Clinical significance of PD-L1 and PD-L2 copy number gains in non-small-cell lung cancer

The Genetic Analysis and Clinical Therapy in Lung Cancer: Current Advances and Future Directions

Lung cancer, including both non-small cell lung cancer and small cell lung cancer, remains the leading cause of cancer-related mortality worldwide, representing 18% of the total cancer deaths in 2020. Many patients are identified already at an advanced stage with metastatic disease and have a worsening prognosis. Recent advances in the genetic understanding of lung cancer have opened new avenues for personalized treatments and targeted therapies. This review examines the latest discoveries in the genetics of lung cancer, discusses key biomarkers, and analyzes current clinical therapies based on this genetic information. It will conclude with a discussion of future prospects and potential research directions.

NKX2‑1 copy number alterations are associated with oncogenic, immunological and prognostic remodeling in non‑small cell lung cancer

NK2 homeobox 1 (NKX2-1) copy number alterations (CNAs) are frequently observed in lung cancer. However, little is known about the complete landscape of focal alterations in NKX2-1 copy number (CN), their clinical significance and their therapeutic implications in non-small cell lung cancer (NSCLC). The correlations between NKX2-1 expression and EGFR driver mutations and programmed death ligand 1 (PD-L1) co-expression were studied using immunohistochemistry and PCR from the tumors of recruited Filipino patients (n=45). Clinical features of NSCLC with NKX2-1 CNAs were resolved at the tumor and clonal levels using the molecular profiles of patients with lung adenocarcinoma and lung squamous cell carcinoma from The Cancer Genome Atlas (n=1,130), and deconvoluted single-cell RNA-seq data from the Bivona project (n=1,654), respectively. Despite a significant and positive correlation between expression and CN (r=0.264; P<0.001), NKX2-1 CNAs exerted a stronger influence on the combined EGFR and PD-L1 status of NSCLC tumors than expression. NKX2-1 CN gain was prognostic of favorable survival (P=0.018) and a better response to targeted therapy. NKX2-1 CN loss predicted a worse survival (P=0.041). Mutational architecture in the Y-chromosome differentiated the two prognostic groups. There were 19,941 synonymous mutations and 1,408 genome-wide CN perturbations associated with NKX2-1 CNAs. Tumors with NKX2-1 CN gain expressed lymphocyte markers more heterogeneously than those with CN loss. Higher expression of tumor-infiltrating lymphocyte gene signatures in CN gain was prognostic of longer disease-free survival (P=0.005). Tumors with NKX2-1 CN gain had higher B-cell (P<0.001) and total T-cell estimates (P=0.003). NKX2-1 CN loss was associated with immunologically colder tumors due to higher M2 macrophage infiltrates (P=0.011) and higher expression of immune checkpoint proteins, CD274 (P=0.025), VTCN1 (P<0.001) and LGALS9 (P=0.002). In conclusion, NKX2-1 CNAs are associated with tumors that exhibit clinically diverse characteristics, and with unique oncogenic, immunological and prognostic signatures.

PD-L1 assessment in lung cancer biopsies-pitfalls and limitations

The programmed cell death-ligand 1 (PD-L1) protein expression on tumor cells predicts the efficacy of immunotherapy in patients with non-small cell lung cancer. However, the assessment of PD-L1 expression on tumor cells has limited power for selecting patients for immunotherapy due to intra-tumoral heterogeneity and inter-tumoral heterogeneity of PD-L1 expression, the inter-observer variability in scoring PD-L1 staining, and reproducibility. These difficulties and pitfalls in interpreting the PD-L1 assessment are discussed in detail in this review.

Refining PD-1/PD-L1 assessment for biomarker-guided immunotherapy: A review

Anti-programmed cell death ligand 1 (anti-PD-L1)  immunotherapy is an increasingly crucial in cancer treatment. To date, the Federal Drug Administration (FDA) has approved four PD-L1 immunohistochemistry (IHC) staining protocols, commercially available in the form of "kits", facilitating testing for PD-L1 expression. These kits comprise four PD-L1 antibodies on two separate IHC platforms, each utilizing distinct, non-interchangeable scoring systems. Several factors, including tumor heterogeneity and the size of the tissue specimens assessed, can lead to PD-L1 status misclassification, potentially hindering the initiation of therapy. Therefore, the development of more accurate predictive biomarkers to distinguish between responders and non-responders prior to anti-PD-1/PD-L1 therapy warrants further research. Achieving this goal necessitates refining sampling criteria, enhancing current methods of PD-L1 detection, and deepening our understanding of the impact of additional biomarkers. In this article, we review potential solutions to improve the predictive accuracy of PD-L1 assessment in order to more precisely anticipate patients' responses to anti-PD-1/PD-L1 therapy, monitor disease progression and predict clinical outcomes.

Hope and Challenges: Immunotherapy in EGFR-Mutant NSCLC Patients

EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for non-small cell lung cancer (NSCLC) patients harboring sensitive EGFR mutations. Sadly, remission is transient, and no approved effective treatment options are available for EGFR-TKI-advanced EGFR-mutant NSCLCs. Although immunotherapy with immune checkpoint inhibitors (ICIs) induces sustained cancer remission in a subset of NSCLCs, ICI therapy exhibits limited activity in most EGFR-mutant NSCLCs. Mechanistically, the strong oncogenic EGFR signaling in EGFR-mutant NSCLCs contributes to a non-inflamed tumor immune microenvironment (TIME), characterized by a limited number of CD8+ T cell infiltration, a high number of regulatory CD4+ T cells, and an increased number of inactivated infiltrated T cells. Additionally, EGFR-mutant NSCLC patients are generally non-smokers with low levels of PD-L1 expression and tumor mutation burden. Promisingly, a small population of EGFR-mutant NSCLCs still durably respond to ICI therapy. The hope of ICI therapy from pre-clinical studies and clinical trials is reviewed in EGFR-mutant NSCLCs. The challenges of application ICI therapy in EGFR-mutant NSCLCs are also reviewed.

Programmed cell death ligand 1 (PD-L1) expression in non-small cell lung cancer: Findings from a tertiary care institute in western part of India

BACKGROUND

Immune checkpoint inhibitors targeting either programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) have been established as a novel target for immunotherapy in non-small cell lung cancer (NSCLC). Prevalence of PD-L1 expression in NSCLC varies from 13% to 70%, with sparse data from the Indian subcontinent. In this study, we looked at PD-L1 expression and its association with demographic, clinical, radiologic and pathologic parameters in NSCLC patients.

METHODS

This was an observational study carried over a period of 18 months in which 65 patients of NSCLC were included. Immunohistochemistry (IHC) for PD-L1 was done using an automated IHC stainer and testing was performed using PD-L1 IHC CAL10. For statistical analysis, unpaired t test, Chi square test, Fisher's exact test and binomial logistic regression were used. P < 0.05 was taken to be statistically significant.

RESULTS

Mean age of the patients was 62.9 ± 9.2 years, and majority (87.3%) of them were males. Seventeen (26.2%) patients expressed PD-L1, among whom 10 had high PD-L1 expression (≥50%) and 7 had low PD-L1 expression (1-49%). PD-L1 expression was seen in 13 out of 43 cases of squamous cell carcinoma (SCC) and 4 out of 15 cases of adenocarcinoma. On applying binomial logistic regression analysis, association between smoking and PD-L1 expression was found to be insignificant.

CONCLUSION

Almost a quarter of NSCLC cases were PD-L1 positive without any difference in expression between SCC and adenocarcinoma. PD-L1 status was not associated with any specific demographic, clinical or radiologic parameter including the histologic subtype.

Programmed Death-Ligand 1 Copy Number Alteration as an Adjunct Biomarker of Response to Immunotherapy in Advanced NSCLC

INTRODUCTION

This study aimed to evaluate the value of programmed death-ligand 1 (PD-L1) copy number (CN) alteration as an additional biomarker to standard immunohistochemistry (IHC) in predicting response to immune checkpoint inhibitor (ICI) therapy in advanced NSCLC.

METHODS

Before ICI monotherapy, tumor PD-L1 CN alteration (gain, neutral, or loss) was called using whole-exome sequencing data and compared with IHC results (tumor proportion score ≥50, 1-49, or 0). Progression-free survival (PFS) and overall survival were correlated with both biomarkers. In addition, the impact of CN alteration was further evaluated in two independent cohorts using next-generation sequencing panel.

RESULTS

A total of 291 patients with advanced-stage NSCLC met the study inclusion criteria. Although the IHC classification distinguished the best responsive group (tumor proportion score ≥ 50), the CN-based classification distinguished the worst responsive group (CN loss) from the others (PFS, p = 0.020; overall survival, p = 0.004). After adjusting for IHC results, CN loss was an independent risk factor for progression (adjusted hazard ratio = 1.32, 95% confidence interval: 1.00-1.73, p = 0.049) and death (adjusted hazard ratio = 1.39, 95% confidence interval: 1.05-1.85, p = 0.022). A risk classification system was developed on the basis of IHC and CN profiles, which outperformed the conventional IHC system. In the validation cohorts, CN loss determined by next-generation sequencing panel was independently associated with worse PFS after ICI treatment, revealing its practical value.

