PD-1/PD-L1 expression in non-small-cell lung cancer and its correlation with EGFR/KRAS mutations

WFDC2 is a potential prognostic and immunotherapy biomarker in lung adenocarcinoma

OBJECTIVE

The prognosis of lung adenocarcinoma (LUAD), which is the most common type of lung cancer, remains poor. Little is known about the function and mechanism of whey acidic protein four-disulfide core domain 2 (WFDC2) in LUAD.

METHODS

In this study, we used online databases to compare WFDC2 expression between LUAD and normal tissues, to analyze the relationship between WFDC2 and overall survival, and to investigate the potential roles of WFDC2.

RESULTS

We found that WFDC2 protein and mRNA expression levels were significantly higher in LUAD tissue than in normal tissue, and high WFDC2 mRNA expression was associated with better overall survival. WFDC2 mRNA expression was correlated with the mutation status of TP53. The biological function of WFDC2 was associated with the cell cycle, and low WFDC2 mRNA expression was associated with an elevated tumor mutational burden and neoantigen levels. A negative relationship was observed between WFDC2 and immune gene expression, and high WFDC2 mRNA expression was found in patients with LUAD and low programed cell death 1 mRNA expression.

CONCLUSIONS

We propose that WFDC2 is associated with clinical benefits of immune checkpoint inhibitors in LUAD.

From immune checkpoints to therapies: understanding immune checkpoint regulation and the influence of natural products and traditional medicine on immune checkpoint and immunotherapy in lung cancer

Lung cancer is a disease of global concern, and immunotherapy has brought lung cancer therapy to a new era. Besides promising effects in the clinical use of immune checkpoint inhibitors, immune-related adverse events (irAEs) and low response rates are problems unsolved. Natural products and traditional medicine with an immune-modulating nature have the property to influence immune checkpoint expression and can improve immunotherapy's effect with relatively low toxicity. This review summarizes currently approved immunotherapy and the current mechanisms known to regulate immune checkpoint expression in lung cancer. It lists natural products and traditional medicine capable of influencing immune checkpoints or synergizing with immunotherapy in lung cancer, exploring both their effects and underlying mechanisms. Future research on immune checkpoint modulation and immunotherapy combination applying natural products and traditional medicine will be based on a deeper understanding of their mechanisms regulating immune checkpoints. Continued exploration of natural products and traditional medicine holds the potential to enhance the efficacy and reduce the adverse reactions of immunotherapy.

Influence of TP53 Comutation on the Tumor Immune Microenvironment and Clinical Outcomes With Immune Checkpoint Inhibitors in STK11-Mutant Non-Small-Cell Lung Cancer

PURPOSE

Non-small-cell lung cancer (NSCLC) with STK11mut has inferior outcomes to immune checkpoint inhibitors (ICIs). Using multiomics, we evaluated whether a subtype of STK11mut NSCLC with a uniquely inflamed tumor immune microenvironment (TIME) harboring TP53 comutations could have favorable outcomes to ICIs.

PATIENTS AND METHODS

NSCLC tumors (N = 16,896) were analyzed by next-generation sequencing (DNA-Seq/592 genes). A subset (n = 5,034) underwent gene expression profiling (RNA-Seq/whole transcriptome). Exome-level neoantigen load for STK11mut NSCLC was obtained from published pan-immune analysis. Tumor immune cell content was obtained from transcriptome profiles using the microenvironment cell population (MCP) counter. ICI data from POPLAR/OAK (n = 34) and the study by Rizvi et al (n = 49) were used to model progression-free survival (PFS), and a separate ICI-treated cohort (n = 53) from Dana-Farber Cancer Institute (DFCI) was used to assess time to treatment failure (TTF) and tumor RECIST response for STK11mutTP53mut versus STK11mutTP53wt NSCLC.

RESULTS

Overall, 12.6% of NSCLC tumors had a STK11mut with the proportions of tumor mutational burden (TMB)-high (≥10 mut/Mb), PD-L1 ≥50%, and microsatellite instability-high being 38.3%, 11.8%, and 0.72%, respectively. Unsupervised hierarchical clustering of STK11mut (n = 463) for stimulator of interferon-gamma (STING) pathway genes identified a STING-high cluster, which was significantly enriched in TP53mut NSCLC (P < .01). Compared with STK11mutTP53wt, tumors with STK11mutTP53mut had higher CD8+T cells and natural killer cells (P < .01), higher TMB (P < .001) and neoantigen load (P < .001), and increased expression of MYC and HIF-1A (P < .01), along with higher expression (P < .01) of glycolysis/glutamine metabolism genes. Meta-analysis of data from OAK/POPLAR and the study by Rizvi et al showed a trend toward improved PFS in patients with STK11mutTP53mut. In the DFCI cohort, compared with the STK11mut TP53wt cohort, the STK11mutTP53mut tumors had higher objective response rates (42.9% v 16.7%; P = .04) and also had longer TTF (14.5 v 4.5 months, P adj = .054) with ICI.

CONCLUSION

STK11mut NSCLC with TP53 comutation is a distinct subgroup with an immunologically active TIME and metabolic reprogramming. These properties should be exploited to guide patient selection for novel ICI-based combination approaches.

First-line immunotherapy in non-small cell lung cancer: how to select and where to go

INTRODUCTION

Immunotherapy (IO) has established a new milestone in lung cancer treatment. Several registrational studies have approved immune checkpoint inhibitors (ICIs) in different settings, including the metastatic nonsmall cell lung cancer (NSCLC). As well known, responders are just a certain proportion of patients; therefore, their selection by using predictive factors has stood out as a crucial issue to address in tailoring a patient-centered care.

AREAS COVERED

In our review we propose a detailed yet handy cross section on ICIs as first-line treatment in metastatic NSCLC, regarding indications, histological, clinical, and blood-based biomarkers, other than their mechanisms of resistance and new immunological actionable targets. We performed a literature search through PubMed entering keywords complying with crucial features of immunotherapy.

EXPERT OPINION

IO represents the backbone of lung cancer treatment. Trials are currently testing novel immune blockade agents assessing combinatorial approaches with standard ICIs, or antibody drug conjugates (ADC), harboring immunological targets. Perfecting patients' selection is an ongoing challenge and a more and more urgent need in order to best predict responders who will consistently benefit from it.

Immune checkpoints as potential theragnostic biomarkers for epithelial ovarian cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is the leading cause of death associated with gynecologic tumors. EOC is asymptomatic in early stages, so most patients are not diagnosed until late stages, highlighting the need to develop new diagnostic biomarkers. Mediators of the tumoral microenvironment may influence EOC progression and resistance to treatment.

AIM

To analyze immune checkpoints to evaluate them as theranostic biomarkers for EOC.

PATIENTS AND METHODS

Serum levels of 16 immune checkpoints were determined in EOC patients and healthy controls using the MILLIPLEX MAP® Human Immuno-Oncology Checkpoint Protein Magnetic Bead Panel.

RESULTS

Seven receptors: BTLA, CD40, CD80/B7-1, GITRL, LAG-3, TIM-3, TLR-2 are differentially expressed between EOC and healthy controls. Serum levels of immune checkpoints in EOC patients are positively significantly correlated with levels of their ligands, with a higher significant correlation between CD80 and CTLA4 than between CD28 and CD80. Four receptors, CD40, HVEM, PD-1, and PD-L1, are positively associated with the development of resistance to Taxol-platinum-based chemotherapy. All of them have an acceptable area under the curve (>0.7).

CONCLUSION

This study has yielded a first panel of seven immune checkpoints (BTLA, CD40, CD80/B7-1, GITRL, LAG-3, TIM-3, TLR-2) associated with a higher risk of EOC and a second panel of four immune checkpoints (CD40, HVEM, PD-1, PD-L1) that may help physicians to identify EOC patients who are at high risk of developing resistance to EOC chemotherapy.

Efficacy of immunotherapy as second-line or later-line therapy and prognostic significance of KRAS or TP53 mutations in advanced non-small cell lung cancer patients

OBJECTIVE

In this retrospective study, we aimed to assess the relationship between mutations in the Kirsten rats sarcoma viral oncogene (KRAS )/ tumor protein p53 (TP53 ) genes and the efficacy of immune checkpoint inhibitors (ICIs) therapy as a second-line or later-line treatment for patients with stage IIIB/IV non-small cell lung cancer (NSCLC).

METHODS

We retrospectively analyzed the clinical data of 143 patients with stage IIIB/IV NSCLC who were admitted to the Cancer Hospital of Harbin Medical University between January 2019 and September 2022. Kaplan-Meier survival curve analysis was performed to analyze the survival outcomes. Univariate and multivariate Cox proportional risk models were used to analyze the factors associated with the progression-free survival (PFS) and overall survival (OS) of advanced-stage NSCLC patients who received ICIs as second-line or later-line therapy.

