Epidermal growth factor receptor expression status in lung cancer correlates with its mutation

Targeting exon mutations in NSCLC: clinical insights into LAG-3, TIM-3 pathways, and advances in fourth-generation EGFR-TKIs

Lung cancer remains the second leading cause of cancer-related morbidity and mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for the majority of cases. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have become the standard first-line therapy for advanced NSCLC with EGFR mutations, offering significant improvements in progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) compared to chemotherapy alone. Recent studies suggest that their effectiveness decreased with the emergence of acquired resistance, such as C797S and T790M. Immunotherapy alone also shows enhanced PFS and OS over chemotherapy; however, its applicability can be limited in cases with low programmed cell death ligand 1 (PD-L1) expression and result in immune-related adverse effects like those observed in retrospective, non-randomized studies. Emerging fourth-generation EGFR-TKIs, currently under clinical trials, show promising potential to address these resistance mechanisms. Advanced inhibitors, including BBT-176, BLU-945, and BLU-701, have effectively targeted resistant mutations and reduced disease progression. Studies have suggested that combining fourth-generation EGFR-TKIs with immunotherapies targeting novel pathways like LAG-3 and TIM-3 may enhance patient outcomes. Such combination regimens aim to optimize PFS, OS, and ORR while minimizing adverse effects and addressing the limitations of current therapies. This study explores the landscape of EGFR mutations, their clinical significance, and the integration of innovative fourth-generation EGFR-TKIs with immunotherapies, emphasizing the potential of precision medicine in advancing the management of EGFR-mutated NSCLC.

An Efficient Suppression of EGFR and B-Raf mRNA Overexpression in the Lung of Benzo[a]pyrene-induced mice by Cationic Lipo-ATRA Nanoformulation

BACKGROUND

The molecular drug all-trans retinoic acid (ATRA) acts on cancer cells via different molecular pathways, but its poor bioavailability in cancer cells limits its potency. Recently few patents have been published for the development of liposome-based drug for enhanced action. This study was, therefore, carried out to analyse the oncogene expressions in the lung tissue of benzo[ a]pyrene (B[a]P)-induced mice and compare between free ATRA and cationic liposome nanoformulation (lipo-ATRA) treatments.

OBJECTIVE

This study was designed to analyse the changes in the expression levels of epidermal growth factor receptor (EGFR) and B-Raf in the lung tissues of B[a]P-induced mice during the cancer development stage itself and to find the suppressive effect of free ATRA and lipo-ATRA.

METHODS

Lung cancer was induced in mice by oral ingestion of 50mg/kg body weight B[a]P weekly twice for four consecutive weeks. Then, the mice were treated with free and lipo-ATRA (0.60 mg/kg) for 30 days via i.v injection. The EGFR and B-Raf gene expressions were analyzed in lung cells by reverse transcriptase polymerase chain reaction (RT-PCR) and quantitative polymerase chain reaction (qPCR).

RESULTS

The RT-PCR gene band density and the relative quantity (RQ) values from qPCR revealed both EGFR and B-Raf genes to be significantly overexpressed in B[a]P control mice while having very low or no expression in normal mice. This indicates that they function as oncogenes in B[a]P-induced lung carcinogenesis. The lipo-ATRA treatment has shown a highly significant increase in RQ values for both EGFR and BRaf when compared to the free ATRA treatment.

CONCLUSION

The study results have revealed the cationic lipo-ATRA treatment to have enhanced the bioavailability of ATRA in lung tissue due to its significant suppression action on EGFR-mediated oncogenes' expressions. Furthermore, the EGFR and BRaf could be the molecular targets of ATRA action in lung carcinogenesis.

The Impact of Genetic Mutations on the Efficacy of Immunotherapies in Lung Cancer

Lung cancer is the leading cause of cancer-related mortality worldwide, primarily driven by genetic mutations. The most common genetic alterations implicated in lung cancer include mutations in TP53, KRAS, KEAP1, NF1, EGFR, NRF2, ATM, ALK, Rb1, BRAF, MET, and ERBB2. Targeted therapies have been developed to inhibit cancer growth by focusing on these specific genetic mutations. However, either the mutations are undruggable or the efficacy of these therapies is often compromised over time due to the emergence of drug resistance, which can occur through additional mutations in the targeted protein or alternative growth signaling pathways. In recent years, immunotherapy has emerged as a promising approach to enhance the effectiveness of cancer treatment by leveraging the body's immune system. Notable advancements include immune checkpoint inhibitors, monoclonal antibodies targeting cell surface receptors, antibody-drug conjugates, and bispecific antibodies. This review provides an overview of the mechanisms of FDA-approved immunotherapeutic drugs, offering an updated perspective on the current state and future developments in lung cancer therapy. More importantly, the factors that positively and negatively impact the immunotherapy's efficacy will also be discussed.

Unlocking the power of sugar: carbohydrate ligands as key players in nanotherapeutic-assisted targeted cancer therapy

Cancer cells need as much as 40-times more sugar than their normal cell counterparts. This sugar demand is attained by the excessive expression of inimitable transporters on the surface of cancer cells, driven by their voracious appetite for carbohydrates. Nanotechnological advances drive research utilizing ligand-directed therapeutics and diverse carbohydrate analogs. The precise delivery of these therapeutic cargos not only mitigates toxicity associated with chemotherapy but also reduces the grim toll of mortality and morbidity among patients. This in-depth review explores the potential of these ligands in advanced cancer treatment using nanoparticles. It offers a broader perspective beyond the usual ways we deliver drugs, potentially changing the way we fight cancer.

EGFR signaling pathway as therapeutic target in human cancers

Epidermal Growth Factor Receptor (EGFR) enacts major roles in the maintenance of epithelial tissues. However, when EGFR signaling is altered, it becomes the grand orchestrator of epithelial transformation, and hence one of the most world-wide studied tyrosine kinase receptors involved in neoplasia, in several tissues. In the last decades, EGFR-targeted therapies shaped the new era of precision-oncology. Despite major advances, the dream of converting solid tumors into a chronic disease is still unfulfilled, and long-term remission eludes us. Studies investigating the function of this protein in solid malignancies have revealed numerous ways how tumor cells dysregulate EGFR function. Starting from preclinical models (cell lines, organoids, murine models) and validating in clinical specimens, EGFR-related oncogenic pathways, mechanisms of resistance, and novel avenues to inhibit tumor growth and metastatic spread enriching the therapeutic portfolios, were identified. Focusing on non-small cell lung cancer (NSCLC), where EGFR mutations are major players in the adenocarcinoma subtype, we will go over the most relevant discoveries that led us to understand EGFR and beyond, and highlight how they revolutionized cancer treatment by expanding the therapeutic arsenal at our disposal.

Prognostic Characteristics and Immunotherapy Response of Patients With Nonsquamous NSCLC With Kras Mutation in East Asian Populations: A Single-Center Cohort Study in Taiwan

Introduction

Kras mutation is the most common driver oncogene present in patients with NSCLC. Recently, the precision medicine for patients with Kras-mutated NSCLC has been under investigation, but the best treatment is still unknown. This study aimed to analyze the clinical characteristics, immune checkpoint inhibitor (ICI) response, and prognostic factors of patients with NSCLC with different Kras mutation subtypes.

Methods

From 2005 to 2018, we collected nonsquamous NSCLC tissue samples for Kras mutation analysis using direct Sanger sequencing or MassARRAY genotyping (Agena Bioscience, San Diego, CA) at the National Taiwan University Hospital. Clinical characteristics, ICI treatment effectiveness, time-to-tumor recurrence (TTR), and overall survival (OS) were analyzed using multivariate Cox models, to estimate adjusted hazard ratios (HRs).

