非小细胞肺癌人群中c-MET基因的扩增检测

目的：c-MET基因扩增是非小细胞肺癌对EGFR TKIs（吉非替尼或厄罗替尼）产生耐药的主要机制之一。本研究探讨没有接受TKIs治疗与TKIs治疗后耐药的NSCLC中c-MET基因的扩增是否存在差异。方法:获得55例术后非小细胞肺癌（NSCLC）的肿瘤组织（基线组）以及23例对TKIs耐药的肿瘤组织（耐药组）后,通过激光显微切割筛选癌细胞后提取基因组DNA,实时荧光定量PCR TaqMan探针法检测所有标本的c-MET基因的拷贝数。 结果:1.基线组和耐药组的临床病理特征均与c-MET基因的扩增无关。2.基线组中c-MET基因扩增阳性率为5.5% (3/55);耐药组的c-MET基因扩增阳性率为21.7% (5/23)。两组之间有统计学差异（Fisher精确概率法,P=0.045）。3.在7例获得TKI治疗前后肿瘤组织的NSCLC中,TKI治疗前没有出现c-MET的基因扩增,TKI治疗后有2例患者出现了c-MET的基因扩增（2/7）。TKI治疗前后的c-MET基因扩增差异无统计学意义。结论:NSCLC的临床病理特征不能预测c-MET基因扩增;在没有接受EGFR TKIs治疗的NSCLC中,c-MET基因扩增仅为少见事件。但经过吉非替尼或厄罗替尼治疗后出现耐药情况NSCLC中,部分患者的c-MET基因出现扩增。     

非小细胞肺癌原发灶和转移淋巴结EGFR、KRAS和MET基因状态比较

目的:比较配对的原发肺癌灶和转移淋巴结EGFR、KRAS和MET基因状态,探讨NSCLC原发灶和转移淋巴结基因变化规律并指导临床实践。方法:22例手术切除的Ⅲa期非小细胞肺癌,术前未经靶向和化学治疗,获取配对的原发灶和N2站转移淋巴结。采用直接测序法检测EGFR外显子19-21,KRAS密码子12和13突变,实时定量PCR检测MET基因拷贝数。结果:原发灶和N2转移淋巴结中EGFR基因突变率分别为7/22例(31.82%)和6/22例(27.27%),EGFR基因型一致率达95.45%。KRAS基因突变率分别为2/22例(9.09%)和1/22例(4.55%)。转移淋巴结MET基因拷贝数(1.54±0.71)显著高于原发灶(1.19±0.41),P=0.038。EGFR 19和21基因突变与原发灶(P=0.24)、转移灶(P=0.97)的MET基因拷贝数以及原发灶和转移灶MET基因拷贝数变化(P=0.69)之间都无相关性,P>0.05。不同的EGFR基因状态和MET基因拷贝数其1年无病生存无显著差异(P>0.05)。结论:肺癌原发灶和相应转移淋巴结中EGFR基因突变较稳定;EGFR敏感基因突变与MET基因拷贝数可能无关;而未经EGFR-TKI治疗的肺癌患者其MET基因拷贝数在淋巴结转移时即已开始出现明显增高。     

非小细胞肺癌驱动基因检测及其与临床病理特征的相关性

目的:探讨非小细胞肺癌(NSCLC)驱动基因的变化情况及其与临床病理特征的相关性。方法:回顾性分析我院2016年01月至2020年07月NSCLC患者607例临床及病理学特征资料,采用扩增阻滞突变系统(ARMS)荧光PCR法检测EGFR突变,RT-PCR法检测ALK、ROS1基因融合,荧光原位杂交法（FISH）检测MET基因扩增。结果:607例NSCLC组织中325例(53.5%,325/607)检测到基因改变,分别为EGFR突变（45.5%,276/607）、ALK融合（5.1%,31/607）、ROS1融合（1.3%,8/607）和MET扩增（2.8%,17/607）,EGFR双位点突变15例（2.5%,15/607）,双驱动基因改变7例（1.2%,7/607）,其中EGFR突变与ALK融合阳性共存3例,EGFR突变与ROS1融合阳性共存2例,EGFR突变与MET扩增阳性共存2例。EGFR在女性、非吸烟、腺癌患者中突变率更高（P＜0.05）,EGFR突变更容易发生在以贴壁为主型、腺泡为主型、乳头为主型、微乳头为主型腺癌中（P＜0.05）;ALK融合多见于女性、年轻、非吸烟、实性为主型的腺癌患者（P＜0.05）;MET基因扩增在老年男性患者中发生率更高（P＜0.05）。结论:在NSCLC中EGFR突变率较高,驱动基因联合突变不容忽视,基因分型对临床治疗具有重要指导意义。     

