high density of both intratumoral CD8⁺ and CD3⁺ T-cells were associated to a statistically better DFS (aHR[high-high vs. low-low] 0.24, 95%CI 0.10–0.56, p < 0.001) and those with high density of both intratumoral CD8⁺ and CD68⁺ were associated to a statistically longer OS (aHR[high-high vs. low-low] 0.28, 95%CI 0.09–0.86, p = 0.025). Conclusion: our findings suggest that a specific preexisting profile of T cells and macrophages distribution in melanomas may predict the risk of recurrence and death with potential implications for the stratification of stage II–III melanoma patients.

Augmented Lipocalin-2 Is Associated with Chronic Obstructive Pulmonary Disease and Counteracts Lung Adenocarcinoma Development

Rationale: Early pathogenesis of lung adenocarcinoma (LUAD) remains largely unknown. We found that, relative to wild-type littermates, the innate immunomodulator Lcn2 (lipocalin-2) was increased in normal airways from mice with knockout of the airway lineage gene Gprc5a (Gprc5a^-/-) and that are prone to developing inflammation and LUAD. Yet, the role of LCN2 in lung inflammation and LUAD is poorly understood.Objectives: Delineate the role of Lcn2 induction in LUAD pathogenesis.Methods: Normal airway brushings, uninvolved lung tissues, and tumors from Gprc5a^-/- mice before and after tobacco carcinogen exposure were analyzed by RNA sequencing. LCN2 mRNA was analyzed in public and in-house data sets of LUAD, lung squamous cancer (LUSC), chronic obstructive pulmonary disease (COPD), and LUAD/LUSC with COPD. LCN2 protein was immunohistochemically analyzed in a tissue microarray of 510 tumors. Temporal lung tumor development, gene expression programs, and host immune responses were compared between Gprc5a^-/- and Gprc5a^-/-/Lcn2^-/- littermates.Measurements and Main Results: Lcn2 was progressively elevated during LUAD development and positively correlated with proinflammatory cytokines and inflammation gene sets. LCN2 was distinctively elevated in human LUADs, but not in LUSCs, relative to normal lungs and was associated with COPD among smokers and patients with LUAD. Relative to Gprc5a^-/- mice, Gprc5a^-/-/Lcn2^-/- littermates exhibited significantly increased lung tumor development concomitant with reduced T-cell abundance (CD4⁺) and richness, attenuated antitumor immune gene programs, and increased immune cell expression of protumor inflammatory cytokines.Conclusions: Augmented LCN2 expression is a molecular feature of COPD-associated LUAD and counteracts LUAD development in vivo by maintaining antitumor immunity.

Fecal microbiota transplant promotes response in immunotherapy-refractory melanoma patients

The gut microbiome has been shown to influence the response of tumors to anti-PD-1 (programmed cell death-1) immunotherapy in preclinical mouse models and observational patient cohorts. However, modulation of gut microbiota in cancer patients has not been investigated in clinical trials. In this study, we performed a phase 1 clinical trial to assess the safety and feasibility of fecal microbiota transplantation (FMT) and reinduction of anti-PD-1 immunotherapy in 10 patients with anti-PD-1-refractory metastatic melanoma. We observed clinical responses in three patients, including two partial responses and one complete response. Notably, treatment with FMT was associated with favorable changes in immune cell infiltrates and gene expression profiles in both the gut lamina propria and the tumor microenvironment. These early findings have implications for modulating the gut microbiota in cancer treatment.

Clinical outcomes of immune checkpoint blockades and the underlying immune escape mechanisms in squamous and adenocarcinoma NSCLC

Immune checkpoint blockades (ICBs) have changed the standard of care of squamous and adenocarcinoma non‐small cell lung cancer (NSCLC). Whereas detailed researches regarding ICBs in the two major histological subtypes are rare. In order to uncover the clinical efficacy differences between squamous and adenocarcinoma NSCLC and better understand the underlying immune‐regulatory mechanisms, we compared the survival benefits of ICBs between the two subtypes by revealing phase 3 randomized trials and attempted to uncover the immune‐regulatory discrepancy. Generally, compared with nonsquamous NSCLC, squamous NSCLC benefited more from ICBs in Keynote 024, CheckMate 026, CheckMate 227 and CheckMate 017 and similar in OAK, but less in Keynote 010 and PACIFIC. We revealed that the tumor mutation burden (TMB) level, the programmed cell death ligand 1 (PD‐L1) expression, tumor infiltrating lymphocytes (TILs) in the tumor microenvironment (TME), chemokines, and oncogenic driver alterations within the two subtypes may contributed to the clinical outcomes of ICBs. We prospected that the combinations of ICBs with chemotherapy, radiation therapy, and antiangiogenic therapy could be promising strategies to re‐immunize the less immunogenic tumors and further enhance the efficacy of ICBs.

Prognostic implications of programmed death ligand 1 expression in resected lung adenocarcinoma: a systematic review and meta-analysis

OBJECTIVES

Conflicting results have been reported about the prognostic value of programmed death ligand 1 (PD-L1) protein and gene expression in lung adenocarcinoma.

METHODS

We performed a comprehensive online search to explore the association between PD-L1 expression (protein and messenger RNA) and overall survival (OS) or disease-free survival. Outcomes also included pooled rates of high PD-L1 protein expression in different cell types, per threshold used and per antibody used. A pooled gene expression analysis was also performed on 3 transcriptomic data sets that were obtained from The Cancer Genome Atlas database and the Gene Expression Omnibus database.

RESULTS

A total of 6488 patients from 25 studies were included. The pooled results suggested that high PD-L1 expression was associated with shorter OS [hazard ratio (HR) 1.57; P < 0.001] and disease-free survival (HR 1.341; P = 0.037) in the overall population. The overall pooled rate of high PD-L1 protein expression was 29% (95% confidence interval 23-34%) in tumour cells. In subgroup analysis, high PD-L1 protein expression in tumour cells predicted worse OS and disease-free survival. A pooled analysis of The Cancer Genome Atlas and Gene Expression Omnibus data sets revealed that higher levels of PD-L1 messenger RNA predicted poorer OS in the entire population.

CONCLUSIONS

This study is, to our knowledge, the largest pooled analysis on the subject to shed light on the high expression rate of PD-L1 and the prognostic value of high PD-L1 expression in resected lung adenocarcinomas. PD-L1 gene expression is a promising prognostic factor for patients with surgically resected lung adenocarcinoma. Standardization of staining should be underscored prior to routine implementation.

Variants in Epithelial-Mesenchymal Transition and Immune Checkpoint Genes Are Associated With Immune Cell Profiles and Predict Survival in Non-Small Cell Lung Cancer

CONTEXT.—

Identification of gene mutations that are indicative of epithelial-mesenchymal transition and a noninflammatory immune phenotype may be important for predicting response to immune checkpoint inhibitors.

OBJECTIVE.—

To evaluate the utility of multiplex immunofluorescence for immune profiling and to determine the relationships among tumor immune checkpoint and epithelial-mesenchymal transition genomic profiles and the clinical outcomes of patients with nonmetastatic non-small cell lung cancer.

DESIGN.—

Tissue microarrays containing 164 primary tumor specimens from patients with stages I to IIIA non-small cell lung carcinoma were examined by multiplex immunofluorescence and image analysis to determine the expression of programmed death ligand-1 (PD-L1) on malignant cells, CD68+ macrophages, and cells expressing the immune markers CD3, CD8, CD57, CD45RO, FOXP3, PD-1, and CD20. Immune phenotype data were tested for correlations with clinicopathologic characteristics, somatic and germline genetic variants, and outcome.

RESULTS.—

A high percentage of PD-L1+ malignant cells was associated with clinicopathologic characteristics, and high density of CD3+PD-1+ T cells was associated with metastasis, suggesting that these phenotypes may be clinically useful to identify patients who will likely benefit from immunotherapy. We also found that ZEB2 mutations were a proxy for immunologic ignorance and immune tolerance microenvironments and may predict response to checkpoint inhibitors. A multivariate Cox regression model predicted a lower risk of death for patients with a high density of CD3+CD45RO+ memory T cells, carriers of allele G of CTLA4 variant rs231775, and those whose tumors do not have ZEB2 mutations.

CONCLUSIONS.—

Genetic variants in epithelial-mesenchymal transition and immune checkpoint genes are associated with immune cell profiles and may predict patient outcomes and response to immune checkpoint blockade.

Collagen promotes anti-PD-1/PD-L1 resistance in cancer through LAIR1-dependent CD8+ T cell exhaustion

Tumor extracellular matrix has been associated with drug resistance and immune suppression. Here, proteomic and RNA profiling reveal increased collagen levels in lung tumors resistant to PD-1/PD-L1 blockade. Additionally, elevated collagen correlates with decreased total CD8⁺ T cells and increased exhausted CD8⁺ T cell subpopulations in murine and human lung tumors. Collagen-induced T cell exhaustion occurs through the receptor LAIR1, which is upregulated following CD18 interaction with collagen, and induces T cell exhaustion through SHP-1. Reduction in tumor collagen deposition through LOXL2 suppression increases T cell infiltration, diminishes exhausted T cells, and abrogates resistance to anti-PD-L1. Abrogating LAIR1 immunosuppression through LAIR2 overexpression or SHP-1 inhibition sensitizes resistant lung tumors to anti-PD-1. Clinically, increased collagen, LAIR1, and TIM-3 expression in melanoma patients treated with PD-1 blockade predict poorer survival and response. Our study identifies collagen and LAIR1 as potential markers for immunotherapy resistance and validates multiple promising therapeutic combinations.