RESULTS

NSCLC patients with KRAS or TP53 mutations treated with ICIs showed significantly higher objective response rate, disease control rate, PFS, and OS compared to NSCLC patients with wild-type KRAS / TP53 (P  < 0.05). Multivariate Cox regression analysis showed that a combined treatment regimen of ICIs plus chemotherapy was significantly associated with prolonged PFS [hazard ratio = 0.192; 95% confidence interval (CI), 0.094-0.392; P  < 0.001] and OS (hazard ratio = 0.414; 95% CI, 0.281-0.612; P  < 0.001).

CONCLUSION

KRAS or TP53 mutations were associated with improved PFS of advanced NSCLC patients treated with ICIs as second-line or later-line therapy. KRAS or TP53 mutations show great potential as clinical biomarkers to predict the efficacy of ICIs therapy.

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.

Role of sex and sex hormones in PD-L1 expression in NSCLC: clinical and therapeutic implications

Currently, immunotherapy based on PD-1/PD-L1 pathway blockade has improved survival of non-small cell lung cancer (NSCLC) patients. However, differential responses have been observed by sex, where men appear to respond better than women. Additionally, adverse effects of immunotherapy are mainly observed in women. Studies in some types of hormone-dependent cancer have revealed a role of sex hormones in anti-tumor response, tumor microenvironment and immune evasion. Estrogens mainly promote immune tolerance regulating T-cell function and modifying tumor microenvironment, while androgens attenuate anti-tumor immune responses. The precise mechanism by which sex and sex hormones may modulate immune response to tumor, modify PD-L1 expression in cancer cells and promote immune escape in NSCLC is still unclear, but current data show how sexual differences affect immune therapy response and prognosis. This review provides update information regarding anti-PD-1/PD-L immunotherapeutic efficacy in NSCLC by sex, analyzing potential roles for sex hormones on PD-L1 expression, and discussing a plausible of sex and sex hormones as predictive response factors to immunotherapy.

Anti-PD-1 antibody armored γδ T cells enhance anti-tumor efficacy in ovarian cancer

γδ T cells have the unique ability to detect a wide range of tumors with low mutation burdens, making them attractive candidates for CAR-T-cell therapy. Unlike αβ T cells and other immune cells, γδ T cells are superior in MHC non-restriction, selective cell recruitment, and rapid activation. However, clinical trials have shown limited clinical benefits, and the adoptive transplantation of γδ T cells has often fallen short of expectations. We hypothesized that the limited effectiveness of γδ T cells in eradicating tumor cells may be attributed to the inhibitory tumor microenvironment induced by the suppressive PD-1/PD-L1 axis. Herein, we constructed novel armored γδ T cells capable of secreting humanized anti-PD-1 antibodies, referred to as "Lv-PD1-γδ T cells. Lv-PD1-γδ T cells showed improved proliferation and enhanced cytotoxicity against tumor cells, resulting in augmented therapeutic effects and survival benefits in ovarian tumor-bearing mice. These engineered cells demonstrated a prolonged in vivo survival of more than 29 days, without any potential for tumorigenicity in immunodeficient NOD/SCID/γ null mice. We also found that Lv-PD1-γδ T cells exhibited excellent tolerance and safety in humanized NOD/SCID/γ null mice. With attenuated or eliminated immunosuppression and maximized cytotoxicity efficacy by the local secretion of anti-PD1 antibodies in tumors, Lv-PD1-γδ T cells can serve as a promising "off-the-shelf" cell therapy against cancers.

Prognostic impact of PD-L1 and TIGIT expression in non-small cell lung cancer following concurrent chemo-radiotherapy

We investigated the effect of preoperative therapy for non-small cell lung cancer on programmed death-ligand 1 (PD-L1), programmed death-1 (PD-1), poliovirus receptor (CD155), and T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) expression and prognosis with the cases of 28 patients received preoperative concurrent chemo-radiotherapy (cCRT) and 27 received preoperative drug therapy. The post-treatment PD-L1 expression was higher in cCRT group than in the drug therapy (50.0% vs 5.0%, p = 0.000), whereas that of CD155 did not significantly differ (40.0% vs 60.0%, p = 0.131). The PD-1 expression was not significantly different between the cCRT and drug therapy groups (51.1% vs 42.9%, p = 0.076), while the TIGIT was significantly higher in the cCRT group (41.5% vs 34.0%, p = 0.008). The patients who received cCRT resulted in elevated PD-L1and TIGIT values had a worse prognosis (p = 0.008). The PD-L1 and TIGIT expression after cCRT was significantly higher than after drug treatment. The cCRT population with high expression of both had a significantly poorer prognosis, indicating elevation of PD-L1 and TIGIT after cCRT as a negative prognostic factor. Combination therapy with anti-PD-L1 and anti-TIGIT antibodies after cCRT may contribute to an improved prognosis.

Case Report: Chemotherapy-free treatment with camrelizumab and anlotinib for elderly patients with KRAS and TP53 mutated advanced lung cancer

Background: Lung cancer is a major public health issue and an enormous burden on society in China. Most lung cancers occur in elderly patients with non-small cell lung cancer (NSCLC), and many factors limit their treatment options. Chemotherapy-free therapy can avoid psychological fear, treatment pain, and adverse reactions caused by chemotherapy. Patients with non-small cell lung cancer with tumour protein p53 (TP53) gene mutations or Kirsten rat sarcoma viral oncogene homologue (KRAS) gene mutations tend to be more sensitive to anlotinib or programmed cell death protein 1 (PD-1) drugs. However, Kirsten rat sarcoma viral oncogene homologue is a proto-oncogene downstream of the epidermal growth factor receptor (EGFR) gene; therefore, if the Kirsten rat sarcoma viral oncogene homologue gene has an activating mutation, EGFR-targeted drug resistance may occur. Further studies are needed to explore whether patients with dual Kirsten rat sarcoma viral oncogene homologue and tumour protein p53 mutations can be treated with targeted immunotherapy without chemotherapy. Case presentation: A 74-year-old man was referred to the Lanzhou University Second Hospital due to chest tightness, shortness of breath, and weight loss for 2 months and was diagnosed with moderately to poorly differentiated adenocarcinoma. Laboratory examinations showed increased alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), cancer antigen (CA)-125, and CA199 levels, and gene sequencing indicated mutations in Kirsten rat sarcoma viral oncogene homologue and tumour protein p53. Immunohistochemical analysis showed positive PD-L1 and PD-1 expression. Peripheral blood immune checkpoint test using flow cytometry indicated that the PD-1 + CD8 levels were positive. After multi-disciplinary treatment, therapy with a combination of anlotinib and camrelizumab was initiated. Camrelizumab 200 mg was administered intravenously once every 3 weeks. Anlotinib 12 mg was administered orally daily before breakfast for 2 weeks with a week of rest in every cycle of 21 days. A reduction in alpha-fetoprotein, carcinoembryonic antigen, CA125, CA199, and CA724 levels was observed up to the first cycle, which decreased within the normal limits up to the second cycle and continued until the eighteenth cycle. The patient's chest tightness, shortness of breath, weight loss, and other symptoms significantly improved following treatment. Computed tomography imaging showed that the neoplastic lesion was dramatically reduced. The patient is currently being followed-up for more than 2 years to evaluate the duration of the response. Conclusion: Chemotherapy-free immunotherapy combined with targeted therapy is an effective treatment for advanced non-small cell lung cancer in elderly patients with Kirsten rat sarcoma viral oncogene homologue and tumour protein p53 mutations. Such therapies should be supported with further clinical studies with larger sample sizes.

Correlation of preclinical and clinical biomarkers with efficacy and toxicity of cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have revealed significant clinical values in different solid tumors and hematological malignancy, changing the landscape for the treatment of multiple types of cancer. However, only a subpopulation of patients has obvious tumor response and long-term survival after ICIs treatment, and many patients may experience other undesirable clinical features. Therefore, biomarkers are critical for patients to choose exact optimum therapy. Here, we reviewed existing preclinical and clinical biomarkers of immunotherapeutic efficacy and immune-related adverse events (irAEs). Based on efficacy prediction, pseudoprogression, hyperprogressive disease, or irAEs, these biomarkers were divided into cancer cell-derived biomarkers, tumor microenvironment-derived biomarkers, host-derived biomarkers, peripheral blood biomarkers, and multi-modal model and artificial intelligence assessment-based biomarkers. Furthermore, we describe the relation between ICIs efficacy and irAEs. This review provides the overall perspective of biomarkers of immunotherapeutic outcome and irAEs prediction during ICIs treatment.