Results

Among 5278 patients with nonsquamous NSCLC, 246 (4.7%) had Kras mutations. The major Kras mutation subtypes were G12C (32.9%), G12D (23.7%), and G12V (18.9%). Patients with Kras-G12C had a higher proportion of male individuals (p = 0.018) and smokers (p < 0.001). Among the 25 patients treated with ICIs, patients with Kras-G12C had a higher response rate (53.8% versus 8.3%, p = 0.030) and longer progression-free survival (4.8 mo versus 2.1 mo, p = 0.028) than those with Kras-non-G12C. For the 85 patients with early-stage NSCLC, those with G12C had shorter TTR (22.8 mo) than those with Kras-non-G12C (97.7 mo, p = 0.004). For the 143 patients with advanced-stage NSCLC, there was a significant difference in OS between patients with Kras-G12C and Kras-non-G12C (7.7 mo versus 6.0 mo, p = 0.018) and patients with Kras-G12V had the shortest OS (5.2 mo). Multivariate analysis revealed association of shorter OS with Kras-G12V (HR = 2.47, p = 0.002), stage IV disease status (HR = 2.69, p = 0.008), and NSCLC-not otherwise specified histology (HR = 3.12, p = 0.002).

Conclusions

Kras-G12C was associated with favorable ICI treatment effectiveness in patients with NSCLC. Kras-G12C mutation was associated with shorter TTR in patients with early-stage NSCLC, and Kras-G12V mutation was associated with shorter OS in patients with advanced-stage NSCLC when comparing with Kras-G12C.

Structural and Functional Characterizations of Cancer Targeting Nanoparticles Based on Hepatitis B Virus Capsid

Cancer targeting nanoparticles have been extensively studied, but stable and applicable agents have yet to be developed. Here, we report stable nanoparticles based on hepatitis B core antigen (HBcAg) for cancer therapy. HBcAg monomers assemble into spherical capsids of 180 or 240 subunits. HBcAg was engineered to present an affibody for binding to human epidermal growth factor receptor 1 (EGFR) and to present histidine and tyrosine tags for binding to gold ions. The HBcAg engineered to present affibody and tags (HAF) bound specifically to EGFR and exterminated the EGFR-overexpressing adenocarcinomas under alternating magnetic field (AMF) after binding with gold ions. Using cryogenic electron microscopy (cryo-EM), we obtained the molecular structures of recombinant HAF and found that the overall structure of HAF was the same as that of HBcAg, except with the affibody on the spike. Therefore, HAF is viable for cancer therapy with the advantage of maintaining a stable capsid form. If the affibody in HAF is replaced with a specific sequence to bind to another targetable disease protein, the nanoparticles can be used for drug development over a wide spectrum.

Extended-spectrum of KRAS and NRAS mutations in lung cancer tissue specimens obtained with bronchoscopy

Background

Mutations in the RAS genes, HRAS, KRAS, and NRAS, are the most common modifications in many types of human tumors and are found in approximately 30% of all human cancers. These mutations are usually found in codons 12, 13, or 61.

Methods

The aim of this study is to evaluate mutations in codons 59, 117, and 146 of KRAS and NRAS genes in addition to codons 12,13, and 61 of KRAS gene in lung cancer tissue specimens obtained with bronchoscopy. KRAS and NRAS mutation analyses with pyrosequencing were performed on DNA isolated from formalin-fixed paraffin-embedded (FFPE) tissue samples of 64 patients histopathologically diagnosed as lung cancer after bronchoscopic biopsy.

Results

In all, 20 patients (31.2%) had mutations in KRAS gene (8/27 squamous cell carcinoma, 8/11 adenocarcinoma, 3/16 small cell carcinoma, and 1/1 pleomorphic carcinoma). The most common mutation in codon 12 was in c.35G>T (G12V). When the mutation rate of adenocarcinoma (72.7%) and squamous cell carcinoma (22.9%) patients was compared with each other, a statistically significant difference was observed (P = 0.008). There were no mutations in codons 59, 117, or 146 of KRAS and NRAS genes in patients with lung cancer.

Conclusion

In this study, we firstly examined mutations in codons 59, 117, and 146 of KRAS and NRAS genes in addition to codons 12, 13, and 61 of KRAS gene in Turkish lung cancer patients both in non-small cell lung cancer and small cell lung cancer. Although no mutation was detected in codons 59, 117, and 146 of KRAS and NRAS genes, the frequency of KRAS gene mutation was higher than the rate of mutation in both Asian and Western countries, and multicenter studies including more cases should be performed to further explore our results.

Understanding Lineage Plasticity as a Path to Targeted Therapy Failure in EGFR-Mutant Non-small Cell Lung Cancer

Somatic alterations in the epidermal growth factor receptor gene (EGFR) result in aberrant activation of kinase signaling and occur in ∼15% of non-small cell lung cancers (NSCLC). Patients diagnosed with EGFR-mutant NSCLC have good initial clinical response to EGFR tyrosine kinase inhibitors (EGFR TKIs), yet tumor recurrence is common and quick to develop. Mechanisms of acquired resistance to EGFR TKIs have been studied extensively over the past decade. Great progress has been made in understanding two major routes of therapeutic failure: additional genomic alterations in the EGFR gene and activation of alternative kinase signaling (so-called “bypass activation”). Several pharmacological agents aimed at overcoming these modes of EGFR TKI resistance are FDA-approved or under clinical development. Phenotypic transformation, a less common and less well understood mechanism of EGFR TKI resistance is yet to be addressed in the clinic. In the context of acquired EGFR TKI resistance, phenotypic transformation encompasses epithelial to mesenchymal transition (EMT), transformation of adenocarcinoma of the lung (LUAD) to squamous cell carcinoma (SCC) or small cell lung cancer (SCLC). SCLC transformation, or neuroendocrine differentiation, has been linked to inactivation of TP53 and RB1 signaling. However, the exact mechanism that permits lineage switching needs further investigation. Recent reports indicate that LUAD and SCLC have a common cell of origin, and that trans-differentiation occurs under the right conditions. Options for therapeutic targeting of EGFR-mutant SCLC are limited currently to conventional genotoxic chemotherapy. Similarly, the basis of EMT-associated resistance is not clear. EMT is a complex process that can be characterized by a spectrum of intermediate states with diverse expression of epithelial and mesenchymal factors. In the context of acquired resistance to EGFR TKIs, EMT frequently co-occurs with bypass activation, making it challenging to determine the exact contribution of EMT to therapeutic failure. Reversibility of EMT-associated resistance points toward its epigenetic origin, with additional adjustments, such as genetic alterations and bypass activation, occurring later during disease progression. This review will discuss the mechanistic basis for EGFR TKI resistance linked to phenotypic transformation, as well as challenges and opportunities in addressing this type of targeted therapy resistance in EGFR-mutant NSCLC.

