Is there a relationship between c-erbB-1 and c-erbB-2 amplification and protein overexpression in NSCLC?

Quantitative Measurement of HER2 Expression in Non-Small Cell Lung Cancer With a High-Sensitivity Assay

Recently, low human epidermal growth factor receptor 2 (HER2) protein expression has been proposed as a predictive biomarker for response to the antibody-drug conjugate trastuzumab deruxtecan (T-DXd) in metastatic breast cancer. HER2 expression in non-small cell lung cancer (NSCLC) patients has never been carefully measured, and little is known about the frequency of cases with unamplified but detectable levels of the protein. Although some HER2-targeted therapies have been studied in NSCLC patients, they have been restricted to those with genomic ERBB2 gene alterations, which only represent relatively rare cases of NSCLC. Still, emerging investigations of T-DXd in NSCLC have shown promise in patients with unamplified HER2. Taken together, we hypothesize that there may be many cases of NSCLC with levels of HER2 protein expression comparable with levels seen in breast cancer that benefit from T-DXd. Here, we used a previously validated, analytic, quantitative immunofluorescence (QIF) assay that is more sensitive than legacy clinical HER2 immunohistochemistry assays. We measured HER2 protein levels in NSCLC cases to determine the proportion of cases with detectable HER2 expression. Using cell line calibration microarrays alongside our QIF method enabled us to convert HER2 signal into units of attomoles per mm2. We found that over 63% of the 741 analyzed NSCLC cases exhibited HER2 expression above the limit of detection, with more than 17% of them exceeding the lower limit of quantification. Although the threshold for response to T-DXd in breast cancer is still unknown, many cases of NSCLC have expression in a range comparable to breast cancer cases with immunohistochemistry scores of 1+ or 2+. Our assay could potentially select NSCLC cases with a detectable target (ie, HER2) that might benefit from HER2 antibody-drug conjugates, irrespective of ERBB2 genomic alterations.

[Assessment of HER2 status of carcinomas of various localizations]

A detailed description of the methodological aspects of the evaluation of HER2-status in carcinomas of such localizations as the mammary gland, pancreas, salivary glands, stomach, colon, endometrium, bladder, lungs is presented. Approaches and criteria for assessing HER2 status from methodological and clinical points of view are analyzed. The data are systematized in tables for use in practical diagnostic work.

Evidence for frequent concurrent DCUN1D1, FGFR1, BCL9 gene copy number amplification in squamous cell lung cancer

Non-small cell lung cancer (NSCLC) targeted therapies are mostly based on activating mutations and rearrangements which are rare events in Lung Squamous Cell Carcinomas (LUSC). Recently advances in immunotherapy have improved the therapeutic repository for LUSC, but there is still an urgent need for novel targets and biomarkers. We examined 73 cases of LUSC for relative copy number amplification of DCUN1D1, BCL9, FGFR1 and ERBB2 genes and searched for correlations with molecular alterations and clinicopathological characteristics. In our cohort BCL9 gene was amplified in 57.5 % of the cases, followed by DCUN1D1 in 37 %, FGFR1 in 19 % whereas none of the cases were amplified in ERBB2 gene. The majority of the samples exhibited amplification in at least one gene while half of them displayed concurrent amplification of two/three genes. Interestingly, 93 % of the FGFR1 amplified cases were also found co amplified with DCUN1D1 and/or BCL9 genes. Linear correlations were found between BCL9 and DCUN1D1 as well as BCL9 and FGFR1 gene amplification. BCL9 and DCUN1D1 genes' amplification was correlated with poorly differentiated tumors (p = 0.035 and p = 0.056 respectively), implying their possible role in tumor aggressiveness. This is the first study, to the best of our knowledge that examines the correlation of DCUN1D1 and BCL9 genes relative copy number amplification with molecular alterations and clinicopathologic characteristics of squamous cell lung cancer tissue samples. Our findings show concurrent amplification of genes in different chromosomes, with possible involvement in tumor aggressiveness. These results support the complexity of LUSC tumorigenesis and imply the necessity of multiple biomarkers / targets for a more effective therapeutic result in LUSC.