非小细胞肺癌靶向治疗的耐药特点及应对策略

分子靶向治疗在驱动基因阳性的晚期非小细胞肺癌（non-small cell lung cancer,NSCLC）患者中已经获得显著的疗效,但靶向治疗后期发生的耐药问题也成为了非小细胞肺癌进一步治疗的难题。现有分子靶向治疗中已知多种肿瘤驱动基因靶点,常见的有EGFR、ALK、ROS1、HER-2、BRAF、MET等。本文将对上述基因突变靶点抑制剂的耐药特点及耐药后的进一步治疗进行综述。     

肺肉瘤样癌的诊断和治疗进展

肺肉瘤样癌(PSC)是一种罕见的非小细胞肺癌(NSCLC),其临床症状和影像学表现无特异性,很难与其他NSCLC鉴别,需要病理和免疫组化协助明确诊断.早期PSC首选手术治疗,但术后复发率高,对放化疗不敏感,局部介入治疗无相关报道.Kirsten大鼠肉瘤病毒癌基因同源物(KRAS)和间质-上皮细胞转化因子(MET)基因是NSCLC的重要肿瘤驱动基因,且在PSC中的突变率高,KRAS抑制剂和MET抑制剂有望成为PSC的治疗靶点.PSC患者的肿瘤组织和淋巴细胞中程序性死亡受体配体1(PD-L1)高表达,因此免疫治疗可能作为PSC治疗的新选择.本文对PSC的诊断和治疗进展作一综述.     

吉非替尼在非小细胞肺癌治疗中的继发耐药

吉非替尼是一种表皮生长因子受体(EGFR)酪氨酸激酶抑制剂,对非小细胞肺癌(NSCLC)有良好的抗肿瘤活性,但大多数患者最终因继发耐药出现病情进展.在发生EGFR基因突变的肺腺癌患者中,约半数吉非替尼继发耐药与二次突变有关,这种二次突变导致EGFR 790位上的苏氨酸被甲硫氨酸所取代(T790M).其他导致耐药的机制包括EGFR受体的内化现象以及MET基因扩增.     

肺癌驱动基因与非小细胞肺癌生存关系的相关性研究

目的探讨非小细胞肺癌驱动基因EGFR、KRAS、BRAF、PIK3CA、ALK、MET、HER-2、RET、ROS-1与患者预后相关性,寻找更有效防治分子靶标。方法利用Kaplan-Meier(KM)plotter在线数据库分析EGFR、KRAS、BRAF、PIK3CA、ALK、MET、HER-2、RET、ROS-1表达与非小细胞肺癌患者总生存期(overall survival OS),性别与吸烟状态等参数的相关性,并得出相应的危险比(Hazard ratio,HR)、95%置信区间(CI)和P值。结果研究结果显示:高表达EGFR、BRAF、MET、RET、ROS-1的患者有较好的OS。进一步引入吸烟状态和性别参数显示,BRAF、MET,PIK3CA、HER-2、ALK的表达与患者的吸烟状态存在相关性(P<0.05)。BRAF、MET、EGFR、ALK表达与OS的相关性存在性别差异(P<0.05)。结论各驱动基因在患者预后评判中既是独立因素,又相互作用,吸烟状态与性别也是决定患者预后的关键因素,提示临床治疗时要对患者进行综合的评判,要进行多基因的共同分析、多靶点的联合治疗才能使病人获得更大的收益。     

