Diagnostic and Predictive Immunohistochemistry for Non-Small Cell Lung Carcinomas

Immunohistochemistry of Lung Cancer Biomarkers

Immunohistochemical (IHC) staining represents a comparatively inexpensive testing method that is attractive as a potential alternative to molecular sequencing methods or fluorescence in situ hybridization for pulmonary biomarker testing. While a variety of IHC tests directed at actionable genetic alterations have been developed and evaluated since the advent of targeted therapy, specific antibody clones for anaplastic lymphoma kinase, ROS-1, and potentially neurotrophic tropmyosin receptor kinase have been the primary antibodies that provide sufficiently robust results to be utilized as either a primary testing or screening method to direct targeted therapy. Antibodies for a variety of other targets such as epidermal growth factor receptors, for example, have lacked sufficient sensitivity and specificity to cover the range of mutations that may occur and are generally not recommended in lieu of molecular testing with the exception of limited resource settings. IHC is also used as a predictive marker for response to immunotherapy through evaluation of programmed death ligand 1 expression. In addition, multiple antibody-drug conjugates (ADCs) are under investigation, designed to deliver drugs directly to tumor cells through binding to specific target antigens. Some ADCs have already received accelerated FDA approval, and IHC was incorporated in many clinical trials evaluating ADC efficacy. As such, it is anticipated that ADCs may have a companion diagnostic IHC to guide patient selection.

Rediscovering immunohistochemistry in lung cancer

Several observations indicate that protein expression analysis by immunohistochemistry (IHC) remains relevant in individuals with non-small-cell lung cancer (NSCLC) when considering targeted therapy, as an early step in diagnosis and for therapy selection. Since the advent of next-generation sequencing (NGS), the role of IHC in testing for NSCLC biomarkers has been forgotten or ignored. We discuss how protein-level investigations maintain a critical role in defining sensitivity to lung cancer therapies in oncogene- and non-oncogene-addicted cases and in patients eligible for immunotherapy, suggesting that IHC testing should be reconsidered in clinical practice. We also argue how a panel of IHC tests should be considered complementary to NGS and other genomic assays. This is relevant to current clinical diagnostic practice but with potential future roles to optimize the selection of patients for innovative therapies. At the same time, strict validation of antibodies, assays, scoring systems, and intra- and interobserver reproducibility is needed.

The rapidly changing field of predictive biomarkers of non-small cell lung cancer

Lung cancer is a leading cause of cancer-related death worldwide in both men and women, however mortality in the US and EU are recently declining in parallel with the gradual cut of smoking prevalence. Consequently, the relative frequency of adenocarcinoma increased while that of squamous and small cell carcinomas declined. During the last two decades a plethora of targeted drug therapies have appeared for the treatment of metastasizing non-small cell lung carcinomas (NSCLC). Personalized oncology aims to precisely match patients to treatments with the highest potential of success. Extensive research is done to introduce biomarkers which can predict the effectiveness of a specific targeted therapeutic approach. The EGFR signaling pathway includes several sufficient targets for the treatment of human cancers including NSCLC. Lung adenocarcinoma may harbor both activating and resistance mutations of the EGFR gene, and further, mutations of KRAS and BRAF oncogenes. Less frequent but targetable genetic alterations include ALK, ROS1, RET gene rearrangements, and various alterations of MET proto-oncogene. In addition, the importance of anti-tumor immunity and of tumor microenvironment has become evident recently. Accumulation of mutations generally trigger tumor specific immune defense, but immune protection may be upregulated as an aggressive feature. The blockade of immune checkpoints results in potential reactivation of tumor cell killing and induces significant tumor regression in various tumor types, such as lung carcinoma. Therapeutic responses to anti PD1-PD-L1 treatment may correlate with the expression of PD-L1 by tumor cells. Due to the wide range of diagnostic and predictive features in lung cancer a plenty of tests are required from a single small biopsy or cytology specimen, which is challenged by major issues of sample quantity and quality. Thus, the efficacy of biomarker testing should be warranted by standardized policy and optimal material usage. In this review we aim to discuss major targeted therapy-related biomarkers in NSCLC and testing possibilities comprehensively.