CONCLUSIONS

This is the first study to directly compare CN alterations with IHC results and survival outcomes after anti-PD-(L)1 therapy. Tumor PD-L1 CN loss can serve as an adjunct biomarker to predict the lack of response. Prospective studies are required to further validate this biomarker.

Anti-PD-1 Monoclonal Antibodies (mAbs) Are Superior to Anti-PD-L1 mAbs When Combined with Chemotherapy in First-Line Treatment for Metastatic Non-Small Cell Lung Cancer (mNSCLC): A Network Meta-Analysis

Platinum-based chemotherapy combined with anti-PD-1 or PD-L1 monoclonal antibodies (mAbs) is now standard first-line therapy for mNSCLC patients without sensitizing driver mutations. Anti-PD-1 and anti-PD-L1 mAbs are considered to be equivalent in efficacy. In the absence of head-to-head randomized control trials (RCTs), we utilized network meta-analysis (NWM) to provide an indirect comparison of their efficacy. A systematic literature review and NWM were performed using RCTs that investigated anti-PD-1 or PD-L1 mAbs ± chemotherapy in patients with mNSCLC in the first-line setting. The primary outcome was comparative overall survival (OS), while secondary outcomes were comparative progression-free survival (PFS), objective response rate (ORR), and rate of grade 3 and higher toxicities. We identified 24 RCTs. Patients treated with anti-PD-1 mAb + chemotherapy compared with anti-PD-L1 mAb + chemotherapy showed superior mOS, mPFS, and ORR with a similar rate of grade 3 and higher toxicities. This difference in mOS was most pronounced in the PD-L1 TPS 1-49% population. The two mAbs were equivalent as single agents. Anti-PD-1 mAb + chemotherapy improved mOS when compared to anti-PD-1 mAb monotherapy, whereas anti-PD-L1 mAbs + chemotherapy did not when compared to anti-PD-L1 mAb monotherapy. Head-to-head RCTs are warranted in the future.

Fascaplysin Induces Apoptosis and Ferroptosis, and Enhances Anti-PD-1 Immunotherapy in Non-Small Cell Lung Cancer (NSCLC) by Promoting PD-L1 Expression

Fascaplysin is a natural product isolated from sponges with a wide range of anticancer activities. However, the mechanism of fascaplysin against NSCLC has not been clearly studied. In this study, fascaplysin was found to inhibit migration by regulating the wnt/β-catenin signaling pathway and reversing the epithelial-mesenchymal transition phenotype. Further research showed that the anti-NSCLC effect of fascaplysin was mainly through the induction of ferroptosis and apoptosis. Fascaplysin-induced ferroptosis in lung cancer cells, evidenced by increased levels of ROS and Fe²⁺ and downregulation of ferroptosis-associated protein and endoplasmic reticulum stress, was involved in fascaplysin-induced ferroptosis. In addition, ROS was found to mediate fascaplysin-induced apoptosis. Fascaplysin significantly upregulated the expression of PD-L1 in lung cancer cells, and enhanced anti-PD-1 antitumor efficacy in a syngeneic mouse model. Therefore, these results suggest that fascaplysin exerts anticancer effects by inducing apoptosis and ferroptosis in vitro, and improving the sensitivity of anti-PD-1 immunotherapy in vivo. Fascaplysin is a promising compound for the treatment of NSCLC.

Delta radiomics model for the prediction of progression-free survival time in advanced non-small-cell lung cancer patients after immunotherapy

Objective

To assess the validity of pre- and posttreatment computed tomography (CT)-based radiomics signatures and delta radiomics signatures for predicting progression-free survival (PFS) in stage III-IV non-small-cell lung cancer (NSCLC) patients after immune checkpoint inhibitor (ICI) therapy.

Methods

Quantitative image features of the largest primary lung tumours were extracted on CT-enhanced imaging at baseline (time point 0, TP0) and after the 2^nd-3^rd immunotherapy cycles (time point 1, TP1). The critical features were selected to construct TP0, TP1 and delta radiomics signatures for the risk stratification of patient survival after ICI treatment. In addition, a prediction model integrating the clinicopathologic risk characteristics and phenotypic signature was developed for the prediction of PFS.

Results

The C-index of TP0, TP1 and delta radiomics models in the training and validation cohort were 0.64, 0.75, 0.80, and 0.61, 0.68, 0.78, respectively. The delta radiomics score exhibited good accuracy for distinguishing patients with slow and rapid progression to ICI treatment. The predictive accuracy of the combined prediction model was higher than that of the clinical prediction model in both training and validation sets (P<0.05), with a C-index of 0.83 and 0.70, respectively. Additionally, the delta radiomics model (C-index of 0.86) had a higher predictive accuracy compared to PD-L1 expression (C-index of 0.50) (P<0.0001).

Conclusions

The combined prediction model including clinicopathologic characteristics (tumour anatomical classification and brain metastasis) and the delta radiomics signature could achieve the individualized prediction of PFS in ICIs-treated NSCLC patients.

Mutational Landscape and Expression of PD-L1 in Patients with Non-Small Cell Lung Cancer Harboring Genomic Alterations of the MET gene

Background

Mesenchymal-to-epithelial transition (MET) exon 14 skipping mutations and MET gene amplification occur in 3–5% of non-small cell lung cancer (NSCLC) patients. Tyrosine kinase inhibitors (TKIs) targeting MET alterations have shown promising results in these patients.

Objective

The aim of this study was to describe the genomic profile, PD-L1 expression and clinicopathological features of MET dysregulated NSCLC.

Patients and Methods

We identified 188 patients with advanced-stage NSCLC with data on MET expression by immunohistochemistry (IHC). IHC for PD-L1 expression was performed in 131 patient samples, and next-generation sequencing (NGS) analysis was performed in 109 patient samples.

Results

MET exon 14 skipping alterations were identified in 16 (14.7%) samples, MET amplifications with cut-off ≥4 copy number variations were identified in 11 (10.1%) samples, and an oncogenic MET mutation (MET p.D1228N) was identified in 1 (0.9%) sample. 12/15 tumors (80.0%) harboring MET exon 14 alterations and 7/11 (63.6%) MET-amplified tumors expressed PD-L1 in ≥1% of tumor cells. Tumors harboring MET exon 14 skipping alterations expressed PD-L1 more frequently than MET wild-type IHC-positive tumors (p = 0.045). Twenty-five percent of MET exon 14-altered cases and 33% of MET-amplified cases harbored potentially targetable oncogenic co-mutations in KRAS, BRAF, and EGFR. The most frequent co-occurring mutations in all MET-altered tumors were TP53, KRAS, BRAF, and CDK4.

Conclusions

We demonstrated that MET exon 14 skipping alterations and MET amplification are not mutually exclusive to other oncogenic co-mutations, and report the association of genomic MET alterations with PD-L1 expression. Since genomic MET alterations are emerging targets requiring upfront treatment, optimal understanding of the co-mutational landscape for this patient population is needed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11523-022-00918-6.

EGFR mutation status in non-small cell lung cancer receiving PD-1/PD-L1 inhibitors and its correlation with PD-L1 expression: a meta-analysis

Meta-analysis was performed on the Web of Science, PubMed, Embase, and Cochrane databases to evaluate the effect of epidermal growth factor receptor (EGFR) mutation status on programmed cell death protein 1/programmed death ligand 1 (PD-1/PD-L1) immune checkpoint inhibitors, and the association between EGFR mutation status and PD-L1 expression in non-small cell lung cancer (NSCLC) patients. Pooled effect (hazard ratio/odds ratio, HR/OR) with 95% confidence interval (CI) was calculated, and the source of heterogeneity was explored by subgroup analysis and meta-regression using Stata/SE 15.0. Meta-analysis of the association between EGFR mutation status and overall survival (OS) in NSCLC with immunotherapy was calculated from four randomized controlled trials. We found that immune checkpoint inhibitors significantly prolonged OS over docetaxel overall (HR 0.71, 95% CI 0.64-0.79) and in the EGFR wild type (HR = 0.67, 95% CI = 0.60-0.75), but not in the EGFR mutant subgroup (HR = 1.11, 95% CI = 0.80-1.52). Meta-analysis of the association between EGFR mutation status and PD-L1 expression in NSCLC included 32 studies. The pooled OR and 95% CI were 0.60 (0.46-0.80), calculated by random effects model. No source of heterogeneity was found in subgroup analysis. Sensitivity analysis was carried out with a fixed model, and the influence of a single study on the pooled results showed no significant change with robust meta-analysis methods. Harbord's weighted linear regression test (P = 0.956) and Peters regression test (P = 0.489) indicated no significant publication bias. The limited benefit of single-agent PD-1/PD-L1 inhibitors in the second-line or later setting for EGFR-mutated NSCLC may be partly due to the lower expression of PD-L1.