CheckMate-722: The Rise and Fall of Nivolumab with Chemotherapy in TKI-Refractory EGFR-Mutant NSCLC

The treatment of non-small cell lung cancer (NSCLC) has increasingly been driven by the presence of targetable driver mutations, including epidermal growth factor receptor (EGFR) mutations. Tyrosine receptor inhibitors (TKIs) have subsequently emerged as the standard-of-care treatment for EGFR-mutant NSCLC. However, there are currently limited treatment options for TKI-refractory EGFR-mutant NSCLC. It is in this context that immunotherapy has arisen as a particularly promising player, especially in the context of favorable results from the ORIENT-31 and IMpower150 trials. Thus, the results of the CheckMate-722 trial were highly anticipated, as it was the first global trial to evaluate the efficacy of immunotherapy in addition to standard platinum-based chemotherapy, specifically in the treatment of EGFR-mutant NSCLC post-progression on TKIs.

Transient Systemic Autophagy Inhibition Is Selectively and Irreversibly Deleterious to Lung Cancer

Autophagy is a conserved catabolic process that maintains cellular homeostasis. Autophagy supports lung tumorigenesis and is a potential therapeutic target in lung cancer. A better understanding of the importance of tumor cell-autonomous versus systemic autophagy in lung cancer could facilitate clinical translation of autophagy inhibition. Here, we exploited inducible expression of Atg5 shRNA to temporally control Atg5 levels and to generate reversible tumor-specific and systemic autophagy loss mouse models of KrasG12D/+;p53-/- (KP) non-small cell lung cancer (NSCLC). Transient suppression of systemic but not tumor Atg5 expression significantly reduced established KP lung tumor growth without damaging normal tissues. In vivo13C isotope tracing and metabolic flux analyses demonstrated that systemic Atg5 knockdown specifically led to reduced glucose and lactate uptake. As a result, carbon flux from glucose and lactate to major metabolic pathways, including the tricarboxylic acid cycle, glycolysis, and serine biosynthesis, was significantly reduced in KP NSCLC following systemic autophagy loss. Furthermore, systemic Atg5 knockdown increased tumor T-cell infiltration, leading to T-cell-mediated tumor killing. Importantly, intermittent transient systemic Atg5 knockdown, which resembles what would occur during autophagy inhibition for cancer therapy, significantly prolonged lifespan of KP lung tumor-bearing mice, resulting in recovery of normal tissues but not tumors. Thus, systemic autophagy supports the growth of established lung tumors by promoting immune evasion and sustaining cancer cell metabolism for energy production and biosynthesis, and the inability of tumors to recover from loss of autophagy provides further proof of concept that inhibition of autophagy is a valid approach to cancer therapy.

SIGNIFICANCE

Transient loss of systemic autophagy causes irreversible damage to tumors by suppressing cancer cell metabolism and promoting antitumor immunity, supporting autophagy inhibition as a rational strategy for treating lung cancer. See related commentary by Gan, p. 4322.

RAS oncogenic activity predicts response to chemotherapy and outcome in lung adenocarcinoma

Activating mutations in KRAS occur in 32% of lung adenocarcinomas (LUAD). Despite leading to aggressive disease and resistance to therapy in preclinical studies, the KRAS mutation does not predict patient outcome or response to treatment, presumably due to additional events modulating RAS pathways. To obtain a broader measure of RAS pathway activation, we developed RAS84, a transcriptional signature optimised to capture RAS oncogenic activity in LUAD. We report evidence of RAS pathway oncogenic activation in 84% of LUAD, including 65% KRAS wild-type tumours, falling into four groups characterised by coincident alteration of STK11/LKB1, TP53 or CDKN2A, suggesting that the classifications developed when considering only KRAS mutant tumours have significance in a broader cohort of patients. Critically, high RAS activity patient groups show adverse clinical outcome and reduced response to chemotherapy. Patient stratification using oncogenic RAS transcriptional activity instead of genetic alterations could ultimately assist in clinical decision-making.

Therapeutic Potential of Fingolimod and Dimethyl Fumarate in Non-Small Cell Lung Cancer Preclinical Models

New therapies are required for patients with non-small cell lung cancer (NSCLC) for which the current standards of care poorly affect the patient prognosis of this aggressive cancer subtype. In this preclinical study, we aim to investigate the efficacy of Fingolimod, a described inhibitor of sphingosine-1-phosphate (S1P)/S1P receptors axis, and Dimethyl Fumarate (DMF), a methyl ester of fumaric acid, both already approved as immunomodulators in auto-immune diseases with additional expected anti-cancer effects. The impact of both drugs was analyzed with in vitro cell survival analysis and in vivo graft models using mouse and human NSCLC cells implanted in immunocompetent or immunodeficient mice, respectively. We demonstrated that Fingolimod and DMF repressed tumor progression without apparent adverse effects in vivo in three preclinical mouse NSCLC models. In vitro, Fingolimod did not affect either the tumor proliferation or the cytotoxicity, although DMF reduced tumor cell proliferation. These results suggest that Fingolimod and DMF affected tumor progression through different cellular mechanisms within the tumor microenvironment. Fingolimod and DMF might uncover potential therapeutic opportunities in NSCLC.

KRAS G12C-Mutant Non-Small-Cell Lung Adenocarcinoma: First Documented Report in the Arabian Gulf

We report the first documented case series of two lung adenocarcinoma patients demonstrating Kirsten rat sarcoma viral oncogene homolog (KRAS) G12C mutations by reverse transcription-polymerase chain reaction techniques from Saudi Arabia. Both patients were males aged 64 and 76 years. The first had a heavy smoking history, while the second did not report any history of smoking. The tumor subtype was identified to be non-mucinous lung adenocarcinoma in both cases. The younger patient presented with generalized lymphadenopathy and a right-sided lung mass lesion, while the older patient exhibited stage III-A left lung adenocarcinoma that required rapid response. An initial examination of the first case showed a right-sided mediastinal shift, bilateral neck lymphadenopathy, and poorly differentiated neoplasm from a right supraclavicular core biopsy, leading to treatment with palliatives along with regular checkups. The second case was afebrile after being confirmed to be vitally stable and laboratory testing (Neutr 100). Further studies, specifically on large numbers of patients from the Arabian Gulf, are needed to confirm significant differences between the national and international populations. Additionally, future studies should investigate more differences in the differentiation of KRAS-mutant lung adenocarcinoma between patients from the Arabian Gulf and others.

Resistance to TKIs in EGFR-Mutated Non-Small Cell Lung Cancer: From Mechanisms to New Therapeutic Strategies

Simple Summary

Resistance to tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR) in advanced mutant non-small cell lung cancer (NSCLC) constitutes a therapeutic challenge. Resistance may occur as a result of EGFR-dependent and independent molecular pathways. The first commonly includes T790M, C797S, L792X and L718X mutations, while the latter pertains to HER2 and MET amplifications, gene rearrangements, disruption in PIK3CA, MAPK signaling and SCLC and epithelial–mesenchymal cells transformation. Liquid biopsies detecting mutant cell-free DNA (cfDNA) have a major potential in the detection of mutant clones before they become clinically apparent. Newer-generation TKIs, bispecific antibodies and antibody-drug conjugates or combinations of TKIs with other TKIs or chemotherapy, immunotherapy and anti-vascular endothelial growth factors (anti-VEGFs) are currently in use or under investigation in EGFR mutant NSCLC. In EGFR mutant NSCLC metastatic to the brain, the blood–brain barrier (BBB) decreases the ability of TKIs to reach the central nervous system (CNS), acting as an additional resistance factor, which can presently be addressed with osimertinib. The potential of rechallenging EFGR TKIs after chemotherapy and combining it with anti-PD-1 immunotherapeutics remains ambivalent. Harnessing nanocarriers to improve drug delivery in EGFR TKIs-resistant NSCLC has been promising in preclinical settings, but it is yet to be determined in a clinical context.