187例非小细胞肺癌中EGFR基因突变和扩增的检测及其临床意义

背景与目的 现有的研究表明表皮生长因子受体(EGFR)相关信号通路在肺癌的发生和发展中起重要作用.EGFR酪氨酸激酶抑制剂(EGFR-TKIs)是目前针对EGFR治疗非小细胞肺癌(NSCLC)的重要分子靶向药物.EGFR的不同存在状态(基因突变和基因扩增)与TKIs的疗效相关.本研究旨在探讨非小细胞肺癌患者中EGFR的存在状态及其临床意义,从而为肺癌病人"个体化分子治疗"提供依据.方法 研究对象为187例NSCLC病例.用Real-time PCR技术检测EGFR基因19、21外显子的突变状态;用荧光原位杂交(FISH)技术检测EGFR基因的扩增情况,并进一步分析EGFR基因的突变和扩增与患者临床病理生理特征的关系.结果 :FISH结果显示,47.6%(98/187)的肺癌患者存在EGFR基因的扩增,而EGFR基因的扩增与患者的年龄、性别、组织学类型、吸烟状态及是否存在转移无关(P>0.05);Real-time PCR结果显示:20.3%(38/187)的肺癌患者存在EGFR外显子19、21的突变.EGFR基因突变率在女性(32.3%vs14.4%男性)、腺癌(35.5%vs9.9%非腺癌)、不吸烟(38.2%vs10.1%吸烟)患者中明显高(P<0.05).EGFR基因扩增与基因突变之间具有一定的相关性,在早期肺癌、腺癌及非吸烟的女性患者中,EGFR基因外显子突变常同时伴有EGFR基因的扩增.有EGFR基因突变或/和基因扩增的患者生存期均高于无EGFR基因异常者,但是没有统计学差异(P>0.05).有EGFR基因突变的患者易对TKIs治疗有效.结论 EGFR基因突变率在不同的NSCLC患者中不同,其中,在女性、腺癌和不吸烟患者中突变率高;层GFR基因扩增与患者的性别、组织类型、吸烟状态等临床特征无明显关系,与患者预后的相关性有待进一步研究.     

KIF5B-RET融合基因在非小细胞肺癌中的研究进展

KIF5B-RET融合基因存在于部分非小细胞肺癌(NSCLC)中,是除EGFR、k-ras、EML4-ALK驱动基因之外另一个重要的酪氨酸激酶抑制剂作用靶点。该融合基因在不吸烟或少量吸烟、腺癌、无EGFR及k-ras突变、无EML4-ALK融合基因的NSCLC患者中发生率较高,并且对RET抑制剂(如凡德他尼)有较好的治疗反应。全文就KIF5B-RET融合基因的基本结构、功能、检测及其在NSCLC中的研究进展进行综述。     

HER-2改变在非小细胞肺癌靶向治疗中的研究进展

肺癌是恶性程度和死亡率最高的恶性肿瘤之一,非小细胞肺癌(NSCLC)约占85%。靶向治疗是NSCLC的首选治疗方案。靶向治疗显著改善了ALK、ROS1、BRAF、NTRK、MET和大多数EGFR突变的NSCLC患者的临床结果。但自从发现异常激活的人类表皮生长因子受体2(HER-2)对EGFR抑制剂有耐药性并且其对化疗并不敏感以来,便促进了对HER-2改变的NSCLC患者靶向治疗的深入研究。HER-2改变包括基因突变、扩增和蛋白过表达。HER-2改变的不同类型针对不同的靶向治疗药物,其中HER-2第20外显子突变是NSCLC中具有功能意义的最为重要的驱动突变。本文针对HER-2改变的NSCLC患者的靶向治疗药物：阿法替尼、波齐替尼、吡咯替尼、曲妥珠单抗-美坦新偶联物、溴他替尼等的研究进展进行了详细综述。     

Targeting MET in Lung Cancer: Will Expectations Finally Be MET?

The hepatocyte growth factor receptor (MET) is a potential therapeutic target in a number of cancers, including NSCLC. In NSCLC, MET pathway activation is thought to occur through a diverse set of mechanisms that influence properties affecting cancer cell survival, growth, and invasiveness. Preclinical and clinical evidence suggests a role for MET activation as both a primary oncogenic driver in subsets of lung cancer and as a secondary driver of acquired resistance to targeted therapy in other genomic subsets. In this review, we explore the biology and clinical significance behind MET proto-oncogene receptor tyrosine kinase (MET) exon 14 alterations and MET amplification in NSCLC, the role of MET amplification in the setting of acquired resistance to EGFR tyrosine kinase inhibitor therapy in EGFR-mutant NSCLC, and the history of MET pathway inhibitor drug development in NSCLC, highlighting current strategies that enrich for biomarkers likely to be predictive of response. Whereas previous trials that focused on MET pathway–directed targeted therapy in unselected or MET-overexpressing NSCLC yielded largely negative results, more recent investigations focusing on MET exon 14 alterations and MET amplification have been notable for meaningful clinical responses to MET inhibitor therapy in a substantial proportion of patients.     