Prognostic Value of Programmed Death Ligand-1 Expression in Solid Tumors Irrespective of Immunotherapy Exposure: A Systematic Review and Meta-Analysis

BACKGROUND

The programmed cell death-1/programmed cell death ligand-1 (PD-L1) pathway, which plays a crucial role in cancer immune surveillance, is the target of several approved immunotherapeutic agents and is used as a predictive biomarker in some solid tumors. However, its use as a prognostic marker (i.e., regardless of therapy used) is not established clearly with available data demonstrating inconsistent prognostic impact of PD-L1 expression in solid tumors.

METHODS

We conducted a systematic literature search of electronic databases and identified publications exploring the effect of PD-L1 expression on overall survival and/or disease-free survival. Hazard ratios were pooled in a meta-analysis using generic inverse-variance and random-effects modeling. We used the Deeks method to explore subgroup differences based on disease site, stage of disease, and method of PD-L1 quantification.

RESULTS

One hundred and eighty-six studies met the inclusion criteria. Programmed cell death ligand-1 expression was associated with worse overall survival (hazard ratio 1.33, 95% confidence interval 1.26-1.39; p < 0.001). There was significant heterogeneity between disease sites (subgroup p = 0.002) with pancreatic, hepatocellular, and genitourinary cancers associated with the highest magnitude of adverse outcomes. Programmed cell death ligand-1 was also associated with worse overall disease-free survival (hazard ratio 1.19, 95% confidence interval 1.09-1.30; p < 0.001). Stage of disease did not significantly affect the results (subgroup p = 0.52), nor did the method of quantification via immunohistochemistry or messenger RNA (subgroup p = 0.70).

CONCLUSIONS

High expression of PD-L1 is associated with worse survival in solid tumors albeit with significant heterogeneity among tumor types. The effect is consistent in early-stage and metastatic disease and is not sensitive to method of PD-L1 quantification. These data can provide additional information for the counseling of patients with cancer about prognosis.

[Correlation Study on Expression of PD-1 and PD-L1 in Non-small Cell Lung Cancer and Epidermal Growth Factor Receptor Mutations]

BACKGROUND

The treatment mode of lung cancer is epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) as a first-line treatment for patients with EGFR mutant in non-small cell lung cancer (NSCLC). At the same time programmed death receptor 1 (PD-1) and its programmed death receptor ligand 1 (PD-L1) inhibitors therapy as the representative immune checkpoint inhibitors (ICIs) has a significant effect in the treatment of lung cancer. The aim of this study was to investigate the correlation between the expression of PD-1 and PD-L1 in NSCLC and clinicopathologic feature, EGFR gene mutation.

METHODS

The protein expression of PD-1 and PD-L1 was detected by immunohistochemistry from 127 patients with NSCLC and EGFR gene mutation was detected by quantitative polymerase chain reaction (qPCR) to analyze its relation with clinicopathologic feature. Also, the correlation between protein expression of PD-1 and PD-L1 and EGFR mutation.

RESULTS

The PD-1 positive expression in NSCLC tumor cells and tumor infiltrating immune cells is 53.5% (68/127), PD-L1 is 57.5% (73/127). The PD-1 and PD-L1 expression significantly higher in well-differentiated and moderately-differentiated carcinoma than poorly differentiated carcinoma, I+II than III+IV in clinical staging (P<0.05). The EGFR mutation rate was 46.5% (59/127), correlate with female, without smoking history, adenocarcinoma and well-differentiated and moderately-differentiated patients respectively higher than male, smoking history, squamous carcinoma and poorly differentiated patients (P<0.05). The protein expression of PD-L1 and PD-1 had the consistency in NSCLC patients (kappa=0.107,5, P=0.487). There was a negative correlation between the EGFR mutation and PD-1 and PD-L1 expression (Φ=-0.209, Φ=-0.221, P<0.05). Follow-up of NSCLC patients, the median total survival in under the age of 65, adenocarcinoma, well-differentiated and moderately-differentiated, with PD-L1 expression patients respectively higher than over the age of 65, squamous carcinoma, poorly differentiated, without PD-L1 expression patients (P<0.05). The median survival of hypo expression patients of PD-L1 significantly higher than hyper expression patient (P=0.04).

CONCLUSIONS

According to the Chinese Expert Consensus on Standards of PD-L1 immunohistochemistry testing for NSCLC, we tested the PD-L1 expression in NSCLC and then the dominant population of anti-PD-1/PD-L1 treatment was screened out. Patients with EGFR mutation were also detected and EGFR mutation was negatively correlated with the expression of PD-1 and PD-L1 as well. On the basis of PD-L1 expression and EGFR mutation status, it may benefit NSCLC patients from individualized treatment. Meanwhile, patients who were under the age of 65, adenocarcinoma, well-differentiated and moderately-differentiated, hypo expression of PD-L1 have a relatively good prognosis, to provide reference for the prognosis evaluation of NSCLC.

YTHDF1 and YTHDF2 are associated with better patient survival and an inflamed tumor-immune microenvironment in non-small-cell lung cancer

The human YTH domain family (YTHDF) proteins are RNA-binding proteins that recognize N6-methyladenosine (m6A), facilitating various biological processes via m6A RNA modification. How these molecules associate with non–small-cell lung cancer (NSCLC) molecular mechanisms remain unclear. The protein expression levels of YTHDF1 and YTHDF2 in 603 cases of resected NSCLC were evaluated using immunohistochemistry. We analyzed the associations of these attributes with patient characteristics and survival. We also assessed four subsets of lymphocytes (PD-1+, CD8+, Foxp3+, and CD45RO+) as tumor-infiltrating lymphocytes (TILs) in the tumor nest and in the surrounding stroma separately. In addition, we investigated differentially expressed genes and the expression of PD-L1 in YTHDF1– and YTHDF2-deprived lung cancer cells. The expressions of both YTHDF1 and YTHDF2 were less in the advanced-stage tumors than in the early-stage tumors. The expressions of both YTHDF1 and YTHDF2 were also independent favorable prognostic factors for recurrence-free survival (HR, 0.745; 95% CI, 0.562–0.984 for YTHDF1; HR, 0.683; 95% CI, 0.503–0.928 for YTHDF2). The TIL densities of almost all four lymphocyte subsets in the stroma were significantly higher in the tumors with high YTHDF1 and YTHDF2 expression. In vitro, YTHDF1 and YTHDF2 knockdown in cells upregulated tumor PD-L1 expression and altered multiple immune-related genes. High expressions of both YTHDF1 and YTHDF2 are associated with a favorable prognostic outcome of NSCLC patients, a greater amount of TILs, and downregulation of PD-L1. YTHDF1 and YTHDF2 could be novel prognostic and druggable targets related to the tumor-immune microenvironment in lung cancers.

PD-L1 Protein Expression and Gene Amplification Correlate with the Clinicopathological Characteristics and Prognosis of Lung Squamous Cell Carcinoma

Purpose

To investigate PD-L1 protein expression and gene amplification in lung squamous cell carcinoma (LUSC) and analyse their correlation with the clinicopathological characteristics and prognosis of LUSC patients.

Patients and Methods

Tissue samples from 164 LUSC patients were collected. PD-L1 protein was detected by immunochemistry (IHC), and PD-L1 gene amplification was investigated by fluorescence in situ hybridization in LUSC patients.

Results

The positive expression rate of PD-L1 in LUSC was 47.6% (78/164), and the amplification rate of PD-L1 was 6.7% (11/164); both rates were higher than those of paratumor tissue. Both PD-L1 positive expression and gene amplification were correlated with clinical stage and lymph node metastasis (P<0.05). PD-L1 protein expression, PD-L1 gene amplification, late stage, lymph node metastasis and distant metastasis were significantly correlated with the prognosis of patients. Among these factors, late stage, lymph node metastasis, PD-L1 protein expression and PD-L1 gene amplification were independent prognostic factors for LUSC.

Conclusion

Positive PD-L1 protein expression and gene amplification are involved in the malignant progression and metastasis of LUSC. Both PD-L1 protein expression and gene amplification are associated with poor prognosis.