PD-L1 as a prognostic biomarker in surgically resectable non-small cell lung cancer: a meta-analysis

Background

PD-L1 tumor expression has been associated with poor prognosis in a variety of solid tumors, including lung cancer, and represents a validated target for immune checkpoint inhibition in advanced malignances. It remains unknown, however, if PD-L1 can be used to predict survival in early stage, surgically treated cancers. This meta-analysis compares PD-L1 tumor expression and long term survival after surgical resection in early non-small cell lung cancer (NSCLC).

Methods

PubMed was searched to identify eligible studies that compared survival of surgically resected stage I–III NSCLC patients according to PD-L1 tumor expression. Included studies were grouped according to measurement criteria of PD-L1 expression: 1%, 5%, 50% cutoffs or H-score. Meta-analysis was performed using a linear mixed-effects model to determine overall survival (OS). I² was used as a measure of heterogeneity.

Results

There were 40 eligible studies, including 10,380 patients. Regardless of cut-off used, higher PD-L1 tumor expression was associated with worse OS [hazard ratio (HR)_1%: 1.59, 95% confidence interval (CI), 1.17–2.17; HR_5%: 1.44, 95% CI, 1.03–2.00; HR_50%: 1.52, 95% CI, 1.02–2.25, HR_H-score: 1.34, 95% CI, 1.04–1.73]. Study heterogeneity was low and not statistically significant under all PD-L1 cutoffs.

Conclusions

PD-L1 expression is consistently associated with worse survival, regardless of how it is quantified. In addition to acting as a prognostic biomarker, PD-L1 may also be used in future as a predictive biomarker for patients most likely to benefit from adjuvant immunotherapy.

PD-L1 expression in bone marrow plasma cells as a biomarker to predict multiple myeloma prognosis: developing a nomogram-based prognostic model

PD-L1 expression is associated with poor prognosis, although this relationship is unclear in bone marrow-derived haematologic malignancies, including multiple myeloma. We aimed to determine whether PD-L1 expression could predict the prognosis of newly diagnosed multiple myeloma (NDMM). We evaluated 126 NDMM patients (83, retrospectively; 43, prospectively) who underwent bone marrow examinations. Bone marrow aspirates were analysed for PD-L1 expression, categorized as low or high expression, using quantitative immunofluorescence. High PD-L1 expression could independently predict poor overall survival (OS) (95% CI = 1.692-8.346) in multivariate analysis. On subgroup analysis, high PD-L1 expression was associated with poor OS (95% CI = 2.283-8.761) and progression-free survival (95% CI = 1.024-3.484) in patients who did not undergo autologous stem cell transplantation (ASCT) compared with those who did. High PD-L1 expression was associated with poor OS despite frontline treatments with or without immunomodulators. Thus, PD-L1 expression can be a useful prognosis predictor in NDMM patients, whereas ASCT may be used in patients with high PD-L1 expression. We developed a prognostic nomogram and found that a combination of PD-L1 expression in bone marrow plasma cells and clinical parameters (age, cytogenetics, and lactate dehydrogenase) effectively predicted NDMM prognosis. We believe that our nomogram can help identify high-risk patients and select appropriate treatments.

Fit-For-Purpose PD-L1 Biomarker Testing For Patient Selection in Immuno-Oncology: Guidelines For Clinical Laboratories From the Canadian Association of Pathologists-Association Canadienne Des Pathologistes (CAP-ACP)

Since 2014, programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) checkpoint inhibitors have been approved by various regulatory agencies for the treatment of multiple cancers including melanoma, lung cancer, urothelial carcinoma, renal cell carcinoma, head and neck cancer, classical Hodgkin lymphoma, colorectal cancer, gastroesophageal cancer, hepatocellular cancer, and other solid tumors. Of these approved drug/disease combinations, a subset also has regulatory agency-approved, commercially available companion/complementary diagnostic assays that were clinically validated using data from their corresponding clinical trials. The objective of this document is to provide evidence-based guidance to assist clinical laboratories in establishing fit-for-purpose PD-L1 biomarker assays that can accurately identify patients with specific tumor types who may respond to specific approved immuno-oncology therapies targeting the PD-1/PD-L1 checkpoint. These recommendations are issued as 38 Guideline Statements that address (i) assay development for surgical pathology and cytopathology specimens, (ii) reporting elements, and (iii) quality assurance (including validation/verification, internal quality assurance, and external quality assurance). The intent of this work is to provide recommendations that are relevant to any tumor type, are universally applicable and can be implemented by any clinical immunohistochemistry laboratory performing predictive PD-L1 immunohistochemistry testing.

PD-L1 expression correlates with tumor-infiltrating lymphocytes and better prognosis in patients with HPV-negative head and neck squamous cell carcinomas

INTRODUCTION

The importance of immune tumor microenvironment in the prognosis of patients with head and neck squamous carcinomas (HNSCC) is increasingly recognized. We analyzed the prognostic relevance of PD-L1 and PD-1 expressions in relation to the infiltration by CD8⁺ and FOXP3⁺ tumor-infiltrating lymphocytes (TILs).

METHODS

Samples from 372 surgically treated HPV-negative HNSCC patients were evaluated by immunohistochemistry for PD-L1 expression [both tumor proportion score (TPS) and combined proportion score (CPS)], PD-1 expression in immune cells, and density of infiltrating CD8⁺ and FOXP3⁺ TILs. PD-L1 expression and CD8⁺ TIL density were combined to establish the type of tumor microenvironment.

RESULTS

29.5% cases exhibited PD-L1 TPS positivity (≥ 1%), whereas PD-L1 CPS positivity (≥ 1%) was observed in 40% cases. 47.5% cases showed positive PD-1 expression (≥ 1%). PD-L1 and PD-1 positivity correlated with a high density of both CD8⁺ and FOXP3⁺ TILs. In univariate analysis, PD-L1 TPS positivity (P = 0.026), PD-L1 CPS positivity (P = 0.004), high density of CD8⁺ TIL (P = 0.001), and high density of FOXP3⁺ TIL (P = 0.004) were associated with a better disease-specific survival (DSS). However, in multivariate analysis, only high density of CD8⁺ TIL was associated with a better DSS (P = 0.002). The type of tumor microenvironment correlated with DSS (P = .008), with the better DSS observed in cases with type I (PD-L1 CPS positivity and high density of CD8⁺ TIL).

CONCLUSIONS

High infiltration by CD8⁺ TIL is associated with better survival outcomes. Positive PD-L1 expression correlates with a high infiltration by TILs, explaining its association with better prognosis.

LKB1/STK11 Expression in Lung Adenocarcinoma and Associations With Patterns of Recurrence

BACKGROUND

Mutations in the serine/threonine kinase 11 (STK11)/liver kinase B1 (LKB1) have been implicated in mediating resistance to checkpoint blockade among patients with advanced lung adenocarcinoma. We sought to examine the associations between clinicopathologic characteristics, tumor LKB1 expression, features of the immune microenvironment, and postoperative prognosis among patients with early stage lung adenocarcinoma undergoing surgical therapy.

METHODS

Formalin-fixed, paraffin-embedded specimens of patients undergoing resection of stage I to III, chemotherapy-naïve adenocarcinomas (1997 to 2008) were analyzed using tissue microarray sectioning. Sublobar resections were excluded. Intratumoral LKB1/STK11 expression was quantified as H-score. In a subset, tumor-associated immune cell populations were quantified using whole tumor sections in peritumoral and intratumoral compartments.

RESULTS

In all, 104 patients met inclusion criteria. Expression of LKB1/STK11 (median H-score 102.9) was higher in women (median 123.3) than in men (100, P = .004) and in never-smokers (median 145) than in former/current smokers (100, P = .002). Expression of LKB1/STK11 was positively correlated with intratumoral infiltration of cluster of differentiation (CD) 3⁺ (r = 0.351, P = .005), CD4⁺ (r = 0.436, P < .001), and CD8⁺ (r = 0.263, P = .049) cells. Patients with extrathoracic recurrence had lower tumor expression of LKB1/STK11 than did other patients with recurrent disease. On multivariate analysis, low LKB1/STK11 expression remained independently associated with poor disease-free survival and distant disease-free survival.

CONCLUSIONS

Low LKB1/STK11 expression is associated with specific patient characteristics and poor postoperative prognosis in chemotherapy-naïve lung adenocarcinoma. Further investigation is warranted to delineate its clinical significance in the context of evaluating novel therapeutic agents in patients with resectable disease.