Targeting HER2 Alterations in Non–Small-Cell Lung Cancer: A Comprehensive Review

PURPOSE

HER2 is a critical gene that drives various solid tumors in addition to those of breast cancer. For example, HER2 plays a role in non–small-cell lung cancer (NSCLC). Overexpression, amplification, and point mutations in HER2 have been described in patients with NSCLC; however, the potential roles of these alterations remain unclear.

METHODS

We summarize the evidence regarding the distinct impacts of different HER2 aberrations on antitumor agents. Also, we update the therapeutic efficacy of HER2-targeted agents, including anti-HER2 antibodies, antibody-drug conjugates, and small-molecule tyrosine kinase inhibitors, tested in HER2-aberrant NSCLC.

RESULTS

Although these drugs are not yet standard treatments, certain patients may benefit from these therapies. In this review, we aim to provide an improved understanding of HER2 aberrations in NSCLC, including NSCLC biology and the impacts of each aberration on prognosis and standard treatment. We also highlight the potential of novel anti-HER2 therapies approved by regulatory bodies and those in clinical development.

CONCLUSION

Compared with HER2 amplification or overexpression, HER2 mutations, especially HER2 exon 20 mutations, are emerging as the most clear targetable driver for HER2-directed therapies in lung cancer. De novo and inducible HER2 pathway activation need to be differentially managed. Further investigations with new strategies are needed.

Erlotinib for Patients with EGFR Wild-Type Metastatic NSCLC: a Retrospective Biomarkers Analysis

Erlotinib is approved for the treatment of patients with EGFR mutation positive, metastatic NSCLC. It is also approved as second/third line therapy for EGFR mutation negative patients, but in this setting the benefit of erlotinib is modest and there is no validated biomarker for selecting EGFR wild-type patients who may benefit the most from the treatment. We retrospectively assessed EGFR and K-RAS mutational status, and EGFR, c-MET and IGF1-R expression in tumor samples of 72 patients with metastatic NSCLC treated with erlotinib after at least one prior line of chemotherapy, from 2008 to 2012. We analyzed the association between biomarkers and outcome (RR, PFS, and OS). EGFR mutated patients achieved a better RR (56% vs 8%, p = .002), PFS (10 vs 3 months, HR 0.53, p = 0.48) and OS (20 vs 6 months, HR 0.55, p = .07), compared to EGFR wild-type patients. Among 63 EGFR wild-type patients, those with EGFR high-expression had a better outcome in terms of RR (40% vs 2%, p = .002), PFS (7.5 vs 2 months, HR 0.45, p = .007) and OS (30 vs 5 months, HR 0.34, p < .001) compared to patients with EGFR intermediate or low/negative-expression. IGF1-R expression, c-MET expression and K-RAS mutational status did not significantly affect the outcome; however, no patients with K-RAS mutation or c-MET high-expression achieved an objective response. In patients with metastatic, chemo-refractory EGFR wild-type NSCLC, EGFR high-expression may represent a positive predictor of activity for erlotinib, whereas K-RAS mutation and c-MET high-expression may predict lack of activity. These findings deserve further prospective evaluation.

[Role of HER2 in NSCLC]

过去几年中, 随着分子靶向药物的引入, 非小细胞肺癌(non-small cell lung cancer, NSCLC)的药物治疗策略发生了巨大变化, 向基于组织学和分子水平的治疗手段转变。表皮生长因子受体(epidermal growth factor receptor, EGFR)突变、Kirsten鼠肉瘤(Kirsten rat sarcoma, KRAS)癌基因突变、间变淋巴瘤激酶(anaplastic lymphoma kinase, ALK)重排等的发现, 影响着NSCLC治疗的发展。最近, 对人表皮生长因子受体2(human epidermal growth factor receptor 2, HER2)研究重燃兴趣, 这一基因改变与NSCLC对不同酪氨酸激酶抑制剂(tyrosine kinase inhibitors, TKIs)的敏感性相关, 其具有可能的预测作用, HER2扩增可能是EGFR突变肿瘤对EGFR-TKIs获得性耐药的机制之一。其次, HER2突变可能阐明一条新的靶向治疗NSCLC的策略。本文将对NSCLC中HER2异常调节发挥的作用做一简要介绍。

