EGFR and KRAS mutations and altered c-Met gene copy numbers in primary non-small cell lung cancer and associated stage N2 lymph node-metastasis

Preoperative prediction of mediastinal lymph node metastasis in non-small cell lung cancer based on 18F-FDG PET/CT radiomics

AIM

To establish and verify a 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT)-based radiomics nomogram to predict mediastinal lymph node metastasis (LNM) in non-small cell lung cancer (NSCLC) patients preoperatively.

MATERIALS AND METHODS

This retrospective study enrolled 155 NSCLC patients (primary cohort, n=93; validation cohort, n=62). For each patient, 2,704 radiomic features were extracted from the primary lung cancer regions. Four procedures including the Mann-Whitney U-test, Spearman's correlation analysis, minimum redundancy-maximum relevance (mRMR), and least absolute shrinkage and selection operator (LASSO) binary logistic regression were utilised for determining essential features and establishing a radiomics signature. After that, a nomogram was established. The nomogram's potential was assessed based on its discrimination, calibration, and clinical usefulness. The radiomics signature and nomogram predictive performances were evaluated with respect to the area under the receiver operating characteristic curve (AUC), specificity, accuracy, and sensitivity.

RESULTS

The radiomics signature composed of eight selected features had good discriminatory performance of LNM versus non-LNM groups an AUC of 0.851 and 0.826 in primary and validation cohorts, respectively. The nomogram also indicated good discrimination with an AUC of 0.869 and 0.847 in the primary and validation cohorts, respectively. Furthermore, good calibration was demonstrated utilising the nomogram.

CONCLUSIONS

An ¹⁸F-FDG PET/CT-based radiomics nomogram that integrates the radiomics signature and age was promoted to predict mediastinal LNM within NSCLC patients, which could potentially facilitate individualised therapy for mediastinal LNM before treatment. The nomogram was beneficial in clinical practice, as illustrated by decision curve analysis.

A nomogram for predicting the risk of lymph node metastasis in T1-2 non-small-cell lung cancer based on PET/CT and clinical characteristics

Background

Accurately predicting the risk level for a lymph node metastasis is critical in the treatment of non-small cell lung cancer (NSCLC). This study aimed to construct a novel nomogram to identify patients with a risk of lymph node metastasis in T1–2 NSCLC based on positron emission tomography/computed tomography (PET/CT) and clinical characteristics.

Methods

From January 2011 to November 2017, the records of 318 consecutive patients who had undergone PET/CT examination within 30 days before surgical resection for clinical T1–2 NSCLC were retrospectively reviewed. A nomogram to predict the risk of lymph node metastasis was constructed. The model was confirmed using bootstrap resampling, and an independent validation cohort contained 156 patients from June 2017 to February 2020 at another institution.

Results

Six factors [age, tumor location, histology, the lymph node maximum standardized uptake value (SUVmax), the tumor SUVmax and the carcinoembryonic antigen (CEA) value] were identified and entered into the nomogram. The nomogram developed based on the analysis showed robust discrimination, with an area under the receiver operating characteristic curve of 0.858 in the primary cohort and 0.749 in the validation cohort. The calibration curve for the probability of lymph node metastasis showed excellent concordance between the predicted and actual results. Decision curve analysis suggested that the nomogram was clinically useful.

Conclusions

We set up and validated a novel and effective nomogram that can predict the risk of lymph node metastasis for individual patients with T1–2 NSCLC. This model may help clinicians to make treatment recommendations for individuals.

[Research Progress in Consistency of Driver Gene Status between Primary and Corresponding Metastatic Lesions in Non-small Cell Lung Cancer]

非小细胞肺癌（non-small cell lung cancer, NSCLC）作为肺癌最常见的病理类型，具有恶性程度高和侵袭性强的特点，晚期极易发生淋巴结和不同脏器转移。近年来，随着精准医学应用的深入，不断出现NSCLC转移部位的耐药和治疗失效为分子靶向治疗带来困扰，研究证实这些可能与肿瘤转移后发生的分子学改变有关。本文旨在阐述NSCLC原发灶与转移部位驱动基因状态，系统性综述两者间驱动基因状态一致性的研究进展，为探讨转移性NSCLC的分子靶向治疗提供新的思路。

Relationship of radiometabolic biomarkers to KRAS mutation status and ALK rearrangements in cases of lung adenocarcinoma

PURPOSE

Rapid diagnosis of genetic mutations is important for targeted therapies such as EGFR tyrosine kinase inhibitors. KRAS mutation and ALK rearrangement are also important in determining treatment. The purpose of our study was to evaluate the diagnostic value of 18F-FDG PET to predict KRAS mutation and ALK rearrangement in order to determine the frequency of these genetic markers in our lung adenocarcinoma cases and contribute to forthcoming meta-analysis studies.

METHODS

A total of 218 patients with lung adenocarcinoma (EGFR analyzed) who were seen at our clinic between 2012 and 2014 were included in the study. The results of the 18 F-FDG-PET scans for each patient were retrospectively recorded with the associated medical documents. ALK rearrangements were analyzed in 166 of the 218 patients, while 50 of the 218 patients were analyzed for KRAS mutational status. SPSS 15.0 for Windows was used for statistical analysis.