T-cell exhaustion interrelates with immune cytolytic activity to shape the inflamed tumor microenvironment

Direct quantification of exhausted T cells in human cancer is lacking, and its predictive value for checkpoint-based treatment remains poorly investigated. We sought to systematically characterize the pan-cancer landscape and molecular hallmarks of T-cell dysfunction for the purpose of precision immunotherapy. Here, we defined a transcriptional signature for T-cell exhaustion through analyzing differential gene expression between PD-1-high and PD-1-negative CD8⁺ T lymphocytes from primary non-small cell lung cancer (NSCLC), followed by positive correlation tests with PDCD1 in TCGA lung carcinomas. A 78-gene signature for exhausted CD8⁺ T cells (GET) was identified and validated to reflect dysfunctional immune state spanning different species and disease models. We discovered that GET estimation significantly correlated with intratumoral immune cytolytic activity (CYT) and T-cell-inflamed gene expression profile (GEP) across 30 solid tumor types. Miscellaneous tumor-intrinsic and -extrinsic properties, in particular leukocyte proportions, genomic abnormalities, specific mutational signatures, and signaling pathways, were notably associated with GET levels. Furthermore, higher GET expression predicted an increased likelihood of clinical response to immune checkpoint inhibitors. These findings highlight the interrelation between T-cell exhaustion and immune cytolytic activity at the pan-cancer scale. The resulting inflamed tumor microenvironment may further crosstalk with other molecular and clinicopathological factors, which should be properly considered during immunotherapy biomarker development. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Comprehensive Molecular Characterization Identifies Distinct Genomic and Immune Hallmarks of Renal Medullary Carcinoma

Renal medullary carcinoma (RMC) is a highly lethal malignancy that mainly afflicts young individuals of African descent and is resistant to all targeted agents used to treat other renal cell carcinomas. Comprehensive genomic and transcriptomic profiling of untreated primary RMC tissues was performed to elucidate the molecular landscape of these tumors. We found that RMC was characterized by high replication stress and an abundance of focal copy-number alterations associated with activation of the stimulator of the cyclic GMP-AMP synthase interferon genes (cGAS-STING) innate immune pathway. Replication stress conferred a therapeutic vulnerability to drugs targeting DNA-damage repair pathways. Elucidation of these previously unknown RMC hallmarks paves the way to new clinical trials for this rare but highly lethal malignancy.

Weighted Gene Coexpression Network Analysis of Features That Control Cancer Stem Cells Reveals Prognostic Biomarkers in Lung Adenocarcinoma

Purpose We aimed to identify new prognostic biomarkers of lung adenocarcinoma (LUAD) based on cancer stem cell theory.

Materials and Methods: RNA-seq and microarray data were obtained with clinical information downloaded from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Weighted gene coexpression network analysis (WGCNA) was applied to identify significant module and hub genes. The hub genes were validated via microarray data from GEO, and a prognostic signature with prognostic hub genes was constructed.

Results LUAD patients enrolled from TCGA had a higher mRNA expression-based stemness index (mRNAsi) in tumor tissue than in adjacent normal tissue. Some clinical features and prognoses were found to be highly correlated with mRNAsi. WGCNA found that the green module and blue module were the most significant modules related to mRNAsi; 50 key genes were identified in the green module and were enriched mostly in the cell cycle, chromosome segregation, chromosomal region and microtubule binding. Six hub genes were revealed through the protein-protein interaction (PPI) network and Molecular Complex Detection (MCODE) plugin of Cytoscape software. Based on external verification with the GEO database, these six genes are not only expressed at different levels in LUAD and normal tissues but also associated with different clinical features. In addition, the construction of a prognostic signature with three hub genes showed high predictive value.

Conclusion mRNAsi-related biomarkers may suggest a new potential treatment strategy for LUAD.

The Multiple Faces of Programmed Cell Death Ligand 1 Expression in Malignant and Nonmalignant Cells

Preliminary data suggest that tumor expression of programmed cell death ligand 1 (PD-L1) protein in human cancers, as determined by immunohistochemistry in formalin-fixed, paraffin-embedded tissue samples, may predict clinical response to anti-PD-1/PD-L1 therapy. PD-L1 is not a specific tumor marker and its expression is also observed in various nonmalignant cells, such as macrophages and lymphocytes, causing confusion in immunohistochemistry analysis when these inflammatory cells are overlapping with tumors cells. The aim of the current study was to examine PD-L1 expression in formalin-fixed, paraffin-embedded malignant and nonmalignant cells from human tumors to establish potential characteristic patterns of PD-L1 expression in tumor tissues. We used a commercial PD-L1 clone (E1L3N) previously validated in our laboratory to characterize PD-L1 expression in surgically resected lung adenocarcinomas, lung squamous cell carcinomas, malignant melanomas, renal cell carcinomas, hepatocellular carcinomas, and ductal breast carcinomas. We observed different patterns of PD-L1 expression by malignant cells and nonmalignant cells as membrane, cytoplasmic, and nuclear expression. The distribution of expression was variable including the entire malignant cells population, heterogonous with random distribution, peripheral distribution, minimal expression by few cells and negative expression. Similar, nonmalignant cells showed randomly and peripherally distribution through the tumors. We concluded that the PD-L1 cell protein expression patterns and distributions are variable and differ between resected tumor specimens. The expression and distribution pattern described here provide a useful knowledgment of PD-L1 expression in tumor samples.

18F-fluorodeoxyglucose positron emission tomography correlates with tumor immunometabolic phenotypes in resected lung cancer

Enhanced tumor glycolytic activity is a mechanism by which tumors induce an immunosuppressive environment to resist adoptive T cell therapy; therefore, methods of assessing intratumoral glycolytic activity are of considerable clinical interest. In this study, we characterized the relationships among tumor ¹⁸F-fluorodeoxyglucose (FDG) retention, tumor metabolic and immune phenotypes, and survival in patients with resected non-small cell lung cancer (NSCLC). We retrospectively analyzed tumor preoperative positron emission tomography (PET) ¹⁸F-FDG uptake in 59 resected NSCLCs and investigated correlations between PET parameters (SUV_Max, SUV_Total, SUV_Mean, TLG), tumor expression of glycolysis- and immune-related genes, and tumor-associated immune cell densities that were quantified by immunohistochemistry. Tumor glycolysis-associated immune gene signatures were analyzed for associations with survival outcomes. We found that each ¹⁸F-FDG PET parameter was positively correlated with tumor expression of glycolysis-related genes. Elevated ¹⁸F-FDG SUV_Max was more discriminatory of glycolysis-associated changes in tumor immune phenotypes than other ¹⁸F-FDG PET parameters. Increased SUV_Max was associated with multiple immune factors characteristic of an immunosuppressive and poorly immune infiltrated tumor microenvironment, including elevated PD-L1 expression, reduced CD57⁺ cell density, and increased T cell exhaustion gene signature. Elevated SUV_Max identified immune-related transcriptomic signatures that were associated with enhanced tumor glycolytic gene expression and poor clinical outcomes. Our results suggest that ¹⁸F-FDG SUV_Max has potential value as a noninvasive, clinical indicator of tumor immunometabolic phenotypes in patients with resectable NSCLC and warrants investigation as a potential predictor of therapeutic response to immune-based treatment strategies.

Immune Checkpoint Inhibitors in Thoracic Malignancies: Review of the Existing Evidence by an IASLC Expert Panel and Recommendations

In the past 10 years, a deeper understanding of the immune landscape of cancers, including immune evasion processes, has allowed the development of a new class of agents. The reactivation of host antitumor immune response offers the potential for long-term survival benefit in a portion of patients with thoracic malignancies. The advent of programmed cell death protein 1/programmed death ligand-1 immune checkpoint inhibitors (ICIs), both as single agents and in combination with chemotherapy, and more recently, the combination of ICI, anti-programmed cell death protein 1, and anticytotoxic T-lymphocyte antigen 4 antibody, have led to breakthrough therapeutic advances for patients with advanced NSCLC, and to a lesser extent, patients with SCLC. Encouraging activity has recently emerged in pretreated patients with thymic carcinoma (TC). Conversely, in malignant pleural mesothelioma, pivotal positive signs of activity have not been fully confirmed in randomized trials. The additive effects of chemoradiation and immunotherapy suggested intriguing potential for therapeutic synergy with combination strategies. This has led to the introduction of ICI consolidation therapy in stage III NSCLC, creating a platform for future therapeutic developments in earlier-stage disease. Despite the definitive clinical benefit observed with ICI, primary and acquired resistance represent well-known biological phenomena, which may affect the therapeutic efficacy of these agents. The development of innovative strategies to overcome ICI resistance, standardization of new patterns of ICI progression, identification of predictive biomarkers of response, optimal treatment duration, and characterization of ICI efficacy in special populations, represent crucial issues to be adequately addressed, with the aim of improving the therapeutic benefit of ICI in patients with thoracic malignancies. In this article, an international panel of experts in the field of thoracic malignancies discussed these topics, evaluating currently available scientific evidence, with the final aim of providing clinical recommendations, which may guide oncologists in their current practice and elucidate future treatment strategies and research priorities.

Comprehensive T cell repertoire characterization of non-small cell lung cancer

Immunotherapy targeting T cells is increasingly utilized to treat solid tumors including non-small cell lung cancer (NSCLC). This requires a better understanding of the T cells in the lungs of patients with NSCLC. Here, we report T cell repertoire analysis in a cohort of 236 early-stage NSCLC patients. T cell repertoire attributes are associated with clinicopathologic features, mutational and immune landscape. A considerable proportion of the most prevalent T cells in tumors are also prevalent in the uninvolved tumor-adjacent lungs and appear specific to shared background mutations or viral infections. Patients with higher T cell repertoire homology between the tumor and uninvolved tumor-adjacent lung, suggesting a less tumor-focused T cell response, exhibit inferior survival. These findings indicate that a concise understanding of antigens and T cells in NSCLC is needed to improve therapeutic efficacy and reduce toxicity with immunotherapy, particularly adoptive T cell therapy.

Relevant features of T cell repertoire in human cancer remain to be delineated. Here the authors show, by TCR sequencing in a large cohort of lung cancer patients, that while a majority of T cell clones are shared between tumor and adjacent lung tissue, less frequent tumor-unique T cell clones correlate with worse prognosis.