Abstract

Resistance to tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR) in advanced mutant Non-Small Cell Lung Cancer (NSCLC) constitutes a therapeutic challenge. This review intends to summarize the existing knowledge about the mechanisms of resistance to TKIs in the context of EGFR mutant NSCLC and discuss its clinical and therapeutic implications. EGFR-dependent and independent molecular pathways have the potential to overcome or circumvent the activity of EGFR-targeted agents including the third-generation TKI, osimertinib, negatively impacting clinical outcomes. CNS metastases occur frequently in patients on EGFR-TKIs, due to the inability of first and second-generation agents to overcome both the BBB and the acquired resistance of cancer cells in the CNS. Newer-generation TKIs, TKIs targeting EGFR-independent resistance mechanisms, bispecific antibodies and antibody-drug conjugates or combinations of TKIs with other TKIs or chemotherapy, immunotherapy and Anti-Vascular Endothelial Growth Factors (anti-VEGFs) are currently in use or under investigation in EGFR mutant NSCLC. Liquid biopsies detecting mutant cell-free DNA (cfDNA) provide a window of opportunity to attack mutant clones before they become clinically apparent. Overall, EGFR TKIs-resistant NSCLC constitutes a multifaceted therapeutic challenge. Mapping its underlying mutational landscape, accelerating the detection of resistance mechanisms and diversifying treatment strategies are essential for the management of the disease.

Differential expression of Tim3 protein in colorectal cancer associated with MSI and Braf mutation

Tim3 is a negative immune checkpoint molecule and plays a crucial part in tumor-induced immune suppression. Tim3 is a cell surface molecule expressed on T cells marking dysfunctional CD8+ cells in various kinds of cancers. Tim3 expression was mainly reported in tumor-infiltrating lymphocytes (TILs). There are few studies focusing on the expression of Tim3 in tumor cells. Immunohistochemistry was performed to determine Tim3 expression level. The relationships between Tim3 expression in colorectal cancer cells and in tumor-infiltrating lymphocytes and cilicopathological parameters were statistically analyzed. Tim3 was differentially detected in TILs and in colorectal cancer cells. Positive expression of Tim3 in colorectal cancer cells was associated with tumor location (P=0.001), depth of tumor invasion (P<0.001), lymph node metastasis (P=0.001), TNM stage (P=0.001), MSI (P=0.008), and Braf V600E mutation (P=0.001). On the other hand, positive expression of Tim3 in TILs was only related to depth of tumor invasion (P<0.001). Positive expression of Tim3 in both colorectal cancer cells and TILs was associated with depth of tumor invasion (P<0.001), lymph node metastasis (P=0.002), TNM stage (P=0.002), MSI (P=0.039), and Braf V600E mutation (P=0.009). Kaplan-Meier survival analysis showed that Tim3 expression in colorectal cancer and in TILs was significantly associated with patient overall survival (OS) rate (P=0.039, and 0.001). Tim3 may be a potential prognostic marker and a therapy target for colorectal cancer.

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.

ESMO expert consensus statements on the management of EGFR mutant non-small-cell lung cancer

The European Society for Medical Oncology (ESMO) held a virtual consensus-building process on epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer in 2021. The consensus included a multidisciplinary panel of 34 leading experts in the management of lung cancer. The aim of the consensus was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where the available evidence is either limited or conflicting. The main topics identified for discussion were: (i) tissue and biomarkers analyses; (ii) early and locally advanced disease; (iii) metastatic disease and (iv) clinical trial design, patient's perspective and miscellaneous. The expert panel was divided into four working groups to address questions relating to one of the four topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the recommendations developed, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation.

Biomarkers related to immune checkpoint inhibitors therapy

Immune checkpoint inhibitors (ICIs) therapy is an emerging cancer treatment. During treatment it is necessary to monitor the patient at all times and respond to any adverse reactions that may occur, such as immune-related adverse events and unconventional reactions. Biomarkers, the biochemical indicators that mark changes in the structure or function of systems, organs, tissues, and cells, may be used to predict and design treatment for such reactions. Anti-tumor immunotherapy biomarkers can be derived from the tumors themselves (e.g. negative regulatory molecules and dynamic changes in genome sequence) or from the immune system (e.g. peripheral blood cell population counts, various cytokines, tumor-infiltrating lymphocytes, and intestinal microbes). The development of biomarkers is important for monitoring the effect of treatment, assessing the patient's response to ICIs, determining adverse reactions, and predicting the direction of disease development. In addition, organ toxicity and systemic events also have an impact on the therapeutic effect of ICIs.

Precision Medicine in Lung Cancer Theranostics: Paving the Way from Traditional Technology to Advance Era

Precision medicine for lung cancer theranostics is an advanced model combining prevention, diagnosis, and treatment for individual or specific population diseases to match individual patient differences. It involves collection and integration of genome, transcriptome, proteome, and metabolome features of lung cancer patients, combined with clinical characteristics. Subsequently, large data and artificial intelligence (AI) analysis have emerged to identify the most suitable therapeutic targets and personal treatment strategies for treatment of patients with lung cancer. We review the development and challenges associated with diagnosis and therapy of lung cancer from traditional technology, including immunotherapy prediction markers, liquid biopsy, surgery, and tumor immune microenvironment and patient-derived xenograft models, to AI in the era of precision medicine. AI has improved precision medicine and the predictive ability and accuracy of patient outcomes. Finally, we discuss some opportunities and challenges for lung cancer theranostics. Precision medicine in lung cancer can help us find the optimum treatment dose and time for a specific patient, which can advance the development of lung cancer therapeutics.

Clinical Application Perspectives of Lung Cancers 3D Tumor Microenvironment Models for In Vitro Cultures

Despite the enormous progress and development of modern therapies, lung cancer remains one of the most common causes of death among men and women. The key element in the development of new anti-cancer drugs is proper planning of the preclinical research phase. The most adequate basic research exemplary for cancer study are 3D tumor microenvironment in vitro models, which allow us to avoid the use of animal models and ensure replicable culture condition. However, the question tormenting the scientist is how to choose the best tool for tumor microenvironment research, especially for extremely heterogenous lung cancer cases. In the presented review we are focused to explain the key factors of lung cancer biology, its microenvironment, and clinical gaps related to different therapies. The review summarized the most important strategies for in vitro culture models mimicking the tumor–tumor microenvironmental interaction, as well as all advantages and disadvantages were depicted. This knowledge could facilitate the right decision to designate proper pre-clinical in vitro study, based on available analytical tools and technical capabilities, to obtain more reliable and personalized results for faster introduction them into the future clinical trials.

Resistance to Immunotherapy: Mechanisms and Means for Overcoming

Immune checkpoint blockade transformed cancer therapy during the last decade. However, durable responses remain uncommon, early and late relapses occur over the course of treatment, and many patients with PD-L1-expressing tumors do not respond to PD-(L)1 blockade. In addition, while some malignancies exhibit inherent resistance to treatment, others develop adaptations that allow them to evade antitumor immunity after a period of response. It is crucial to understand the pathophysiology of the tumor-immune system interplay and the mechanisms of immune escape in order to circumvent primary and acquired resistance. Here we provide an outline of the most well-defined mechanisms of resistance and shed light on ongoing efforts to reinvigorate immunoreactivity.

Programmed Cell Death Ligand 1 Expression in Cytological and Surgical Non-Small Cell Lung Cancer Specimens in Association with EGFR Mutation and Overall Survival: A Single-Institution Experience

OBJECTIVE

The aim of this study was to evaluate programmed cell death ligand-1 (PD-L1) expression and the relationship between driver mutations and survival analysis in advanced-stage non-small cell lung carcinoma (NSCLC).

MATERIAL AND METHOD

A total of 122 advanced-stage NSCLC patients were included in this retrospective study. The patients were diagnosed based on cytological examination and histopathological analysis of biopsy or resection material that had undergone at least 1 molecular analysis. The expression of PD-L1 in tumors and tumor-infiltrating lymphocytes (TIL) was scored and compared with age, sex, organ, biopsy method, tumor subtype, driver mutation status, and overall survival data.

RESULTS

There was no statistically significant difference between PD-L1-positivity and age, gender, location, pattern, or pathological diagnosis of the type of sample. When the threshold value for PD-L1 IHC evaluation was accepted as ≥1% and ≥50%, the rate of positivity was 19.7% and 7.4%, respectively.

CONCLUSION

Since there is a wide range of positivity rates reported in the literature, we could not reach a conclusion as to whether the PD-L1-positivity rate we observed was high or low. There is a need for comparative studies where the technique, clones, threshold values, and phases are homogenized. There is an inverse correlation between the EGFR-mutant population and PD-L1 positivity. In terms of overall survival, no relationship was found between PD-L1 positivity, the presence of TIL, and EGFR mutation status.

Clinical and Prognostic Significance of Tumor-Infiltrating CD8+ T Cells and PD-L1 Expression in Primary Gastrointestinal Stromal Tumors

Purpose

Immunotherapy for gastrointestinal stromal tumors (GISTs) remains a clinical challenge. The present study aimed to explore the clinical and prognostic significance of immune cell infiltration and PD-L1 expression in GISTs.