RESULTS

FDG avidity was higher in cases with KRAS mutations and ALK rearrangements than those without, but the difference was not significant. ALK rearrangements were more common in younger, female, and nonsmoking patients with lung adenocarcinoma.

CONCLUSIONS

The small numbers of KRAS mutations and ALK rearrangements are the limitation of this study for evaluation of diagnostic imaging. The frequency of these genetic alterations was as reported in the literature. We believe that our work will contribute to future meta-analysis.

Clinical Validation of Discordant Trunk Driver Mutations in Paired Primary and Metastatic Lung Cancer Specimens

OBJECTIVES

To propose an operating procedure for validation of discordant trunk driver mutations.

METHODS

Concordance of trunk drivers was examined by next-generation sequencing in 15 patients with two to three metastatic lung cancers and 32 paired primary and metastatic lung cancers.

RESULTS

Tissue identity was confirmed by genotyping 17 single-nucleotide polymorphisms within the panel. All except three pairs showed concordant trunk drivers. Quality assessment conducted in three primary and metastatic pairs with discordant trunk drivers indicates metastasis from a synchronous or remote lung primary in two patients. Review of literature revealed high discordant rates of EGFR and KRAS mutations, especially when Sanger sequencing was applied to examine primary and lymph node metastatic tumors.

CONCLUSIONS

Trunk driver mutations are highly concordant in primary and metastatic tumors. Discordance of trunk drivers, once confirmed, may suggest a second primary cancer. Guidelines are recommended to establish standard operating procedures for validation of discordant trunk drivers.

Discordance of epidermal growth factor receptor mutation between primary lung tumor and paired distant metastases in non-small cell lung cancer: A systematic review and meta-analysis

Purpose

To evaluate the rate of discordance of epidermal growth factor receptor (EGFR) mutation between primary lung tumor and paired distant metastases in non-small-cell lung cancer (NSCLC).

Methods

We performed a meta-analysis of 17 studies (518 cases) assessing discordance rates of EGFR mutation in primary tumors and paired distant metastases. We performed subgroup analyses based on EGFR mutation status in primary tumor (mutant or wildtype), site of distant metastasis (bone, central nervous system (CNS) or lung/ pleural), methods of testing (direct sequencing or allele-specific testing) and timing of metastasis (synchronous or metachronous).

Results

The overall discordance rate in EGFR mutation was low at 10.36% (95% CI = 4.23% to 18.79%) and varied widely between studies (I² = 83.18%). The EGFR discordance rate was statistically significantly higher in bone metastases (45.49%, 95% CI = 14.13 to 79.02) than CNS (17.26%, 95% CI = 7.64 to 29.74; P = 0.002) and lung/ pleural metastases (8.17%, 95% CI = 3.35 to 14.85; P < 0.001). Subgroup analyses did not demonstrate any significant effect modification on the discordance rates by the EGFR mutation status in primary lung tumor, methods of testing and timing of metastasis.

Conclusion

The overall discordance rate in EGFR mutation between primary lung tumor and paired distant metastases in NSCLC is low, although higher discordance rates were observed in bone metastases compared with CNS and lung/pleural metastases. Future studies assessing the impact of EGFR mutation discordance on treatment outcomes are required.

YB-1 regulates tumor growth by promoting MACC1/c-Met pathway in human lung adenocarcinoma

Aberrant overexpression of the transcription/translation factor Y-box-binding protein (YB-1) is associated with poor prognosis of lung adenocarcinoma, however the underlying mechanism by which YB-1 acts has not been fully elucidated. Here, we reported that inhibition of YB-1 diminished proliferation, migration and invasion of lung adenocarcinoma cells. Interestingly, we identified metastasis associated in colon cancer-1 (MACC1) as a target of YB-1. Depletion of YB-1 markedly decreased MACC1 promoter activity and suppressed the MACC1/c-Met signaling pathway in lung adenocarcinoma cells. Additionally, chromatin immunoprecipitation (ChIP) assay demonstrated that YB-1 bound to the MACC1 promoter. Moreover, YB-1 was positively correlated with MACC1, and both proteins were over-expressed in lung adenocarcinoma tissues. The Cox-regression analysis indicated that high YB-1 expression was an independent risk factor for prognosis in enrolled patients. Furthermore, depletion of YB-1 attenuated tumorigenesis in a xenograft mouse model and reduced MACC1 expression in tumor tissues. Collectively, our data suggested that targeting YB-1 suppressed lung adenocarcinoma progression through the MACC1/c-Met pathway and that the high expression of YB-1/MACC1 is a potential prognostic marker in lung adenocarcinoma.

A new approach to predict lymph node metastasis in solid lung adenocarcinoma: a radiomics nomogram

Background

Lymph node metastasis (LNM) of lung cancer is an important factor related to survival and recurrence. The association between radiomics features of lung cancer and LNM remains unclear. We developed and validated a radiomics nomogram to predict LNM in solid lung adenocarcinoma.