Biomarker recommendation for PD-1/PD-L1 immunotherapy development in pediatric cancer based on digital image analysis of PD-L1 and immune cells

Anti-PD-1/PD-L1 immunotherapy could offer an alternative to traditional chemo- and/or radiotherapy to treat pediatric cancer patients. To unveil the potential benefit of this new therapeutic approach, the prevalence of PD-L1 and other relevant immune markers using quantitative digital image analysis (DIA) could help to clarify this point. A bridging study was first conducted using commercially available normal formalin-fixed paraffin-embedded (FFPE) tonsils to compare immunostaining patterns and intensities from PD-L1, tumor infiltrating lymphocyte (TIL) markers CD3, CD8, FoxP3, CD45RO, and macrophage marker CD68 in adult (n = 5) and pediatric (n = 10) samples. Then, commercially available pediatric FFPE tumor samples from five prevalent pediatric solid tumor indications: ganglioneuroblastoma (n = 7); neuroblastoma (n = 23); nephroblastoma (n = 30); osteosarcoma (n = 24); and rhabdomyosarcoma (n = 25) were immunostained and their images (n = 654) digitally analyzed using predefined algorithms. The qualitative analysis of staining patterns and intensities in all 15 tonsils for all 6 biomarkers was similar regardless of age category. Quantitative DIA showed that PD-L1 values varied across cancer-types, nephroblastoma having the lowest counts. PD-L1 counts in ganglioneuroblastoma, our pediatric indication with the highest average value, was approximately 12-times lower than in a similar nonsmall cell lung cancer study, an indication approved for anti-PD-1/PD-L1 immunotherapies. Variable values were measured for the TIL markers CD3, CD8, and CD45RO. FoxP3 was scant across all indications. The macrophage marker CD68 showed highest values in ganglioneuroblastoma, with lowest levels in nephroblastoma. In conclusion, the low PD-L1 levels uncorrelated with TIL values from the present biomarker morphological study suggest that a PD-L1 immunohistochemistry patient selection strategy used for anti-PD-1/PD-L1 monotherapy in adult tumors may not succeed in these pediatric indications.

Changes in CT Radiomic Features Associated with Lymphocyte Distribution Predict Overall Survival and Response to Immunotherapy in Non-Small Cell Lung Cancer

No predictive biomarkers can robustly identify patients with non-small cell lung cancer (NSCLC) who will benefit from immune checkpoint inhibitor (ICI) therapies. Here, in a machine learning setting, we compared changes ("delta") in the radiomic texture (DelRADx) of CT patterns both within and outside tumor nodules before and after two to three cycles of ICI therapy. We found that DelRADx patterns could predict response to ICI therapy and overall survival (OS) for patients with NSCLC. We retrospectively analyzed data acquired from 139 patients with NSCLC at two institutions, who were divided into a discovery set (D1 = 50) and two independent validation sets (D2 = 62, D3 = 27). Intranodular and perinodular texture descriptors were extracted, and the relative differences were computed. A linear discriminant analysis (LDA) classifier was trained with 8 DelRADx features to predict RECIST-derived response. Association of delta-radiomic risk score (DRS) with OS was determined. The association of DelRADx features with tumor-infiltrating lymphocyte (TIL) density on the diagnostic biopsies (n = 36) was also evaluated. The LDA classifier yielded an AUC of 0.88 ± 0.08 in distinguishing responders from nonresponders in D1, and 0.85 and 0.81 in D2 and D3 DRS was associated with OS [HR: 1.64; 95% confidence interval (CI), 1.22-2.21; P = 0.0011; C-index = 0.72). Peritumoral Gabor features were associated with the density of TILs on diagnostic biopsy samples. Our results show that DelRADx could be used to identify early functional responses in patients with NSCLC.

Prognostic value of immune cells in the tumor microenvironment of early-stage lung cancer: a meta-analysis

BACKGROUND

Early-stage non-small cell lung cancer (NSCLC) patients carry significant risk of recurrence post-surgery. In-depth characterization of the immune tumor microenvironment (TME) can have prognostic value. This study aimed to evaluate the association of individual immune cell types in the TME with clinical outcomes in surgically resected, early-stage NSCLC.

METHODS

We performed a systematic literature search of the National Library of Medicine database through November 2019, investigating predefined biomarkers (CD3+ T cells, CD4+ T helper cells, CD8+ cytotoxic T cells, CD20+ B cells, CD56+ & CD57+ Natural Killer (NK) cells, CD68+ Tissue Associated Macrophages (TAMS), FoxP3+ T regulatory cells, and Mast Cells (MC)), and their association with survival following PRISMA guidelines.

RESULTS

Studies that adjusted for important clinical covariates (such as stage and age) showed that higher levels of CD8+ cytotoxic T cells were associated with improved OS (HR = 0.68; 95% CI, 0.50-0.93) and DFS (HR = 0.60; 95% CI, 0.41-0.87), while increased CD20+ B cells (HR = 0.16; 95% CI, 0.04-0.64) and CD 56/57+ NK cells (HR = 0.50; 95% CI, 0.26-0.95) were associated with improved OS; lung cancers with increased FoxP3+ T regulatory cells (HR = 2.22; 95% CI, 1.47-3.34) had worse OS.

CONCLUSIONS

Immune cell components of the TME have prognostic value in early-stage, surgically resected NSCLC, and may reveal which patients are more likely to need additional systemic treatment, including immunotherapy. Clinical covariates need to be considered when evaluating the prognostic value of immune cells in the TME.

Combining Immune Checkpoint Blockade and Tumor-Specific Vaccine for Patients With Incurable Human Papillomavirus 16-Related Cancer: A Phase 2 Clinical Trial

Importance

In recurrent human papilloma virus (HPV)-driven cancer, immune checkpoint blockade with anti-programmed cell death 1 (PD-1) antibodies produces tumor regression in only a minority of patients. Therapeutic HPV vaccines have produced strong immune responses to HPV-16, but vaccination alone has been ineffective for invasive cancer.

Objective

To determine whether the efficacy of nivolumab, an anti-PD-1 immune checkpoint antibody, is amplified through treatment with ISA 101, a synthetic long-peptide HPV-16 vaccine inducing HPV-specific T cells, in patients with incurable HPV-16-positive cancer.

Design, Setting, and Participants

In this single-arm, single-center phase 2 clinical trial, 24 patients with incurable HPV-16-positive cancer were enrolled from December 23, 2015, to December 12, 2016. Duration of follow-up for censored patients was 12.2 months through August 31, 2017.

Interventions

The vaccine ISA101, 100 μg/peptide, was given subcutaneously on days 1, 22, and 50. Nivolumab, 3 mg/kg, was given intravenously every 2 weeks beginning day 8 for up to 1 year.

Main Outcomes and Measures

Assessment of efficacy reflected in the overall response rate (per Response Evaluation Criteria in Solid Tumors, version 1.1).

Results

Of the 24 patients (4 women and 20 men; 22 with oropharyngeal cancer; median age, 60 years [range, 36-73 years]), the overall response rate was 33% (8 patients; 90% CI, 19%-50%). Median duration of response was 10.3 months (95% CI, 10.3 months to inestimable). Five of 8 patients remain in response. Median progression-free survival was 2.7 months (95% CI, 2.5-9.4 months). Median overall survival was 17.5 months (95% CI, 17.5 months to inestimable). Grades 3 to 4 toxicity occurred in 2 patients (asymptomatic grade 3 transaminase level elevation in 1 patient and grade 4 lipase elevation in 1 patient), requiring discontinuation of nivolumab therapy.

Conclusions and Relevance

The overall response rate of 33% and median overall survival of 17.5 months is promising compared with PD-1 inhibition alone in similar patients. A randomized clinical trial to confirm the contribution of HPV-16 vaccination to tumoricidal effects of PD-1 inhibition is warranted for further study.

Trial Registration

ClinicalTrials.gov identifier: NCT02426892.

High OX-40 expression in the tumor immune infiltrate is a favorable prognostic factor of overall survival in non-small cell lung cancer

Introduction

OX-40 co-stimulatory signaling plays a role in mounting anti-tumor immune responses and clinical trials targeting this pathway are ongoing. However, the association of with OX-40 protein expression with clinical outcomes and pathological features in non-small cell lung cancer (NSCLC) are largely unknown.

Methods

Surgically-resected stage I-III NSCLC specimens (N = 100) were stained by immunohistochemistry (IHC) for the following immune markers: OX-40, PD-L1, PD-1, CD3, CD4, CD8, CD45RO, CD57, CD68, FOXP3, granzyme B, and ICOS. Immune-related markers mRNA expression were also assessed. We evaluated the association of OX-40 levels with major clinicopathologic variables, including molecular driver mutations.

Results

OX-40 IHC expression was observed in all tested tumors, predominantly localized in the membrane of the tumor immune infiltrate, and was not associated with a specific clinicopathologic or molecular subtype. High OX-40 expression levels measured by IHC median score were associated with better overall survival (OS) (p = 0.002), independent of CD3/CD8, PD-L1, and ICOS expression. High OX-40 IHC score was associated with increased expression of immune-related genes such as CD3, IFN-gamma, ICOS, CD8, CXCL9, CXCL10, CCL5, granzyme K.

Conclusions

High OX-40 IHC expression in the tumor immune infiltrate is associated with favorable prognosis and increased levels of immune-related genes including IFN-gamma in patients with surgically resected stage I-III NSCLC. Its prognostic utility is independent of PD-L1 and other common markers of immune activation. High OX-40 expression potentially identifies a unique subgroup of NSCLC that may benefit from co-stimulation with OX-40 agonist antibodies and potentially enhance the efficacy of existing immune checkpoint therapies.