Roles of tissue-resident immune cells in immunotherapy of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common and lethal type of lung cancer, with limited treatment options and poor prognosis. Immunotherapy offers hope for improving the survival and quality of life of NSCLC patients, but its efficacy depends on the tumor immune microenvironment (TME). Tissue-resident immune cells are a subset of immune cells that reside in various tissues and organs, and play an important role in fighting tumors. In NSCLC, tissue-resident immune cells are heterogeneous in their distribution, phenotype, and function, and can either promote or inhibit tumor progression and response to immunotherapy. In this review, we summarize the current understanding on the characteristics, interactions, and roles of tissue-resident immune cells in NSCLC. We also discuss the potential applications of tissue-resident immune cells in NSCLC immunotherapy, including immune checkpoint inhibitors (ICIs), other immunomodulatory agents, and personalized cell-based therapies. We highlight the challenges and opportunities for developing targeted therapies for tissue-resident immune cells and optimizing existing immunotherapeutic approaches for NSCLC patients. We propose that tissue-resident immune cells are a key determinant of NSCLC outcome and immunotherapy response, and warrant further investigation in future research.

Circ_0006324 regulates cell proliferation, cell-cycle progression, apoptosis, and glycolysis of non-small cell lung cancer cells through miR-496/TRIM59 axis

Increasing evidence suggests that circular RNA (circRNA) plays an important role in non-small cell lung cancer (NSCLC) progression. This study aimed to investigate the role and potential molecular mechanism of circ_0006324 in NSCLC. The expression levels of circ_0006324, miR-496, miR-488-5p, and tripartite motif-containing 59 (TRIM59) mRNA were determined by quantitative real-time polymerase chain reaction (PCR). 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, EdU assay, and flow cytometry were carried out to evaluate cell proliferation and apoptosis. The extracellular acidification rate and lactic acid production were examined to assess cell glycolysis. Western blot assay was used to detect protein levels. The target relationship of circ_0006324/miR-496/TRIM59 axis was validated by RNA pull-down assay, dual luciferase reporter assay, and radio immunoprecipitation assay. Xenograft tumor assay was performed to reveal the function of circ_0006324 in vivo. Circ_0006324 was upregulated in NSCLC and related to tumor node metastasis stage and distant metastasis. Knockdown of circ_00006324 impeded NSCLC cell proliferation, glycolysis, and promoted cell apoptosis. MiR-496 was verified as a target of circ_0006324 and circ_00006324 mediated the altering of cell proliferation, apoptosis, and glycolysis of NSCLC cells through targeting miR-496. TRIM59 was verified as a target of miR-496, and circ_0006324 positively regulated TRIM59 expression by targeting miR-496. Overexpression of TRIM59 could reverse the effects of circ_0006324 silencing on the proliferation, apoptosis, and glycolysis of NSCLC cells. Circ_0006324 knockdown impeded NSCLC tumor growth in vivo. Circ_0006324 functioned as a tumor promoter in NSCLC to promote cell proliferation, cell cycle progression, and glycolysis and inhibit cell apoptosis via miR-496/TRIM59 axis.

State of the Art of Pathologic and Molecular Testing

Advances in the treatment of non-small cell lung carcinoma have resulted in improved histologic classification and the implementation of molecular testing for predictive biomarkers into the routine diagnostic workflow. Over the past decade, molecular testing has evolved from single-gene assays to high-thoroughput comprehensive next-generation sequencing. Economic barriers, suboptimal turnaround time to obtain the results, and limited tissue available for molecular assays resulted in adoption of liquid biopsies (ctDNA) into clinical practice. Multiplex immunohistochemical/immunofluorescence assays evaluating tumor microenvironment together with the AI approaches are anticipated to translate from research into clinical care.

Current treatments for non-small cell lung cancer

Despite improved methods of diagnosis and the development of different treatments, mortality from lung cancer remains surprisingly high. Non-small cell lung cancer (NSCLC) accounts for the large majority of lung cancer cases. Therefore, it is important to review current methods of diagnosis and treatments of NSCLC in the clinic and preclinic. In this review, we describe, as a guide for clinicians, current diagnostic methods and therapies (such as chemotherapy, chemoradiotherapy, targeted therapy, antiangiogenic therapy, immunotherapy, and combination therapy) for NSCLC.