Spectroscopic insights into the effect of pH, temperature, and stabilizer on erlotinib adsorption behavior onto Ag nanosurface

In this study, surface - enhanced Raman spectroscopy (SERS) was applied at the first time for estimation of how pH, temperature, and nanoparticle (NP) stabilizer affect an adsorption behavior of erlotinib (drug approved in a non-small cell lung cancer therapy) onto citrate-stabilized silver nanoparticles (AgNPs). Novel approach to improve cancer therapy assumes application of NPs as an efficient drug delivery system. This strategy requires designing stable drug/nanocarrier conjugates that can effectively interact in the target site. It is also important to perform deeply characterization of a drug orientation on the potential carrier surface and estimation how stable the appeared interaction is. Performed analysis, indicates that pH, temperature, presence of NP stabilizers, and time of incubation have an influence on the occurring adsorption geometry of the drug. However, the observed erlotinib/AgNP interaction remains stable regardless of the applied conditions. These considerations were supported by insightful physicochemical characteristics of the AgNPs and the erlotinib/AgNP conjugates by conducting transmission electron microscopy (TEM) imaging, determination of colloid stability conducted with the use of dynamic light scattering technique (DLS) and measurements of electrophoretic mobility. Such complex approach allows a better understanding of the stability of the erlotinib/AgNP conjugates and provides information how the investigated interaction is affected by the induced perturbations.

Oncogene addiction and tumor mutational burden in non-small-cell lung cancer: Clinical significance and limitations

Lung cancer incidence has increased worldwide over the past decades, with non-small cell lung cancer (NSCLC) accounting for the vast majority (85%) of lung cancer specimens. It is estimated that lung cancer causes about 1.7 million global deaths per year worldwide. Multiple trials have been carried out, with the aim of finding new effective treatment options. Lately, special focus has been placed on immune checkpoint (PD1/PD-L1) inhibitors which impact the tumor immune microenvironment. Tumor mutational burden (TMB) has been found to predict response to immune checkpoint inhibitors. Conversely, recent studies have weakened the significance of TMB as a predictor of response to therapy and survival. In this review article, we discuss the significance of TMB, as well as possible limitations. Furthermore, we give a concise overview of mutations frequently found in NSCLC, and discuss the significance of oncogene addiction in lung cancer as an essential driver of tumorigenesis and tumor progression.

Targeting apoptosis by 1,2-diazole through regulation of EGFR, Bcl-2 and CDK-2 mediated signaling pathway in human non-small cell lung carcinoma A549 cells

Lung cancer is the leading cause of cancer deaths worldwide and non-small cell lung carcinoma (NSCLC), a heterogeneous class of tumors, represents approximately 85% of all new lung cancer diagnosis. Conventional treatment options have limited efficacy because most cases are in the advanced stage at the time of diagnosis. The present study evaluates the anti-cancer activity of 1,2-diazole (pyrazole), a natural compound from mangrove plant Rhizophora apiculata (R.apiculata) on A549 lung carcinoma cells. In the present study the anti-cancer mechanism of pyrazole, was examined by the expression level of proteins Epidermal growth factor receptor (EGFR), Bcl-2-associated X protein (Bax), B-cell lymphoma-2 (Bcl-2) and Cyclin-dependent kinase-2 (CDK-2) which are commonly associated with the cell signaling pathways that control cell survival and apoptosis, that could facilitate to develop a novel target and effective treatment approach for patients with NSCLC. Pyrazole significantly induced cell cycle arrest and initiated apoptosis through inhibition of downstream components of EGFR tyrosine kinase pathway. Pyrazole disrupts the mitochondrial membrane potential and modulated the protein levels of Bax and Bcl-2 which could probably lead to caspase-3 activation. Furthermore, Pyrazole suppresses the expression of CDK-2 resulting in cell cycle arrest at G1 phase and in the G1-S phase transition. Taken together, the current study provides new insight in to the precise molecular mechanisms responsible for the anti-cancer activity of pyrazole in NSCLC, A549 cells. The study opens an avenue for development of a natural compound as a potential therapeutic agent which could target cell signaling pathways to combat human NSCLC.

The role of the cytopathologist in subtyping and epidermal growth factor receptor testing in non-small cell lung cancer: An institutional experience

OBJECTIVE

Approximately 10% of non-small-cell lung cancer (NSCLC) remains unclassifiable as NSCLC-not otherwise specified (NOS), after using a panel of immunomarkers. The present study was undertaken to assess sensitivity and specificity of immunomarkers in sub-typing NSCLC on fine needle aspiration cytology (FNAC). Epidermal growth factor receptor (EGFR) mutations were also detected in these samples.

METHODS

Sixty cases of NSCLC including 15 squamous cell carcinoma (SCC), 15 adenocarcinomas (ADC) and 30 NSCLC-NOS reported on FNAC were included in the study. A panel of CK7, CK5/6, TTF-1 and p63 was applied in these cases. DNA was extracted from 54 cases including 14 effusion samples, and EGFR mutations were detected.

RESULTS

Classic ADC cases (n=15) showed 73.3% TTF-1 positivity and 100% CK7 positivity. Two cases of ADC showed aberrant expression of p63 and 2 cases showed CK5/6 positivity. 80% of classic SCC cases (n=15) showed strong nuclear p63 positivity and 86.6% were positive for CK5/6. TTF-1 was seen exclusively in ADC cases. Immunohistochemistry (IHC) using two immunomarkers (TTF-1 and p63) helped in subtyping 24/30(80%) cases of NSCLC. EGFR mutations were detected in 9/54 (16.7%) cases, and the most common mutation was short in-frame deletion in Exon 19.

CONCLUSIONS

More than 90% of NSCLC can be sub-typed on cytology samples with the help of immunochemistry. The sensitivity of TTF-1, p63, CK5/6 and CK7 was 73.3%, 80%, 100% and 100%, respectively. The specificity of TTF-1, p63, CK5/6 and CK7 was 100%, 86.6%, 86.6% and 93.3%, respectively. TTF-1 is highly specific, and almost 80% of NSCLC-NOS cases can be sub-typed using TTF-1 and p63. EGFR mutations can be detected in cytology samples, and 16.7% samples were positive for EGFR mutations.

Increased EGFR mRNA Expression Levels in Non-Small Cell Lung Cancer

Objective

In this study, we investigated the frequency of Epidermal growth factor receptor (EGFR) gene mutations, the level of EGFR mRNA and protein expressions in Turkish population for indicating substantial differences in the frequency of EGFR mutations, EGFR amplification and EGFR protein expression between populations and the effect of these parameters in response to EGFR tyrosine kinase inhibitors.

Materials and Methods

The study included 34 patients with non-small cell lung cancers. The RNA and DNA were extracted from the normal and tumor side of the lung tissue removed by surgery. To investigate the most common mutations in the EGFR gene, exon 19 was sequenced and mutation specific PCR was performed for detecting the L858R mutation in exon 21. EGFR mRNA expression was measured by relative quantitative reverse transcription PCR. The EGFR protein levels were detected with immunohistochemistry methods from the sections of the patients' paraffin blocks.

Results

No EGFR mutation in exon 19 or L858R mutation in exon 21 were detected in the patients. Overexpression of EGFR gene mRNA was identified in 16 of 34 (%47) patients and overexpression of EGFR protein was detected in 15 of 34 (%44) patients. Statistical analysis was not significant for the correlation between sex, age, smoking, histopathology, pathological stage and overexpression of EGFR mRNA and protein.

Conclusion

It was found that in Turkish population, EGFR mutation in exon 19 and L858R mutation were very rare, EGFR protein expression was similar and EGFR mRNA expression significantly increased compared to the literature. Markedly increased EGFR mRNA expression ratios in the absence of activating mutations showed that identifying the EGFR mRNA expression level for prediction of response to EGFR tyrosine kinase inhibitors might be significant in the Turkish population.