Epidermal growth factor receptor tyrosine kinase inhibitors in previously treated advanced non-small-cell lung cancer with wild-type EGFR

INTRODUCTION

While epidermal growth factor receptor (EGFR) - tyrosine kinase inhibitors (TKIs) lead to longer progression-free survival (PFS) when compared with conventional chemotherapy in non-small-cell lung cancer (NSCLC) harboring activating EGFR mutations, the role of EGFR-TKI remains unclear in EGFR-wild-type (WT) NSCLC.

AREAS COVERED

This article reviews selected data from randomized trials regarding the use of TKIs in EGFR-WT NSCLC. Nine randomized phase III trials have compared EGFR-TKI with chemotherapy in NSCLC patients in a second or later line setting. Two of these trials, TAILOR and DELTA, which were designed to investigate treatment benefits according to EGFR genotype, demonstrated that docetaxel chemotherapy displayed significantly better in progression-free survival (PFS) when compared with the EGFR-TKI erlotinib. Biomarkers to predict clinical benefits of the drug against EGFR WT tumor, and the efficacy of combination regimens using erlotinib or single-use afatinib against tumors are also covered in this article.

EXPERT OPINION

Considering the modest benefits of erlotinib for EGFR-WT tumors, future studies are warranted, including the exploration of useful biomarkers and new treatment strategies for EGFT-TKI use, as well as the development of more sensitive EGFR mutation tests.

[Difficulties and limitations in conducting translational research in thoracic oncology. A practical example]

INTRODUCTION

In a first study, we identified signatures of 3 mRNAs (semaphorin 3D [SEMA3D], cytokeratin 16 [KRT16] and UL16 binding protein 2 [ULBP2]) associated to response to a cisplatin-vinorelbin chemotherapy and to survival of advanced non-small cell lung cancers (NSCLC).

MATERIAL AND METHODS

The aim of this study was to develop immunohistochemistry tests for KRT16, ULBP2 and SEMA3D and to test proteins expression for prediction of response and survival in biopsies of the same patients.

RESULTS

We were not able to reproduce by the protein expression study the signature predicting response to chemotherapy in advanced NSCLC.

CONCLUSION

We highlight the difficulties of translational research in thoracic oncology emphasizing the complexity in obtaining adequate tissue samples and the difficulties in conduction and transposing in routine practice high throughput technique for transcriptomic analyses.

NSCLC and HER2: between lights and shadows

The therapeutic landscape of non-small-cell lung cancer (NSCLC) has dramatically changed in the last few years with the introduction of molecularly targeted agents, leading to unprecedented results in lung tumors with a paradigmatic shift from a "one size fits all" approach to an histologic and molecular-based approach. The discovery of epidermal growth factor receptor (EGFR) mutations in NSCLC in 2004 and the marked response to the EGFR tyrosine kinase inhibitor gefitinib, in a small subset of patients harboring these genetic abnormalities, stimulated the study of other kinase mutants involvement in NSCLC. The incredible story of ALK rearranged tumors, with the rapid Food and Drug Administration approval of Crizotinib after only 4 years from the discovery of EML4-ALK translocation in NSCLC, has profoundly influenced the concept of drug development in NSCLC, paving the way to a novel series of molecularly selected studies with specific inhibitors. The identification of these oncogenic drivers has dramatically changed the genetic landscape of NSCLC moving away from the old concept of a large indistinct histological entity to a combination of rare clinically relevant molecular subsets. Recently, a renewed interest has been emerging on the human epidermal growth factor-2 (HER2) pathway. Genetic aberrations of this signaling pathway have been reported over time to be associated in NSCLC with different sensitivity to the EGFR tyrosine kinase inhibitors, to have a possible prognostic role and more recently HER2 amplification has been emerged as a possible mechanism in EGFR-mutated tumors of acquired resistance to the EGFR tyrosine kinase inhibitors. In addition, dysregulation of the HER2 pathway, in particular HER2 mutations (mostly, in-frame exon 20 insertions), may represent a possible novel therapeutic target in NSCLC, paving the way for a new generation of targeted agents in NSCLC. Since anecdotal case reports of clinical activity of anti-HER2 agents in NSCLC patients with HER2 mutations, several targeted agents have been evaluated in HER2-mutated patients, generating a growing interest upon this oncogenic driver, leading to the design of molecularly selected trials with anti-HER2 compounds and the rediscover of hastily thrown out drugs, such as neratinib. The aim of this article is to provide an overview of the role of HER2 dysregulation in NSCLCs, trying to throw a light not only on the strengths but also the weaknesses of the studies conducted so far. It is a long way to the clinical implementation of these biomarkers and probably the increasing use of next generation sequencing techniques, the creation of large multi-institutional molecular testing platforms and the design of rationally based trials can get closer personalized medicine in NSCLC.