Methods

A total of 159 eligible patients with solid lung adenocarcinoma were divided into training (n=106) and validation cohorts (n=53). Radiomics features were extracted from venous-phase CT images. We built a radiomics nomogram using a multivariate logistic regression model combined with CT-reported lymph node (LN) status. The performance of the radiomics nomogram was evaluated using the area under curve (AUC) of receiver operating characteristic curve. We performed decision curve analysis (DCA) within training and validation cohorts to assess the clinical usefulness of the nomogram.

Results

Fourteen radiomics features were chosen from 94 candidate features to build a radiomics signature that significantly correlated with LNM. The model showed good calibration and discrimination in the training cohort, with an AUC of 0.871 (95% CI: 0.804-0.937), sensitivity of 85.71% and specificity of 77.19%. In the validation cohort, AUC was 0.856 (95% CI: 0.745-0.966), sensitivity was 91.66%, and specificity was 82.14%. DCA demonstrated that the nomogram was clinically useful. The nomogram also showed good predictive ability in patients at high risk for LNM in the CT-reported LN negative (cN0) subgroup.

Conclusions

The radiomics nomogram, based on preoperative CT images, can be used as a noninvasive method to predict LNM in patients with solid lung adenocarcinoma.

High expression of c-Met and EGFR is associated with poor survival of patients with glottic laryngeal squamous cell carcinoma

The present study was undertaken to explore the association between the expression of hepatocyte growth factor receptor (c-Met) and epidermal growth factor receptor (EGFR) with clinicopathological factors and survival status, to obtain prognostic biomarkers in patients with glottis laryngeal squamous cell carcinoma (GLSCC). The expression status of c-Met and EGFR protein was analyzed in 71 archival laryngeal cancer samples by immunohistochemistry. Statistical methods, including univariate and multivariate Cox regression analysis, were used to determine risk factors of progression. In addition, survival analysis was performed by the Kaplan-Meier method. The present study detected positive expression of c-Met and EGFR in 69.0 and 91.5% of GLSCC samples, respectively. The median disease-free survival (DFS) and overall survival (OS) times of all patients were 42.4 and 81.8 months, respectively, and the 2-year DFS and OS rates were 60.1 and 84.91%, respectively. Univariate Cox regression analysis revealed that patients with high expression of EGFR or c-Met had a predisposition for tumor recurrence. The expression of c-Met expression was significantly associated with that of EGFR (P=0.001). High expression of c-Met or EGFR was associated with shorter DFS and OS times. Findings of the multivariate Cox regression analysis indicated that c-Met-expression may be used as an independent predictor of DFS and OS (P=0.002 and P=0.008, respectively). However, EGFR expression was not an independent predictor for DFS and OS (P=0.352 and P=0.24, respectively). The high expression of c-Met and EGFR was associated with poor survival and are important predictors for prognosis of patients with GLSCC.

Comparison of the c-MET gene amplification between primary tumor and metastatic lymph nodes in non-small cell lung cancer

BACKGROUND

c-MET has recently been identified as a promising novel target in non-small cell lung cancer (NSCLC). We detected the consistency of c-MET gene amplification in metastatic lymph nodes and tumor tissues of NSCLC patients and discuss the clinical application value of c-MET gene amplification in metastatic lymph nodes.

METHODS

Real-time fluorescent quantitative PCR was used to test tumor tissues in 368 NSCLC patients and 178 paired metastatic lymph node samples. The amplification consistency in metastatic lymph nodes and tissue samples were compared and the correlation between c-MET gene amplification and the clinical characteristics of patients was analyzed.

RESULTS

The c-MET gene amplification rate was 8.97% (33/368) in tumor tissues. Of the 178 paired cases, c-MET gene amplification was positive in 7.95% (15/178) of cancerous tissues and 18.54% (33/178) of metastatic lymph nodes. c-MET gene amplification was detected more frequently in metastatic lymph nodes than in primary cancerous tissue. When metastatic lymph nodes were used as surrogate samples of primary cancerous tissues, the sensitivity was 86.67% (13/15) and the specificity was 87.69% (143/163).

CONCLUSIONS

Screening for c-MET gene amplification in lymph node metastases could determine which patients are eligible for tyrosine kinase inhibitor therapy. Lymph node metastasis can predict c-MET gene amplification in a primary tumor and guide the clinical use of c-MET gene targeted drugs.

Endobronchial ultrasound-guided transbronchial needle aspiration for thyroid cyst therapy: A case report

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is of limited usefulness for diagnosing thyroid disease, and few studies have reported its use in diagnosing and treating thyroid cysts. The present study investigated a unique case of diagnosis and treatment of a thyroid cyst by EBUS-TBNA. A 67-year-old male presented with back pain. Positron emission tomography/computed tomography scanning revealed low-density signals in the right lobe of the thyroid. Needle aspiration biopsies and drainage at this site was performed, and EBUS was used for guidance in diagnosing the thyroid cyst. A follow-up chest computed tomography scan indicated that the thyroid lesion had subsequently disappeared. The present study concludes that EBUS-TBNA provides an alternative approach for diagnosing and treating deep thyroid cysts located close to the airway. In all other cases, percutaneous needle aspiration or surgery should be the first choice.