Expression of PD-L1 Is Associated with Inflammatory Microenvironment in Surgical Specimens of Non-Small Cell Lung Cancer

The aim of this study was to analyse the expression of PD-L1 in non-small cell lung cancer (NSCLC) and its correlation with immune microenvironment response (IMR), clinic-pathological parameters, and outcome. The sample included 76 male and 32 female patients who underwent surgical resection. The mean age of the males was 66 years, and that of the females was 64 years. Adenocarcinoma (ADC) was diagnosed in 68 (63%) cases, squamous cell carcinoma in 35 (32%) cases, and NSCLC (not otherwise specified) in 5 (5%) cases. Metastatic lymph nodes were found in 38 (36%) patients, 18 with N1 nodes and 20 with N2 nodes. PD-L1 expression was valuated as the percentage of positive cancer cells among all cancer cells. Gender, age, and histologic type were not associated with PD-L1 expression (all p > 0.05). The subtypes of ADC were associated with PD-L1 expression (p = 0.050). The papillary subtype was 4.3 times more common among PD-L1 negative than PD-L1 positive ADC; the solid subtype was 1.9 times more common among PD-L1 positive than PD-L1 negative ADC. IMR was predominantly strong in 19 cases, weak in 36, and absent in 53 cases. The median value of PD-L1 expression in cancer cells was positively correlated with IMR (p = 0.039). PD-L1 expression was not correlated with overall survival (p = 0.643). The patients with strong, inflammatory-like IMR had an average survival time that was 12 months longer than patients with absent/low IMR (LR = 2.8; p = 0.132). In conclusion, the papillary subtype was more commonly PD-L1 negative in comparison with other subtypes of ADC. Positive PD-L1 expression in tumour cells was connected with strong, inflammatory-like IMR. Patients with strong IMR tended to experience better outcomes. Further investigations are needed on larger-scale cohorts to elucidate the insights of this descriptive study.

Neutralization of PD-L2 is Essential for Overcoming Immune Checkpoint Blockade Resistance in Ovarian Cancer

PURPOSE

Ovarian cancer represents a major clinical hurdle for immune checkpoint blockade (ICB), with reported low patient response rates. We found that the immune checkpoint ligand PD-L2 is robustly expressed in patient samples of ovarian cancers and other malignancies exhibiting suboptimal response to ICB but not in cancers that are ICB sensitive. Therefore, we hypothesize that PD-L2 can facilitate immune escape from ICB through incomplete blockade of the PD-1 signaling pathway.

EXPERIMENTAL DESIGN

We engineered a soluble form of the PD-1 receptor (sPD-1) capable of binding and neutralizing both PD-L2 and PD-L1 with ×200 and ×10,000 folds improvement in binding affinity over wild-type PD-1 leading to superior inhibition of ligand-mediated PD-1 activities.

RESULTS

Both in vitro and in vivo analyses performed in this study demonstrated that the high-affinity sPD-1 molecule is superior at blocking both PD-L1- and PD-L2-mediated immune evasion and reducing tumor growth in immune-competent murine models of ovarian cancer.

CONCLUSIONS

The data presented in this study provide justification for using a dual targeting, high-affinity sPD-1 receptor as an alternative to PD-1 or PD-L1 therapeutic antibodies for achieving superior therapeutic efficacy in cancers expressing both PD-L2 and PD-L1.

Downregulation of m6A Reader YTHDC2 Promotes the Proliferation and Migration of Malignant Lung Cells via CYLD/NF-κB Pathway

Lung cancer is one of the most common types of carcinoma worldwide. Cigarette smoking is considered the leading cause of lung cancer. Aberrant expression of several YT521-B homology (YTH) family proteins has been reported to be closely associated with multiple cancer types. The present study aims to evaluate the function and regulatory mechanisms of the N6-methyladenosine (m6A) reader protein YTH domain containing 2 (YTHDC2) by in vitro, in vivo and bioinformatics analyses. The results revealed that YTHDC2 was reduced in lung cancer and cigarette smoke-exposed cells. Notably, bioinformatics and tissue arrays analysis demonstrated that decreased YTHDC2 was highly associated with smoking history, pathological stage, invasion depth, lymph node metastasis and poor outcomes. The in vivo and in vitro studies revealed that YTHDC2 overexpression inhibited the proliferation and migration of lung cancer cells as well as tumor growth in nude mice. Furthermore, YTHDC2 decreased expression was modulated by copy number deletion in lung cancer. Importantly, the cylindromatosis (CYLD)/NF-κB pathways were confirmed as the downstream signaling of YTHDC2, and this axis was mediated by m6A modification. The present results indicated that smoking-related downregulation of YTHDC2 was associated with enhanced proliferation and migration in lung cancer cells, and appeared to be regulated by DNA copy number variation. Importantly, YTHDC2 functions as a tumor suppressor through the CYLD/NF-κB signaling pathway, which is mediated by m6A modification.

Programmed Death-Ligand 1 as a Regulator of Tumor Progression and Metastasis

Programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint has long been implicated in modeling antitumor immunity; PD-1/PD-L1 axis inhibitors exert their antitumor effects by relieving PD-L1-mediated suppression on tumor-infiltrating T lymphocytes. However, recent studies have unveiled a distinct, tumor-intrinsic, potential role for PD-L1. In this review, we focus on tumor-intrinsic PD-L1 signaling and delve into preclinical evidence linking PD-L1 protein expression with features of epithelial-to-mesenchymal transition program, cancer stemness and known oncogenic pathways. We further summarize data from studies supporting the prognostic significance of PD-L1 in different tumor types. We show that PD-L1 may indeed have oncogenic potential and act as a regulator of tumor progression and metastasis.

Impact of copy number variant and single nucleotide polymorphism of the programmed death-ligand 1 gene, programmed death-ligand 1 protein expression and therapy regimens on overall survival in a large group of Caucasian patients with non-small cell lung carcinoma

Anti-programmed death-1 or anti-programmed death-ligand 1 (PD-L1) blockade may be ineffective in some patients with non-small cell lung cancer (NSCLC) with high percentage of tumor cells with PD-L1 expression. In addition, immunotherapy may provide great benefits in patients without PD-L1 expression. The present study assessed PD-L1 protein expression by immunohistochemistry, copy number variation (CNV) of PD-L1 and two single nucleotide polymorphisms (SNPs), rs822335 and rs822336, in the promoter of PD-L1 by quantitative PCR in 673 patients with NSCLC. Overall survival time of patients with NSCLC depending on the assessed predictive factors (PD-L1 CNV or SNP) and the treatment methods (immunotherapy in first/second line of treatment or chemotherapy) was analyzed. The present study revealed significantly higher PD-L1 copies number in patients with ≥10% and ≥50% of tumor cells with PD-L1 expression compared to patients with lower percentage of PD-L1-positive tumor cells (P=0.02 and P=0.0002, respectively). There was a significant positive correlation (R=0.2; P=0.01) between number of PD-L1 copies and percentage of tumor cells with PD-L1 protein expression. Percentage of tumor cells with PD-L1 expression was lower in patients with TT genotype of the rs822335 polymorphism compared to those with CC genotype (P=0.03). The present study observed significantly higher risk of death in patients treated with chemotherapy compared to those treated with immunotherapy (P<0.0001; hazard ratio=2.4768; 95% confidence interval, 2.0120–3.0490). The present study demonstrated a close relationship between PD-L1 copies number, genotype of rs822335 PD-L1 polymorphism and PD-L1 protein expression on tumor cells. However, the impact of CNV and SNPs of PD-L1 on overall survival of patients with NSCLC requires further investigation.

A comprehensive pan-cancer analysis of CD274 gene amplification, tumor mutation burden, microsatellite instability, and PD-L1 expression in Chinese cancer patients

Background

Immune checkpoint inhibitors blocking programmed cell death 1 (PD-1) or programmed cell death ligand 1 (PD-L1) have emerged as effective treatment options for cancer. However, immunotherapy is only effective in a subset of patients. Identifying effective biomarkers to predict the treatment response to PD-1/PD-L1 inhibitors remains an unmet clinical need.

Methods

This study retrospectively analyzed clinical information and genetic profiling results of 16,013 samples from Chinese patients with various cancer types in order to investigate the prevalence of CD274 (also known as PD-L1) amplification in various cancer types and its association with existing PD-1/PD-L1 biomarkers, including tumor mutational burden (TMB), microsatellite instability (MSI), and PD-L1 expression.

Results

Amplification of CD274 was identified in 174 samples with an overall prevalence of 1.09% among all cancer types in the cohort. The prevalence of CD274 amplification in different cancer types and histological subtypes of lung cancer was varied, with cervical cancer having the highest prevalence. Distinct distributions of TMB, MSI, and PD-L1 expression between CD274-amplified and wild-type samples were observed in several cancer types as well as among different histological subtypes of lung cancer.

Conclusions

Although CD274 amplification was only observed in a small proportion of patients, it demonstrated an association with TMB, MSI, and PD-L1 expression in several common cancer types. The molecular features of CD274 in different cancer types are heterogeneous. The role of CD274 amplification as a novel biomarker of PD-1/PD-L1 inhibitors remains to be characterized in future prospective clinical studies.

A CT-Based Radiomics Approach to Predict Nivolumab Response in Advanced Non-Small-Cell Lung Cancer

Purpose

This study aims to develop a CT-based radiomics model to predict clinical outcomes of advanced non-small-cell lung cancer (NSCLC) patients treated with nivolumab.