The METeoric rise of MET in lung cancer

Over the years, there has been a continuous increase in clinically relevant driver mutations in patients with non–small cell lung cancer (NSCLC). Among these, dysregulated activation of the MET tyrosine kinase receptor has gained importance due to the recent development of quite effective treatments. MET dysregulation encompasses a heterogeneous array of alterations leading to the prolonged activation of the cellular MET (c-MET or MET) receptor and downstream proliferation pathways. It can arise through several mechanisms, including gene amplification, overexpression of the receptor and/or its ligand hepatocyte growth factor, and the acquisition of activating mutations. MET mutations are found in approximately 3% to 5% of patients with NSCLC, mainly adenocarcinoma, and are overrepresented in the sarcomatoid subtype. De novo MET amplifications are found in 1% to 5% of NSCLC cases, also predominantly in adenocarcinoma. In the current review, the authors discussed the biology of MET, how to diagnose clinically relevant alterations, and the rising clinical importance of these alterations in light of the emergence of multiple targeted therapies, both within the context of MET as a driver of resistance and in its own right.     

MET as a target for treatment of chest tumors

The receptor tyrosine kinase MET has been studied of a large variety of human cancers, including lung and mesothelioma. The MET receptor and its ligand HGF (hepatocyte growth factor) play important roles in cell growth, survival and migration, and dysregulation of the HGF-MET pathway leads to oncogenic changes including tumor proliferation, angiogenesis and metastasis. In small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC), and malignant pleural mesothelioma (MPM), MET is dysregulated via overexpression, constitutive activation, gene amplification, ligand-dependent activation, mutation or epigenetic mechanisms. New drugs targeted against MET and HGF are currently being investigated in vitro and in vivo, with promising results. These drugs function at a variety of steps within the HGF-MET pathway, including MET expression at the RNA or protein level, the ligand-receptor interaction, and tyrosine kinase function. This paper will review the structure, function, mechanisms of tumorigenesis, and potential for therapeutic inhibition of the MET receptor in lung cancer and mesothelioma.     

The potential for crizotinib in non-small cell lung cancer: a perspective review

Tyrosine kinases have a crucial role as key regulators of signaling pathways that influence cell differentiation and growth. Dysregulation of tyrosine kinase-mediated signaling is understood to be an important oncogenic driver. Genetic rearrangements involving the tyrosine kinase anaplastic lymphoma kinase (ALK) gene occur in non-small cell lung cancer (NSCLC), anaplastic large cell lymphomoas, inflammatory myofibroblastic tumors, and other cancers. Cells with abnormal ALK signaling are sensitive to ALK inhibitors such as crizotinib. This review will highlight the discovery of the fusion between echinoderm microtubule-associated protein-like 4 (EML4) and ALK as an oncogenic driver, recognition of other ALK gene rearrangements in NSCLC, and the confirmation that crizotinib is an effective treatment for patients with ALK-positive NSCLC. Work is underway to further define the role for crizotinib in the treatment of ALK-positive lung cancer and other cancers and to investigate the molecular mechanisms for resistance to ALK inhibition with crizotinib.     

The Role of MET Receptor Tyrosine Kinase in Non‐Small Cell Lung Cancer and Clinical Development of Targeted Anti‐MET Agents

A better understanding of the pathophysiology and evolution of non‐small cell lung cancer (NSCLC) has identified a number of molecular targets and spurred development of novel targeted therapeutic agents. The MET receptor tyrosine kinase and its ligand hepatocyte growth factor (HGF) are implicated in tumor cell proliferation, migration, invasion, and angiogenesis in a broad spectrum of human cancers, including NSCLC. Amplification of MET has been reported in approximately 5%–22% of lung tumors with acquired resistance to small‐molecule inhibitors of the epidermal growth factor receptor (EGFR). Resistance to EGFR inhibitors is likely mediated through downstream activation of the phosphoinositide 3‐kinase /AKT pathway. Simultaneous treatment of resistant tumors with a MET inhibitor plus an EGFR inhibitor can abrogate activation of downstream effectors of cell growth, proliferation, and survival, thereby overcoming acquired resistance to EGFR inhibitors. Development and preclinical testing of multiple agents targeting the HGF–MET pathway, including monoclonal antibodies targeting HGF or the MET receptor and small‐molecule inhibitors of the MET tyrosine kinase, have confirmed the crucial role of this pathway in NSCLC. Several agents are now in phase III clinical development for the treatment of NSCLC. This review summarizes the role of MET in the pathophysiology of NSCLC and in acquired resistance to EGFR inhibitors and provides an update on progress in the clinical development of inhibitors of MET for treatment of NSCLC.     