Methods

A total of 507 clinical tissue specimens of primary GISTs were collected for immunohistochemical analysis of immune cell infiltration and PD-L1 expression. Influencing factors of survival were evaluated by Kaplan–Meier analysis. Univariate and multivariate analyses were performed using the Cox regression model.

Results

There were significant differences in sex, tumor location, size, mitotic index, NIH risk grade, and cell morphology between different gene mutation types of GISTs. Immune cell infiltration in GISTs mainly involved macrophages and T cells. PD-1 was expressed in 48.5% of the tissue specimens, and PD-L1 expression was detected in 46.0% of the samples. PD-L1 expression was negatively correlated with the tumor size and mitotic index but positively correlated with the number of CD8+ T cells. There were significant differences in the number of CD8+ T cells between different gene mutation types. Wild type-mutant GISTs were enriched with CD8+ T cells as compared with KIT- and PDGFRA-mutant GISTs. The number of CD8+ T cells was higher in non-gastric GISTs. PD-L1 and CD8+ T cells were independent predictors for better relapse-free survival of GISTs.

Conclusions

PD-L1 expression is a predictive biomarker for better prognosis of GISTs. Non-gastric GIST patients with wild-type mutations may be the beneficiaries of PD-1/PD-L1 inhibitors.

Differences in Immunological Landscape between EGFR-Mutated and Wild-Type Lung Adenocarcinoma

Recent clinical trials of lung adenocarcinoma with immune checkpoint inhibitors revealed that lung adenocarcinoma patients with EGFR mutations have a poor response to immunotherapy. However, the mechanisms have not been addressed. We performed immunohistochemistry analyses of resected lung adenocarcinoma tissues with and without EGFR mutations to investigate and compare the characteristics of the tumor microenvironment (TME). We retrospectively enrolled a total of 323 lung adenocarcinoma patients (164 had EGFR mutations), and their corresponding tissue samples were analyzed by the EGFR mutation test and immunohistochemistry. We selected the markers of the immune checkpoint molecule (PD1, PD-L1, and LAG-3) and immune cell (CD3, CD4, CD8, and Foxp3) as markers of the tumor microenvironment. Our results revealed that patients had a distinct tumor microenvironment between EGFR-mutant and wild-type lung adenocarcinomas; the expression of CD3, CD4, PD-L1, and Foxp3 in EGFR-mutant tumors was significantly higher than that in wild-type tumors, while the expression of LAG3 and PD-1 showed a positive correlation with EGFR-wild-type tumors. In survival analysis, EGFR-wild-type patients had longer disease-free survival (DFS) than EGFR-mutant patients (P = 0.0065). Our research demonstrates significant differences in tumor microenvironment composition between EGFR-mutant and wild-type patients. Our findings provide novel evidence that contributes to understanding the mechanism underlying the poor efficacy of immune checkpoint inhibitors.

Correlation between PD-L1 expression and MET gene amplification in patients with advanced non-small cell lung cancer and no other actionable oncogenic driver

Non-small cell lung cancers (NSCLC) are the most common type of lung cancer and can be classified according to the presence of mutually exclusive oncogenic drivers. The majority of NSCLC patients present a non-actionable oncogenic driver, and treatment resistance through the amplification of the METproto-oncogene (MET) or the expression of programmed cell death protein 1 ligand (PD-L1) is common. Herein, we investigated the relation between MET gene amplification and PD-L1 expression in patients with advanced NSCLC and no other actionable oncogenic driver (i.e., EGFR, ALK, ROS1). Our retrospective observational study analyzed data from 48 patients (78% men, median age 66 years) admitted to the Germans Trias i Pujol Hospital, Spain, between July 2015 and February 2019. Patients presenting MET amplification showed a higher proportion of PD-L1 expression (93% vs. 39%; p < 0.001) and overexpression (64% vs. 27%; p = 0.020) than those with non-amplified MET. PD-L1 expression was not significantly different when analyzed by sex (p = 0.624), smoking history (p = 0.429), and Eastern Cooperative Oncology Group Performance Status (p = 0.597) Overall survival rates were not significantly affected by MET amplification (high and intermediate amplification vs low amplification and non-amplificated) (p = 0.252) nor PD-L1 expression (> vs =< 50%) (p = 0.893). In conclusion, a positive correlation was found between MET gene amplification and PD-L1 expression and highly expressed (above 50%) in patients with NSCLC and no other actionable oncogenic driver. It could be translated as new guided-treatment oportunities for these patients.

Retrospective analysis of eleven gene mutations, PD-L1 expression and clinicopathological characteristics in non-small cell lung cancer patients

OBJECTIVES

To investigate the associations among expression of programmed cell death ligand 1 (PD-L1), eleven mutated genes, and clinicopathological characteristics in 273 patients with non-small cell lung cancer (NSCLC).

METHODS

We retrospectively examined tumor PD-L1 expression in 247 surgically resected primary and 26 advanced NSCLC patients by immunohistochemistry using SP263 antibody assay. Gene mutations of EGFR, TP53, KRAS, PIK3CA, ERBB2, MET, RET, ALK, BRAF, ROS1, and APC were examined by NGS sequence. Data analysis was carried out using SPSS 22.0. The associations among PD-L1 expression, eleven mutated genes and clinicopathological characteristics were assessed by univariate and multivariate analysis.

RESULTS

Among the total 273 patients, 68 (24.9%) patients were positive for PD-L1 expression. Data showed that mutated rate of EGFR gene was the highest with 63.0% (172/273), followed by TP53 (11.7%, 32/273) and KRAS (5.5%, 15/273). The female, non-smoker, and patients with adenocarcinoma (ADC) were more likely to have EGFR mutations. Multivariate logistic regression showed that PD-L1 expression was significantly associated with Non-ADC, lymphatic invasion, EGFR wild type and TP53 mutation (p = 0.041, <0.001, 0.004 and 0.014, respectively). Moreover, PD-L1 expression in adenocarcinoma was associated with lymphatic invasion, mutation of TP53 and KRAS gene (p = 0.012, <0.025 and 0.041, respectively).

CONCLUSIONS

Mutations of EGFR, KRAS and TP53 should be routinely detected in clinical practice to better guide the immunotherapy for NSCLC patients. Future investigations are warranted to illustrate the potential mechanisms between driver mutations and PD-L1 expression for guiding immunotherapy in patients with NSCLC.

Immunotherapy in Treating EGFR-Mutant Lung Cancer: Current Challenges and New Strategies

Lung cancer is the leading cause of cancer-related deaths worldwide. Immune checkpoint inhibitors, including monoclonal antibodies against programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1), have dramatically improved the survival and quality of life of a subset of non-small cell lung cancer (NSCLC) patients. Multiple predictive biomarkers have been proposed to select the patients who may benefit from the immune checkpoint inhibitors. EGFR-mutant NSCLC is the most prevalent molecular subtype in Asian lung cancer patients. However, patients with EGFR-mutant NSCLC show poor response to anti-PD-1/PD-L1 treatment. While small-molecule EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for EGFR-mutant NSCLC, acquired drug resistance is severely limiting the long-term efficacy. However, there is currently no further effective treatment option for TKIs-refractory EGFR-mutant NSCLC patients. The reasons mediating the poor response of EGFR-mutated NSCLC patients to immunotherapy are not clear. Initial investigations revealed that EGFR-mutated NSCLC has lower PD-L1 expression and a low tumor mutational burden, thus leading to weak immunogenicity. Moreover, the use of PD-1/PD-L1 blockade prior to or concurrent with osimertinib has been reported to increase the risk of pulmonary toxicity. Furthermore, emerging evidence shows that PD-1/PD-L1 blockade in NSCLC patients can lead to hyperprogressive disease associated with dismal prognosis. However, it is difficult to predict the treatment toxicity. New biomarkers are urgently needed to predict response and toxicity associated with the use of PD-1/PD-L1 immunotherapy in EGFR-mutated NSCLC. Recently, promising data have emerged to suggest the potentiation of PD-1/PD-L1 blockade therapy by anti-angiogenic agents and a few other novel therapeutic agents. This article reviews the current investigations about the poor response of EGFR-mutated NSCLC to anti-PD-1/PD-L1 therapy, and discusses the new strategies that may be adopted in the future.

Immune Checkpoint Inhibitors in EGFR-Mutated NSCLC: Dusk or Dawn?