A CTC-Cluster-Specific Signature Derived from OMICS Analysis of Patient-Derived Xenograft Tumors Predicts Outcomes in Basal-Like Breast Cancer

Circulating tumor cell clusters (CTCcl) have a higher metastatic potential compared to single CTCs and predict long-term outcomes in breast cancer (BC) patients. Because of the rarity of CTCcls, molecular characterization of primary tumors that give rise to CTCcl hold significant promise for better diagnosis and target discovery to combat metastatic BC. In our study, we utilized the reverse-phase protein array (RPPA) and transcriptomic (RNA-Seq) data of 10 triple-negative BC patient-derived xenograft (TNBC PDX) transplantable models with CTCs and evaluated expression of upregulated candidate protein Bcl2 (B-cell lymphoma 2) by immunohistochemistry (IHC). The sample-set consisted of six CTCcl-negative (CTCcl-) and four CTCcl-positive (CTCcl+) models. We analyzed the RPPA and transcriptomic profiles of CTCcl- and CTCcl+ TNBC PDX models. In addition, we derived a CTCcl-specific gene signature for testing if it predicted outcomes using a publicly available dataset from 360 patients with basal-like BC. The RPPA analysis of CTCcl+ vs. CTCcl- TNBC PDX tumors revealed elevated expression of Bcl2 (false discovery rate (FDR) < 0.0001, fold change (FC) = 3.5) and reduced acetyl coenzyme A carboxylase-1 (ACC1) (FDR = 0.0005, FC = 0.3) in CTCcl+ compared to CTCcl- tumors. Genome-wide transcriptomic analysis of CTCcl+ vs. CTCcl- tumors revealed 549 differentially expressed genes associated with the presence of CTCcls. Apoptosis was one of the significantly downregulated pathways (normalized enrichment score (NES) = -1.69; FDR < 0.05) in TNBC PDX tumors associated with CTCcl positivity. Two out of four CTCcl+ TNBC PDX primary tumors had high Bcl2 expression by IHC (H-score > 34); whereas, only one of six CTCcl- TNBC PDX primary tumors met this criterion. Evaluation of epithelial-mesenchymal transition (EMT)-specific signature did not show significant differences between CTCcl+ and CTCcl- tumors. However, a gene signature associated with the presence of CTCcls in TNBC PDX models was associated with worse relapse-free survival in the publicly available dataset from 360 patients with basal-like BC. In summary, we identified the multigene signature of primary PDX tumors associated with the presence of CTCcls. Evaluation of additional TNBC PDX models and patients can further illuminate cellular and molecular pathways facilitating CTCcl formation.

The landscape of immune microenvironment in lung adenocarcinoma and squamous cell carcinoma based on PD-L1 expression and tumor-infiltrating lymphocytes

AIMS

The aim of this study was to investigate the tumor microenvironment immune types (TMIT) based on tumor cell programmed cell death ligand 1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs) distribution and whether distinct TMIT subtypes (TMIT I, PD-L1^high /TIL^high ; TMIT II, PD-L1^low /TIL^low ; TMIT III, PD-L1^high /TIL^low ; and TMIT IV, PD-L1^low /TIL^high ) differentially affect clinical outcomes of patients with lung adenocarcinoma (LAC) and squamous cell carcinoma (SCC).

METHODS AND RESULTS

Immunohistochemistry (IHC) was applied to evaluate the expression of PD-L1 and the spatial distribution of programmed cell death 1 (PD-1) and CD8 TILs on the surgically resected specimens from 205 cases of LAC and 149 cases of SCC. PD-1 and CD8 TILs were more frequently distributed in SCC than those in LAC, regardless of their infiltrating in the tumor islets or stroma. The density of TILs was a poor prognostic factor in LAC but a favorable one in SCC. PD-L1 levels and its clinical prognostic significance differed in LAC vs SCC. LAC patients with TMIT III and SCC patients with TMIT I had the longest survival, respectively (P = .0197 and .0049). Moreover, TMIT stratification based on tumor cell PD-L1 expression and stromal CD8⁺ TILs could be considered as an independent prognostic factor of SCC patients' survival as determined by both univariate and multivariate analysis.

CONCLUSION

Our study indicates that different type of TMIT provides its specific microenvironment with diverse impact on survival of LAC and SCC patients and highlights the importance of the integrative assessment of PD-L1 status and TILs' spatial distribution to predict patients' prognosis.

Tumor cellular proliferation is associated with enhanced immune checkpoint expression in stage I non-small cell lung cancer

OBJECTIVES

Ki67 is a marker for tumor proliferative activity and is known to have prognostic significance in multiple solid malignancies. We sought to characterize the relationships among Ki67 expression, immune cell infiltration, and immune checkpoint expression in patients with resected non-small cell lung cancer.

METHODS

Specimens of patients undergoing resection of stage I to III non-small cell lung cancer (1997-2012) were analyzed using tissue microarrays. Proliferative index was quantified as the percentage of malignant cells expressing Ki67. Checkpoints expressed on malignant cells (programmed death ligand 1, B7H3, B7H4, indoleamine 2,3-dioxygenase 1) and lymphocytes (T-cell immunoglobulin and mucin-domain containing 3, V-domain suppressor of T-cell activation, tumor necrosis factor receptor superfamily member 4, lymphocyte activation gene 3, inducible T-cell co-stimulator) were analyzed in intratumoral and stromal compartments, respectively. Immune cell densities were quantified in intratumoral and peritumoral compartments in a representative subset.

RESULTS

A total of 190 patients met inclusion criteria. Higher Ki67 expression was noted in squamous cell carcinoma (median 31.4% positive malignant cells vs 15.2% adenocarcinoma, P < .001), advanced-stage tumors (25.7% stages II/III vs 20.8% stage I, P = .013), and poorly differentiated tumors (28.8% vs 15.4% well/moderately, P < .001). Ki67 was positively correlated with intratumoral expression of programmed death ligand 1, B7-H3, and indoleamine 2,3-dioxygenase 1, and elevated stromal expression of lymphocyte activation gene 3 and inducible T-cell co-stimulator. Ki67 expression was inversely associated with intratumoral densities of CD57+ and CD4+ cells. The relationship between Ki67 and checkpoint expression was strongest in stage I tumors. Among patients with stage I, increased Ki67 was independently associated with worse overall survival.

CONCLUSIONS

Increased Ki67 expression is associated with biologically aggressive non-small cell lung cancer, enhanced immune checkpoint expression, and reduced intratumoral immune cell infiltration. These findings were strongest in early-stage disease and warrant further investigation in the context of novel therapeutic agents.

PD-L1 Expression and Immune Cell Infiltration in Gastroenteropancreatic (GEP) and Non-GEP Neuroendocrine Neoplasms With High Proliferative Activity

The potential of neuroendocrine neoplasms (NEN) to respond to checkpoint inhibitors is largely unknown and full of great expectations. Immunohistochemical (IHC) studies of programmed cell death ligand 1 (PD-L1) expression in the tumor microenvironment and its implications in predicting the response to checkpoint inhibition is a very active subject. Currently, the combined analysis of PD-L1 expression and tumor-associated immune cell (TAIC) infiltration is considered the best predictive marker of therapeutic response. Here we investigated the expression of PD-L1 on tumor cells (TC) and tumor-infiltrating immune cells (IC) by IHC in 68 NEN samples with a high proliferation rate (Ki-67 >20%) from 57 patients and in 22 samples we correlated it with TAIC density by assessing intratumoral infiltration of CD3+, CD8+, and CD68+ cells. Furthermore, the tumor microenvironment was evaluated according to the classification of Teng et al. We detected PD-L1 expression in 31.6% of NEN G3. Its expression usually was weak and more IC than TC expressed PD-L1. The proportion of tumors positive for PD-L1 was comparable in NEN from different sites of origin but varied depending on tumor differentiation and disease extension. No positive IHC staining was found in 3 well-differentiated neuroendocrine tumors (NETs) with a proliferation rate above 20% (NET G3). When analyzing TAIC, we rarely (18.2%) detected intratumoral CD8+ cells, whereas infiltration by CD3+ and CD68+ cells was more common (45.5 and 59.1%, respectively). By combining CD3+ cells and PD-L1 status, we identified the immune ignorant phenotype of tumor microenvironment as being the most common phenotype, supporting the concept of a preferably combined immunotherapeutic approach in neuroendocrine carcinoma (NEC).

Combination of Peri- and Intratumoral Radiomic Features on Baseline CT Scans Predicts Response to Chemotherapy in Lung Adenocarcinoma

Purpose

To identify the role of radiomics texture features both within and outside the nodule in predicting (a) time to progression (TTP) and overall survival (OS) as well as (b) response to chemotherapy in patients with non-small cell lung cancer (NSCLC).

Materials and Methods

Data in a total of 125 patients who had been treated with pemetrexed-based platinum doublet chemotherapy at Cleveland Clinic were retrospectively analyzed. The patients were divided randomly into two sets with the constraint that there were an equal number of responders and nonresponders in the training set. The training set comprised 53 patients with NSCLC, and the validation set comprised 72 patients. A machine learning classifier trained with radiomic texture features extracted from intra- and peritumoral regions of non-contrast-enhanced CT images was used to predict response to chemotherapy. The radiomic risk-score signature was generated by using least absolute shrinkage and selection operator with the Cox regression model; association of the radiomic signature with TTP and OS was also evaluated.