Relationship of Radiometabolic Biomarkers to KRAS Mutation Status and ALK Rearrangements in Cases of Lung Adenocarcinoma

Purpose Rapid diagnosis of genetic mutations is important for targeted therapies such as EGFR tyrosine kinase inhibitors. KRAS mutation and ALK rearrangement are also important in determining treatment. The purpose of our study was to evaluate the diagnostic value of 18F-FDG PET to predict KRAS mutation and ALK rearrangement in order to determine the frequency of these genetic markers in our lung adenocarcinoma cases and contribute to forthcoming meta-analysis studies. Methods A total of 218 patients with lung adenocarcinoma (EGFR analyzed) who were seen at our clinic between 2012 and 2014 were included in the study. The results of the 18 F-FDG-PET scans for each patient were retrospectively recorded with the associated medical documents. ALK rearrangements were analyzed in 166 of the 218 patients, while 50 of the 218 patients were analyzed for KRAS mutational status. SPSS 15.0 for Windows was used for statistical analysis. Results FDG avidity was higher in cases with KRAS mutations and ALK rearrangements than those without, but the difference was not significant. ALK rearrangements were more common in younger, female, and nonsmoking patients with lung adenocarcinoma. Conclusions The small numbers of KRAS mutations and ALK rearrangements are the limitation of this study for evaluation of diagnostic imaging. The frequency of these genetic alterations was as reported in the literature. We believe that our work will contribute to future meta-analysis.

Comparison of Epidermal Growth Factor Receptor Mutations between Metastatic Lymph Node Diagnosed by EBUS-TBNA and Primary Tumor in Non-Small Cell Lung Cancer

Introduction

Although the use of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is increasing for epidermal growth factor receptor (EGFR) testing in lung cancer, the discordance rate in EGFR mutations between lymph node (LN) samples obtained by EBUS-TBNA and primary tumor (PT) is not well known. Thus, we compared the EGFR mutation status of LN samples obtained by EBUS-TBNA and PTs to estimate the efficacy of using EBUS-TBNA specimens for EGFR testing in advanced, non-squamous, non-small cell lung cancer (NSCLC).

Materials and Methods

Using data of patients from the EBUS-TBNA database (N = 1914) obtained between January 2009 and January 2013, we identified 100 treatment-naïve, advanced, non-squamous NSCLC patients (stage 3 and 4) with matched LN specimens obtained by EBUS-TBNA and PT specimens. Of these, 74 patients with paired specimens were feasible for EGFR mutation analysis, which we performed using a direct sequencing method.

Results

Of the 74 cases, at least one major [exon 19 deleted (19del) and L858R] or minor (T790M, exon 20 insertion, and other point mutations) EGFR mutation was detected in 31 cases (41.9%), which included PT (n = 31, 41.9%) and LN (n = 28, 37.8%) specimens. Major mutations were detected in 25 PT (33.8%, 19del = 13, L858R = 12) and 22 LN (29.8%, 19del = 11, L858R = 11) specimens. The discordance rate in major mutations between matched PT and LN specimens was 4.1% (3/74). Among minor mutations, T790M was detected in LN specimen only in 2 cases with L858R in PT and LN. The discordance rate major and minor EGFR mutations combined between matched PT and LN specimens was 12% (9/74).

Conclusions

We observed a high concordance rate of major EGFR mutations between matched LN specimens sampled by EBUS-TBNA and PTs, suggesting that LN samples obtained by EBUS-TBNA from advanced non-squamous NSCLC patients are effective for use in EGFR mutation testing.

Roles of c-Met and RON kinases in tumor progression and their potential as therapeutic targets

c-Met and receptor originated from nantes (RON) are structurally related transmembrane phosphotyrosine kinase receptors. c-Met and RON show increased expression or activity in a variety of tumors leading to tumor progression and may play a role in acquired resistance to therapy. Although often co-expressed, the distinct functional roles of c-Met and RON are not fully understood. c-Met and RON form both activated homodimers and heterodimers with themselves and other families of phosphotyrosine kinase receptors. Inhibitors for c-Met and RON including small molecular weigh kinase inhibitors and neutralizing antibodies are in pre-clinical investigation and clinical trials. Several of the tyrosine kinase inhibitors have activity against both c-Met and RON kinases whereas the antibodies generally are target specific. As with many targeted agents used to treat solid tumors, it is likely that c-Met/RON inhibitors will have greater benefit when used in combination with chemotherapy or other targeted agents. A careful analysis of c-Met/RON expression or activity and a better elucidation of how they influence cell signaling will be useful in predicting which tumors respond best to these inhibitors as well as determining which agents can be used with these inhibitors for combined therapy.

