MET overexpression and gene amplification: prevalence, clinico-pathological characteristics and prognostic significance in a large cohort of patients with surgically resected NSCLC

Reproducibility of c-Met Immunohistochemical Scoring (Clone SP44) for Non-Small Cell Lung Cancer Using Conventional Light Microscopy and Whole Slide Imaging

Emerging therapies for non-small cell lung cancer targeting c-Met overexpression have recently demonstrated promising results. However, the evaluation of c-Met expression can be challenging. We aimed to study the inter and intraobserver reproducibility of c-Met expression evaluation. One hundred ten cases with non-small cell lung cancer (40 biopsies and 70 surgical specimens) were retrospectively selected in a single laboratory (LPCE) and evaluated for c-Met expression. Six pathologists (4 seniors and 2 juniors) evaluated the H-score and made a 3-tier classification of c-Met expression for all cases, using conventional light microscopy (CLM) and whole slide imaging (WSI). The interobserver reproducibility with CLM gave global Cohen Kappa coefficients (ƙ) ranging from 0.581 (95% CI: 0.364-0.771) to 0.763 (95% CI: 0.58-0.92) using the c-Met 3-tier classification and H-score, respectively. ƙ was higher for senior pathologists and biopsy samples. The interobserver reproducibility with WSI gave a global ƙ ranging from 0.543 (95% CI: 0.33-0.724) to 0.905 (95% CI: 0.618-1) using the c-Met H-score and 2-tier classification (≥25% 3+), respectively. ƙ for intraobserver reproducibility between CLM and WSI ranged from 0.713 to 0.898 for the c-Met H-score and from 0.600 to 0.779 for the c-Met 3-tier classification. We demonstrated a moderate to excellent interobserver agreement for c-Met expression with a substantial to excellent intraobserver agreement between CLM and WSI, thereby supporting the development of digital pathology. However, some factors (scoring method, type of tissue samples, and expertise level) affect reproducibility. Our findings highlight the importance of establishing a consensus definition and providing further training, particularly for inexperienced pathologists, for c-Met immunohistochemistry assessment in clinical practice.

Prediction of MET Overexpression in Lung Adenocarcinoma from Hematoxylin and Eosin Images

Mesenchymal epithelial transition (MET) protein overexpression is a targetable event in non-small cell lung cancer and is the subject of active drug development. Challenges in identifying patients for these therapies include lack of access to validated testing, such as standardized immunohistochemistry assessment, and consumption of valuable tissue for a single gene/protein assay. Development of prescreening algorithms using routinely available digitized hematoxylin and eosin (H&E)-stained slides to predict MET overexpression could promote testing for those who will benefit most. Recent literature reports a positive correlation between MET protein overexpression and RNA expression. In this work, a large database of matched H&E slides and RNA expression data were leveraged to train a weakly supervised model to predict MET RNA overexpression directly from H&E images. This model was evaluated on an independent holdout test set of 300 overexpressed and 289 normal patients, demonstrating a receiver operating characteristic area under curve of 0.70 (95th percentile interval: 0.66 to 0.74) with stable performance characteristics across different patient clinical variables and robust to synthetic noise on the test set. These results suggest that H&E-based predictive models could be useful to prioritize patients for confirmatory testing of MET protein or MET gene expression status.

Profile of Capmatinib for the Treatment of Metastatic Non-Small Cell Lung Cancer (NSCLC): Patient Selection and Perspectives

Aberrant c-MET (Mesenchymal-Epithelial Transition) signaling contributes to cancer cell development, proliferation, and metastases of non-small cell lung cancer (NSCLC). MET exon 14 (METex14) skipping mutation is noted in approximately 4% of NSCLC cases and is targetable with the recently approved tyrosine kinase inhibitors capmatinib and tepotinib. Capmatinib, the focus of this review article, is a highly selective MET inhibitor approved for use in patients with METex14 mutated NSCLC. In this review, we discuss cMET as a target, the pharmacology of capmatinib, key trials of capmatinib in MET-altered lung cancer, and toxicity profile. We highlight some ongoing capmatinib clinical trials that expand their role to other subsets of patients, especially those with EGFR mutations, who develop MET alterations as a resistance pathway. We further provide our perspective on the management of METex14 NSCLC, strategies for sequencing agents, and toxicity management.