Results

A combination of radiomic features in conjunction with a quadratic discriminant analysis classifier yielded a mean maximum area under the receiver operating characteristic curve (AUC) of 0.82 ± 0.09 (standard deviation) in the training set and a corresponding AUC of 0.77 in the independent testing set. The radiomics signature was also significantly associated with TTP (hazard ratio [HR], 2.8; 95% confidence interval [CI]: 1.95, 4.00; P < .0001) and OS (HR, 2.35; 95% CI: 1.41, 3.94; P = .0011). Additionally, decision curve analysis demonstrated that in terms of clinical usefulness, the radiomics signature had a higher overall net benefit in prediction of high-risk patients to receive treatment than the clinicopathologic measurements.

Conclusion

This study suggests that radiomic texture features extracted from within and around the nodule on baseline CT scans are (a) predictive of response to chemotherapy and (b) associated with TTP and OS for patients with NSCLC.© RSNA, 2019Supplemental material is available for this article.

Distribution of PD-L1 expression and its relationship with clinicopathological variables: an audit from 1071 cases of surgically resected non-small cell lung cancer

BACKGROUND

Programmed death ligand 1 (PD-L1) was reported to predict the response of immunotherapy; however, the association between PD-L1 expression and clinicopathologic characteristics has yet to be elucidated in non-small cell lung cancer (NSCLCs).

MATERIALS AND METHODS

We reviewed PDL1 expression investigated by immunohistochemical analysis using FFPE tissue in a total of 1071 cases of primary or metastatic NSCLC tissues analyzed between 2015-2017, and evaluated the association between PD-L1 expression and the clinicopathologic characteristics.

RESULTS

PD-L1 expression was observed in 361 (33.7%) cases with positive staining in at least 1% tumor cells and 116 (10.8%) cases had positive staining in ≥50% tumor cells. The PD-L1 positive prevalence was significantly higher in squamous cell carcinoma (SCC) than in adenocarcinoma (AD). In the AD subgroup, PD-L1 expression on tumors was higher in males and smokers, and with high histologic grade, relative high T, N, M status, advanced AJCC stage, and in ALK rearrangement patients. However, EGFR mutated patients showed relatively lower PD-L1 expression than wild type patients.

CONCLUSION

This study revealed the unique distribution of PD-L1 expression with clinicopathologic features in East Asian NSCLCs in a single, large cohort of patients. Since immunohistochemistry of the PD-L1 protein (PD-L1 IHC) is the only clinically approved predictive biomarker for anti-PD-1/-PD-L1 therapy currently, our outcomes could help to stratify patients to ensure selection of those who would most benefit from PD-1/PD- L1 inhibitor therapy.

Multiplexed Immunohistochemistry for Molecular and Immune Profiling in Lung Cancer-Just About Ready for Prime-Time?

As targeted molecular therapies and immuno-oncology have become pivotal in the management of patients with lung cancer, the essential requirement for high throughput analyses and clinical validation of biomarkers has become even more intense, with response rates maintained in the 20%–30% range. Moreover, the list of treatment alternatives, including combination therapies, is rapidly evolving. The molecular profiling and specific tumor-associated immune contexture may be predictive of response or resistance to these therapeutic strategies. Multiplexed immunohistochemistry is an effective and proficient approach to simultaneously identify specific proteins or molecular abnormalities, to determine the spatial distribution and activation state of immune cells, as well as the presence of immunoactive molecular expression. This method is highly advantageous for investigating immune evasion mechanisms and discovering potential biomarkers to assess mechanisms of action and to predict response to a given treatment. This review provides views on the current technological status and evidence for clinical applications of multiplexing and how it could be applied to optimize clinical management of patients with lung cancer.

Surgical Resection of SCLC: Prognostic Factors and the Tumor Microenvironment

INTRODUCTION

Surgery in SCLC is limited to very early stages, but several reports suggest a potential broader role. Little is known of the influence of microenvironment on the biology of SCLC.

METHODS

We assessed the clinical prognostic factors in a large series of resected SCLC patients. The prognostic value of programmed cell death ligand 1 (PD-L1) expression in tumor cells and tumor infiltrating lymphocytes (TILs) and the percentage of CD3-, CD20-, CD45- and CD68-positive cells, were also investigated.

RESULTS

Two hundred five SCLC cases were resected between 2005 and 2015 and the median follow-up was 29 months (range: 2 to 135 months). Median survival of all patients was 69 months, and 5-year survival rates were 63.8%, 65.5%, 34.9%, and 0% for pathologic stages I, II, III, and IV, respectively. By multivariate analysis complete resection, cigarette index, lymph node metastatic rate, percentage of CD3-positive cells, PD-L1 expression in tumor cells, and TILs were independent prognostic factors. High PD-L1 expression was present in 3.2% and 33.5% of all tumor samples in tumor cells and TILs, respectively. High PD-L1 expression in tumor cells or TILs correlated with shorter survival, whereas high expression of CD3, CD20, and CD45 correlated with better survival.

CONCLUSIONS

Resected stage II SCLC patients have similar survival as stage I, suggesting that surgery could be extended to patients with hilar lymph node involvement. Survival was better in tumors with a higher percentage of T cells and B cells, whereas PD-L1 expression in tumor cells and TILs correlated with worse survival, which suggests a potential role of immunotherapy in resected SCLC.

Predictive biomarkers of response for immune checkpoint inhibitors in non-small-cell lung cancer

Immune checkpoint blockade has been a pivotal development in the management of advanced non-small-cell lung cancer (NSCLC). Although durable antitumour activity and improved survival have been observed in a subset of patients, there is a need for additional predictive biomarkers to improve patient selection and avoid toxicity in potential non-responders. This review will address the use and limitations of tumour programmed death-ligand 1 expression as a predictive biomarker and review emerging biomarker strategies specifically related to NSCLC including genetic alterations (tumour mutation burden, loss and gain activated mutations), tumour-related factors (tumour microenvironment) and factors related to the host immune system. Novel approaches in biomarker detection such as peripheral blood monitoring will also be reviewed.

TCR repertoire intratumor heterogeneity of CD4+ and CD8+ T cells in centers and margins of localized lung adenocarcinomas

Intratumor heterogeneity (ITH) of T cell receptor (TCR) repertoire in different T-cell subsets and locations in lung adenocarcinomas was unclear. Here, we investigated percentages and TCR repertoire of freshly isolated CD4⁺ and CD8⁺ tumor infiltrating lymphocytes (TILs) in tumor centers and margins by flow cytometry on 80 tumor samples from 20 patients and high-throughput TCR sequencing on 27 and 25 samples of CD4⁺ and CD8⁺ TILs from seven patients. Our results demonstrated that amount and TCR repertoire diversity of CD4⁺ TILs were significantly higher than those of CD8⁺ TILs and moreover substantial ITH regarding amount and TCR repertoire of CD4⁺ and CD8⁺ TILs were observed. Additionally, ITH of CD4/CD8 T-cell ratio and CD8⁺ TIL repertoire across center regions was lower than that across margin regions. The amount and TCR repertoire ITH of CD4⁺ and CD8⁺ TILs and mean clonality of CD8⁺ TILs in tumor centers were associated with relapse. Our study provides insights into amount and TCR repertoire ITH of CD4⁺ and CD8⁺ TILs in tumor centers and margins as well as corresponding association with prognosis in lung adenocarcinoma patients, suggesting potential clinical significance of TCR repertoire.

Immune Microenvironment Differences Between Squamous and Non-squamous Non-small-cell Lung Cancer and Their Influence on the Prognosis

INTRODUCTION

Checkpoint blockades have entered routine clinical use for non-small-cell lung cancer (NSCLC). However, there were some differences in efficacy and response predictors for anti-programmed cell death protein 1 (PD-1) antibodies between squamous (SQ) and nonsquamous (non-SQ) NSCLC. The study aims to elucidate the possible difference in immune microenvironment between SQ-NSCLC and non-SQ-NSCLC and their influence on the prognosis.

PATIENTS AND METHODS

A total of 197 patients with stages I to III NSCLC were included. cluster of differentiation 8 (CD8), cluster of differentiation 4 (CD4), transcription factor forkhead box P3 (FOXP3), and programmed death-ligand 1 (PD-L1) expression were examined in cancer nest and stroma on 85 SQ-NSCLC and 112 non-SQ-NSCLC samples using immunohistochemistry.

RESULTS

More CD8+ tumor infiltrating lymphocytes (TILs) were detected in the cancer nests (cCD8) from patients with SQ-NSCLC than those with non-SQ-NSCLC (56% vs. 34%; P = .002). There were no significant differences between the SQ and non-SQ groups in terms of other TIL markers or PD-L1 expression. Multivariate analysis showed that the degree of cCD8+ TIL infiltration was an independent positive predictor for overall survival (OS) in the SQ-NSCLC group (P = .003) and in the non-SQ-NSCLC group (P = .024). In the univariate analysis, CD8+ TILs in the stroma, CD4+ TILs in the cancer nest and stroma, and FOXP3+ TILs in the cancer stroma associated with different prognoses for patients with either non-SQ-NSCLC or SQ-NSCLC. Using a 10% cutoff, PD-L1 expression was a poor prognostic factor in total NSCLC (P = .011), stage I (P = .037), SQ-NSCLC (P = .097), and non-SQ-NSCLC (P = .051).