Mutation status concordance between primary lesions and metastatic sites of advanced non-small-cell lung cancer and the impact of mutation testing methodologies: a literature review

Increased understanding of the genetic aetiology of advanced non-small-cell lung cancer (aNSCLC) has facilitated personalised therapies that target specific molecular aberrations associated with the disease. Biopsy samples for mutation testing may be taken from primary or metastatic sites, depending on which sample is most accessible, and upon differing diagnostic practices between territories. However, the mutation status concordance between primary tumours and corresponding metastases is the subject of debate. This review aims to ascertain whether molecular diagnostic testing of either the primary or metastatic tumours is equally suitable to determine patient eligibility for targeted therapies. A literature search was performed to identify articles reporting studies of mutations in matched primary and metastatic aNSCLC tumour samples. Clinical results of mutation status concordance between matched primary and metastatic tumour samples from patients with aNSCLC were collated. Articles included in this review (N =26) all reported mutation status data from matched primary and metastatic tumour samples obtained from adult patients with aNSCLC. Generally, substantial concordance was observed between primary and metastatic tumours in terms of EGFR, KRAS, BRAF, p16 and p53 mutations. However, some level of discordance was seen in most studies; mutation testing methodologies appeared to play a key role in this, along with underlying tumour heterogeneity. Substantial concordance in mutation status observed between primary and metastatic tumour sites suggests that diagnostic testing of either tumour type may be suitable to determine a patient's eligibility for personalised therapies. As with all diagnostic testing, highly sensitive and appropriately validated mutation analysis methodologies are desirable to ensure accuracy. Additional work is also required to define how much discordance is clinically significant given natural tumour heterogeneity. The ability of both primary and metastatic tumour sites to accurately reflect the tumour mutation status will allow more patients to receive therapies personalised to their disease.

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.

Somatic gene copy number alterations in colorectal cancer: new quest for cancer drivers and biomarkers

Colorectal cancer (CRC) results from the accumulation of genetic alterations, and somatic copy number alterations (CNAs) are crucial for the development of CRC. Genome-wide survey of CNAs provides opportunities for identifying cancer driver genes in an unbiased manner. The detection of aberrant CNAs may provide novel markers for the early diagnosis and personalized treatment of CRC. A major challenge in array-based profiling of CNAs is to distinguish the alterations that play causative roles from the random alterations that accumulate during colorectal carcinogenesis. In this view, we systematically discuss the frequent CNAs in CRC, focusing on functional genes that have potential diagnostic, prognostic and therapeutic significance.

Comprehensive Molecular Analysis of NSCLC; Clinicopathological Associations

BACKGROUND

Selection of NSCLC patients for targeted therapy is currently based upon the presence of sensitizing mutations in EGFR and EML4/ALK translocations. The heterogeneity of molecular alterations in lung cancer has led to the ongoing discovery of potential biomarkers and targets in order to improve survival.

AIM

This study aimed to detect alterations in EGFR, KRAS, BRAF, PIK3CA, MET-gene copy number and ALK rearrangements in a large cohort of 956 NSCLC patients of Hellenic origin using highly sensitive techniques and correlations with clinicopathological characteristics.

RESULTS

Mutations were detected in EGFR 10.6% (101 out of 956 samples), KRAS 26.5% (191 out of 720 samples), BRAF 2.5% (12 out of 471 samples), PIK3CA 3.8% (7 out of 184 samples), MET gene amplification was detected in 18% (31 out of 170) and ALK rearrangements in 3.7% (4 out of 107 samples). EGFR mutations were detected in exon 19 (61.4% of mutant cases), exon 21 p.Leu858Arg (19.8%), exon 20 (15.8%), exon 18 (2.9%) and were correlated with gender histology, smoking status and TTF1 staining. p.Thr790Met mutant cases (3.9%) displayed concurrent mutations in exons 19 or 21. Negative TTF-1 staining showed strong negative predictive value for the presence of EGFR mutations. KRAS mutations were associated with histology, the most common mutation being p.Gly12Cys (38%).

DISCUSSION

In conclusion, only 89 patients were eligible for EGFR -TKIs and ALK inhibitors therapy, whereas 257 patients showed other alterations, highlighting the necessity for a detailed molecular profiling potentially leading to more efficient individualized therapies for NSCLC patients.

Identification of a novel MET mutation in high-grade glioma resulting in an auto-active intracellular protein

MET has gained interest as a therapeutic target for a number of malignancies because of its involvement in tumorigenesis, invasion and metastasis. At present, a number of inhibitors, both antibodies against MET or its ligand hepatocyte growth factor, and small molecule MET tyrosine kinase inhibitors are in clinical trials. We here describe a novel variant of MET that is expressed in 6 % of high-grade gliomas. Characterization of this mutation in a glioma cell line revealed that it consists of an intronic deletion, resulting in a splice event connecting an intact splice donor site in exon 6 with the next splice acceptor site being that of exon 9. The encoded protein lacks parts of the extracellular IPT domains 1 and 2, encoded by exons 7 and 8, resulting in a novel pseudo-IPT and is named MET^Δ7−8. MET^Δ7−8 is located predominantly in the cytosol and is constitutively active. The auto-activating nature of MET^Δ7−8, in combination with a lack of transmembrane localization, renders MET^Δ7−8 not targetable using antibodies, although the protein is efficiently deactivated by MET-specific tyrosine kinase inhibitors. Testing of MET-expressing tumors for the presence of this variant may be important for treatment decision making.