Significance of EGFR signaling pathway genetic alterations in radically resected non-small cell lung cancers from a Polish cohort. One institutional study

PURPOSE

We evaluated the distribution and clinical impact of EGFR, KRAS and HER2 copy number gains and EGFR, KRAS and BRAF activating mutations in resected non-small cell lung cancers (NSCLCs) from 151 Polish patients.

MATERIALS AND METHODS

Quantitative PCR and DNA sequencing were used for copy number evaluation and mutational analysis, respectively.

RESULTS

An increased EGFR CN was found in 21.2% of the tumors, more commonly of the non-squamous histology (P=0.029), larger in size (P=0.004) and those obtained from women (P=0.040). HER2 copy gain was observed in 21.8% of the patients, more frequently with lymph node metastases (P=0.048) and stage IIIA disease (P=0.061). KRAS gain was found in 29.3% of the tumors, and was not associated with patients' clinicopathological features. No BRAF mutations were found. EGFR and KRAS mutation frequency and associations with clinicopathological characteristics did not differ significantly from those previously described for the NSCLC patients of Caucasian ethnicity. Strong associations existed between most of the analyzed alterations. In the multivariate model, EGFR mutations constituted an independent prognostic factor of the disease recurrence in adenocarcinoma patients (HR 7.20; 95%CI 1.31-39.48; P=0.023), while an increased EGFR copy number tended to indicate a shorter overall survival (HR 4.85; 95%CI 0.92-25.58; P=0.062).

CONCLUSIONS

EGFR pathway genes alterations are frequent in NSCLCs from Polish patients and have a prognostic potential for patients' clinical outcome after a curative tumor resection. Gene CN evaluation by quantitative PCR provides comparable results and enables assay standardization, yet the optimal scoring system needs to be developed.

Drug resistance to molecular targeted therapy and its consequences for treatment decisions in non-small-cell lung cancer

Our ability to detect and directly target the oncogenic alterations responsible for tumor proliferation has contributed significantly to the management of lung cancer in the last decade. The therapeutic efficacy of molecularly targeted therapy is, however, mainly limited to patients harboring certain genetic mutations and is generally short-lived. Herein, we review primary and secondary drug resistance using the most well-studied of the molecularly targeted agents, the tyrosine kinase inhibitors targeting the epidermal growth factor (EGF) receptor, and the anaplastic lymphoma kinase (ALK) rearrangement, the current limitations of targeted therapies and their consequences on the management of patients with lung cancer.

Sex disparities in the association of lung adenocarcinoma with colorectal cancer

BACKGROUND

Most cancers share common risk factors. It might provide evidence of shared risk factors with cancers by investigating cross-country and cross-township comparisons.