MET Amplification as a Resistance Driver to TKI Therapies in Lung Cancer: Clinical Challenges and Opportunities

Targeted therapy has emerged as an important pillar for the standard of care in oncogene-driven non-small cell lung cancer (NSCLC), which significantly improved outcomes of patients whose tumors harbor oncogenic driver mutations. However, tumors eventually develop resistance to targeted drugs, and mechanisms of resistance can be diverse. MET amplification has been proven to be a driver of resistance to tyrosine kinase inhibitor (TKI)-treated advanced NSCLC with its activation of EGFR, ALK, RET, and ROS-1 alterations. The combined therapy of MET-TKIs and EGFR-TKIs has shown outstanding clinical efficacy in EGFR-mutated NSCLC with secondary MET amplification-mediated resistance in a series of clinical trials. In this review, we aimed to clarify the underlying mechanisms of MET amplification-mediated resistance to tyrosine kinase inhibitors, discuss the ways and challenges in the detection and diagnosis of MET amplifications in patients with metastatic NSCLC, and summarize the recently published clinical data as well as ongoing trials of new combination strategies to overcome MET amplification-mediated TKI resistance.

Targeting molecular alterations in non-small-cell lung cancer: what's next?

In recent years, major advances have been achieved in our understanding of non-small-cell lung cancer (NSCLC) with oncogenic driver alterations and in the specific treatment of these with tyrosine kinase inhibitors. Currently, state-of-the-art management of patients with NSCLC (particularly adenocarcinoma or non-adenocarcinoma but with mild tobacco exposure) consists of the determination of EGFR, ALK, ROS1 and BRAF status, as they have US FDA and EMA approved targeted therapies. The increase in molecular knowledge of NSCLC and the development of drugs against other targets has settled new therapeutic indications. In this review we have incorporated the development around MET, KRAS and NTRK in the diagnosis of NSCLC given the therapeutic potential that they represent, as well as the drugs approved for these indications.

Recent advances in lung cancer genomics: Application in targeted therapy

Genomic characterization of lung cancer has not only improved our understanding of disease biology and carcinogenesis but also revealed several therapeutic opportunities. Targeting tumor dependencies on specific genomic alterations (oncogene addiction) has accelerated the therapeutic developments and significantly improved the outcomes even in advanced stage of disease. Identification of genomic alterations predicting response to specific targeted treatment is the key to success for this "personalized treatment" approach. Availability of multiple choices of therapeutic options for specific genomic alterations highlight the importance of optimum sequencing of drugs. Multiplex gene testing has become mandatory in view of constantly increasing number of therapeutic targets and effective treatment options. Influence of genomic characteristics on response to immunotherapy further makes comprehensive genomic profiling necessary before therapeutic decision making. A comprehensive elucidation of resistance mechanisms and directed treatments have made the continuum of care possible and transformed this deadly disease into a chronic condition. Liquid biopsy-based approach has made the dynamic monitoring of disease possible and enabled treatment optimizations accordingly. Current lung cancer management is the perfect example of "precision-medicine" in clinical oncology.