Regulation of metastatic ability and drug resistance in pulmonary adenocarcinoma by matrix rigidity via activating c-Met and EGFR

Lung fibrosis is a poor prognostic factor for pulmonary adenocarcinoma, and the effect of a rigid microenvironment on cancer behavior is unclear. We cultured A549 cells on matrices of 0.2, 2, and 25 kPa to mimic the rigidities of normal lung parenchyma, progressive fibrotic change, and lung fibrosis, respectively. Lung tissue from patients with pulmonary adenocarcinoma was used to confirm the in vitro findings. Increased matrix rigidity promoted cell proliferation and upregulated the epidermal growth factor receptor (EGFR), hepatocyte growth factor receptor (c-Met), and Snail expression in A549 cells. A549 cells became more resistant to the EGFR inhibitor (Erlotinib) and c-Met inhibitor (PHA-665752) when matrix rigidity increased; however, a high concentration of PHA-665752 reversed the rigidity-induced morphological pleomorphism. In human lung tissue, expression of type I collagen was more consistent with clinical fibrosis than the expression of alpha-smooth muscle antibody was. c-Met- and Snail-expressing tumor cells, rather than EGFR-experssing cells, were localized with lung parenchyma rich in type I collagen. Our findings suggest that c-Met causes the rigidity-induced biophysical reaction in pulmonary adenocarcinoma. Treatment targeting both EGFR and c-Met should be considered for patients with lung fibrosis and who are abundant type I collagen expression in the tumor mass.

Comparison of epidermal growth factor receptor mutations between primary tumors and lymph nodes in non-small cell lung cancer: a review and meta-analysis of published data

BACKGROUND

Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) can predict the clinical response to tyrosine kinase inhibitor (TKI) therapy. However, EGFR mutations may be different in primary tumors (PT) and metastatic lymph nodes (MLN). The aim of this study was to compare EGFR mutations between PT and the corresponding MLN in NSCLC patients, and provide some guidelines for clinical treatment using TKI therapy.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed with several research databases. Relative risk (RR) with the 95% confidence interval (CI) were used to investigate the EGFR mutation status between PT and the corresponding MLN. A random-effects model was used.

RESULTS

9 publications involving 707 patients were included in the analysis. It was found that activation of EGFR mutations identified in PT and the corresponding MLN was 26.4% (187/707) and 19.9% (141/707), respectively. The overall discordance rate in our meta-analysis was 12.2% (86/707). The relative risk (RR) for EGFR mutation in PT relative to MLN was 1.33 (95%CI: 1.10-1.60; random-effects model). There was no significant heterogeneity between the studies (I2=5%, p=0.003).

CONCLUSIONS

There exists a considerable degree of EGFR mutation discrepancy in NSCLC between PT and corresponding MLN, suggesting that tumor heterogeneity might arise at the molecular level during the process of metastasis.

Increased MET Gene Copy Number but Not mRNA Level Predicts Postoperative Recurrence in Patients with Non-Small Cell Lung Cancer

The aim of the present study was to investigate the relationship of MET copy number (CN) and MET mRNA expression to other molecular alterations, clinicopathologic characteristics, and survival of patients with resected non–small cell lung cancer. One hundred fifty-one paired surgical samples of tumor and tumor-distant normal lung tissues were analyzed by comparative quantitative polymerase chain reaction (PCR) methods with commercially available assays and the CopyCaller software v. 1.0 for post-PCR data processing (downloadable from www.appliedbiosystems.com). MET copy gain (set as more than 3.0 copies per cell) was found in 18.5% of the samples and occurred more frequently in the adenocarcinomas (ADCs) with an increased epidermal growth factor receptor (EGFR) or human epidermal growth factor receptor 2 (HER2) CN (P = .001 and .030 for EGFR and HER2, respectively) and in the ADCs with EGFR activating mutations (P = .051) but did not correlate with KRAS dosage or mutational status. MET mRNA level was 1.76-fold higher [95% confidence interval (CI), 1.29-2.40] in the tumor compared to unaffected lung tissue and associated significantly with MET CN (beta coefficient, 1.51; 95% CI, 1.22-1.87; P < .001). In the multivariable analysis, patients diagnosed with ADC with increased MET CN had a significantly higher risk of disease recurrence (hazard ratio, 1.76; 95% CI, 1.20-2.57; P = .004). An increased MET CN in combination with histologic type appears to be a prognostic factor in patients with ADC after a curative surgery.