Identification and Validation of Noncanonical RET Fusions in Non-Small-Cell Lung Cancer through DNA and RNA Sequencing

RET fusion has emerged as a targetable driver in non-small-cell lung cancer. A comparative analysis on RET fusions at DNA [DNA sequencing (DNA-seq)] and RNA [RNA sequencing (RNA-seq)] levels was performed in this study. Archived tumor samples from 54 non-small-cell lung cancer patients with DNA-level noncanonical RET fusions were selected for RNA-seq. RNA-seq identified RET fusion transcripts in 41 of 44 samples passing quality control. In the subset of cases harboring RET 3'-end fusions and predicted to produce in-frame proteins (group A; n = 33), RNA-seq identified the same 3'-end fusions in 32 (96.9%). A total of 26 of 32 also had a reciprocal RET 5'-end fusion detected by DNA-seq that was not transcribed. In the subset with DNA-level out-of-frame RET fusions (group B; n = 9), RNA-seq identified in-frame RET fusion transcripts in 8 cases (88.9%). In the subset only identified with a RET 5'-end fusion by DNA-seq (group C; n = 2), RNA-seq detected the corresponding 3'-end fusion in one case. The discordant DNA- and RNA-level fusions observed in group B may be mediated by complex genomic rearrangement events and transcriptional or post-transcriptional processes. In conclusion, DNA-seq demonstrates a high concordance of 96.9% on detecting in-frame RET fusion, but shows a low concordance on detecting out-of-frame RET fusion and RET 5'-end fusion compared with RNA-seq.

Zebrafish xenograft model for studying mechanism and treatment of non-small cell lung cancer brain metastasis

Background

Brain metastasis (BM) is thought to be related to the mortality and poor prognosis of non-small cell lung cancer (NSCLC). Despite promising development of NSCLC treatment, the treatment of NSCLC BM is still not optimistic due to the existence of the blood-brain barrier (BBB) that prevent drug penetration, as well as the short median survival time of the patients left for treatment. In this context, further development of quick and effective pre-clinical models is needed in NSCLC BM treatment. Here, we report a model system using zebrafish to promote the development of drugs for patients with NSCLC BM.

Methods

Three different NSCLC cell lines (H1975, A549 and H1299) were used to establish zebrafish BM models. The embryo age and cell number for injection were first optimized. Metastatic cells were observed in the brain blood vessels of zebrafish and were verified by hematoxylin-eosin (HE) staining. Then, the metastasis potentials of H1975 and A549 with manipulated microRNA-330-3p (miR-330-3p) expression were also investigated. Finally, sensitivities of H1975 and A549 to osimertinib and gefitinib were tested.

Results

This zebrafish BM model could distinguish NSCLC cell lines with different BM potential. Over-expressed miR-330-p significantly improved the BM potential of the A549 cells while knockdown miR-330-p reduced the BM ability of the H1975 cells. Both osimertinib and gefitinib showed inhibition effect in zebrafish BM model with the inhibition rate higher than 50 %. H1975 cell showed much higher sensitivity to osimertinib rather than gefitinib both in vivo and in vitro.

Conclusions

We established zebrafish brain metastasis model for studying mechanism and treatment of NSCLC BM. This study provided a useful model for NSCLC brain metastasis that could be used to study the mechanism that drive NSCLC cells to the brain as well as identify potential therapeutic options.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02173-5.

CT-Based Sarcopenic Nomogram for Predicting Progressive Disease in Advanced Non-Small-Cell Lung Cancer

Background

It is prudent to identify the risk for progressive disease (PD) in patients with non-small-cell lung cancer (NSCLC) who undergo platinum-based chemotherapy. The present study aimed to develop a CT imaging-based sarcopenic nomogram for predicting the risk of PD prior to chemotherapy treatment.

Methods

We retrospectively enrolled patients with NSCLC who underwent platinum-based chemotherapy. Imaging-based body composition parameters such as skeletal muscle index (SMI) for assessment of sarcopenia were obtained from pre-chemotherapy chest CT images at the level of the eleventh thoracic vertebral body (T11). Sarcopenic nomogram was constructed using multivariate logistic regression and performance of the nomogram was evaluated by discrimination, calibration curve, and decision curve.