MET Amplification in Non-Small Cell Lung Cancer (NSCLC)-A Consecutive Evaluation Using Next-Generation Sequencing (NGS) in a Real-World Setting

Simple Summary

Lung cancer has a high incidence and affects both men and women. Targeted therapy options directed at certain mutant proteins, and which avoid systemic chemotherapy are already available and emerging. The gene mesenchymal epithelial transition (MET), encoding a receptor tyrosine kinase protein, is amplified in a subpopulation of lung cancer patients. The aim of our consecutive study was to assess whether next-generation sequencing (NGS) is a reliable method for the detection of MET gene copy number. Our study confirmed that NGS is able to detect cases harboring a high-level MET gene amplification but is unreliable and fails to detect the various levels of MET gene amplification. Therefore, NGS cannot replace the gold standard method of fluorescence in situ hybridization for the detection of MET gene copy number.

Abstract

In non-small cell lung cancer (NSCLC), approximately 1–3% of cases harbor an increased gene copy number (GCN) of the MET gene. This alteration can be due to de novo amplification of the MET gene or can represent a secondary resistance mechanism in response to targeted therapies. To date, the gold standard method to evaluate the GCN of MET is fluorescence in situ hybridization (FISH). However, next-generation sequencing (NGS) is becoming more relevant to optimize therapy by revealing the mutational profile of each NSCLC. Using evaluable n = 205 NSCLC cases of a consecutive cohort, this study addressed the question of whether an amplicon based NGS assay can completely replace the FISH method regarding the classification of MET GCN status. Out of the 205 evaluable cases, only n = 9 cases (43.7%) of n = 16 high-level MET amplified cases assessed by FISH were classified as amplified by NGS. Cases harboring a MET GCN > 10 showed the best concordance when comparing FISH versus NGS (80%). This study confirms that an amplicon-based NGS assessment of the MET GCN detects high-level MET amplified cases harboring a MET GCN > 10 but fails to detect the various facets of MET gene amplification in the context of a therapy-induced resistance mechanism.

Intermediate between Idiopathic Hypereosinophilia and Chronic Eosinophilic Leukemia: A Report of Two Hypereosinophilic Cases with Possible Novel Molecular Mutations

To distinguish a reactive eosinophilia from its malignant counterpart is challenging. Establishing clonality of the eosinophils is crucial and considered the determining factor for establishing a diagnosis. Cases of hypereosinophilia without clear reactive etiologies, no evidence of end-organ damage, normal cytogenetics, and no molecular mutations are termed as “Idiopathic Hypereosinophilia (IHE).” For cases which lie between the spectrum of chronic eosinophilic leukemia (CEL) and IHE, identification of underlying molecular abnormalities might be helpful in better understanding the disease process and prognosis. Here, we report two cases of hypereosinophilia in which five possible novel molecular mutations were identified by targeted next-generation sequencing (NGS) analysis. They were FBXW7, KM2A, TCF3, ERBB4, and MET. With multiple genetic mutations, these cases could be classified as chronic eosinophilic leukemia. Both these young patients responded well to steroid therapy. While targeted NGS is a useful tool in identifying new molecular mutation associated with hypereosinophilia, our cases raise the question of further investigating this entity and if there is a possibility of an intermediate category lying between the spectrum of CEL and IHE. Defining hypereosinophilia with clonal molecular abnormality as a malignant process may need to be revisited. Even though attempts are being made to identify mutations in IHE, it might be more significant clinically to differentiate them based on response to steroid therapy and prognosis.

Cluster Analysis According to Immunohistochemistry is a Robust Tool for Non-Small Cell Lung Cancer and Reveals a Distinct, Immune Signature-defined Subgroup

Clustering in medicine is the subgrouping of a cohort according to specific phenotypical or genotypical traits. For breast cancer and lymphomas, clustering by gene expression profiles has already resulted in important prognostic and predictive subgroups. For non-small cell lung cancer (NSCLC), however, little is known. We performed a cluster analysis on a cohort of 365 surgically resected, well-documented NSCLC patients, which was followed-up for a median of 62 months, incorporating 70 expressed proteins and several genes. Our data reveal that tumor grading by architecture is significant, that large cell carcinoma is likely not a separate entity, and that an immune signature cluster exists. For squamous cell carcinomas, a prognostically relevant cluster with poorer outcome was found, defined by a high CD4/CD8 ratio and lower presence of granzyme B+ tumor-infiltrating lymphocytes (TIL). This study shows that clustering analysis is a useful tool for verifying established characteristics and generating new insights for NSCLC. Importantly, for one "immune signature" cluster, the signature of the TIL (especially the amount of CD8+ TIL) was more crucial than the histologic or any other phenotypical aspect. This may be an important finding toward explaining why only a fraction of eligible patients respond to immunomodulating anticancer therapies.