Predicting EGFR mutation status in lung cancer:Proposal for a scoring model using imaging and demographic characteristics

OBJECTIVE

To determine if a combination of CT and demographic features can predict EGFR mutation status in bronchogenic carcinoma.

METHODS

We reviewed demographic and CT features for patients with molecular profiling for resected non-small cell lung carcinoma. Using multivariate logistic regression, we identified features predictive of EGFR mutation. Prognostic factors identified from the logistic regression model were then used to build a more practical scoring system.

RESULTS

A scoring system awarding 5 points for no or minimal smoking history, 3 points for tumours with ground glass component, 3 points for airbronchograms, 2 points for absence of preoperative evidence of nodal enlargement or metastases and 1 point for doubling time of more than a year, resulted in an AUROC of 0.861. A total score of at least 8 yielded a specificity of 95 %. On multivariate analysis sex was not found to be predictor of EGFR status.

CONCLUSIONS

A weighted scoring system combining imaging and demographic data holds promise as a predictor of EGFR status. Further studies are necessary to determine reproducibility in other patient groups. A predictive score may help determine which patients would benefit from molecular profiling and may help inform treatment decisions when molecular profiling is not possible.

KEY POINTS

• EGFR mutation-targeted chemotherapy for bronchogenic carcinoma has a high success rate. • Mutation testing is not possible in all patients. • EGFR associations include subsolid density, slow tumour growth and minimal/no smoking history. • Demographic or imaging features alone are weak predictors of EGFR status. • A scoring system, using imaging and demographic features, is more predictive.

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

This study was aimed to detect the correlation among EGFR/KRAS status and PD-1/PD-L1 expression in non-small-cell lung cancer (NSCLC) patients. PD-1 and PD-L1 expressions were detected by immunohistochemistry in 100 surgically resected lung adenocarcinoma tissues and were statistically correlated with clinicopathological characteristics including EGFR and KRAS statuses. Besides, the overall survival (OS) times were analyzed. There was a statistical significances between PD-1 expression in tumor and KRAS status (P = 0.043), with a higher mutation rate in with lower PD-1 expression patients. There was a statistical significance between PD-L1 expression in tumor and EGFR status (P = 0.012), with a higher mutation rate in patients with lower PD-L1 expression. The OS of patients with EGFR mutation was significantly longer than those without EGFR mutation. The OS of patients with lower PD-L1 in tumor was significantly longer than those with higher PD-L1 expression. We found negative associations between PD-L1 expression in tumor and mutated EGFR status, as well as between PD-1 expression in tumor and mutated KRAS status.

Expression of EGFR Is Closely Related to Reduced 3-Year Survival Rate in Chinese Female NSCLC

BACKGROUND

Non-small cell lung cancer (NSCLC) accounts for approximately 80% of lung carcinoma cases, which becomes more and more important in the field of lung carcinoma as well as primary lung carcinoma in females.

MATERIAL AND METHODS

We analyzed the medical history of 62 female NSCLC patients. Immunohistochemistry was used to observe and compare the expression of EGFR. The chi-square test was conducted to analyze associations between EGFR expression and the different variables. The cumulative survival rate was determined by the Kaplan-Meier product-limit method. The prognosis of female patients with NSCLC was examined by using a multivariate Cox proportional hazard regression model.

RESULTS

The expression proportion of EGFR in Chinese female NSCLC patients was 70.97%, and it was remarkably higher in adenocarcinoma than in squamous cell carcinoma and bronchioloalveolar carcinoma. A positive correlation was observed between EGFR expression and tumor-node metastasis staging or lymph node metastasis. The Cox proportional risk model analysis showed a correlation between postoperative survival time of the patients and pathology of the tumor type and lymph node metastasis.

CONCLUSIONS

Expression of EGFR was closely related to pathology of the tumor type, tumor-node metastasis staging, and lymph node metastasis, which could be used as a promising indicator of NSCLC in Chinese female patients.

PD-1/PD-L1 pathway in non-small-cell lung cancer and its relation with EGFR mutation

Immunotherapy has become a crucial modality for non-small-cell lung cancer treatment. Recently, two immune checkpoints, PD-1 and PD-L1, have emerged as important targets for immunotherapy. Their antitumor efficacy has been confirmed by in vitro and in vivo studies. But the correlation between PD-1/PD-L1 expression and EGFR expression was controversial and needs more evidences to support the combination of PD-1/PD-L1 inhibitors and tyrosine kinase inhibitors.

Circulating Her-2/neu extracellular domain in breast cancer patients-correlation with prognosis and clinicopathological parameters including steroid receptor, Her-2/neu receptor coexpression

HER-2/neu extracellular domain (ECD) can be detected in blood as a soluble circulating protein. The aim of this study was to analyze the relationship between HER-2/neu extracellular domain in the serum and the prognosis in breast cancer patients. We also correlated HER-2/neu ECD with various clinicopathological factors including steroid receptor, HER-2/neu receptor coexpression. The serum from seventy nine patients with invasive breast cancer and twenty individuals without malignancy was analyzed using the enzyme-linked immune adsorbent assay method. The cut-off value was estimated by the ROC curve analysis (15.86 μg/L). HER-2/neu ECD values in the serum of patients with breast cancer were significantly higher than in control subjects. Circulating HER-2/neu ECD was significantly associated with the histological grade of tumors and the status of axillary lymph nodes. Negative correlation was observed between HER-2/neu ECD in the serum and estrogen receptor positivity. When we analyzed HER-2/neu ECD in relation with coexpression of steroid receptor and HER-2/neu receptor in tissue, statistically higher values were found in the subgroup of patients with steroid receptor negative, HER-2/neu negative tumors than in the other subgroups. HER-2/neu ECD was not an independent factor in the univariate and multivariate analysis. However, elevated HER-2/neu ECD levels were found in patients with breast cancer possessing more aggressive phenotype.

Pre-clinical characterization of Dacomitinib (PF-00299804), an irreversible pan-ErbB inhibitor, combined with ionizing radiation for head and neck squamous cell carcinoma

Epidermal growth factor receptor (EGFR) is over-expressed in nearly all cases of squamous cell carcinoma of the head and neck (SCCHN), and is an important driver of disease progression. EGFR targeted therapies have demonstrated clinical benefit for SCCHN treatment. In this report, we investigated the pre-clinical efficacy of Dacomitinib (PF-00299804), an irreversible pan-ErbB inhibitor, both alone and in combination with ionizing radiation (IR), a primary curative modality for SCCHN. One normal oral epithelial (NOE) and three SCCHN (FaDu, UT-SCC-8, UT-SCC-42a) cell lines were used to conduct cell viability, clonogenic survival, cell cycle, and immunoblotting assays in vitro, using increasing doses of Dacomitinib (10–500 nM), both with and without IR (2–4 Gy). The FaDu xenograft model was utilized for tumor growth delay assays in vivo, and immunohistochemical analyses were conducted on extracted tumors. A dose-dependent reduction in cell viability and clonogenic survival after Dacomitinib treatment was observed in all three SCCHN models. Treatment led to a significant reduction in EGFR signalling, with a subsequent decrease in phosphorylation of downstream targets such as ERK, AKT, and mTOR. In vivo, Dacomitinib treatment delayed tumor growth, while decreasing phospho-EGFR and Ki-67 immunoexpression. These effects were further enhanced when combined with IR, both in vitro and in vivo. The preclinical data support the further evaluations of Dacomitinib combined with IR for the future management of patients with SCCHN.