Results

Sixty (14.7%) of the 408 patients in the study cohort developed PD during chemotherapy. The prediction nomogram for developing PD achieved a moderate efficiency with an area under the curve (AUC) of 0.75 (95% CI: 0.69-0.80) for the training cohort, and 0.76 (95%CI: 0.68-0.84) for the validation cohort, as well as a good performance of consistence (bootstrap for training cohort: 0.75 ± 0.02; validation cohort: 0.74 ± 0.06). Favorable clinical application was observed in the decision curve analysis.

Conclusion

Our CT-based sarcopenic nomogram showed the potential for an individualized prediction of progression for patients with NSCLC receiving platinum-based chemotherapy.

What Is New in Biomarker Testing at Diagnosis of Advanced Non-Squamous Non-Small Cell Lung Carcinoma? Implications for Cytology and Liquid Biopsy

The discovery and clinical validation of biomarkers predictive of the response of non-squamous non-small-cell lung carcinomas (NS-NSCLC) to therapeutic strategies continue to provide new data. The evaluation of novel treatments is based on molecular analyses aimed at determining their efficacy. These tests are increasing in number, but the tissue specimens are smaller and smaller and/or can have few tumor cells. Indeed, in addition to tissue samples, complementary cytological and/or blood samples can also give access to these biomarkers. To date, it is recommended and necessary to look for the status of five genomic molecular biomarkers (EGFR, ALK, ROS1, BRAFV600, NTRK) and of a protein biomarker (PD-L1). However, the short- and more or less long-term emergence of new targeted treatments of genomic alterations on RET and MET, but also on others’ genomic alteration, notably on KRAS, HER2, NRG1, SMARCA4, and NUT, have made cellular and blood samples essential for molecular testing. The aim of this review is to present the interest in using cytological and/or liquid biopsies as complementary biological material, or as an alternative to tissue specimens, for detection at diagnosis of new predictive biomarkers of NS-NSCLC.

[NSCLC and new oncogenic mutations: Diagnosis and perspectives]

The development of new targeted therapies in non-small cell lung carcinoma (NSCLC) depends on a better understanding of the molecular basis of carcinogenesis, a knowledge of the role of molecular aberrations in disease progression and the development of molecular biology platforms with the capacity to identify new biomarkers. In the current article, we review the techniques routinely used in cancer molecular biology platforms as well as new techniques under development. These new NSCLC biomarkers have been made available to clinicians and biologists in parallel with the development of targeted drugs. New molecular abnormalities of EGFR exon 20, HER2, MET, RET, BRAF, ROS1 and NTRK have been identified and there have been clinical trials of the most innovative targeted drugs.

ESMO recommendations on the standard methods to detect RET fusions and mutations in daily practice and clinical research

Aberrant activation of RET is a critical driver of growth and proliferation in diverse solid tumours. Multikinase inhibitors (MKIs) showing anti-RET activities have been tested in RET-altered tumours with variable results. The low target specificity with consequent increase in side-effects and off-target toxicities resulting in dose reduction and drug discontinuation are some of the major issues with MKIs. To overcome these issues, new selective RET inhibitors such as pralsetinib (BLU-667) and selpercatinib (LOXO-292) have been developed in clinical trials, with selpercatinib recently approved by the Food and Drug Administration (FDA). The results of these trials showed marked and durable antitumour activity and manageable toxicity profiles in patients with RET-altered tumours. The European Society for Medical Oncology (ESMO) Translational Research and Precision Medicine Working Group (TR and PM WG) launched a collaborative project to review the available methods for the detection of RET gene alterations, their potential applications and strategies for the implementation of a rational approach for the detection of RET fusion genes and mutations in human malignancies. We present here recommendations for the routine clinical detection of targetable RET rearrangements and mutations.

Practical Considerations Relating to Routine Clinical Biomarker Testing for Non-small Cell Lung Cancer: Focus on Testing for RET Fusions