Capmatinib in Japanese patients with MET exon 14 skipping-mutated or MET-amplified advanced NSCLC: GEOMETRY mono-1 study

MET mutations leading to exon 14 skipping (METΔex14) are strong molecular drivers for non-small-cell lung cancer (NSCLC). Capmatinib is a highly potent, selective oral MET inhibitor that showed clinically meaningful efficacy and a manageable safety profile in a global phase II study (GEOMETRY mono-1, NCT02414139) in patients with advanced METΔex14-mutated/MET-amplified NSCLC. We report results of preplanned analyses of 45 Japanese patients according to MET status (METΔex14-mutated or MET-amplified) and line of therapy (first- [1L] or second-/third-line [2/3L]). The starting dose was 400 mg twice daily. The primary endpoint was the objective response rate (ORR) assessed by a blinded independent review committee. A key secondary endpoint was duration of response (DOR). Among METΔex14-mutated patients, in the 1L group, one patient achieved partial response (DOR of 4.24 months) and the other had stable disease. In the 2/3L group, the ORR was 36.4% (95% confidence interval [CI] 10.9%-69.2%), median DOR was not evaluable, and progression-free survival was 4.70 months. One patient (2/3L group) showed partial resolution of brain lesions per independent neuroradiologist review. In MET-amplified patients with a MET gene copy number of ≥10, the ORR was 100% (2/2 patients) in the 1L group and 45.5% (5/11 patients) in the 2/3L group, with DOR of 8.2 and 8.3 months, respectively. Common treatment-related adverse events among the 45 Japanese patients were blood creatinine increased (53.3%), nausea (35.6%), and oedema peripheral (31.1%); most were grade 1/2 severity. In conclusion, capmatinib was effective and well tolerated by Japanese patients with METΔex14/MET-amplified NSCLC, consistent with the overall population.

Epidemiologic Features of NSCLC Gene Alterations in Hispanic Patients from Puerto Rico

Simple Summary

We have analyzed the molecular genetic profiles of Hispanic non-small cell lung cancer (NSCLC) patients from Puerto Rico. In addition to the general characteristics, especially on EGFR mutations, we have also reported some novel findings on the incidences of KRAS mutation subgroups, other driver gene alterations, and passenger gene alterations, as well as KRAS/TP53 and KRAS/STK11 co-mutations. Moreover, our study has identified the FGFR2-TACC2 translocation in this population.