Methods

Forty-six stage IIIB/IV NSCLC patients without EGFR mutation or ALK rearrangement who received nivolumab were enrolled. After segmenting primary tumors depicting on the pre-anti-PD1 treatment CT images, 1,106 radiomics features were computed and extracted to decode the imaging phenotypes of these tumors. A L1-based feature selection method was applied to remove the redundant features and build an optimal feature pool. To predict the risk of progression-free survival (PFS) and overall survival (OS), the selected image features were used to train and test three machine-learning classifiers namely, support vector machine classifier, logistic regression classifier, and Gaussian Naïve Bayes classifier. Finally, the overall patients were stratified into high and low risk subgroups by using prediction scores obtained from three classifiers, and Kaplan–Meier survival analysis was conduct to evaluate the prognostic values of these patients.

Results

To predict the risk of PFS and OS, the average area under a receiver operating characteristic curve (AUC) value of three classifiers were 0.73 ± 0.07 and 0.61 ± 0.08, respectively; the corresponding average Harrell’s concordance indexes for three classifiers were 0.92 and 0.79. The average hazard ratios (HR) of three models for predicting PFS and OS were 6.22 and 3.54, which suggested the significant difference of the two subgroup’s PFS and OS (p<0.05).

Conclusion

The pre-treatment CT-based radiomics model provided a promising way to predict clinical outcomes for advanced NSCLC patients treated with nivolumab.

PD-L1 amplification is associated with an immune cell rich phenotype in squamous cell cancer of the lung

Gene amplification is considered to be one responsible cause for upregulation of Programmed Death Ligand-1 (PD-L1) in non-small cell lung cancer (NSCLC) and to represent a specific molecular subgroup possibly associated with immunotherapy response. Our aim was to analyze the frequency of PD-L1 amplification, its relation to PD-L1 mRNA and protein expression, and to characterize the immune microenvironment of amplified cases. The study was based on two independent NSCLC cohorts, including 354 and 349 cases, respectively. Tissue microarrays were used to evaluate PD-L1 amplification by FISH and PD-L1 protein by immunohistochemistry. Immune infiltrates were characterized immunohistochemically by a panel of immune markers (CD3, CD4, CD8, PD-1, Foxp3, CD20, CD138, CD168, CD45RO, NKp46). Mutational status was determined by targeted sequencing. RNAseq data was available for 197 patients. PD-L1 amplification was detected in 4.5% of all evaluable cases. PD-L1 amplification correlated only weakly with mRNA and protein expression. About  37% of amplified cases were negative for PD-L1 protein. PD-L1 amplification did not show any association with the mutational status. In squamous cell cancer, PD-L1 amplified cases were enriched among patients with high tumoral immune cell infiltration and showed gene expression profiles related to immune exhaustion. In conclusion, PD-L1 amplification correlates with PD-L1 expression in squamous cell cancer and was associated with an immune cell rich tumor phenotype. The correlative findings help to understand the role of PD-L1 amplification as an important immune escape mechanism in NSCLC and suggest the need to further evaluate PD-L1 amplification as predictive biomarker for checkpoint inhibitor therapy.

Tissue MicroRNA Expression as a Predictor of Response to Immunotherapy in NSCLC Patients

Introduction

Expression of PD-L1 protein on tumor cells, which is so far the only validated predictive factor for immunotherapy, is regulated by epigenetic and genetic factors. Among the most important ones that regulate gene expression are microRNAs.

Materials and Methods

The study included 60 patients with NSCLC who underwent first or second line immunotherapy with pembrolizumab or nivolumab. FFPE materials were collected before the start of immunotherapy. We examined relative expression of microRNAs (miR-141, miR-200a, miR-200b, miR-200c, miR-429, miR-508-3p, miR-1184, miR-1255a) and PD-L1 mRNA expression. Copy number variation (CNV) of PD-L1 gene by qPCR and FISH methods were assessed. Two single nucleotide polymorphisms (SNPs) in promoter region of PD-L1 gene (rs822335 and rs822336) were examined. Expression of PD-L1 protein on tumor cells was assessed by immunohistochemistry (IHC). The response rate to immunotherapy and progression free survival (PFS) measured in weeks and overall survival (OS) measured in months from the start of immunotherapy were evaluated.

Results

Response to immunotherapy was observed in nine patients (15%, including one complete response), disease stabilization in 22 patients (36.7%), and progression in 29 patients (48.3%). Significantly higher (p=0.015) expression of miR-200b and significantly lower (p=0.043) expression of miR-429 were observed in responders compared to patients who did not respond to immunotherapy. The median PFS in the whole group of patients was 16 weeks, and the median OS was 10.5 month. In univariate analysis, the median PFS was significantly higher in patients with high miR-200b expression (HR=0.4253, 95%CI: 0.1737–1.0417, p=0.05) and high miR-508 expression (HR=0.4401, 95%CI: 0.1903–1.0178, p=0.05) and with low expression of miR-429 (HR=0.1288, 95%CI: 0.01727–0.9606, p=0.0456) compared to patients with low and high expression of these molecules, respectively. The median OS was higher in patients with low expression of miR-429 (HR=0,6288, 95%CI: 0,3053–1,2949, p=0.06) compared with patients with high expression of this microRNA. In multivariate analysis, we found that patients with PD-L1 expression on ≥1% of tumor cells compared to patients without PD-L1 expression on cancer cells had a significantly lower risk of progression (HR=0.3857, 95%CI: 0.1612–0.9226, p=0.0323) and death (HR=0.377, 95%CI: 0.1636–0.8688, p=0.022).

Conclusion

The miR-200b and miR-429 molecules in tumor cells seem to have greatest impact on the effectiveness of immunotherapy in NSCLC patients.

PD-L1 versus tumor mutation burden: Which is the better immunotherapy biomarker in advanced non-small cell lung cancer?

PD-L1 and tumor mutation burden (TMB) are the most widely used immunotherapy biomarkers to identify populations who would attain clinical benefit, with the higher values predicting better therapeutic efficacy. This review addresses the predictive values and unresolved challenges of these two biomarkers. PD-1 and PD-L1 inhibitors have induced durable and effective responses in patients with advanced non-small cell lung cancer, confirmed by multiple clinical trials and real-world studies. Different clinical trials, involving both PD-1/PD-L1 inhibitors alone and combination regimens, adopted either PD-L1 or TMB to stratify the patients, although the predictive capabilities of these two biomarkers are different. In the first-line setting, PD-L1 of 50% or more as a cut-off value can help select candidates for pembrolizumab or atezolizumab monotherapy; however, these two biomarkers poorly predict the efficacy of immunotherapy combination regimens as first-line treatments. In the second-line setting, although patients can benefit from nivolumab regardless of PD-L1 expression, both PD-L1 and blood TMB can be used as biomarkers to find patients suitable for atezolizumab. Except for inaccurate predictiveness, there are many unresolved problems with regard to the two biomarkers, such as the lack of standard detection methods, and their susceptibilities to other dynamic changes. The predictive values of TMB and PD-L1 were low in most circumstances; however, PD-L1 expression greater than ≥ 50% can help select appropriate patients for pembrolizumab and atezolizumab, respectively, as first-line monotherapies. Higher PD-L1 or TMB was associated with greater efficacy for atezolizumab as a second-line monotherapy.

Prognostic and clinicopathological value of PD-L2 in lung cancer: A meta-analysis

OBJECTIVE

The prognostic role of programmed death ligand-2 (PD-L2) expression in lung cancer has been widely studied, however, the results are controversial. Accordingly, we investigated the prognostic and clinicopathological value of PD-L2 in patients with lung cancer in this meta-analysis.

METHODS

Relevant studies were systematically searched in the PubMed, Web of Science, EMBASE, ClinicalTrials.gov., Scopus, and Cochrane Library until July 10, 2020. The hazard ratio (HR), odds ratio (OR), and their corresponding 95% confidence intervals (CIs) were calculated.

RESULTS

Thirteen studies with 3107 participants were included. High PD-L2 expression was associated with poor overall survival (OS) (HR 1.248, 95% CI: 1.071-1.455, p = 0.004) and worse disease-free survival (DFS)/progression-free survival (PFS)/relapse-free survival (RFS) (HR 1.224, 95% CI: 1.058-1.417, p = 0.007) in lung cancer. Furthermore, unfavorable OS was found in lung adenocarcinoma (HR 1.349, 95% CI: 1.051-1.731, p = 0.019), but not in other pathological types (HR 1.192, 95% CI: 0.982-1.447 p = 0.076) with higher PD-L2 expression in our subgroup analysis. Concerning the clinicopathological characteristics, high PD-L2 expression was associated with smoking (OR 0.725, 95% CI: 0.591-0.890, p = 0.002) and PD-L1 (OR 1.607, 95% CI:1.115-2.314, p = 0.011) and vascular invasion (OR 1.500, 95% CI: 1.022-2.203, p = 0.039).

CONCLUSION

PD-L2 overexpression might predict a poor prognosis in lung cancer patients after surgery. PD-L2 expression might be a potential biomarker for PD-1/PD-L1-targeted immunotherapy in lung cancer, which should be investigated in future studies.