Meta-analysis of epidermal growth factor receptor and KRAS gene status between primary and corresponding metastatic tumours of non-small cell lung cancer

The epidermal growth factor receptor (EGFR) and KRAS gene status in paired primary non-small cell lung cancer (NSCLC) and metastatic tumours has been investigated by many studies, but remains controversial. We systematically reviewed studies in English of EGFR and KRAS gene status in primary and corresponding metastatic NSCLC up to 15 January 2014. Studies were selected rigorously from PubMed, EMBASE, as well as Cochrane Library databases. We carried out a meta-analysis to clarify EGFR mutations, EGFR amplification, positive rate of EGFR protein expression and KRAS mutations in primary and corresponding metastatic NSCLC. Our data suggested that the overall EGFR mutation rate, gene copy number, protein expression were not different between primary tumours and corresponding metastases, with the pooled odd ratios and 95% confidence interval 1.043 (0.686-1.586, P = 0.844), 0.604 (0.355-1.027, P = 0.063) and 1.447 (0.948-2.208, P = 0.087), respectively. The overall KRAS mutation rate of primary tumours was not different from that of matched metastases, with the odds ratio and 95% confidence interval being 1.224 (0.808-1.856, P = 0.340). The discordant rates of EGFR and KRAS mutations in paired primary and metastatic NSCLC were 14.5 and 16.7%, respectively. Among the discordant gene mutations in primary and metastatic lesions, the frequency of occurrence of mutation was not different from the frequency of loss of mutation for EGFR (P = 0.093) and KRAS gene (P = 0.227). These results indicate that EGFR and KRAS mutations are present frequently in metastases and occur before metastasis. Therefore, routine analysis of EGFR or KRAS gene status both in primary and metastatic tumours is not recommended.

Lymph node metastases of melanoma: challenges for BRAF mutation detection

Detection of B-Raf proto-oncogene, serine/threonine kinase (BRAF) mutations is required to predict response to BRAF or mitogen-activated protein kinase kinase 1 and 2 inhibitors in metastatic melanoma. Lymph node (LN) specimens carrying melanoma cells intermingled with abundant lymphocytes often contain low tumor cellularity. This study is aimed to examine challenges in the clinical detection of BRAF mutations in LN specimens with metastatic melanoma and to illustrate characteristic features of p.V600E and non-p.V600E mutations. In this retrospective study for quality assessment of the pyrosequencing assay, we compared characteristics of 53 LN and 135 non-LN formalin-fixed, paraffin-embedded specimens with metastatic melanoma submitted for BRAF mutation detection over a 40-month period. LN specimens showed a significantly higher incidence of p.V600E mutations than non-LN specimens (49% versus 22%, P < .01) but a significantly lower tumor cellularity, particularly in the case of subcapsular or infiltrative metastases. Mutant allele-specific imbalance of the p.V600E mutation was predominantly present in specimens with distant organ metastases (79% versus 27% in LN metastases versus 13% in primary cutaneous tumors or adjacent soft tissue, P < .001). p.V600K was detected in 23% of men older than 60 years old, compared with 6% in women older than 60 years old and 2% in both men and women younger than 60 years old (P < .001). LN specimens with low tumor cellularity due to numerous adjacent lymphocytes may pose a challenge to clinical detection of BRAF mutations of melanoma. The higher incidence of p.V600E mutations in LNs may prompt further studies to elucidate if the p.V600E mutation in primary tumors is associated with a higher risk of LN metastasis.

Amplification and overexpression of CMET is a common event in brain metastases of non-small cell lung cancer

BACKGROUND

CMET represents an emerging therapy target for monoclonal antibodies and tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC).

METHODS

We investigated CMET gene amplification status by fluorescence in-situ hybridization (FISH) and CMET protein expression by immunohistochemistry in a large series of 209 NSCLC brain metastases (BM; 165 adenocarcinoma, 20 squamous cell carcinoma, 11 adenosquamous carcinomas, 11 large cell carcinomas and two large cell neuroendocrine carcinomas) and correlated our results to clinic-pathological parameters and molecular data from previous studies.

RESULTS

We found CMET gene amplification in 36/167 (21.6%) and CMET protein expression in 87/196 (44.4%) of evaluable BM. There was a strong correlation between the presence of CMET gene amplification and CMET protein expression (P < 0.001, chi-square test). Furthermore, presence of CMET amplification correlated positively with presence of ALK amplifications (P = 0.039, chi-square test) and high HIF1 alpha index (P = 0.013, Mann-Whitney U-test). Neither CMET expression nor CMET gene amplification status correlated with patient outcome parameters or known prognostic factors.

CONCLUSIONS

CMET overexpression and CMET amplification are commonly found in NSCLC BM and may represent a promising therapeutic target.