Abstract

Targeted therapy has changed the paradigm of advanced NSCLC management by improving the survival rate of patients carrying actionable gene alterations using specific inhibitors. The epidemiologic features of these alterations vary among races. Understanding the racial differences benefits drug development, clinical trial design, and health resource allocation. Compared to Caucasian and Asian populations, current knowledge on Hispanic patients is less and no data of Hispanic patients from Puerto Rico have been reported. We retrieved and analyzed the demographic, clinical, and molecular data of Hispanic NSCLC patients from Puerto Rico with molecular tests performed in the Genoptix Medical Laboratory in Carlsbad, CA, USA between 2011 and 2018. The majority of the NSCLC patients in our study had either adenocarcinoma (75.4%) or squamous cell carcinoma (15.1%). The incidence of EGFR mutations was 24%. They were more common in female and younger patients (<60 years). The deletion of Exon 19 and Exon 21 L858R comprised 55.1% and 31.0% of all EGFR mutations, respectively. The frequency of the T790M mutation was lower compared to that of Hispanic patients reported in the literature (0.5% vs. 2.1%). In addition, 18.7% of the patients were positive for KRAS mutations, which was at the high end of that reported in Hispanic patients. Other driver gene alterations, ALK, MET, RET, ROS1, KRAS, ERBB2, etc., demonstrated similar incidences, as well as gender and age distributions to those previously reported. The KRAS/TP53 and KRAS/STK11 co-mutations were of very low frequencies (3.6%), which could potentially affect the responsiveness to PD1/PD-L1 immunotherapy. Our study demonstrated that the prevalence of NSCLC gene alterations in Hispanic patients from Puerto Rico was comparable to the reported average prevalence in Latin American countries, supporting the intermediate NSCLC gene alteration rate of Hispanic patients between Asian and Caucasian patients. Novel information of the frequencies of KRAS mutation subtypes, driver gene alterations in ROS1, BRAF, and ERBB2, and passenger gene alterations including a rare case with the FGFR2-TACC2 translocation in Hispanic NSCLC patients from Puerto Rico were also described.

Targeting the MET-Signaling Pathway in Non-Small-Cell Lung Cancer: Evidence to Date

The c-MET proto-oncogene (MET) plays an important role in lung oncogenesis, affecting cancer-cell survival, growth and invasiveness. The MET receptor in non-small-cell lung cancer (NSCLC) is a potential therapeutic target. The development of high-output next-generation sequencing techniques has enabled better identification of anomalies in the MET pathway, like the MET exon-14 (METex14) mutation. Moreover, analyses of epidermal growth factor-receptor (EGFR) and mechanisms of resistance to tyrosine-kinase inhibitors (TKIs) demonstrated the importance of MET amplification as an escape mechanism in patients with TKI-treated EGFR-mutated NSCLCs. This review summarizes the laboratory findings on MET and its anomalies, trial results on METex14 alterations and MET amplification in non-EGFR mutated NSCLCs, and acquired resistance to TKI in EGFR-mutated NSCLCs. The outcomes of the first trials with anti-MET agents on non-selected NSCLC patients or those selected for MET overexpression were disappointing. Two situations seem the most promising today for the use of anti-MET agents to treat these patients: tumors harboring METex14 and those EGFR-sensitive mutation mutated under TKI-EGFR with a MET-amplification mechanism of resistance or EGFR-resistance mutation.

HGF/MET pathway aberrations as diagnostic, prognostic, and predictive biomarkers in human cancers

Cancer is a major cause of death worldwide. MET tyrosine kinase receptor [MET, c-MET, hepatocyte growth factor (HGF) receptor] pathway activation is associated with the appearance of several hallmarks of cancer. The HGF/MET pathway has emerged as an important actionable target across many solid tumors; therefore, biomarker discovery becomes essential in order to guide clinical intervention and patient stratification with the aim of moving towards personalized medicine. The focus of this review is on how the aberrant activation of the HGF/MET pathway in tumor tissue or the circulation can provide diagnostic and prognostic biomarkers and predictive biomarkers of drug response. Many meta-analyses have shown that aberrant activation of the MET pathway in tumor tissue, including MET gene overexpression, gene amplification, exon 14 skipping and other activating mutations, is almost invariably associated with shorter survival and poor prognosis. Most meta-analyses have been performed in non-small cell lung cancer (NSCLC), breast, head and neck cancers as well as colorectal, gastric, pancreatic and other gastrointestinal cancers. Furthermore, several studies have shown the predictive value of MET biomarkers in the identification of patients who gain the most benefit from HGF/MET targeted therapies administered as single or combination therapies. The highest predictive values have been observed for response to foretinib and savolitinib in renal cancer, as well as tivantinib in NSCLC and colorectal cancer. However, some studies, especially those based on MET expression, have failed to show much value in these stratifications. This may be rooted in lack of standardization of methodologies, in particular in scoring systems applied in immunohistochemistry determinations or absence of oncogenic addiction of cancer cells to the MET pathway, despite detection of overexpression. Measurements of amplification and mutation aberrations are less likely to suffer from these pitfalls. Increased levels of MET soluble ectodomain (sMET) in circulation have also been associated with poor prognosis; however, the evidence is not as strong as it is with tissue-based biomarkers. As a diagnostic biomarker, sMET has shown its value in distinguishing cancer patients from healthy individuals in prostate and bladder cancers and in melanoma. On the other hand, increased circulating HGF has also been presented as a valuable prognostic and diagnostic biomarker in many cancers; however, there is controversy on the predictive value of HGF as a biomarker. Other biomarkers such as circulating tumor DNA (ctDNA) and tumor HGF levels have also been briefly covered. In conclusion, HGF/MET aberrations can provide valuable diagnostic, prognostic and predictive biomarkers and represent vital assets for personalized cancer therapy.