CONCLUSION

The different cCD8+ TIL profile and different prognostic value with certain TILs indicates that SQ-NSCLC and non-SQ-NSCLC are likely different cancer types with respect to their immune microenvironments.

Avelumab versus docetaxel in patients with platinum-treated advanced non-small-cell lung cancer (JAVELIN Lung 200): an open-label, randomised, phase 3 study

BACKGROUND

Antibodies targeting the immune checkpoint molecules PD-1 or PD-L1 have demonstrated clinical efficacy in patients with metastatic non-small-cell lung cancer (NSCLC). In this trial we investigated the efficacy and safety of avelumab, an anti-PD-L1 antibody, in patients with NSCLC who had already received platinum-based therapy.

METHODS

JAVELIN Lung 200 was a multicentre, open-label, randomised, phase 3 trial at 173 hospitals and cancer treatment centres in 31 countries. Eligible patients were aged 18 years or older and had stage IIIB or IV or recurrent NSCLC and disease progression after treatment with a platinum-containing doublet, an Eastern Cooperative Oncology Group performance status score of 0 or 1, an estimated life expectancy of more than 12 weeks, and adequate haematological, renal, and hepatic function. Participants were randomly assigned (1:1), via an interactive voice-response system with a stratified permuted block method with variable block length, to receive either avelumab 10 mg/kg every 2 weeks or docetaxel 75 mg/m² every 3 weeks. Randomisation was stratified by PD-L1 expression (≥1% vs <1% of tumour cells), which was measured with the 73-10 assay, and histology (squamous vs non-squamous). The primary endpoint was overall survival, analysed when roughly 337 events (deaths) had occurred in the PD-L1-positive population. Efficacy was analysed in all PD-L1-positive patients (ie, PD-L1 expression in ≥1% of tumour cells) randomly assigned to study treatment (the primary analysis population) and then in all randomly assigned patients through a hierarchical testing procedure. Safety was analysed in all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT02395172. Enrolment is complete, but the trial is ongoing.

FINDINGS

Between March 24, 2015, and Jan 23, 2017, 792 patients were enrolled and randomly assigned to receive avelumab (n=396) or docetaxel (n=396). 264 participants in the avelumab group and 265 in the docetaxel group had PD-L1-positive tumours. In patients with PD-L1-positive tumours, median overall survival did not differ significantly between the avelumab and docetaxel groups (11·4 months [95% CI 9·4-13·9] vs 10·3 months [8·5-13·0]; hazard ratio 0·90 [96% CI 0·72-1·12]; one-sided p=0·16). Treatment-related adverse events occurred in 251 (64%) of 393 avelumab-treated patients and 313 (86%) of 365 docetaxel-treated patients, including grade 3-5 events in 39 (10%) and 180 (49%) patients, respectively. The most common grade 3-5 treatment-related adverse events were infusion-related reaction (six patients [2%]) and increased lipase (four [1%]) in the avelumab group and neutropenia (51 [14%]), febrile neutropenia (37 [10%]), and decreased neutrophil counts (36 [10%]) in the docetaxel group. Serious treatment-related adverse events occurred in 34 (9%) patients in the avelumab group and 75 (21%) in the docetaxel group. Treatment-related deaths occurred in four (1%) participants in the avelumab group, two due to interstitial lung disease, one due to acute kidney injury, and one due to a combination of autoimmune myocarditis, acute cardiac failure, and respiratory failure. Treatment-related deaths occurred in 14 (4%) patients in the docetaxel group, three due to pneumonia, and one each due to febrile neutropenia, septic shock, febrile neutropenia with septic shock, acute respiratory failure, cardiovascular insufficiency, renal impairment, leucopenia with mucosal inflammation and pyrexia, infection, neutropenic infection, dehydration, and unknown causes.

INTERPRETATION

Compared with docetaxel, avelumab did not improve overall survival in patients with platinum-treated PD-L1-positive NSCLC, but had a favourable safety profile.

FUNDING

Merck and Pfizer.

Computational measurement of tumor immune microenvironment in gastric adenocarcinomas

The use of four groups of tumor immune microenvironments (TME) based on PD-L1 and tumor-infiltrating T lymphocytes (TIL) is a reliable biomarker for anti-PD-1/PD-L1 inhibitor therapy. We classified the TME in 241 gastric cancers which were subdivided according to 40 EBV+, 76 microsatellite instability-high (MSI-H), and 125 EBV-/microsatellite-stable (MSS) subtypes by quantitative image analysis (QIA) and correlated the results with mRNA expression levels. The mean PD-L1 ratio and CD8 ratio in EBV+, MSI-H, and EBV−/MSS GCs were significantly different (P < 0.006). The PD-L1 ratio and CD8 ratio obtained by QIA correlated well with the RNA levels of PD-L1 (r = 0.63) and CD8 (r = 0.67), respectively. The TME were type I (PD-L1^H/CD8^H) in 45, type II (PD-L1^L/CD8^L) in 106, type III (PD-L1^H/CD8^L) in 8, and type IV (PD-L1^L/CD8^H) in 82 cases. The type I TME was significantly associated with high TIL (P = 3.0E-11) and EBV+ status (P = 8.55E-08). In conclusion, QIA results correlated well with the mRNA expression levels and classified TME of gastric cancers.

Chromogenic Multiplex Immunohistochemistry Reveals Modulation of the Immune Microenvironment Associated with Survival in Elderly Patients with Lung Adenocarcinoma

With underrepresentation of elderly patients with lung adenocarcinoma (LADC) in anti-PD-1/PD-L1 clinical trials, better understanding of the interplay of PD-L1 and tumor-associated immune cells (TAICs) could assist clinicians in stratifying these patients for immunotherapy. One hundred and one patients with LADCs, stratified by age, were included for analysis of PD-L1 expression and density of TAICs expressing CD4, CD8, and CD33, by using multiplex chromogenic immunohistochemistry (IHC) assays and automated digital quantification. The CD4⁺/CD8⁺ ratio was significantly higher in elderly patients. In patients <75 years, the density of CD4⁺, CD8⁺, and PD-L1 in TAICs showed a positive significant correlation with PD-L1 expression in tumor cells (TCs), while a lower correlation was observed in the elderly population. In the latter, a high CD4⁺/CD8⁺ ratio, and combined PD-L1 expression ≥1% TCs with a low CD8⁺ density, low CD33⁺ density, and a high CD4⁺ density correlated to worse overall survival. We identified differences according to age in the CD4⁺/CD8⁺ ratio and in correlation between PD-L1 expression and the density of TAICs in LADC patients. Distinct groups of tumor microenvironments had an impact on the OS of elderly patients with LADC.

Comparison of Different Antibody Clones for Immunohistochemistry Detection of Programmed Cell Death Ligand 1 (PD-L1) on Non-Small Cell Lung Carcinoma

Programmed cell death ligand 1 (PD-L1) is a major immune checkpoint protein that mediates antitumor immune suppression and response. Preliminary data suggest that its detection using immunohistochemistry (IHC) in formalin-fixed and paraffin-embedded tissues may predict clinical response to PD-1/PD-L1 therapy. In diagnostic pathology, it is essential to count with a validated IHC that can reliably detect PD-L1-positive cases. The present study was conducted to compare and validate different PD-L1 commercial clones and identify which ones can be reliably used by surgical pathologist to detect PD-L1 expression in human cancer tissues. Eight commercial available PD-L1 clones were tested and compared with a noncommercial PD-L1 antibody clone 5H1. Western blot and IHC using cell lines and human tissues were used to validate these clones. From all PD-L1 antibodies, only the clones E1L3N, E1J2J, SP142, 28-8, 22C3, and SP263 passed the Western blot and IHC validation, providing similar pattern than the clone 5H1 and then they were tested in 259 non–small cell lung cancer cases placed in 9 tissue microarrays. Among all cases, only those with ≥2 cores were included (185 cases). Positive and significant correlation was found between the median PD-L1 H-score in tumor and stroma compartments, for all selected antibodies. Overall, 56 of 185 cases were detected as positive cases in malignant cells expressing membranous PD-L1 by all the clones. However, the clone SP263 identified more PD-L1-positive cases compared with the other clones. Our results show that clones E1L3N, E1J2J, SP142, 28-8, 22C3, and SP263 provide positive membrane staining pattern comparable with clone 5H1. These commercial clones are comparable, but a careful evaluation by the pathologist is necessary to minimize error of positive misinterpretations.

The prognostic value of PD-L1 expression in upper tract urothelial carcinoma varies according to platelet count

Programmed cell death ligand-1 (PD-L1) is a ligand for programmed cell death-1 (PD-1) that negatively regulates T-cell activation and plays a crucial role in suppressing anti-tumor host immunity. Although PD-L1 is a promising immunotherapy target in various cancers, including urothelial carcinoma (UC), the prognostic significance of PD-L1 in UC is unclear. As platelets help protect tumor cells from immune elimination in the circulatory system, we hypothesized that tumor PD-L1 and circulating platelets might synergistically promote tumor metastasis, and that the prognostic significance of PD-L1 might vary according to platelet count. We immunohistochemically examined tumor PD-L1 expression in 271 patients with upper tract UC, which revealed PD-L1 positivity in 31 of 271 cases (11%). The associations of tumor PD-L1 expression with outcomes varied among patients with high or low platelet counts (P_interaction  < 0.004). Among patients with high platelet counts (N = 136), PD-L1 positivity (N = 15) was significantly associated with shorter metastasis-free survival (univariate hazard ratio [HR]: 6.23, 95% confidence interval [CI]: 2.95-13.1; multivariate HR: 2.68, 95% CI: 1.27-5.64) and shorter overall survival (univariate HR: 4.92, 95% CI: 2.14-11.3, multivariate HR: 2.78, 95% CI: 1.19-6.51). In contrast, among patients with low platelet counts (N = 135), PD-L1 positivity (N = 16) was not significantly associated with these outcomes. Our results suggest that tumor PD-L1 expression and platelet count might interact and help regulate tumor progression. Although a larger prospective study is needed to validate our findings, this relationship is important to consider, as immunotherapies targeting the PD-1/PD-L1 axis have gained significant attention as promising therapies for UC.