Incidence and risk of treatment-related mortality with anti-epidermal growth factor receptor monoclonal antibody in cancer patients: a meta-analysis of 21 randomized controlled trials

BACKGROUND

Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (MoAbs) cetuximab and panitumumab have emerged as an effective targeted therapy in the treatment of cancer patients, but the overall incidence and risk of fatal adverse events (FAEs) associated with these agents is still unclear.

METHODS

Databases from PubMed, Web of Science and abstracts presented at ASCO meeting up to May 31, 2013 were searched to identify relevant studies. Eligible studies included prospective randomized controlled trials evaluating MoAbs in cancer patients with adequate data on FAEs. Statistical analyses were conducted to calculate the summary incidence, odds ratio and 95% confidence intervals (CIs) by using either random effects or fixed effect models according to the heterogeneity of included studies.

RESULTS

A total of 14,776 patients with a variety of solid tumors from 21 clinical trials were included in our analysis. The overall incidence of MoAbs associated FAEs was 1.7% (95%CI: 1.1-2.5%), and the incidence of cetuximab-related FAEs was higher than that of panitumumab (2.0% versus 0.9%). Compared with the controls, the use of MoAbs was associated with a significantly increased risk of FAEs, with an OR of 1.37 (95%CI: 1.04-1.81, p=0.024). Subgroup analysis based on EGFR-MoAbs drugs, phase of trials and tumor types demonstrated a tendency to increase the risk of FAEs, but the risk did not increase in breast cancer, esophagus cancer and phase II trials.

CONCLUSIONS

With present evidence, the use of EGFR-MoAbs is associated with an increased risk of FAEs in patients with advanced solid tumors.

Molecular Pathology of Non-Small Cell Lung Cancer

This review offers an overview of the molecular pathology of lung cancer, with a focus on analyses that are most commonly part of the current clinical testing paradigm. Molecular testing of lung cancer has proved integral to the success of new targeted therapies, and their use is now commonplace in treatment selection. Traditional pathologic evaluation, however, plays a major role in these advances and serves an equally critical role to aid in determining optimal therapy.

EML4-ALK translocation predicts better outcome in lung adenocarcinoma patients with wild-type EGFR

INTRODUCTION

The echinoderm microtubule-associated protein like 4-anaplastic lymphoma kinase (EML4-ALK) fusion represents a novel target in a subset of non-small cell lung cancer, especially adenocarcinoma. EML4-ALK fusion is mutually exclusive with epidermal growth factor receptor (EGFR) mutations. To understand the impact of EML4-ALK on the prognosis of non-small cell lung cancer, we examined EML4-ALK fusion in lung adenocarcinoma from patients with wild-type EGFR and analyzed their clinical treatment outcomes.

METHODS

Lung adenocarcinoma patients with malignant pleural effusions having wild-type EGFR and measurable target lesions were enrolled for EML4-ALK analysis by reverse transcription-polymerase chain reaction and direct sequencing. Demographic data, EML4-ALK status, and survival data were analyzed. We also performed fluorescence in situ hybridization on some available tumor samples to validate the PCR result. In addition, K-ras mutation was analyzed for patients without EML4-ALK fusion genes.

RESULTS

A total of 116 patients with wild-type EGFR sequencing results had complete clinical data for analysis. No patients received ALK inhibitor therapy. There were 39 patients (34%) with the EML4-ALK fusion gene. The concordance rate between reverse transcription-polymerase chain reaction and fluorescence in situ hybridization was 85%. The K-ras mutation rate for patients without EML4-ALK fusion gene was 6.5%. By multivariate analysis, patients who had better performance status (p < 0.001) and EML4-ALK translocation (p = 0.017) had longer overall survival. Comparing patients with tumors harboring variant 1 with those harboring nonvariant 1 EML4-ALK fusion genes, there were no significant differences in clinical factors and survival outcome.

CONCLUSION

For lung adenocarcinoma patients with wild-type EGFR, EML4-ALK translocation is associated with longer overall survival.

Poor Prognostic Factors in Surgically Resected Stage I Non-small Cell Lung Cancer: Histopathologic and Immunohistochemical Analysis

Background

A better understanding of the histopathology and molecular biology of lung cancer might improve our capability to predict the outcome for any individual patient. The purpose of this study was to evaluate several histopathologic and molecular markers in order to assess their prognostic value in stage I non-small cell lung cancer.

Materials and Methods

One hundred ten patients at the Kyungpook National University Hospital were enrolled in the study. Histopathologic factors and molecular markers were selected.

Results

Univariate analysis showed that the T stage, differentiation, visceral pleural invasion, and survivin expression were significantly associated with recurrence. Multivariate analysis demonstrated that differentiation and survivin overexpression emerged as independent prognostic factors of recurrence.

Conclusion

In resected stage I non-small cell lung cancer, poor differentiation and survivin overexpression have been identified as independent predictors of poor disease-free survival.

EGFR gene amplification is related to adverse clinical outcomes in cervical squamous cell carcinoma, making the EGFR pathway a novel therapeutic target

Background:

The aim of this study was to investigate the patterns of epidermal growth factor receptor (EGFR) overexpression, EGFR gene amplification, and the presence of activating mutations in the tyrosine kinase domain of this gene in squamous cell carcinomas and adenocarcinomas/adenosquamous carcinomas of the uterine cervix.

Methods:

The EGFR expression, amplification, and mutation in cervical carcinomas were assessed by immunohistochemistry, fluorescence in situ hybridisation, and PCR–SSCP, respectively, and correlated with clinical data collected by a retrospective chart review. A functional assessment was performed by inactivating EGFR in cervical cancer cells with the potent inhibitor AG1478.

Results:

Immunohistochemical analysis revealed that 6 out of 59 (10.2%) cervical squamous cell carcinomas showed significant amplification of the EGFR locus, whereas none of the 52 adeno/adenosquamous cell carcinomas had detectable EGFR amplification (P<0.05). The EGFR amplification significantly correlated with shorter overall survival (P=0.001) in cervical squamous cell carcinomas. Multivariate analysis showed that EGFR gene amplification was an independent prognostic factor for overall survival (P=0.011). None of the squamous cell carcinomas (0%: 0 out of 32) had detectable oncogenic mutations in EGFR exons 18 through 21. The frequencies of KRAS and BRAF mutations were very low in both squamous and adeno/adenosquamous cell carcinomas. Sensitivity of cervical cancer cells to AG1478 depended on the presence of EGFR overexpression. AG1478-induced EGFR inactivation in cell lines with EGFR overexpression significantly suppressed tumour development and progression in a mouse xenograft model.

Conclusion:

Our data suggest that EGFR signalling is important in a subset of cervical squamous cell carcinomas and that anti-EGFR therapy may benefit patients who carry the 7p11.2 amplicon in their tumours.

Comparison of KRAS and EGFR gene status between primary non-small cell lung cancer and local lymph node metastases: implications for clinical practice

Background

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) have been widely used for the treatment of non-small cell lung cancer (NSCLC). KRAS and EGFR somatic mutations in NSCLC may predict resistance and responsiveness to TKI, respectively. Nevertheless, most research to date has been conducted on samples from primary tumors. For many patients with advanced disease, their samples can only be obtained from metastases for test. The molecular characteristics of metastasized tumors may be different from those of primary tumors.

Materials and methods

Mutation status of KRAS and EGFR between primary tumors and local lymph node metastases of 80 Chinese patients with NSCLC were analyzed by direct sequencing. Five of them were given gefitinib as neoadjunvant treatment after the EGFR-TKI sensitive mutations were detected in their biopsies of mediastinal lymph nodes metastases. McNemar's test was used to compare the EGFR and KRAS mutation status between primary tumors and corresponding local lymph node metastases. Data evaluation was carried out with SPSS_13.0 statistical software.