Identification of chromosomal copy number variations and novel candidate loci in hereditary nonpolyposis colorectal cancer with mismatch repair proficiency

The pathogenesis of microsatellite stable hereditary non-polyposis colorectal cancers (MSS HNPCC) is unclear. To identify genomic regions that might be involved in MSS HNPCC pathogenesis, we selected 20 pairs of MSS HNPCC for a genome-wide study using copy number variation targeted (CNV-targeted) CytoScan HD Array. A remarkably increased frequency of 20q gain (70%) and high levels of copy-neutral loss of heterozygosity (40%) were observed. The most frequent tumor-specific CNVs included amplifications (7p21.3-15.1, 8q13.3-24.3, 13q14.1-33.3 and 20q12-13.33) and deletions (8p11.23-23.1, 15q11.2-26.1, 17p13.1-13.3 and 18q11.2-21.33). In addition, 10 novel CNVs were discovered and led to identification of WDR16 and RAPGEF5 as candidate genes involved in tumorigenesis, displaying a robust correlation between expression and genomic alterations. Moreover, WDR16 and RAPGEF5 exhibited altered protein expression levels as assessed by immunohistochemistry (IHC) in 41 other independent samples. Finally, high consistencies (68-84%) were observed between CNVs by Array and quantitative PCR. These findings are important for further elucidating MSS HNPCC pathogenesis.

Difference of Genome-Wide Copy Number Alterations between High-Grade Squamous Intraepithelial Lesions and Squamous Cell Carcinomas of the Uterine Cervix

BACKGROUND

About 10% of high-grade squamous intraepithelial lesions (HSILs) progress to invasive carcinomas within 2-10 years. By delineating the events that occur in the early stage of the invasion, the pathogenesis of cervical cancer could be better understood. This will also propose the possible methods for inhibiting the tumor invasion and improving the survival of patients.

METHODS

We compared the genomic profiles between the HSIL and the invasive squamous cell carcinoma (SCC) using an array comparative genomic hybridization. Using recurrently altered genes, we performed a principal component analysis to see variation of samples in both groups. To find possibly affected pathways by altered genes, we analyzed genomic profiles with the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database and GOEAST software.

RESULTS

We found 11q12.3 and 2p24.1 regions have recurrent copy number gains in both groups. 16p12-13 and 20q11-13 regions showed an increased copy number only in cases of HSIL. 1q25.3 and 3q23-29 regions showed copy number gains only in cases of SCC. Altered genes in the SCC group were related to the mitogen-activated protein kinase signaling pathway and the RNA transport. Altered genes in the HSIL group were related to the ubiquitin mediated proteolysis and cell adhesion molecules.

CONCLUSIONS

Our results showed not only that gains in 11q12.3 and 2p24.1 were early events occurring in the premalignant lesions and then maintained in cases of SCC but also that gains in 1q25.3 and 3q23-29 were late events occurring after invasion in those of SCC.

EGFR mutation status in brain metastases of non-small cell lung carcinoma

Brain metastases are a frequent and grave complication of non-small cell lung carcinoma (NSCLC). The prognosis is generally poor, despite standard therapy based on surgery and radiotherapy. A degree of understanding of the molecular basis of tumors has led to the development of targeted agents with promising initial findings for the treatment of NSCLC. EGFR mutations have been identified which are associated with significant sensitivity to EGFR tyrosine kinase inhibitors (TKI) and correlate with improved outcome in patients with NSCLC who are treated with these agents. The adoption of treatment tailored to the genetic make-up of individual tumors could lead to substantial therapeutic improvements, and such targeted therapy might be considered as a therapeutic option for brain metastases in the future. We review current knowledge about EGFR mutation status in the specific context of brain metastasis: its association with the response of brain metastases to TKI, its prevalence in brain metastases, and the correlation between mutation status in metastases as compared to the corresponding primary lung carcinoma.

EGFR and c-Met Cross Talk in Glioblastoma and Its Regulation by Human Cord Blood Stem Cells

Receptor tyrosine kinases (RTK) and their ligands control critical biologic processes, such as cell proliferation, migration, and differentiation. Aberrant expression of these receptor kinases in tumor cells alters multiple downstream signaling cascades that ultimately drive the malignant phenotype by enhancing tumor cell proliferation, invasion, metastasis, and angiogenesis. As observed in human glioblastoma (hGBM) and other cancers, this dysregulation of RTK networks correlates with poor patient survival. Epidermal growth factor receptor (EGFR) and c-Met, two well-known receptor kinases, are coexpressed in multiple cancers including hGBM, corroborating that their downstream signaling pathways enhance a malignant phenotype. The integration of c-Met and EGFR signaling in cancer cells indicates that treatment regimens designed to target both receptor pathways simultaneously could prove effective, though resistance to tyrosine kinase inhibitors continues to be a substantial obstacle. In the present study, we analyzed the antitumor efficacy of EGFR inhibitors erlotinib and gefitinib and c-Met inhibitor PHA-665752, along with their respective small hairpin RNAs (shRNAs) alone or in combination with human umbilical cord blood stem cells (hUCBSCs), in glioma cell lines and in animal xenograft models. We also measured the effect of dual inhibition of EGFR/c-Met pathways on invasion and wound healing. Combination treatments of hUCBSC with tyrosine kinase inhibitors significantly inhibited invasion and wound healing in U251 and 5310 cell lines, thereby indicating the role of hUCBSC in inhibition of RTK-driven cell behavior. Further, the EGFR and c-Met localization in glioma cells and hGBM clinical specimens indicated that a possible cross talk exists between EGFR and c-Met signaling pathway.