PD-L1 immunostaining scoring for non-small cell lung cancer based on immunosurveillance parameters

Non-Small Cell Lung Cancer (NSCLC) is the leading cause of cancer death globally, and new immunotherapies developed and under development targeting PD-1/PD-L1 checkpoint inhibition require accurate patient selection to assure good clinical outcome. PD-L1 immunohistochemistry is the current biomarker assay used for patient selection, but still imprecise in predicting therapy response. Exploring this issue, we performed computational tissue analysis of PD-L1 immunostaining in procured NSCLC tissues (n = 50) using the Merck KGaA anti-PD-L1 clone MKP1A07310. Staining patterns and PD-L1 cut-off points were interrogated using relevant cancer immune-surveillance biomarkers. Groups with high PD-L1 expression levels (above 25/50% staining cut-off points) were enriched for a biomarker profile in the tumor-nest and microenvironment indicating escape from host-immunity, as represented by increased numbers of cells positive for CD8 and Granzyme B (immune-effectors), FOXP3 (immune-suppressive), and CD68 (P < 0.05). Manual analysis of PD-L1 staining patterns identified tumors with an immune-induced reactive pattern relevant for immunotherapy that would ordinarily be excluded by the arbitrary 25% staining threshold (P < 0.05). Conversely, some cases with completely or predominantly immune-independent constitutive PD-L1 staining patterns that indicate insensitivity to immunotherapy may have been incorrectly selected using this staining cut-off point criterion. Therefore, we propose differentiation of reactive vs constitutive PD-L1 staining patterns to improve the accuracy of this biomarker assay in selecting NSCLC patients for PD-1/PD-L1 immunotherapy.

The non-small cell lung cancer immune landscape: emerging complexity, prognostic relevance and prospective significance in the context of immunotherapy

Immunotherapy of non-small cell lung cancer (NSCLC), by immune checkpoint inhibitors, has profoundly improved the clinical management of advanced disease. However, only a fraction of patients respond and no effective predictive factors have been defined. Here, we discuss the prospects for identification of such predictors of response to immunotherapy, by fostering an in-depth analysis of the immune landscape of NSCLC. The emerging picture, from several recent studies, is that the immune contexture of NSCLC lesions is a complex and heterogeneous feature, as documented by analysis for frequency, phenotype and spatial distribution of innate and adaptive immune cells, and by characterization of functional status of inhibitory receptor+ T cells. The complexity of the immune landscape of NSCLC stems from the interaction of several factors, including tumor histology, molecular subtype, main oncogenic drivers, nonsynonymous mutational load, tumor aneuploidy, clonal heterogeneity and tumor evolution, as well as the process of epithelial-mesenchymal transition. All these factors contribute to shape NSCLC immune profiles that have clear prognostic significance. An integrated analysis of the immune and molecular profile of the neoplastic lesions may allow to define the potential predictive role of the immune landscape for response to immunotherapy.

Immunotherapy in non-small-cell lung cancer: a bridge between research and clinical practice

Lung cancer has been historically considered a poorly immunogenic disease because of the few evidence of immune responses in affected patients and the limited efficacy of immunomodulating strategies. Recent understanding of the molecular mechanisms leading to cancer immune evasion has allowed the development of a new class of drugs called immune checkpoint inhibitors, which reactivate host responses with outstanding clinical benefits in a portion of patients with non-small-cell lung cancer. In this review, we briefly summarize the basis of immunogenicity and immune escape of cancer, with specific focus on non-small-cell lung cancer, mechanisms underlying immune checkpoint inhibitors efficacy and the most updated results on potential biomarkers, with the final aim of defining current unmet needs of immunotherapy in clinical practice.

Phase I Study of DNX-2401 (Delta-24-RGD) Oncolytic Adenovirus: Replication and Immunotherapeutic Effects in Recurrent Malignant Glioma

Purpose DNX-2401 (Delta-24-RGD; tasadenoturev) is a tumor-selective, replication-competent oncolytic adenovirus. Preclinical studies demonstrated antiglioma efficacy, but the effects and mechanisms of action have not been evaluated in patients. Methods A phase I, dose-escalation, biologic-end-point clinical trial of DNX-2401 was conducted in 37 patients with recurrent malignant glioma. Patients received a single intratumoral injection of DNX-2401 into biopsy-confirmed recurrent tumor to evaluate safety and response across eight dose levels (group A). To investigate the mechanism of action, a second group of patients (group B) underwent intratumoral injection through a permanently implanted catheter, followed 14 days later by en bloc resection to acquire post-treatment specimens. Results In group A (n = 25), 20% of patients survived > 3 years from treatment, and three patients had a ≥ 95% reduction in the enhancing tumor (12%), with all three of these dramatic responses resulting in > 3 years of progression-free survival from the time of treatment. Analyses of post-treatment surgical specimens (group B, n = 12) showed that DNX-2401 replicates and spreads within the tumor, documenting direct virus-induced oncolysis in patients. In addition to radiographic signs of inflammation, histopathologic examination of immune markers in post-treatment specimens showed tumor infiltration by CD8+ and T-bet+ cells, and transmembrane immunoglobulin mucin-3 downregulation after treatment. Analyses of patient-derived cell lines for damage-associated molecular patterns revealed induction of immunogenic cell death in tumor cells after DNX-2401 administration. Conclusion Treatment with DNX-2401 resulted in dramatic responses with long-term survival in recurrent high-grade gliomas that are probably due to direct oncolytic effects of the virus followed by elicitation of an immune-mediated antiglioma response.

Co-expression of NGF and PD-L1 on tumor-associated immune cells in the microenvironment of Merkel cell carcinoma

PURPOSE

Merkel cell carcinoma (MCC) is a malignant neuroendocrine skin tumor with known viral association. The microenvironment and its interaction with the tumor via the programmed cell death protein 1 (PD-1) pathway are crucial for response to anti-PD-1/anti-PD-L1 treatments. However, not all patients respond, which is suggestive of additional mechanisms for tumor growth and/or persistence. We previously detected tropomyosin receptor kinase A (TrkA) expression on MCC tumor cells and, therefore, gained interest in the expression of its ligand nerve growth factor (NGF).

METHODS

Thirty-nine patients from our department were studied for immunohistochemical NGF, PD-1, and PD-L1 expression and clinico-pathological correlation.

RESULTS

PD-L1 was expressed on the tumor cells in 42%. In 95%, PD-L1 expression was also found on CD68+ spindle cells at the tumor border, which co-expressed NGF in 71%. 66% contained PD-1+ tumor infiltrating lymphocytes. PD-1, PD-L1, and NGF expression seems to correlate with a worse outcome.

CONCLUSIONS

The present study shows that PD-L1 and NGF are co-expressed on spindle cells in the microenvironment. The expression of NGF might be a link of the microenvironment to the TrkA-positive tumor cells. Whether this mechanism is critical for tumor growth and lack of response to anti-PD-1/L1 treatment has to be investigated in further studies.

Intratumoral immune cells expressing PD-1/PD-L1 and their prognostic implications in cancer: a meta-analysis

BACKGROUND

The prognostic value of immune cells expressing programmed cell death 1 (PD-1) and PD-1 ligand 1 (PD-L1) in cancer are controversial, and the potential differential impact of using tissue microarrays and whole tissue sections to assess the positivity of immune cells has not been addressed.

METHODS

The current study included 30 eligible studies with 7251 patients that evaluated the relationship between tumor-infiltrating lymphocytes expressing PD-1/PD-L1 and overall survival and disease-free survival, or progression-free survival. Subgroup analysis was based on the tissue type of cancer and the type of tissue sampling (tissue microarray or whole tissue section).

RESULTS

In the meta-analysis, PD-1-positive and PD-L1-positive tumor-infiltrating lymphocytes had a positive effect on disease-free survival or progression-free survival (hazard ratio [HR] 0.732; 95% confidence interval [CI] 0.565, 0.947; and HR 0.727; 95% CI 0.584, 0.905, respectively). PD-L1-positive tumor-infiltrating lymphocytes had a positive impact on overall survival in studies using tissue microarray (HR 0.586; 95% CI 0.476, 0.721), but had a poor impact when only whole tissue sections were considered (HR 1.558; 95% CI 1.232, 1.969). Lung cancer was associated with good overall survival and disease-free survival (HR 0.639; 95% CI 0.491, 0.831; and HR 0.693; 95% CI 0.538, 0.891, respectively) for PD-1-positive tumor-infiltrating lymphocytes, and colorectal cancer showed favorable disease-free survival (HR 0.471; 95% CI 0.308, 0.722) for PD-L1-positive tumor-infiltrating lymphocytes.

CONCLUSION

Immune cells expressing PD-1 and PD-L1 within tumors are associated with the prognosis. However, the correlation may vary among different tumor types and by the type of tissue sampling used for the assessment.