Results

Among the 160 samples, one primary tumor and seven metastases were identified with KRAS mutations and 21 primary tumors and 26 metastases were found to have EGFR mutations. KRAS and EGFR mutation status was different between primary tumors and corresponding metastases in 6 (7.5%) and 7 (8.75%) patients, respectively. One patient with no TKI sensitive mutations detected in the primary tumor showed disease progression.

Conclusion

Our results suggest that a considerable proportion of NSCLC in Chinese population showed discrepancy in KRAS and EGFR mutation status between primary tumors and corresponding metastases. This observation may have important implication for the use of targeted TKI therapy in the treatment of NSCLC patients.

Molecular MRI for sensitive and specific detection of lung metastases

Early and specific detection of metastatic cancer cells in the lung (the most common organ targeted by metastases) could significantly improve cancer treatment outcomes. However, the most widespread lung imaging methods use ionizing radiation and have low sensitivity and/or low specificity for cancer cells. Here we address this problem with an imaging method to detect submillimeter-sized metastases with molecular specificity. Cancer cells are targeted by iron oxide nanoparticles functionalized with cancer-binding ligands, then imaged by high-resolution hyperpolarized (3)He MRI. We demonstrate in vivo detection of pulmonary micrometastates in mice injected with breast adenocarcinoma cells. The method not only holds promise for cancer imaging but more generally suggests a fundamentally unique approach to molecular imaging in the lungs.

Expanding the utility of beta-galactosidase complementation: piece by piece

The ability to image and quantify multiple biomarkers in disease necessitates the development of split reporter fragment platforms. We have divided the beta-galactosidase enzyme into unique, independent polypeptides that are able to reassemble and complement enzymatic activity in bacteria and in mammalian cells. We created two sets of complementing pairs that individually have no enzymatic activity. However, when brought into close geometric proximity, the complementing pairs associated resulting in detectable enzymatic activity. We then constructed a stable ligand complex composed of reporter fragment, linker, and targeting moiety. The targeting moiety, in this case a ligand, allowed cell surface receptor targeting in vitro. Further, we were able to simultaneously visualize two cell surface receptors implicated in cancer development, epidermal growth factor receptor and transferrin receptor, using complementing pairs of the ligand-reporter fragment complex.

Molecular characterization of chronic obstructive pulmonary disease-related non-small cell lung cancer through aberrant methylation and alterations of EGFR signaling

BACKGROUND

The aim of this study was to evaluate the molecular influence of chronic obstructive pulmonary diseases (COPD) on the pathogenesis of non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

The methylation profiles of 12 genes, and the epidermal growth factor receptor (EGFR) and KRAS mutations were determined for samples from 229 NSCLC patients. In addition, protein expression of EGFR and HER2 in 116 NSCLCs was analyzed based on the presence or absence of COPD.

RESULTS

IL-12Rbeta2 and Wif-1 methylation and HER2 overexpression were more frequent events in the COPD group. Eighty nonmalignant lung tissues had no correlation with any molecular changes between the COPD and the non-COPD group. EGFR mutation was significantly higher in the non-COPD group, while EGFR expression was inversely correlated with %FEV1.0. In the COPD group, unmethylated SPARC and sFRP-2 genes or a negative CpG island methylator phenotype (CIMP) was a negative prognostic factor, while methylation of p16(INK4A) and WNT antagonist genes was a negative prognostic factor in the non-COPD group.

CONCLUSIONS

Novel characteristics of COPD-related NSCLC were identified by examination of methylation profiles and alterations of EGFR signaling. In consideration of the high sensitivity to smoking in patients with COPD, NSCLC with COPD might be a distinct population of smoke-related NSCLC, the genetic profile of which is quite different from non-COPD NSCLC.

Comparison of FISH, PCR, and immunohistochemistry in assessing EGFR status in lung adenocarcinoma and correlation with clinicopathologic features

The purpose of this study is to investigate the relationship between mutation status, copy number, and protein expression of epidermal growth factor receptor (EGFR) in lung adenocarcinoma, and to correlate the genetic status and clinicopathologic features. Forty-nine adenocarcinomas were tested by polymerase chain reaction (PCR) for EGFR gene mutations, by fluorescence in situ hybridization (FISH) for increased EGFR gene copy number, and by immunohistochemistry (IHC) for EGFR protein expression. Terminal respiratory unit (TRU) morphology, tumor grade, mitotic count, and pleural and lymphovascular invasion were also examined. Five of 49 tumors (10%) had EGFR mutation by PCR. Eighteen (36%) had high EGFR gene copy number by FISH, all of which were polysomies without gene amplification. Fifteen (31%) had EGFR protein overexpression by IHC, 13 (87%) of which were also positive by FISH. Of the PCR-positive cases, 4/5 (80%) were positive by FISH and 3/5 (60%) were positive by IHC. TRU morphology was observed in all PCR-positive cases and in about 50% of FISH-positive and IHC-positive cases. Pleural invasion was significantly more common in IHC and FISH-positive cases, and lymphovascular invasion was more often present in FISH-positive cases. No statistically significant differences in mitotic count, age, sex, smoking status, degree of differentiation, or stage were seen. Our findings suggest that a staged approach, with FISH testing as the first step, followed by PCR for the FISH-negative cases would be most effective in the identification of patients with EGFR gene alterations.

Reversed mutation rates of KRAS and EGFR genes in adenocarcinoma of the lung in Taiwan and their implications

BACKGROUND

In western countries, the Kirsten ras oncogene homolog gene (KRAS) mutation rate is high in patients with nonsmall cell lung cancer (NSCLC), especially in those with adenocarcinoma (30%-50%), but the epidermal growth factor receptor gene (EGFR) mutation rate is very low (3%-8%). In addition, KRAS mutations reportedly were associated with EGFR tyrosine kinase inhibitor (EGFR-TKI) resistance. In Taiwan, high EGFR mutation rates associated with high EGFR-TKI response rates in patients with NSCLC have been reported; however, KRAS mutation data are limited and have not been correlated with TKI response.

METHODS

KRAS mutation analysis was performed on 237 NSCLC specimens, and the results were correlated with clinicopathologic features. All but 2 tumors also underwent EGFR mutation analysis.

RESULTS

KRAS mutations were identified in only 9 of 237 patients (3.80%). Five patients were women who were nonsmokers, and 4 patients were men who were ever-smokers. The mutation rate was 5.03% in patients with adenocarcinoma (8 of 159 patients) and 1.56% in patients with squamous cell carcinoma (1 of 64 patients). Four mutations were G12V, 3 mutations were G12D, 1 mutation was L19F, and 1 was the duplication insertion mutation dupT50_M72. In contrast, EGFR mutations were detected in 96 of 235 patients (40.8%) and in 90 of 157 adenocarcinomas (57.3%). None of the KRAS mutations coexisted with EGFR mutations. KRAS mutations were not associated significantly with any clinicopathologic characteristics, including smoking status. Among the 53 patients who had received TKI monotreatment, only 1 patient had a KRAS mutation and had progressive disease.

CONCLUSIONS

The KRAS mutation rate was too low to play a significant role in TKI resistance or tumorigenesis among Taiwanese patients with NSCLC, which was the complete reverse of the results reported in western countries.