Meta-analysis of functional expression and mutational analysis of c-Met in various cancers

Comprehensive genomic profiling is expected to revolutionize cancer therapy. c-Met signaling is responsible for tumorigenesis in various cancers. In this prospective, we present the prevalence of c-Met mutations and copy number alterations across various solid tumors. We used major databases like cBioportal, PubMed, and COSMIC for c-Met mutation and amplification data collection from various cancers. Our result shows complete details about c-Met mutation and its clinical data of various cancers. Hotspot mutation of human c-Met protein reveals that repeatedly and most mutated regions and these hotspots may be a diagnostic tool for cancer confirmation. Amino acid and nucleotide changes and their prevalence were reported in a number of individual cancers. However, we collectively present the amino acid and nucleotide changes in various cancers in this review. Our collection of data for c-Met mutation and its distribution in different cancer tissue is showing that the missense mutation is the major one in all type of cancers. Copy number variation data showing amplification and deletion of human c-Met from various tumor types, lung and central nervous system tumors showing high amplification comparatively other types.

Capmatinib for the treatment of non-small cell lung cancer

Introduction: Activation of the MET pathway through MET amplifications or mutations is present in 3-4% of stage IV non-squamous non-small cell lung cancers (NSCLC). High MET amplifications and exon 14 skipping mutations are associated with poor prognosis: new treatments are needed for these patients. Capmatinib is a highly selective, potent small-molecule MET inhibitor with antitumor activity in NSCLC in vitro and in vivo. Areas covered: This article provides an overview of the capmatinib clinical development program in NSCLC, both as monotherapy in NSCLC with a dysregulated MET pathway, and in combination with epidermal growth factor receptor (EGFR) inhibitor therapy in EGFR-mutant NSCLC with MET-based acquired resistance to previous EGFR inhibition. Expert opinion: In the GEOMETRY Mono-1 study, treatment with capmatinib resulted in high response rates in stage IV NSCLC with MET exon 14 skipping mutations, particularly in first line, supporting testing for this biomarker at the time of diagnosis. Durable responses have been reported and results in MET-amplified NSCLC are eagerly anticipated. In EGFR-mutant NSCLC, notable responses have been observed in combination with an EGFR-tyrosine kinase inhibitor (TKI) in case of acquired resistance to EGFR-TKIs based on high MET amplification.

Mesenchymal–epithelial transition gene amplification and protein overexpression in stage IV pulmonary adenocarcinoma

Background

In non-small cell lung cancer (NSCLC), MET gene copy number gain, including gene amplification and chromosome 7 polysomy, is reportedly associated with patient prognosis. Although relationship between MET copy number gain and poor prognosis has been suggested in surgically resected non-small cell lung cancer, the clinical significance of MET copy number gain and protein overexpression in patients with advanced unresectable tumor is unclear.