Although immune checkpoint inhibitors (ICIs) that target programmed cell death protein-1/programmed cell death ligand-1 axis have significantly shifted the treatment paradigm in advanced NSCLC, clinical benefits of these agents are limited in patients with EGFR-mutated NSCLC. Several predictive biomarkers (e.g., programmed cell death ligand-1 expression, tumor mutation burden), which have been validated in EGFR-wild type NSCLC, however, are not efficacious in EGFR-mutated tumors, suggesting the unique characteristics of tumor microenvironment of EGFR-mutated NSCLC. Here, we first summarized the clinical evidence on the efficacy of ICIs in patients with EGFR-mutated NSCLC. Then, the cancer immunogram features of EGFR-mutated NSCLC was depicted to visualize the state of cancer-immune system interactions, including tumor foreignness, tumor sensitivity to immune effectors, metabolism, general immune status, immune cell infiltration, cytokines, and soluble molecules. We further discussed the potential subpopulations with EGFR mutations that could benefit from ICI treatment. Lastly, we put forward future strategies to adequately maximize the efficacy of ICI treatment in patients with EGFR-mutated NSCLC in the upcoming era of combination immunotherapies.

PD-L1 lncRNA splice isoform promotes lung adenocarcinoma progression via enhancing c-Myc activity

BACKGROUND

Although using a blockade of programmed death-ligand 1 (PD-L1) to enhance T cell immune responses shows great promise in tumor immunotherapy, the immune-checkpoint inhibition strategy is limited for patients with solid tumors. The mechanism and efficacy of such immune-checkpoint inhibition strategies in solid tumors remains unclear.

RESULTS

Employing qRT-PCR, Sanger sequencing, and RNA BaseScope analysis, we show that human lung adenocarcinoma (LUAD) all produce a long non-coding RNA isoform of PD-L1 (PD-L1-lnc) by alternative splicing, regardless if the tumor is positive or negative for the protein PD-L1. Similar to PD-L1 mRNA, PD-L1-lnc in various lung adenocarcinoma cells is significantly upregulated by IFNγ. Both in vitro and in vivo studies demonstrate that PD-L1-lnc increases proliferation and invasion but decreases apoptosis of lung adenocarcinoma cells. Mechanistically, PD-L1-lnc promotes lung adenocarcinoma progression through directly binding to c-Myc and enhancing c-Myc transcriptional activity.

CONCLUSIONS

In summary, the PD-L1 gene can generate a long non-coding RNA through alternative splicing to promote lung adenocarcinoma progression by enhancing c-Myc activity. Our results argue in favor of investigating PD-L1-lnc depletion in combination with PD-L1 blockade in lung cancer therapy.

MUC3A induces PD-L1 and reduces tyrosine kinase inhibitors effects in EGFR-mutant non-small cell lung cancer

The immune checkpoint ligand programmed death-ligand 1 (PD-L1) and the transmembrane mucin (MUC) 3A are upregulated in non-small cell lung cancer (NSCLC), contributing to the aggressive pathogenesis and poor prognosis. Here, we report that knocking down the oncogenic MUC3A suppresses the PD-L1 expression in NSCLC cells. MUC3A is a potent regulator of epidermal growth factor receptor (EGFR) stability, and MUC3A deficiency downregulates the activation of the PI3K/Akt and MAPK pathways, which subsequently reduces the expression of PD-L1. Furthermore, knockdown of MUC3A and tyrosine kinase inhibitors (TKIs) in EGFR-mutant NSCLC cells play a synergistic effect on inhibited proliferation and promoted apoptosis in vitro. In the BALB/c nude mice xenograft model, MUC3A deficiency enhances EGFR-mutated NSCLC sensitivity to TKIs. Our study shows that transmembrane mucin MUC3A induces PD-L1, thereby promoting immune escape in NSCLC, while downregulation of MUC3A enhances TKIs effects in EGFR-mutant NSCLC. These findings offer insights into the design of novel combination treatment for NSCLC.

Antitumour immunity regulated by aberrant ERBB family signalling

Aberrant signalling of ERBB family members plays an important role in tumorigenesis and in the escape from antitumour immunity in multiple malignancies. Molecular-targeted agents against these signalling pathways exhibit robust clinical efficacy, but patients inevitably experience acquired resistance to these molecular-targeted therapies. Although cancer immunotherapies, including immune checkpoint inhibitors (ICIs), have shown durable antitumour response in a subset of the treated patients in multiple cancer types, clinical efficacy is limited in cancers harbouring activating gene alterations of ERBB family members. In particular, ICI treatment of patients with non-small cell lung cancers with epidermal growth factor receptor (EGFR) alterations and breast cancers with HER2 alterations failed to show clinical benefits, suggesting that EGFR and HER2 signalling may have an essential role in inhibiting antitumour immune responses. Here, we discuss the mechanisms by which the signalling of ERBB family members affects not only autonomous cancer hallmarks, such as uncontrolled cell proliferation, but also antitumour immune responses in the tumour microenvironment and the potential application of immune-genome precision medicine into immunotherapy and molecular-targeted therapy focusing on the signalling of ERBB family members.

Biphasic prognostic significance of PD-L1 expression status in patients with early- and locally advanced-stage non-small cell lung cancer

Programmed cell death-ligand 1 (PD-L1) expression on tumor cells is induced by interferon-gamma, suggesting the induction of an anti-tumor immune response. In turn, binding of PD-L1 to programmed cell death 1 (PD-1) triggers an immune checkpoint pathway that contributes to tumor growth. Though it remains to be elucidated, the clinical significance of PD-L1 expression might vary with tumor progression in non-small-cell lung cancer (NSCLC). Immunohistochemical analysis of PD-L1 was done in tumor specimens from patients who underwent radical surgery for stage I-IIIA NSCLC (n = 228). Tumor PD-L1 expression intensity was semi-quantitatively scored and its correlation with various clinicopathological features and postoperative relapse-free survival (RFS) was assessed relative to pathological stage. In stage I, postoperative RFS was significantly prolonged in patients with a high PD-L1 score compared with a low PD-L1 score, exhibiting 5-year relapse-free probabilities of 94.1% and 75.1%, respectively (P = 0.031). A multivariate analysis revealed that a high PD-L1 score was a prognostic factor of longer postoperative RFS (hazard ratio: 0.111, P = 0.033). Conversely, in stages II and IIIA, patients with a high PD-L1 score tended to suffer from postoperative tumor recurrence. In early-stage NSCLC, high tumor PD-L1 expression status represents a biomarker to predict good prognosis after radical surgery and may reflect the induction of an antitumor immune response. However, in locally advanced stage NSCLC, tumor PD-L1 expression status may reflect the execution of an immune checkpoint pathway and predicts the incidence of postoperative tumor recurrence.

The prediction potential of neutrophil-to-lymphocyte ratio for the therapeutic outcomes of programmed death receptor-1/programmed death ligand 1 inhibitors in non-small cell lung cancer patients: A meta-analysis

BACKGROUND

Programmed death receptor-1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors have been demonstrated to improve the prognosis of patients with advanced non-small cell lung cancer (NSCLC) compared with chemotherapy. However, there were still some non-responders. Thus, how to effectively screen the responder may be an important issue. Recent studies revealed the immune-related indicator, neutrophil-lymphocyte ratio (NLR), may predict the therapeutic effects of anti-PD1/PD-L1 antibodies; however, the results were controversial. This study was to re-evaluate the prognostic potential of NLR for NSCLC patients receiving PD1/PD-L1 inhibitors by performing a meta-analysis.

METHODS

Eligible studies were identified by searching online databases of PubMed, EMBASE and Cochrane Library. The predictive values of NLR for overall survival, (OS), progression free survival (PFS) and overall response rate (ORR) were estimated by hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

Twenty-four studies involving 2196 patients were included. The pooled analysis demonstrated that elevated NLR before PD-1/PD-L1 inhibitor treatment was a predictor of poor OS (HR = 2.17; 95% CI: 1.64 - 2.87, P < .001), PFS (HR = 1.54; 95% CI: 1.34 - 1.78, P < .001) and low ORR (HR = 0.64; 95% CI: 0.44 - 0.95, P = .027) in NSCLC patients. Subgroup analysis revealed the predictive ability of NLR for OS and PFS was not changed by ethnicity, sample size, cut-off, HR source, study design or inhibitor type (except the combined anti-PD-L1 group); while its association with ORR was only significant when the cut-off value was less than 5 and the studies were prospectively designed.

CONCLUSION

Our findings suggest patients with lower NLR may benefit from the use of PD-1/PD-L1 inhibitors to prolong their survival period.