METHODS

The data were obtained from International Association of Cancer Registries/World Health Organization and the National Cancer Registration Program of Taiwan. Age standardized incidence rates were calculated among gastric cancer, colorectal cancer and lung adenocarcinoma in 19 countries from 1995 to 1998. The Pearson correlations were also compared among 3 types of cancers for both sexes.

RESULTS

The incidence rates of gastric and colorectal cancer throughout different countries show male dominance with a male-to-female sex ratio of around 2 and 1.5, respectively. Significant cross-country correlations in colorectal cancer (r=0.918, p<0.001), gastric cancer (r=0.985, p<0.001) and lung adenocarcinoma (r=0.685, p=0.001) were observed between men and women. There was a significant international correlation between colorectal cancer and lung adenocarcinoma in men (r=0.526, p=0.021), but not in women. In cross-township comparisons of Taiwan, there were significant correlations in colorectal cancer (r=0.451, p<0.001), gastric cancer (r=0.486, p<0.001), and lung adenocarcinoma (r=0.217, p<0.001) between men and women. There were links of lung adenocarcinoma and gastric cancer (r=0.122, p=0.024) and colorectal cancer (r=0.128, p=0.018) in women, and lung adenocarcinoma and colorectal cancer in men (r=0.276, p<0.001).

CONCLUSIONS

There were associations between lung adenocarcinoma and colorectal cancer between and in both sexes in Taiwan, but not in cross-country comparisons. The results suggest that some factor, like genes, may be important as determinants for the association between lung adenocarcinoma and colorectal cancer.

Co-expression of receptors of the HER family correlates with clinical outcome in non-small cell lung cancer (NSCLC)

HER family receptors play a critical role in lung carcinogenesis. There is a growing body of evidence showing that cooperation between them contributes to a more aggressive tumor phenotype and impacts on their response to targeted therapy. We explored immunohistochemical co-expression of HER family receptors (HER1, HER2, HER3, HER4) and its potential role as prognostic factor in resected non-small cell lung cancer (NSCLC). Expression of HER family receptors was assessed by immunohistochemistry on 125 surgically resected NSCLC. Kaplan-Meier estimates of overall survival (OS), disease-free survival (DFS), and time to recurrence were calculated for clinical variables and HER expression, using the Cox model for multivariate analysis. HER1 and HER3 expression was detected more frequently in squamous cell carcinoma (p = 0.002 and p = <0.001, respectively). HER4 was more often expressed in patients older than 60 years (p = 0.02) and in tumors of low histological grade (p = 0.04). Cases which expressed only HER1 had a worse DFS (p = 0.01) and OS (p = 0.01) compared to cases expressing HER1 and one or more of the other family members and to cases which did not express HER1 but one of the other HERs. By multivariate analysis, stage was an independent prognostic factor for DFS and OS. Furthermore, different patterns of co-expression of HER family receptors showed a statistically significant correlation with a shorter DFS (p = 0.03) and OS (p = 0.02). Our findings suggest that expression of HER1 only is correlated with worse DFS and OS. A better understanding of the functional relationships between these receptors may lead to a useful predictive indicator of response to targeted therapy.

Role of Epidermal Growth Factor Receptor Inhibitors in Epidermal Growth Factor Receptor Wild-Type Non–Small-Cell Lung Cancer

Worldwide, the majority of patients with advanced non–small-cell lung cancer (NSCLC) do not have activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR). These wild-type patients comprise a significant proportion of those treated with inhibitors of this pathway, and data from randomized trials suggest that some of these wild-type patients will derive a modest benefit from these agents. Although the detection of an activating mutation predicts for a greater likelihood of response and longer progression-free survival from an EGFR tyrosine kinase inhibitor, currently there are no biomarkers that consistently and reproducibly predict for lack of benefit in wild-type patients. Several strategies to increase the efficacy of these inhibitors in wild-type NSCLC are the subject of ongoing investigations.