Methods

We assessed MET copy number gain and protein expression using fluorescence in situ hybridization and immunohistochemistry in 88 patients with clinical stage IV pulmonary adenocarcinoma receiving chemotherapy, immunotherapy or palliative care.

Results

We found MET amplification, polysomy 7 and high MET protein expression in 10.2, 18.2 and 62.5% of 88 cases, respectively. Gene amplification and high protein expression were not significantly associated. A univariate analysis showed that MET amplification-positive patients had increased overall survival (HR 0.335, 95% CI: 0.119–0.945; P = 0.0388). Although it was not statistically significant in the multivariate analysis of the whole cohort, with the removal of patients who did not receive any treatment other than palliative care, MET amplification independently improved the overall survival (HR 0.178, 95% CI: 0.041–0.770; P = 0.0209). Chromosome 7 polysomy and high MET protein expression did not affect the overall survival.

Conclusions

Although MET amplification-positive tumor is considered aggressive, our results suggest that it has a more favorable prognosis than amplification-negative cases in stage IV pulmonary adenocarcinoma with medical treatment.

Increased MET gene copy number negatively affects the survival of esophageal squamous cell carcinoma patients

BACKGROUNDS

Since Mesenchymal epithelial transition (MET) amplification has been regarded as a potential treatment target, the knowledge of its prevalence and prognostic importance is crucial. However, its clinical pathologic characteristics are not well known in esophageal squamous cell carcinoma (ESCC).

METHODS

We investigated MET gene status with fluorescence in situ hybridization (FISH) assay in 495 ESCC cases using tissue microarrays. Prognostic significance as well as correlations with various clinicopathological parameters was evaluated.

RESULTS

Among 495 patients, 28 (5.7%) cases were MET FISH positive, including 5 cases (1%) with true gene amplification. There were no statistically significant associations between MET FISH-positivity and clinicopathologic characteristics. A significantly poorer prognosis was observed in 28 patients with MET FISH-positivity (disease free survival/DFS, P < 0.001 and overall survival/OS, P = 0.001). Multivariate analysis revealed MET FISH-positivity was an independent prognostic factor for DFS (hazard ratio/HR, 1.953; 95% confidence interval/CI, 1.271-2.999; P = 0.002) and OS (HR, 1.926; 95% CI, 1.243-2.983; P = 0.003). MET FISH-positivity was associated with DFS (P = 0.022 and 0.020) and OS (P = 0.046 and 0.024) both in stage I-II ESCC and in stage III-IVa ESCC. No statistical significance (DFS, P = 0.492 and OS, P = 0.344) was detected between stage I-II ESCC with MET FISH-positivity and stage III-IVa ESCC with FISH-negativity.

CONCLUSIONS

Increased MET gene copy number is an independent prognostic factor in ESCC, and ESCC might have potentially been up-staged by increased MET gene copy number. The results indicate that increased MET gene copy number is a very promising parameter, in clinical therapy and follow-up plans.

Any Place for Immunohistochemistry within the Predictive Biomarkers of Treatment in Lung Cancer Patients?

The identification of certain genomic alterations (EGFR, ALK, ROS1, BRAF) or immunological markers (PD-L1) in tissues or cells has led to targeted treatment for patients presenting with late stage or metastatic lung cancer. These biomarkers can be detected by immunohistochemistry (IHC) and/or by molecular biology (MB) techniques. These approaches are often complementary but depending on, the quantity and quality of the biological material, the urgency to get the results, the access to technological platforms, the financial resources and the expertise of the team, the choice of the approach can be questioned. The possibility of detecting simultaneously several molecular targets, and of analyzing the degree of tumor mutation burden and of the micro-satellite instability, as well as the recent requirement to quantify the expression of PD-L1 in tumor cells, has led to case by case development of algorithms and international recommendations, which depend on the quality and quantity of biological samples. This review will highlight the different predictive biomarkers detected by IHC for treatment of lung cancer as well as the present advantages and limitations of this approach. A number of perspectives will be considered.