Clinical significance of aberrant methylation of prostaglandin E receptor 2 (PTGER2) in nonsmall cell lung cancer: association with prognosis, PTGER2 expression, and epidermal growth factor receptor mutation

BACKGROUND

The expression of prostaglandin E receptor 2 (PTGER2) affects the biologic behavior of various types of malignant tumors. Recently, transactivation of both PTGER2 and epidermal growth factor receptor (EGFR) has been reported in some tumors.

METHODS

PTGER2 gene expression and possible aberrant methylation of the PTGER2 gene were investigated in 10 nonsmall cell lung cancer (NSCLC) cell lines, 233 primary tumors, and 168 adjacent nonmalignant lung tissues. They were analyzed with reference to an association with EGFR mutation in 133 clinical lung adenocarcinomas and were correlated with patient survival.

RESULTS

Down-regulation of PTGER2 expression was observed in 8 of 10 NSCLC cell lines. Demethylation of 5 expression-negative cell lines restored the expression of PTGER2. Aberrant methylation of the PTGER2 gene was reversely concordant with its messenger RNA expression. PTGER2 methylation was detected in 137 of 233 NSCLC specimens (58%) but was detected in only 2 of 168 nonmalignant lung tissues (1%). Both NSCLCs and adenocarcinomas that had PTGER2 methylation predicted a significantly better prognosis than those without PTGER2 methylation (P = .0051 and P = .0171, respectively). PTGER2 methylation was present with greater frequency in tumors with EGFR mutation than in non-EGFR mutated tumors (P = .0095), and the significance of the correlation was independent after adjusting for sex and smoking status (P = .0144).

CONCLUSIONS

Aberrant methylation of the PTGER2 gene was observed frequently in NSCLC tissues and was associated with the presence of EGFR mutation and a better prognosis.

Salivary gland-type lung carcinomas: an EGFR immunohistochemical, molecular genetic, and mutational analysis study

Salivary gland-type lung carcinomas are uncommon neoplasms of the lung, the two most common being adenoid cystic carcinoma and mucoepidermoid carcinoma. Although they usually have an indolent behavior, adenoid cystic carcinomas can be more aggressive, with 5-year survival as low as 55%. Unfortunately, these tumors do not respond well to chemotherapy. In contrast to the most common subtypes of lung carcinomas, epidermal growth factor receptor studies have not been carried out in this group of tumors. Herein we report a series of 24 cases (12 adenoid cystic and 12 mucoepidermoid carcinomas) tested for epidermal growth factor receptor protein expression, epidermal growth factor receptor gene copy gains, and epidermal growth factor receptor gene mutational status, through immunohistochemistry, fluorescence in situ hybridization, and sequencing of the exons 18-21, respectively. Overall, 91 and 92% of the adenoid cystic carcinomas and mucoepidermoid carcinomas expressed epidermal growth factor receptor protein. Chromosome 7 polysomy occurred in 25% of the cases (four adenoid cystic carcinomas and two mucoepidermoid carcinomas). No epidermal growth factor receptor gene amplification was detected and no mutation was found in exons 18-21 of the epidermal growth factor receptor gene. Immunoexpression of epidermal growth factor receptor in salivary gland-type lung carcinomas is not related to epidermal growth factor receptor gene copy number or mutational status.

Correlation of EGFR mutations with chromosomal alterations and expression of EGFR, ErbB3 and VEGF in tumor samples of lung adenocarcinoma patients

INTRODUCTION

Mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) are frequently detected in lung adenocarcinomas with bronchioloalveolar (BAC) differentiation and have been associated with increased response to small molecule EGFR inhibitors in some clinical studies. However, further molecular characterization of tumor cells carrying EGFR mutations (EGFR-mut) is warranted.

METHODS

By DNA sequencing, 120 patients with lung adenocarcinomas (70 tumors with BAC components) were screened for EGFR mutations within exons 18-21. Performing comparative genomic hybridization (CGH) and immunohistochemistry, chromosomal imbalances and protein expression levels of EGFR, ErbB3 and VEGF (vascular endothelial growth factor) were analyzed, respectively.

RESULTS

EGFR mutations were detected in 20/120 tumors. Tumors with BAC components carried more frequently EGFR mutations compared to adenocarcinomas without BAC histology (17/70=24% vs 3/50=6.0%; p=0.012). In a subsequent matched-pair analysis, CGH-analysis demonstrated similar mean numbers of chromosomal imbalances for EGFR mutated and wild-type tumors (8.6 vs 7.8 gains; 2.4 vs 2.7 losses), respectively. Furthermore, tumors with mutated EGFR demonstrated gains in chromosomes 7p, 16p and 20q and losses in chromosome 8p. Interestingly, EGFR mutated tumors showed higher VEGF expression (p=0.03) while differences in EGFR expression were not statistically significant.

CONCLUSION

EGFR gene mutations are frequently seen in lung adenocarcinomas with BAC differentiation and can be linked to chromosomal imbalances and increased VEGF expression.

Synchronous alterations of Wnt and epidermal growth factor receptor signaling pathways through aberrant methylation and mutation in non small cell lung cancer

PURPOSE

The Wnt and epidermal growth factor receptor (EGFR) signaling pathways play crucial roles in the pathogenesis of a variety of malignant tumors. Although the details of each cascade are understood, very little is known about their collective effects in non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

A total of 238 NSCLC samples were examined for methylation of Wnt antagonists [secreted frizzled-related protein (sFRP)-1, sFRP-2, sFRP-5, Wnt inhibitory factor-1, and Dickkopf-3] and for EGFR and KRAS mutations. Protein expression levels of beta-catenin were assayed in 91 of the 238 NSCLCs.

RESULTS

We found that (a) aberrant methylation of Wnt antagonists is common in NSCLCs; (b) methylation of sFRP-2 is more prevalent in females, nonsmokers, and adenocarcinoma cases; (c) Dickkopf-3 methylation is significantly associated with a poor prognosis in adenocarcinomas; (d) there is a positive correlation between activated EGFR mutation and nuclear accumulation of beta-catenin; (e) KRAS mutation and aberrant methylation of Wnt antagonists are positively correlated; and (f) EGFR mutation is significantly associated with a good prognosis in tumors lacking methylated Wnt antagonist genes.

CONCLUSIONS

These results contribute to a better understanding of the cross-talk between the Wnt and EGFR signaling pathways and help foster development of chemotherapeutic treatments in NSCLCs.

EGFR expression as an ancillary tool for diagnosing lung cancer in cytology specimens

Lung cancer evolves in a multistep process, and its early detection portends a better prognosis. Bronchial washings/brushings and fine-needle aspirations are often used as early screening and cytological diagnosis of lung cancer. In some cases, it is difficult to differentiate morphologically malignant from reactive cells. Epidermal growth factor receptor (EGFR) is a transmembrane receptor overexpressed in high percentage lung cancers, and contributes to tumor growth. Assessing EGFR expression levels by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) may provide critical information of tumor marker abnormalities, assist in the cytological diagnosis, and stratify patients for EGFR inhibitor therapy. Fifty patients with bronchial washings/brushings or fine-needle aspiration specimens, and corresponding histologically confirmed lung biopsies, were studied for EGFR expression with FISH and IHC. Copy numbers of the EGFR gene locus were analyzed with those of chromosome 7 by FISH. EGFR and FISH results were compared to our FISH data with combined EGFR, c-myc, 5p15.2, and chromosome 6 probes in selected cases. Cell blocks, if available, and tissue biopsy sections were used for EGFR IHC. The intensity of IHC was scored, and quantified. Only balanced aneuploidy of EGFR was identified by FISH. Gene amplification was not detected. The chromosomal abnormalities of EGFR were often accompanied by other chromosomal aneuploidies demonstrated in c-myc (8q24), 5p15.2 or 6p, indicating a general genomic instability. About half of the specimens with confirmed malignancy showed EGFR balanced aneuploidy by FISH, and gene copy number was not coupled with protein expression in many cases. The benign or reactive cytology specimens confirmed by biopsies had high specificity by FISH (96%) and IHC (88%). FISH and IHC analysis of EGFR, possibly along with other tumor markers, may be a useful ancillary tool to classify difficult cytology cases and inform clinicians arranging targeted chemotherapy.