EGFR-mutated lung cancer: a paradigm of molecular oncology

The development of EGFR tyrosine kinase inhibitors for clinical use in non-small cell lung cancer and the subsequent discovery of activating EGFR mutations have led to an explosion of knowledge in the fields of EGFR biology, targeted therapeutics and lung cancer research. EGFR-mutated adenocarcinoma of the lung has clearly emerged as a unique clinical entity necessitating the routine introduction of molecular diagnostics into our current diagnostic algorithms and leading to the evidence-based preferential usage of EGFR-targeted agents for patients with EGFR-mutant lung cancers. This review will summarize our current understanding of the functional role of activating mutations, key downstream signaling pathways and regulatory mechanisms, pivotal primary and acquired resistance mechanisms, structure-function relationships and ultimately the incorporation of molecular diagnostics and small molecule EGFR tyrosine kinase inhibitors into our current treatment paradigms.

Gefitinib (ZD1839): therapy in selected patients with non-small cell lung cancer (NSCLC)?

PURPOSE

To evaluate response rate, toxicity and epidermal growth factor (EGFR) mutations and gene copy number as outcome predictive factors in Italian patients with non-small cell lung cancer (NSCLC) treated with gefitinib (Iressa) in an expanded access program (EAP).

PATIENTS AND METHODS

A total of 137 patients with advanced NSCLC received gefitinib as first line treatment or after failure of chemotherapy. In 43 cases, tissue specimens were available for EGFR status evaluation: immunohistochemical (IHC) for EGFR, fluorescence in situ hybridisation (FISH) or Chromogenic in situ hybridisation (CISH)-(ISH) analysis for EGFR and HER2 gene copy number, and PCR-DNA sequencing for mutational analysis of EGFR were performed.

RESULTS

In the study population, response rate (PR) was 13%; disease stabilization (DS) 26%; overall disease control rate 39%; median survival 6.3 months and time to progression 2.7 months. Toxicity was mild (G3 skin toxicity in 3% and G3 liver toxicity in 4% of patients). An EGFR-mutation was detected in 9/43 patients: Eight deletions in exon 19 and 1 missense mutation in exon 21. Increased gene copy number for EGFR and/or HER2 was detected in 17/43 patients. Response rate was significantly higher in women, non-smokers, in mutation carriers than in wild type carriers, in EGFR-trisomy/polysomy carriers and HER2-trisomy/polysomy carriers.

CONCLUSIONS

In this study, response rate and toxicity to gefitinib treatment were consistent with previously reported data for whites. Female gender, absence of smoking history, EGFR-mutations, EGFR and HER2-polysomy were significantly associated with response to gefitinib therapy in NSCLC patients.

Simultaneous expression of c-erbB-1, c-erbB-2, c-erbB-3 and c-erbB-4 receptors in non-small-cell lung carcinomas: correlation with clinical outcome

The expression of c-erbB receptors was immunohistochemically examined in paraffin embedded specimens from non-small-cell lung carcinomas. A total of 209 patients were enrolled [squamous-cell carcinomas (n=59), adenocarcinomas (n=130), large-cell carcinomas (n=15) and giant-cell carcinomas (n=5)]. The HercepTest kit scoring guidelines were used for the interpretation of positivity. C-erbB-1 was overexpressed in older patients, in squamous-cell carcinomas and in poorly-differentiated tumours, whereas c-erbB-2 overexpression with adenocarcinomas and poorly-differentiated tumours. C-erbB-4 overexpression correlated with advanced disease stage. The c-erbB-1/4 pair was the most commonly overexpressed and significantly correlated with female gender, while the c-erbB-1/2 pair with older age. Response to chemotherapy was significantly reduced in patients with tumours overexpressing c-erbB-1 receptor as well as the c-erbB-1/2 and c-erbB-3/4 receptor pairs. Patients' overall survival was significantly correlated with the co-expression of c-erbB-1 and c-erbB-4 receptors. These findings clearly suggest that specific receptors overexpression or co-overexpression is correlated with patients' disease control rate and outcome. A better understanding of the overexpression of the heterodimerized partners of c-erbB family receptors may provide a useful predictive indicator of response to molecular targeted therapies with c-erbB inhibitors.