Biomarkers of immunotherapy in non-small cell lung cancer

Immunotherapy has markedly improved the survival rate of patients with non-small cell lung cancer (NSCLC) and has introduced a new era in lung cancer treatment. However, not all patients with lung cancer benefit from checkpoint blockade, and some suffer from notable immunotoxicities. Thus, it is crucial to identify potential biomarkers suitable for screening the population that may benefit from immunotherapy. Based on the current clinical trials, the aim of the present study was to review the biomarkers for immune checkpoint inhibition, as well as other effective, invalid and hyperprogression markers that may have the potential to better predict responders to immunotherapy among patients with NSCLC. All these biomarkers may be incorporated into the predictive utility of bio-score systems and decision-making algorithms, to better guide the application of immunotherapy in the clinical setting.

Tobacco extracts promote PD-L1 expression and enhance malignant biological differences via mTOR in gefitinib-resistant cell lines

BACKGROUND

The aim of this study was to investigate whether tobacco extracts could regulate PD-L1 expression and enhance malignant biological differences in gefitinib-resistant cell lines.

METHODS

We constructed gefitinib-resistant cells and observed the biological differences in gefitinib-resistant cells. The cells were stimulated with medium containing 5% volume of tobacco extract, and the change in PD-L1 expression and the mammalian target of rapamycin (mTOR) and p-mTOR expression in gefitinib-resistant cells treated with tobacco extracts was observed. We discussed the relationship between PD-L1 and mTOR.

RESULTS

Tobacco extracts could promote PD-L1 expression in the cell line. Western blot analysis showed that mTOR and p-mTOR were significantly enhanced in gefitinib-resistant cell lines cultured in the tobacco extracts. The mTOR signaling pathway was involved in PD-L1 expression and in regulating the expression of cytokines IL-6 and IL-23. In addition, the tobacco extracts could promote macrophage migration via mTOR/IL-6.

CONCLUSIONS

PD-L1 can transmit inhibitory signals and reduce the proliferation of CD8 + T cells in lymph nodes. Tobacco extracts upregulate PD-L1 expression via mTOR/IL-6. These results imply that lung cancer patients should not smoke and stay away from a smoke environment.

Identification of Clonal Neoantigens Derived From Driver Mutations in an EGFR-Mutated Lung Cancer Patient Benefitting From Anti-PD-1

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been recommended as the first-line therapy for non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. However, acquired resistance to EGFR-TKIs is inevitable. Although immune checkpoint blockades (ICBs) targeting the programmed cell death 1 (PD-1)/PD-ligand (L)1 axis have achieved clinical success for many cancer types, the clinical efficacy of anti-PD-1/PD-L1 blockades in EGFR mutated NSCLC patients has been demonstrated to be lower than those without EGFR mutations. Here, we reported an advanced NSCLC patient with EGFR driver mutations benefitting from anti-PD-1 blockade therapy after acquiring resistance to EGFR-TKI. We characterized the mutational landscape of the patient with next-generation sequencing (NGS) and successfully identified specific T-cell responses to clonal neoantigens encoded by EGFR exon 19 deletion, TP53 A116T and DENND6B R398Q mutations. Our findings support the potential application of immune checkpoint blockades in NSCLC patients with acquired resistance to EGFR-TKIs in the context of specific clonal neoantigens with high immunogenicity. Personalized immunomodulatory therapy targeting these neoantigens should be explored for better clinical outcomes in EGFR mutated NSCLC patients.

Resistance Mechanisms of Anti-PD1/PDL1 Therapy in Solid Tumors

In cancer-immunity cycle, the immune checkpoint PD1 and its ligand PDL1 act as accomplices to help tumors resist to immunity-induced apoptosis and promote tumor progression. Immunotherapy targeting PD1/PDL1 axis can effectively block its pro-tumor activity. Anti-PD1/PDL1 therapy has achieved great success in the past decade. However, only a subset of patients showed clinical responses. Most of the patients can not benefit from anti-PD1/PDL1 therapy. Furthermore, a large group of responders would develop acquired resistance after initial responses. Therefore, understanding the mechanisms of resistance is necessary for improving anti-PD1/PDL1 efficacy. Currently, researchers have identified primary resistance mechanisms which include insufficient tumor immunogenicity, disfunction of MHCs, irreversible T cell exhaustion, primary resistance to IFN-γ signaling, and immunosuppressive microenvironment. Some oncogenic signaling pathways also contribute to the primary resistance. Under the pressure applied by anti-PD1/PDL1 therapy, tumors experience immunoediting and preserve beneficial mutations, upregulate the compensatory inhibitory signaling and induce re-exhaustion of T cells, all of which may attenuate the durability of the therapy. Here we explore the underlying mechanisms in detail, review biomarkers that help identifying responders among patients and discuss the strategies that may relieve the anti-PD1/PDL1 resistance.

ZFHX3 mutation as a protective biomarker for immune checkpoint blockade in non-small cell lung cancer

To date, immunotherapy has opened a new chapter in the treatment of lung cancer. Precise biomarkers can help to screen subpopulations of lung cancer to provide the best treatment. Multiple studies suggest that specific gene mutations may be predictive markers in guiding non-small cell lung cancer (NSCLC) immune checkpoint inhibitor (ICI) treatment. A published immunotherapy cohort with mutational and survival data for 350 NSCLC patients was used. First, the mutational data of the immunotherapy cohort were used to identify gene mutations related to the prognosis of ICI therapy. The immunotherapy cohort and TCGA-NSCLC cohort were further studied to elucidate the relationships between specific gene mutations and tumor immunogenicity, antitumor immune response capabilities, and immune cell and mutation counts in the DNA damage response (DDR) pathway. In the immunotherapy cohort (N = 350), ZFHX3 mutations were an independent predictive biomarker for NSCLC patients receiving ICI treatment. Significant differences were observed between ZFHX3-mutant (ZFHX3-MT) and ZFHX3-wild type (ZFHX3-WT) patients regarding the overall survival (OS) time (P < 0.001, HR = 0.26, 95% Cl 0.17-0.41). ZFHX3-MT is significantly associated with higher tumor mutation burden (TMB) and neoantigen load (NAL), and ZFHX3-MT positively correlates with known immunotherapy response biomarkers, including T-cell infiltration, immune-related gene expression, and mutation counts in the DDR pathway in NSCLC. ZFHX3-MT is closely related to longer OS in NSCLC patients treated with ICIs, suggesting that ZFHX3 mutations be used as a novel predictive marker in guiding NSCLC ICI treatment.

Relationship between the efficacy of immunotherapy and characteristics of specific tumor mutation genes in non-small cell lung cancer patients

Background

Immune checkpoint inhibitors (ICIs) have greatly improved the prognosis and overall management of non‐small cell lung cancer (NSCLC) patients, but in the long term less than 20% of patients benefit from treatment with ICIs. Therefore, it is necessary to guide the choice of immunotherapy population through biomarkers in order to maximize the benefit for NSCLC patients. This article mainly explores the relationship between the efficacy of immunotherapy and specific tumor mutation gene characteristics in an NSCLC population.

Methods

This was a prospective analysis of patients with advanced NSCLC who visited the Department of Respiratory Medicine of Peking Union Medical College Hospital from March 2018 to June 2019 and were instructed to use PD‐1 inhibitors. The follow‐up deadline was 31 December 2019. The tumor pathological tissues were tested for tumor mutation genes, and the patients were evaluated for efficacy according to RECIST 1.1. The patients were divided into the durable benefit group (DCB) and the nonsustainable benefit group (NDB). DCB/NDB was used as the outcome variable. Various statistics methods were used to explore the independent predictors of long‐term benefits associated with immunotherapy and to draw a progression‐free survival curve for the relevant predictors.

Results

A total of 44 patients were examined for tumor mutation genes in pathological tissues; 20 in the DCB group and 24 in the NDB group. Specific gene mutations occurred in TP53 38.64%, KRAS 31.82%, EGFR 20.45%, BRCA 20.45%, ERBB (excluding EGFR) 18.18%, PTEN 15.91%, CDK4/6 13.64%, POLE 11.36%, MET 11.36%, PIK3CA 9.10%, FGFR 9.10%, BRAF 9.10%, JAK 9.10%, ALK 6.82%, POLD1 4.55%, BLM 4.55%. Chi‐square test results showed that there were statistically significant differences between DCB and NDB groups with eight mutations such as KRAS. Logistic regression showed that the KRAS mutation was statistically significant (P < 0.001). Two accuracy indicators, Random Forest Classification of Mean Decrease Gini and Mean Decrease Accuracy, evaluated the importance of the impact of different gene mutations on the outcome. Under two different measures, the variables were all KRAS mutations. It is suggested that the mutation of the KRAS gene is an independent predictor of the long‐term benefit of immunotherapy.