Discordance of immunotherapy response predictive biomarkers between primary lesions and paired metastases in tumours: A systematic review and meta-analysis

Background

Several biomarkers predict the efficacy of immunotherapy, which is essential for selecting patients who would potentially benefit. Discordant status of these biomarkers between primary tumours and paired metastases has been increasingly revealed. We aimed to comprehensively summarize the incidence of this phenomenon.

Methods

Databases were searched to identify studies reporting primary-to-metastatic conversion of biomarkers, including programmed death ligand-1 (PD-L1), programmed cell death protein-1 (PD-1), PD-L2, tumour-infiltrating lymphocyte (TIL), tumour mutational burden (TMB), and microsatellite instability (MSI).

Findings

56 studies with 2739 patients were included. The pooled discordance rate of PD-L1 was 22%. The percentage of PD-L1 changed from positive to negative was 41%, whereas that from negative to positive was 16%. The discordance rate for PD-1 and PD-L2 was 26% and 22%, respectively. TIL level was found with a discordance rate of 39%, and changes from high to low (50%) occurred more than that from low to high (16%). No significant difference in TMB was observed between two sites in most studies. MSI status discordance was found in 6% patients, with a percentage of 9% from MSI-high to microsatellite instable (MSS) and 0% from MSS to MSI-high.

Interpretation

Our study demonstrates that PD-L1, PD-1, PD-L2, and TIL level had high frequency of discordance, while TMB and MSI status were less likely to change between primary tumours and paired metastases. Therefore, evaluating those frequently altered biomarkers of both primary and metastatic tumours is strongly recommended for precise clinical decision of immune checkpoint treatment.

Fund

The National Natural Science Foundation of China (81872152).

Biological Function of PD-L2 and Correlation With Overall Survival in Type II Endometrial Cancer

In cancer, upregulation of coinhibitory B7 ligands has been associated with immune evasion. So far, anti-programmed death-1 (PD-1) and anti-PD-ligand 1 (PD-L1) antibodies have been used in immuno-oncology, with promising outcomes; however, it is still needed to identify other markers, especially for endometrial cancer (EC). EC is a gynecological malignancy historically classified into two types: type I, with mostly estrogen-dependent endometrioid diseases, and the most aggressive type II, including mainly estrogen-independent and non-endometrioid tumors. PD ligand-2 (PD-L2) is known as the second ligand of the PD-1 receptor and, upon its binding, contributes to T-cell exhaustion. Up to now, very few information are available about PD-L2 in cancers, and no data have been reported for EC. The aim of this work was to characterize the PD-L1 and PD-L2 ligand expression profile in EC cell lines, focusing the attention on the biological role of PD-L2 and its prognostic impact in human type II EC biopsies. Using in silico analysis of TCGA data, we performed a molecular profiling in a cohort of 506 patients, both types I and II, and PD-1 ligands expression was also analyzed in different primary human EC cell lines. Moreover, PD-L2 staining was evaluated in a cohort of human type II EC samples and correlated with the overall survival (OS), progression-free survival (PFS), and additional clinicopathological data. From the in silico analysis, PD-L2 was more expressed than PD-L1 in EC cell lines. PD-L2 was found highly expressed in 64.44% of tumor specimens, predominantly in the serous subtype, in both stromal and epithelial components, while in peritumoral and normal tissues it was predominantly moderate or low. In vitro, we investigated the cell autonomous role of PD-L2 in controlling cell survival, migration, and chemoresistance.

The Extrinsic and Intrinsic Roles of PD-L1 and Its Receptor PD-1: Implications for Immunotherapy Treatment

Programmed death-ligand 1 (PD-L1) is an immune checkpoint inhibitor that binds to its receptor PD-1 expressed by T cells and other immune cells to regulate immune responses; ultimately preventing exacerbated activation and autoimmunity. Many tumors exploit this mechanism by overexpressing PD-L1 which often correlates with poor prognosis. Some tumors have also recently been shown to express PD-1. On tumors, PD-L1 binding to PD-1 on immune cells promotes immune evasion and tumor progression, primarily by inhibition of cytotoxic T lymphocyte effector function. PD-1/PD-L1-targeted therapy has revolutionized the cancer therapy landscape and has become the first-line treatment for some cancers, due to their ability to promote durable anti-tumor immune responses in select patients with advanced cancers. Despite this clinical success, some patients have shown to be unresponsive, hyperprogressive or develop resistance to PD-1/PD-L1-targeted therapy. The exact mechanisms for this are still unclear. This review will discuss the current status of PD-1/PD-L1-targeted therapy, oncogenic expression of PD-L1, the new and emerging tumor-intrinisic roles of PD-L1 and its receptor PD-1 and how they may contribute to tumor progression and immunotherapy responses as shown in different oncology models.

PD-L1 protein expression and copy number gains in HIV-positive locally advanced cervical cancer

Background:

The programmed death-1/programmed death-ligand-1 (PD-1/PD-L1) axis may represent a target for cervical cancer; however, it is poorly understood in human immunodeficiency virus (HIV)-infected patients.

Methods:

We evaluated HIV-positive (n = 42) and HIV-negative (n = 110) women with locally advanced cervical cancer regarding their PD-L1 expression, determined by combined positive score (CPS) ⩾ 1 and tumor proportion score (TPS) ⩾ 25%, and PD-L1 copy number alterations, assessed by fluorescence in situ hybridization.

Results:

Regardless of HIV status, 84.9% and 44.8% of cases were PD-L1-positive according to CPS ⩾ 1 and TPS ⩾ 25%. Per CPS ⩾ 1, PD-L1 positive rate was similar between HIV-positive and HIV-negative women, whereas a significant difference was seen per TPS ⩾ 25%. Tumor size and parametrial invasion were correlated with PD-L1 positivity in HIV-negative women, whereas anti-retroviral therapy (ART) was correlated with TPS < 25%. Low CD4-positive cell counts were associated with CPS < 1 in HIV-positive women. No significant difference was observed in PD-L1 copy number status between HIV-positive and HIV-negative women. PD-L1 amplification and polysomy were independently associated with TPS ⩾ 25%, whereas the presence of parametrial invasion was independently associated with CPS ⩾ 1. Cancer stage and PD-L1 amplification were identified as independent predictors of recurrence-free survival [hazard ratio (HR) = 2.40 (1.32–4.36) and HR = 5.33 (1.94–14.61)] and cancer-specific survival [HR = 13.62 (5.1–36.38) and HR = 3.53 (1.43–8.69)]. PD-L1 polysomy was an independent predictor of locoregional recurrence-free survival [HR = 3.27 (1.27–8.41)]. HIV status and PD-L1 expression (CPS ⩾ 1 or TPS ⩾ 25%) were not associated with poor patient outcomes.

Conclusion:

PD-L1 amplification and polysomy are the strongest drivers of PD-L1 expression in cervical cancer, and could represent prognostic biomarkers for anti-PD-1/PD-L1 therapy. Cervical cancer biology may be modulated by HIV infection, CD4-positive cells, and HIV treatments.

Evaluation of Programmed Death Ligand 1 (PD-L1) Gene Amplification and Response to Nivolumab Monotherapy in Non-small Cell Lung Cancer

IMPORTANCE

Robust predictors for response to anti-programmed death 1 and its ligand (PD-1/PD-L1) immunotherapy in non-small cell lung cancer (NSCLC) are not fully characterized.

OBJECTIVE

To evaluate whether PD-L1 (CD274) copy number gains (CNGs), comprising amplification and polysomy, in pretreatment specimens assessed by fluorescence in situ hybridization are associated with response to nivolumab monotherapy in NSCLC.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study enrolled 200 patients, of whom 194 had assessable tumors, with advanced or recurrent NSCLC who were treated with nivolumab after progression following prior treatment at 14 institutions in Japan between July 2016 and December 2018. Median (interquartile range) duration of follow-up was 12.6 (5.6-20.4) months. Data were analyzed from December 2019 to February 2020.

EXPOSURES

Sequential nivolumab was given on day 1 of a 14-day cycle. Response was assessed every 4 cycles using Response Evaluation Criteria in Solid Tumors version 1.1.

MAIN OUTCOMES AND MEASURES

Overall response rate (ORR) according to the PD-L1 copy number status. Additional end points were progression-free survival, overall survival, and PD-L1 tumor proportion score (TPS) assessed by immunohistochemistry based on PD-L1 copy number status.

RESULTS

A total of 6 of the 200 patients were excluded because of poor-quality tumor specimens for the biomarker study, resulting in 194 assessable patients. Of these, 155 (79.9%) were men, with a median (range) age of 69 (43-83) years. PD-L1 CNGs were identified in 32 patients (16.5%), including 5 (2.6%) with amplification and 27 (13.9%) with polysomy. The ORR among patients with and without PD-L1 CNGs was 28.1% (95% CI, 13.7%-46.7%) and 17.9% (95% CI, 12.3%-24.7%), respectively. Although patients with PD-L1 polysomy did not demonstrate improved ORR (18.5% [95% CI, 6.3%-38.1%]) compared with those without PD-L1 CNGs, 4 of 5 patients (80.0% [95% CI, 28.4%-99.5%]) with PD-L1 amplification showed response, among whom median duration of response was not reached. Patients with PD-L1 amplification showed excellent survival outcomes for progression-free and overall survival. Overall, 3 PD-L1-amplified tumors (60.0%) showed PD-L1 TPS of at least 80%, but 2 (40.0%) had PD-L1 TPS of 15% or less.