Database of somatic mutations in EGFR with analyses revealing indel hotspots but no smoking-associated signature

We created an Epidermal Growth Factor Receptor (EGFR) Mutation Database (http://www.cityofhope.org/cmdl/egfr_db) that curates a convenient compilation of somatic EGFR mutations in non-small-cell lung cancer (NSCLC) and associated epidemiological and methodological data, including response to the tyrosine kinase inhibitors Gefitinib and Erlotinib. Herein, we analyze 809 mutations collected from 26 publications. Four super hotspots account for 70% of reported mutations while two-thirds of 131 unique mutations have been reported only once and account for only 11% of reported mutations. Consistent with strong biological selection for gain of function, the reported mutations are virtually all missense substitutions or in-frame microdeletions, microinsertions, or microindels (colocalized insertion and deletion with a net gain or loss of 1-50 nucleotides). Microdeletions and microindels are common in a region of exon 19. Microindels, which account for 8% of mutations, have smaller inserted sequences (95% are 1 to 5 bp) and are elevated 16-fold relative to mouse somatic microindels and to human germline microindels. Microdeletions/microindels are significantly more frequent in responders to Gefitinib or Erlotinib (P = 0.003). In addition, EGFR mutations in smokers do not carry signatures of mutagens in cigarette smoke. Otherwise, the mutation pattern does not differ significantly with respect to gender, age, or tumor histology. The EGFR Mutation Database is a central resource of EGFR sequence variant data for clinicians, geneticists, and other researchers. Authors are encouraged to submit new publications with EGFR sequence variants to be included in the database or to provide direct submissions via The WayStation submission and publication process (http://www.centralmutations.org).

Assessment of epidermal growth factor receptor mutation by endobronchial ultrasound-guided transbronchial needle aspiration

BACKGROUND

The presence of somatic mutations in epidermal growth factor receptor (EGFR) predicts the effectiveness of EGFR tyrosine kinase inhibitors (TKIs). It would be ideal if an EGFR mutation could be detected in biopsy samples, since the majority of non-small cell lung cancer patients are inoperable at the time of presentation. We have reported the usefulness of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for the lymph node staging of lung cancer. EBUS-TBNA enables the sampling of histologic cores, which can be used for genetic analysis.

METHODS

The purpose of this study was to develop and analyze the feasibility of detecting EGFR mutations in samples obtained by EBUS-TBNA. Forty-six patients with primary lung cancer in whom metastatic adenocarcinoma in the hilar and/or mediastinal lymph node was diagnosed by EBUS-TBNA were enrolled into the study. DNA was extracted from paraffin-embedded samples, and the EGFR mutation was analyzed in exons 19 and 21 using a newly developed loop-hybrid mobility shift assay. The results were confirmed by direct sequencing.

RESULTS

Forty-three cases were eligible for analysis and in 11 cases, EGFR mutation (25.6%) was detected; one case was an in-frame deletion (E746-A750del) of exon 19, nine cases were point mutations (L858R) of exon 21, and one case was a double point mutation (L858R+L861V). All cases with EGFR mutations were confirmed by direct sequencing.

CONCLUSIONS

EGFR mutation can easily be detected in metastatic lymph nodes sampled by EBUS-TBNA. EBUS-TBNA allows genetic evaluations of tumor cells within the lymph node and may provide us with indications for EGFR-TKI therapy in the near future.

Epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of non-small-cell lung cancer: results and open issues

The medical treatment of non-small-cell lung cancer (NSCLC) has progressively changed since the introduction of "targeted therapy". The development of one of these molecular drug categories, e. g., the epidermal growth factor receptor (EGFR) tyrosine-kinase (TK) selective inhibitors, such as the orally active gefitinib and erlotinib, offers an interesting new opportunity. The clinical response rates obtained with their employment in unselected patient populations only account for approximately 10%. Because of this, over the last two years numerous studies have been performed in order to identify the patient subsets that could better benefit from these agents. Not only patient characteristics and clinical-pathological features, such as never-smoking status, female gender, East Asian origin, adenocarcinoma histology, bronchioloalveolar subtype, but also molecular findings, such as somatic mutations in the EGFR gene, emerge as potentially useful prognostic and predictive factors in advanced NSCLC. Further, specifically designed clinical trials are still needed to completely clarify these and other open issues that are reviewed in this paper, in order to clarify all the interesting findings available in the clinical practice.

EGFR amplification and lack of activating mutations in metaplastic breast carcinomas

Metaplastic breast carcinomas are reported to harbour epidermal growth factor receptor (EGFR) overexpression in up to 80% of the cases, but EGFR gene amplification is the underlying genetic mechanism in around one-third of these. In this study, EGFR gene amplification as defined by chromogenic in situ hybridization and protein overexpression was examined in a cohort of 47 metaplastic breast carcinomas. Furthermore, the presence of activating EGFR mutations in exons 18, 19, 20, and 21 was investigated. Thirty-two cases showed EGFR overexpression and of these, 11 (34%) harboured EGFR gene amplification. In addition, EGFR amplification showed a statistically significant association with EGFR overexpression (p < 0.0094) and was restricted to carcinomas with homologous metaplasia. Ten cases, five with and five without EGFR amplification, were subjected to microarray-based CGH, which demonstrated that EGFR copy number gain may occur by amplification of a discrete genomic region or by gains of the short arm of chromosome 7 with a breakpoint near the EGFR gene locus, the minimal region of amplification mapping to EGFR, LANCL2, and SEC61G. No activating EGFR mutations were identified, suggesting that this is unlikely to be a common alternative underlying genetic mechanism for EGFR expression in metaplastic breast carcinomas. Given that metaplastic breast carcinomas are resistant to conventional chemotherapy or hormone therapy regimens and that tumours with EGFR amplification are reported to be sensitive to EGFR tyrosine kinase inhibitors, these findings indicate that further studies are warranted to explore EGFR tyrosine kinase inhibitors as potential therapeutic agents for metaplastic breast carcinomas harbouring amplification of 7p11.2.

The impact of human EGFR kinase domain mutations on lung tumorigenesis and in vivo sensitivity to EGFR-targeted therapies

To understand the role of human epidermal growth factor receptor (hEGFR) kinase domain mutations in lung tumorigenesis and response to EGFR-targeted therapies, we generated bitransgenic mice with inducible expression in type II pneumocytes of two common hEGFR mutants seen in human lung cancer. Both bitransgenic lines developed lung adenocarcinoma after sustained hEGFR mutant expression, confirming their oncogenic potential. Maintenance of these lung tumors was dependent on continued expression of the EGFR mutants. Treatment with small molecule inhibitors (erlotinib or HKI-272) as well as prolonged treatment with a humanized anti-hEGFR antibody (cetuximab) led to dramatic tumor regression. These data suggest that persistent EGFR signaling is required for tumor maintenance in human lung adenocarcinomas expressing EGFR mutants.