Conclusions

The mutation of KRAS gene in tumor tissues is an independent predictor of the long‐term benefit of immunotherapy, and the predictive ability is better.

Factors related to rapid progression of non-small cell lung cancer in Chinese patients treated using single-agent immune checkpoint inhibitor treatment

Background

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of non‐small cell lung cancer (NSCLC). While rapid progression (RP) has been proposed as a non‐negligible pattern of response to ICIs, its definition and related factors remain unclear. This study aimed to develop a clinical definition of RP and to identify related factors.

Methods

We retrospectively evaluated Chinese patients who had received an ICI as second‐line or later treatment for locally advanced or metastatic NSCLC at a single center. We defined RP as radiological progression at the first response assessment (<2 months after starting the ICI), as well as confirmation of progressive disease or cancer‐related death occurring at <3 months. The clinical outcomes were compared for patients with RP or non‐RP to identify prognostic factors.

Results

The study evaluated 74 eligible patients with detailed records regarding their ICI therapy, including 25 patients (33.8%) who had experienced RP. Relative to patients with non‐RP, patients with RP had significantly shorter median progression‐free survival (1.7 months [95% CI: 1.4–2.0 months] vs. 6.3 months [95% CI 5.2–7.3 months], P < 0.001; hazard ratio: 0.14, 95% CI: 0.08–0.25) and significantly shorter median overall survival (8.2 months [95% CI 3.0–13.4 months] vs. 22.6 months [95% CI 17.0–28.1 months], P < 0.001; hazard ratio: 0.27, 95% CI: 0.15–0.49). Multivariate analysis revealed that RP was independently predicted by the presence of ≥3 metastatic sites (P = 0.039) and a neutrophil‐to‐lymphocyte ratio of ≥3 (P = 0.044).

Conclusions

Among NSCLC patients, RP was a common response to ICI monotherapy and was associated with dramatically reduced progression‐free and overall survival. Care is needed when selecting ICI monotherapy for these patients, especially if they have ≥3 metastatic sites or a neutrophil‐to‐lymphocyte ratio of ≥3.

Key points

Significant findings of the study: Patients with rapid progression after immune checkpoint inhibitor monotherapy had poor survival outcomes. The number of metastatic sites and the neutrophil‐to‐lymphocyte ratio may independently predict treatment response in this setting.What this study adds: This is the first study to evaluate rapid progression after second‐line or later single‐agent immunotherapy in a Chinese population. Our findings may help establish effective immunotherapy strategies for NSCLC.

Clinicopathologic Correlation With Expression of PD-L1 on Both Tumor Cells and Tumor-infiltrating Immune Cells in Patients With Non-Small Cell Lung Cancer

Supplemental Digital Content is available in the text.

Our study was to evaluate the concordance of programmed cell death-ligand 1 (PD-L1) expression between 22C3 and SP263 assay and explore the association of clinicopathologic features with expression of PD-L1 on both tumor cells (TC) and tumor-infiltrating immune cells (IC). We retrospectively assessed the PD-L1 expression in 305 patients with lung adenocarcinoma or adenosquamous carcinoma by 22C3 and SP263 assay. The association of PD-L1 expression by 22C3 assay with clinicopathologic features was also analyzed. The prevalence of PD-L1 expression by 22C3 assay was 20.7% with a ≥50% cutoff and 46.6% with a ≥1% cutoff. The concordance rates between 2 PD-L1 assays while using 1%, 5%, 25%, and 50% positive TC as the cutoffs were 91.8%, 93.1%, 95.1% and 99.0%, respectively. For PD-L1 expression on IC, the concordance rate was 93.4% using a 1% cutoff. According to the results of 22C3 assay, high PD-L1 expression (using a ≥50% cutoff) on TC was significantly associated with smoking, advanced stage disease, and KRAS mutation. PD-L1 expression on IC was significantly associated with smoking and KRAS mutation. PD-L1 expression on TC and IC were both significantly associated with average number of cigarettes smoked ≥20 per day. The 22C3 and SP263 assays were highly concordant for assessment of PD-L1 expression on TC and IC. Patients with KRAS mutation and smoking history, particularly those having a large number of cigarettes smoked per day, were more likely to have PD-L1 expression on both TC and IC.

FRA1 contributes to MEK-ERK pathway-dependent PD-L1 upregulation by KRAS mutation in premalignant human bronchial epithelial cells

Oncogenic KRAS mutations are frequently found in non-small cell lung carcinoma (NSCLC) and cause constitutive activation of the MEK-ERK pathway. Many cancer types have been shown to overexpress PD-L1 to escape immune surveillance. FRA1 is a MEK/ERK-dependent oncogenic transcription factor and a member of the AP-1 transcriptional factor superfamily. This study assesses the hypothesis that KRAS mutation directly regulates PD-L1 expression through the MEK-ERK pathway mediated by FRA1. Premalignant human bronchial epithelial cell (HBEC) lines harboring the KRAS mutation^V12, EGFR mutation, p53 knock-down, or both KRAS mutation and p53 knock-down were tested for levels of PD-L1, FRA1, and ERK activation (pERK). Our results showed that KRAS mutation alone, but not other genetic alterations, induced significantly higher expression of PD-L1 compared to its vector counterparts. The increased PD-L1 expression in the KRAS mutated cells was dramatically reduced by inhibition of ERK activation. Furthermore, the MEK-ERK pathway-dependent PD-L1 expression was markedly reduced by FRA1 silencing. Interestingly, FRA1 silencing led to inhibition of ERK activation, indicating that FRA1 plays a role in PD-L1 regulation via positive feedback of ERK activation. Correlation of PD-L1 and FRA1 mRNA expression was validated using human lung cancer specimens from The Cancer Genome Atlas (TCGA) and established NSCLC cell lines from Cancer Cell Line Encyclopedia (CCLE). FRA1 expression was significantly associated with PD-L1 expression, and high FRA1 expression was correlated with poor overall survival. Our findings suggest that oncogenic KRAS-driven PD-L1 expression is dependent on MEK-ERK and FRA1 in high risk, premalignant HBEC.

Frontiers of ctDNA, targeted therapies, and immunotherapy in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC), a main subtype of lung cancer, is one of the most common causes of cancer death in men and women worldwide. Circulating tumor DNA (ctDNA), tyrosine kinase inhibitors (TKIs) and immunotherapy have revolutionized both our understanding of NSCLC, from its diagnosis to targeted NSCLC therapies, and its treatment. ctDNA quantification confers convenience and precision to clinical decision making. Furthermore, the implementation of TKI-based targeted therapy and immunotherapy has significantly improved NSCLC patient quality of life. This review provides an update on the methods of ctDNA detection and its impact on therapeutic strategies; therapies that target epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) using TKIs such as osimertinib and lorlatinib; the rise of various resistant mechanisms; and the control of programmed cell death-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte antigen-4 (CTLA-4) by immune checkpoint inhibitors (ICIs) in immunotherapy; blood tumor mutational burden (bTMB) calculated by ctDNA assay as a novel biomarker for immunotherapy. However, NSCLC patients still face many challenges. Further studies and trials are needed to develop more effective drugs or therapies to treat NSCLC.

The systemic immune-inflammation index is associated with an increased risk of incident cancer-A population-based cohort study

Several studies found that the systemic immune-inflammation index (SII) is a prognostic factor for mortality in patients with solid tumors. It is unknown whether an increased SII in generally healthy individuals reflects a risk for developing cancer. Our objective was to investigate the association between the SII and incident cancers in a prospective cohort study. Data were obtained from the Rotterdam Study; a population-based study of individuals aged ≥45 years, between 2002 and 2013. The SII at baseline was calculated from absolute blood counts. The association between the SII and the risk of any solid incident cancer during follow-up was assessed using Cox proportional hazard models. Individuals with a prior cancer diagnosis were excluded. Data of 8,024 individuals were included in the analyses. The mean age at baseline was 65.6 years (SD 10.5 years) and the majority were women. During a maximum follow-up period of 10.7 years, 733 individuals were diagnosed with cancer. A higher SII at baseline was associated with a 30% higher risk of developing a solid cancer (HR of 1.30 [95% CI; 1.11-1.53]), after adjustment for age, sex, socioeconomic status, smoking, BMI and type 2 diabetes. The absolute cumulative 10-year cancer risk increased from 9.7% in the lowest quartile of SII to 14.7% in the highest quartile (p-value = 0.009). The risk of developing cancer was persistent over time and increased for individuals with the longest follow-up. In conclusion, a high SII is a strong and independent risk indicator for developing a solid cancer.