For patients with advanced non–small cell lung cancer, genomic profiling of tumors to identify potentially targetable alterations and thereby inform treatment selection is now part of standard care. While molecular analyses are primarily focused on actionable biomarkers associated with regulatory agency-approved therapies, there are a number of emerging biomarkers linked to investigational agents in advanced stages of clinical development will become approved agents. A particularly timely example is the reported data and US Food and Drug Administration approval of highly specific small molecule inhibitors of the proto-oncogene tyrosine-protein kinase receptor RET indicate that testing for tumor RET gene fusions in patients with NSCLC has become clinically important. As the number of biomarkers to be tested in NSCLC grows, it becomes increasingly important to optimize and prioritize the use of biopsy tissue, in order to both continue to allow accurate histopathological diagnosis and also to support concurrent genomic profiling to identify perhaps relatively uncommon genetic events. In order to provide practical expert consensus guidance to optimize processes facilitating genomic testing in NSCLC and to overcome barriers to access and implementation, a multidisciplinary advisory board was held in New York, on January 30, 2019. The panel comprised physicians involved in sample procurement (interventional radiologists and a thoracic surgeon), surgical pathologists specializing in the lung, molecular pathologists, and thoracic oncologists. Particular consideration was given to the key barriers faced by these experts in establishing institutional genomic screening programs for NSCLC. Potential solutions have been devised in the form of consensus opinions that might be used to help resolve such issues.

Immunohistochemical Detection of p40 Expression in Lung Cancer Clinical Samples

Immunohistochemistry is the technique by which antigens in tissues are detected by means of antigen-antibody reaction. The p40 antibody is directed against the ΔN domain of the ΔNp63 isoform of p63 and is a highly specific marker for the squamous cell carcinoma subtype of non-small cell lung carcinomas (NSCLC). As such, immunohistochemical detection of this antigen in NSCLC biopsies is extremely valuable to assess tumor histological subtype. Herein we describe a manual procedure for performing p40 immunohistochemistry on formalin-fixed paraffin-embedded tissue sections by the indirect polymer-based two-step technique using hydrogen peroxide and 3-3'diaminobenzidine detection system.

How should molecular findings be integrated in the classification for lung cancer?

The use of molecular diagnostics in the diagnosis and management of patients with advanced lung cancer has become widespread. Although molecular classification has increasingly been incorporated in the pathologic classification of certain types of human tumors (particularly within the hematologic, glial, and bone/soft tissue malignancies), genetic findings have not been formally incorporated into the pathologic classification of lung cancer, which presently relies solely on the assessment of histologic and immunophenotypic characteristics. Whether molecular classification should be adopted in lung cancer would depend on the diagnostic, prognostic, and predictive impacts of such classification-and whether these impacts confer significant values additive to those derived from the routine histologic and immunophenotypic assessment. We provide a brief overview on the genetics of lung cancer, including adenocarcinoma, squamous cell carcinoma, and neuroendocrine tumors (small cell carcinoma, large cell neuroendocrine carcinoma, and carcinoid tumors). We consider the values of molecular information with some examples, in terms of the current diagnostic, prognostic, and predictive impacts. Finally, we discuss the conceptual and technical challenges of adopting a molecular classification for lung cancer in clinical management for patients. While there are conceptual and technical hurdles to tackle in implementing molecular classification in the pathologic classification of lung cancer, such integrated histologic-molecular diagnosis may allow one to personalize and optimize therapy for patients with advanced lung cancer.

Overview of established and emerging immunohistochemical biomarkers and their role in correlative studies in MRI

Clinical practice in radiology and pathology requires professional expertise and many years of training to visually evaluate and interpret abnormal phenotypic features in medical images and tissue sections to generate diagnoses that guide patient management and treatment. Recent advances in digital image analysis methods and machine learning have led to significant interest in extracting additional information from medical and digital whole-slide images in radiology and pathology, respectively. This has led to significant interest and research in radiomics and pathomics to correlate phenotypic features of disease with image analytics in order to identify image-based biomarkers. The expanding role of big data in radiology and pathology parallels the development and role of immunohistochemistry (IHC) in the daily practice of pathology. IHC methods were initially developed to provide additional information to help classify tumors and then transformed into an indispensable tool to guide treatment in many types of cancer. IHC markers are used in daily practice to identify specific types of cells and highlight their distributions in tissues in order to distinguish benign from neoplastic cells, determine tumor origin, subclassify neoplasms, and support and confirm diagnoses. In this regard, radiomics, pathomics, and IHC methods are very similar since they enable the extraction of image-based features to characterize various properties of diseases. Due to the dramatic advancements in recent radiomics research, we provide a brief overview of the role of established and emerging IHC biomarkers in various tumor types that have been correlated with radiologic biomarkers to improve diagnostic accuracy, predict prognosis, guide patient management, and select treatment strategies. Level of Evidence: 5 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2020;51:341-354.