CONCLUSIONS AND RELEVANCE

In this study, tumor PD-L1 amplification but not polysomy was associated with response to nivolumab monotherapy among patients with NSCLC. External validation with a larger sample size is warranted.

Clinicopathological correlation of PD-L1 and TET1 expression with tumor-infiltrating lymphocytes in non-small cell lung cancer

The immunohistochemical analysis of PD-L1 expression is still important in cancer immunotherapy. PD-L1 expression is affected by various tumor microenvironmental factors including tumor infiltrating lymphocytes (TILs) and DNA methylation biomarkers. Given the complex communication between tumor cells and immune cells, we analyzed the expression of PD-L1 and TET1 with TILs in human NSCLC and the correlation with various clinicopathological characteristics and patient prognosis. A total of 96 cases of NSCLC were enrolled in this study. Using tissue microarray, we performed immunohistochemical staining to analyze PD-L1 and TET1 expression. Image-Pro Plus was used as an automated imaging analysis software program to analyze the density of CD3+, CD4+ and CD8 + TILs. PD-L1 expression was positively correlated with the density of CD3+, CD4+ and CD8 + TILs (p = 0.038, p = 0.020, and p = 0.009, respectively); however, no significant relationship existed between TET1 expression and any TILs. The survival analysis revealed that a high PD-L1 expression was associated with favorable prognosis for OS (p = 0.049) and DFS (p = 0.029) in advanced-stage II-IV patients, but not in early stage I. Density of CD8+ TILs was an independent and favorable prognostic factor for DFS (p = 0.008) and OS (p = 0.002) in early-stage I patients. However, high TET-1 expression was associated with poor prognosis for OS (p = 0.029) in total NSCLC patients. These findings suggest the correlation and favorable prognostic impact of PD-L1 and TILs in NSCLC. In addition, DNA demethylase TET1 has oncogenic effects, showing association with poor prognosis.

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.

Immune checkpoint blockade in solid organ tumours: Choice, dose and predictors of response

Immune checkpoint blockade has transformed outcomes across solid organ tumours. Monoclonal antibodies targeting the negative inhibitory cytotoxic T lymphocyte-associated protein 4 and programmed-death 1/programmed death-ligand 1 axis can lead to deep and durable responses across several tumour streams in the advanced setting. This immunotherapy approach is increasingly used earlier in the treatment paradigm. A rapidly evolving regulatory, reimbursement and drug development landscape has accompanied this novel class of immunotherapy. Unfortunately, only a small proportion of patients respond meaningfully to these agents. Here we review how the underlying tumoural genomic, histological and immunological characteristics interact within various patient phenotypes, leading to variations in response to checkpoint blockade. Concurrently, we outline the clinical trial and real-world evidence that allows for appropriate selection of agent, dose and schedule in solid organ malignancies. An exploration of current trends in basic and translational research in immune checkpoint blockade accompanies a commentary on future clinical directions for checkpoint blockade in oncology.

Prognostic and clinical impact of PD-L2 and PD-L1 expression in a cohort of 437 oesophageal cancers

BACKGROUND

The PD-1/PD-L1 pathway plays critical roles in tumour immunology, and serves as an immune-based therapeutic target. Less is known regarding PD-L2, another ligand of PD-1, and its relation to clinical outcome in human cancers.

METHODS

We used a database of 437 surgically and 100 endoscopically resected oesophageal cancers (squamous cell carcinoma, n = 483; adenocarcinoma, n = 36; others, n = 18) to evaluate PD-L2 and PD-L1 expression by immunohistochemistry.

RESULTS

Compared with PD-L2-negative cases (n = 366, 83.8%), PD-L2-positive cases (n = 71, 16.2%) had worse overall survival (P = 0.011, log-rank test). There was not a significant correlation between PD-L2 and PD-L1 expression. Multiplex immunofluorescence revealed that there was variability in the expression pattern of PD-L2 and PD-L1. In early-stage tumours, PD-L2 expression was more frequently observed compared with PD-L1.

CONCLUSIONS

PD-L2 as well as PD-L1 were associated with an unfavourable prognosis in oesophageal cancer, supporting the role of PD-L2 as a prognostic biomarker. Considering that PD-L2 and PD-L1 had different features in terms of expression timing and responses to chemotherapeutic drugs, evaluation of both PD-L2 and PD-L1 expression may be clinically important.

Immunogenomic profiling determines responses to combined PARP and PD-1 inhibition in ovarian cancer

Combined PARP and immune checkpoint inhibition has yielded encouraging results in ovarian cancer, but predictive biomarkers are lacking. We performed immunogenomic profiling and highly multiplexed single-cell imaging on tumor samples from patients enrolled in a Phase I/II trial of niraparib and pembrolizumab in ovarian cancer (NCT02657889). We identify two determinants of response; mutational signature 3 reflecting defective homologous recombination DNA repair, and positive immune score as a surrogate of interferon-primed exhausted CD8 + T-cells in the tumor microenvironment. Presence of one or both features associates with an improved outcome while concurrent absence yields no responses. Single-cell spatial analysis reveals prominent interactions of exhausted CD8 + T-cells and PD-L1 + macrophages and PD-L1 + tumor cells as mechanistic determinants of response. Furthermore, spatial analysis of two extreme responders shows differential clustering of exhausted CD8 + T-cells with PD-L1 + macrophages in the first, and exhausted CD8 + T-cells with cancer cells harboring genomic PD-L1 and PD-L2 amplification in the second.

Optimizing PD-L1 evaluation on cytological samples from advanced non-small-cell lung cancer

Aim: Programmed cell death-ligand 1 (PD-L1) predicts response to immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC) patients. Most NSCLCs are diagnosed at an advanced stage and using minimally invasive diagnostic procedures that yield small biopsies or cytological samples. Methods: Cytological smears and paired histological samples from 52 advanced NSCLC patients were tested for PD-L1 expression by immunocyto/histochemistry (ICC/IHC) and for PD-L1 gene status by FISH. Results: PD-L1 was overexpressed in 9/52 (17%) cytological samples and in seven (13.5%) matched biopsies. The concordance between immunocytochemistry and IHC was 92.3% (48/52; p < 0.001). The concordance between PD-L1 gene status on cytology and histology was 69.2% (18/26; p < 0.001). No correlation between IHC and fluorescence in situ hybridization results was found. Conclusion: Our data support the feasibility and reliability of PD-L1 protein and PD-L1 gene assessment on direct cytological smears from NSCLC patients whenever histological sample are inadequate.

Elucidation of the relationships of MET protein expression and gene copy number status with PD-L1 expression and the immune microenvironment in non-small cell lung cancer

OBJECTIVES

Alterations in the MET gene, such as mutations and high-level amplification, are important drivers of non-small cell lung cancer (NSCLC). The efficacy of immune checkpoint inhibitors (ICIs) in lung cancer with MET abnormalities is unclear. We evaluate the potential relationship between MET alterations and the tumor immune microenvironment and PD-1/PD-L1 axis.

MATERIAL AND METHODS

MET and phospho-MET protein expression were assessed in 622 resected NSCLC specimens. MET amplification was assessed by fluorescence in-situ hybridization in 272 tumors. PD-L1 expression was evaluated by immunohistochemistry. CD8+, Foxp3+, CD45RO, and PD-1+ tumor-infiltrating lymphocytes (TILs) in the tumor nest and surrounding stroma were profiled. Associations with MET alterations were explored.

RESULTS

The cohort comprised 425 male patients (68.3 %), 184 never-smokers (29.6 %), and 408 adenocarcinoma (ADC) patients (65.6 %). Median age was 68 years. MET alteration was observed mainly in ADCs (18.9 % MET-positive, 3.9 % phospho-MET-positive, and 15.1 % with MET amplification). PD-L1 expression was significantly increased in MET-altered ADCs (P < 0.001 for MET; P = 0.002 for phospho-MET; P = 0.019 for MET amplification). Most TIL subset numbers in the tumor nest were significantly increased in MET-altered tumors. Only MET amplification was independently associated with tumoral CD8 + TILs. Three of the six patients responded to ICI treatment; two of them showed MET overexpression and an increase in MET copy number.

CONCLUSION

MET-altered tumors showed significantly stronger PD-L1 expression and more abundant tumoral TILs than non-MET-altered tumors. Among the MET alterations assessed, MET amplification was particularly implicated in the inflamed microenvironment, suggesting that MET-amplified tumors might respond to ICIs.