New Verse for a Familiar Song: Small Molecule Inhibitors for MET exon 14 Skipping Non-Small Cell Lung Cancer

MET exon 14 skipping alterations (METex14) represent one of the newest discovered driver oncogene alterations for non-small cell lung cancer (NSCLC), which serve to define a distinct elderly patient population. New challenges in detection and treatment have emerged. In the last 15 years, the successes of tumor molecular profiling and therapeutic stratification in patients with advanced-stage disease have made NSCLC a poster child in the era of precision medicine. Each of the oncogenic drivers defines a distinct patient population. The selection of treatments based on oncogenic drivers such as EGFR, ALK, and ROS1, among others, has been transformative in terms of the duration and quality of life for patients with NSCLC receiving effective inhibitors. METex14 have emerged as one of the newest additions of driver oncogenes for NSCLC.     

Tracking MET de-addiction in lung cancer: A road towards the oncogenic target

The discovery of druggable oncogenic drivers (i.e. EGFR and ALK), along with the introduction of comprehensive tumor genotyping techniques into the daily clinical practice define non-small-cell lung cancer (NSCLC) as a group of heterogeneous diseases, requiring a context-personalized clinico-therapeutical approach. Among the most investigated biomarkers, the MET proto-oncogene has been extensively demonstrated to play a crucial role throughout the lung oncogenesis, unbalancing the proliferation/apoptosis signaling and influencing the epithelial-mesenchymal transition and the invasive phenotype. Nevertheless, although different mechanisms eliciting the aberrant MET-associated oncogenic stimulus have been detected in lung cancer (such as gene amplification, increased gene copy number, mutations and MET/HGF overexpression), to date no clinically impactful results have been achieved with anti-MET tyrosine kinase inhibitors and monoclonal antibodies in the context of an unselected or MET enriched population. Recently, MET exon 14 splicing abnormalities have been identified as a potential oncogenic target in lung cancer, able to drive the activity of MET inhibitors in molecularly selected patients.In this paper, the major advancement and drawbacks of MET history in lung cancer are reviewed, underlying the renewed scientific euphoria related to the recent identification of MET exon 14 splicing variants as an actionable oncogenic target.     

The Biology and Clinical Features of Non–small Cell Lung Cancers with EML4-ALK Translocation

The anaplastic lymphoma kinase (ALK) acts as a dominant oncogenic driver following chromosomal rearrangements in certain cancers including non–small cell lung cancer (NSCLC). NSCLC with ALK translocation occurs in a specific subset of patients and results in unique clinical features. Crizotinib is a small molecule inhibitor of ALK kinase that has recently been approved by the FDA for the treatment of patients with ALK-positive NSCLC. Treatment with crizotinib results in clinical benefit rate of 85%–90% and a median progression-free survival of 9–10 months for this molecular subset of patients. Ongoing studies will define the impact of crizotinib on overall survival and provide insights into the resistance mechanisms and potential activation of alternate pathways. Heat shock protein 90 inhibitors also appear promising in the treatment of ALK-positive NSCLC patients, based on early results. This article reviews the characteristics, treatment, and ongoing research in patients with ALK-positive NSCLC.     

Responses to Crizotinib Can Occur in High-Level MET-Amplified Non–Small Cell Lung Cancer Independent of MET Exon 14 Alterations

Activation of the MET proto-oncogene (MET) highly sensitive to MET inhibition has recently been described in NSCLC through two mechanisms: high-level amplification of the MNNG HOS Transforming gene (MET) (usually expressed relative to the chromosome 7 centromere [CEP7] when using fluorescence in situ hybridization) and exon 14 alterations. As partial overlap of these biomarkers occurs, whether one is purely a surrogate for the other or both can represent true oncogenic driver states continues to be explored. Cases of MET inhibitor–sensitive NSCLC harboring exon 14 alterations without coincident amplification have already been described. Here we report two cases of MET inhibitor–sensitive NSCLC harboring high-level MET amplification (MET/CEP7 ratio ≥5) without coincident exon 14 alterations, suggesting that these two methods of MET activation can produce independent MET-addicted states in NSCLC. Molecular profiling designed to capture all cases of potentially MET-addicted NSCLC should address both activation mechanisms.