[Advances in the Influence of EGFR Mutation on the PD-L1 Expression in Non-small Cell Lung Cancer]

近年来，有关程序性死亡受体1（programmed death-1, PD-1）及其配体（programmed death-1 ligand, PD-L1）抑制剂的研究取得突破性进展，迅速改变着非小细胞肺癌（non-small cell lung cancer, NSCLC）的治疗模式。但表皮生长因子受体（epidermal growth factor receptor, EGFR）突变患者应用PD-1/PD-L1抑制剂的治疗效果并不理想。既往研究显示，肿瘤细胞PD-L1表达率与免疫抑制剂治疗效果存在相关性。但目前EGFR突变对PD-L1表达的影响并不能达成一致。我们将对相关研究进行总结，以期对基础研究或临床治疗有所帮助。

Basis of PD1/PD-L1 Therapies

It is obvious that tumor cells have developed a number of strategies to escape immune surveillance including an altered expression of various immune checkpoints, such as the programmed death-1 receptor (PD-1) and its ligands PD-L1 and PD-L2. The interaction between PD-1 and PD-L1 results in an activation of self-tolerance pathways in both immune cells as well as tumor cells. Thus, these molecules represent excellent targets for T cell-based immunotherapies. However, the efficacy of therapies using checkpoint inhibitors is variable and only a limited number of patients receive a long-term response, while others develop resistances. Therefore, a better insight into the constitutive expression levels and their control as well as the predictive and prognostic value of PD-1/PD-L1, which are controversially discussed due to the methodological assessment, the dynamic and time-related variable expression of these molecules, is urgently required. In this review, the current knowledge of the PD-L1 and PD-1 genes, their expression in immune and tumor cells, the underlying molecular mechanisms of their regulation and their association with clinical parameters and therapy responses are summarized.

Impact of antiretroviral drugs on PD-L1 expression and copy number gains with clinical outcomes in HIV-positive and -negative locally advanced cervical cancers

Cervical cancer has become a leading cause of death in both HIV-infected and uninfected women. Previous studies have revealed that antiretroviral therapy (ART) possesses anti-human papillomavirus (HPV) and antitumour properties, potentially serving as an anticancer agent and improving functional immunity in HIV-positive individuals. However, to the best of our knowledge, no studies have examined the association between ART and the clinical outcome of patients with pre-existing invasive cervical cancer. The current study analysed 48 HIV-positive and 123 HIV-negative patients with locally advanced stage IB2-IVA cervical cancer between December 2008 and December 2016. Tumours were categorized based on programmed cell death-ligand 1 (PD-L1) immunoreactivity and copy number alterations in the PD-L1 gene, as determined by fluorescence in situ hybridization. The results revealed that ART-treated patients exhibited a lower prevalence of PD-L1 immunopositivity, PD-L1 amplification and polysomy compared with patients that did not receive ART and those that were HIV-negative. Furthermore, ART-treated patients with PD-L1 immunonegativity exhibited an improved recurrence-free survival (RFS) compared with patients that did not receive ART and HIV-negative individuals with PD-L1 immunopositivity (P=0.041 vs. P=0.030). Additionally, ART-exposed patients with PD-L1 disomy demonstrated improved locoregional recurrence-free survival (LRR) when compared with HIV-negative patients with PD-L1 amplification and polysomy (P=0.039 vs. P=0.007), RFS (P<0.001 vs. P=0.006) and cancer-specific survival (CSS) (P=0.021 vs. P=0.025). ART-exposed patients with PD-L1 disomy also exhibited improved RFS (P<0.001) and CSS (P<0.001) compared with HIV-negative patients with PD-L1 amplification. Improved LRRs were demonstrated in ART-exposed patients with PD-L1 disomy (P=0.028) compared with non-HIV patients with polysomy. Following multivariate analysis, International Federation of Gynaecology and Obstetrics stage and PD-L1 amplification were determined to be predictors of poor a RFS [hazard ratio (HR), 2.43; 95% confidence interval (CI), 1.37–4.30; P=0.002 vs. HR, 7.03; 95% CI, 2.79–17.74; P<0.001) and CSS (HR, 11.47; 95% CI, 4.70–27.99; P<0.001 vs. HR, 4.05; 95% CI, 1.64–9.98; P=0.002). However, only PD-L1 polysomy was determined to be a predictor of poor LRR (HR, 2.50; 95% CI, 1.11–5.63; P=0.027). HIV status was not associated with poor outcomes, as determined using Cox models. The results of the current study indicated that ART may be used for the treatment of cervical cancer in both HIV-infected and uninfected patients. However, additional research is required to further elucidate these results.

Impact of tumor microenvironment on the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors in patients with EGFR-mutant non-small cell lung cancer

We retrospectively investigated the impact of the tumor microenvironment (TME) on the efficacy of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) as first-line treatment in 70 patients with advanced EGFR-mutant non-small cell lung cancer and who were seen at Osaka City University Hospital (Osaka, Japan) between August 2013 and December 2017. Using immunohistochemical staining with 28-8 and D7U8C Abs, the tumor proportion score was assessed for programmed cell death-1 ligand-1 (PD-L1), as high (50% or more) or low (less than 50%), and ligand-2 (PD-L2) expression, respectively. The extent of CD8+ tumor-infiltrating lymphocytes was evaluated on a scale of 0-3, with 0-1 as low and 2-3 as high. The TME of the 52 evaluable pretreatment specimens was categorized into 4 subtypes, according to the respective PD-L1 tumor proportion and CD8+ scores, as follows: (a) high/high (13.5%, n = 7); (b) low/low (42.3%, n = 22); (c) high/low (17.3%, n = 9); and (d) low/high (26.9%, n = 14). Expression of PD-L2 was significantly the highest in type 1 (57.1% vs 4.5% vs 11.1% vs 7.1%, respectively; P = .0090). Response rate was significantly the lowest in type 1 (14.3% vs 81.8% vs 66.7% vs 78.6%, respectively; P = .0085). Progression-free survival was the shortest in type 1 and the longest in type 4 (median, 2.4 vs 11.3 vs 8.4 vs 17.5 months, respectively; P = .00000077). The efficacy of EGFR-TKIs differed according to the TME, and the phenotype with high PD-L1 and CD8+ expression might be the subset that would poorly benefit from such treatment.

Association with PD-L1 Expression and Clinicopathological Features in 1000 Lung Cancers: A Large Single-Institution Study of Surgically Resected Lung Cancers with a High Prevalence of EGFR Mutation

Programmed cell death ligand 1 (PD-L1) expression is an important biomarker for predicting response to immunotherapy in clinical practice. Hence, identification and characterization of factors that predict high expression of PD-L1 in patients is critical. Various studies have reported the association of PD-L1 expression with driver genetic status in non-small cell cancer; however, the results have been conflicting and inconclusive. We analyzed the relationship between PD-L1 expression and clinicopathological factors including driver genetic alterations in 1000 resected lung cancers using a clinically validated PD-L1 immunohistochemical assay. PD-L1 expression was significantly higher in squamous cell carcinoma (SCC) compared to adenocarcinomas. PD-L1 expression in adenocarcinoma was associated with higher N-stage, solid histologic pattern, EGFR wild type, and ALK positive, but no significant association with the clinicopathological factors in SCC. EGFR mutant adenocarcinomas with distinctive clinicopathologic features, especially solid histologic pattern and higher stage showed higher PD-L1 expression. To the best of our knowledge, this study is the largest to evaluate the association between PD-L1 expression and clinicopathological and molecular features in lung cancer with a highly prevalent EGFR mutation. Therefore, our results are useful to guide the selection of lung cancer, even EGFR-mutated adenocarcinoma patients with PD-L1 expression, for further immunotherapy.

The Role of the Lymphocyte Functional Crosstalk and Regulation in the Context of Checkpoint Inhibitor Treatment-Review

During the last decade, the dynamics of the cellular crosstalk have highlighted the significance of the host vs. tumor interaction. This resulted in the development of novel immunotherapeutic strategies in order to modulate/inhibit the mechanisms leading to escape of tumor cells from immune surveillance. Different monoclonal antibodies directed against immune checkpoints, e.g., the T lymphocyte antigen 4 and the programmed cell death protein 1/ programmed cell death ligand 1 have been successfully implemented for the treatment of cancer. Despite their broad activity in many solid and hematologic tumor types, only 20–40% of patients demonstrated a durable treatment response. This might be due to an impaired T cell tumor interaction mediated by immune escape mechanisms of tumor and immune cells as well as alterations in the composition of the tumor microenvironment, peripheral blood, and microbiome. These different factors dynamically regulate different steps of the cancer immune process thereby negatively interfering with the T cell –mediated anti-tumoral immune responses. Therefore, this review will summarize the current knowledge of the different players involved in inhibiting tumor immunogenicity and mounting resistance to checkpoint inhibitors with focus on the role of tumor T cell interaction. A better insight of this process might lead to the development of strategies to revert these inhibitory processes and represent the rational for the design of novel immunotherapies and combinations in order to improve their efficacy.