非小细胞肺癌中EGFR和K-ras基因突变与蛋白表达相关性的研究

背景与目的：当前表皮生长因子受体（epidermal growth factor receptor,EGFR）基因靶向治疗已成为晚期非小细胞肺癌（non-small cell lung cancer,NSCLC）治疗的研究的热点之一。本研究旨在探讨NSCLC患者中EGFR基因和K-ras（Kirsten rat sarcoma viral oncogene）基因突变的情况,分析其与蛋白表达的相关性及对吉非替尼（gefitinib）治疗的指导意义。方法：收集200例NSCLC患者新鲜组织,采用基因测序法检测EGFR及K-ras基因突变的状态;同时采用免疫组织化学法检测EGFR和K-ras蛋白的表达。结果：200例患者中,EGFR基因突变率为33%,主要发生在19号和21号外显子;K-ras基因突变率为5.5%,主要位于第12密码子;不存在同时携带有EGFR和K-ras两种基因突变的病例。腺癌尤其是含细支气管肺泡癌（bronchioloalveolar carcinoma,BAC）病理分型的患者、非吸烟患者和女性患者EGFR突变率较高。EGFR蛋白表达阳性率为16%,与总的EGFR突变无关（P〉0.05）,但与19号外显子突变具有统计学意义（P〈0.05）。K-ras蛋白表达阳性率为52.5%,与K-ras基因突变无关（P〉0.05）。15例携带有EGFR基因突变的NSCLC患者服用吉非替尼,12例（其中8例为EGFR蛋白表达阴性）有效。结论：EGFR蛋白表达与EGFR基因19号外显子突变具有一定相关性;联合检测EGFR和K-ras基因突变可用来筛选对EGFR酪氨酸激酶抑制剂（tyrosine kinase inhibitor,TKI）治疗敏感的人群,并预测吉非替尼治疗晚期NSCLC的疗效及预后。     

DNA直接测序技术检测EGFR基因突变指导厄洛替尼一线治疗晚期非小细胞肺癌的临床观察

目的:通过对晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)患者表皮生长因子受体(epi-dermal growth factor receptor,EGFR)基因突变的检测,探讨厄洛替尼(Erlotinib)一线治疗晚期NSCLC的疗效与安全性。方法:从110例NSCLC患者的肿瘤组织提取DNA,用DNA直接测序技术检测EGFR基因19、21外显子突变情况,31例EGFR基因突变患者中,30例患者口服厄洛替尼150mg/d,持续至疾病进展或发生不能耐受的药物不良反应,评价客观有效率(RR),疾病控制率(DCR),总生存(OS),无疾病进展时间(PFS),一年生存率和药物不良反应。结果:110例NSCLC组织中EGFR基因突变31(28%)例,其中19外显子缺失18(58%)例,21外显子点突变13(42%)例。EGFR基因突变率女性40%、肺腺癌33%、不吸烟者46%,高于男性、非腺癌、吸烟的病人。30例口服厄洛替尼患者,完全缓解(CR)3例,部分缓解(PR)21例,疾病稳定(SD)5例和疾病进展(PD)1例,客观有效率为80%,疾病控制率为97%,截止随访结束,仍有20例患者生存,故中位总生存未获得结果,无疾病进展时间为11.4个月,1年生存率为78%,厄洛替尼治疗晚期NSCLC最常见的不良反应是腹泻和皮疹,多为I-II级。结论:DNA直接测序检测晚期NSCLC患者EGFR基因突变具有高度敏感性,以EGFR基因突变结果为依据,一线应用厄洛替尼治疗晚期NSCLC患者,疗效明显,耐受性好,是治疗晚期NSCLC的最佳选择之一。     

DNA直接测序技术检测EGFR基因突变指导厄洛替尼一线治疗晚期非小细胞肺癌的临床观察

目的：通过对晚期非小细胞肺癌（non-small cell lung cancer,NSCLC）患者表皮生长因子受体（epi-dermal growth factor receptor,EGFR）基因突变的检测,探讨厄洛替尼（Erlotinib）一线治疗晚期NSCLC的疗效与安全性。方法：从110例NSCLC患者的肿瘤组织提取DNA,用DNA直接测序技术检测EGFR基因19、21外显子突变情况,31例EGFR基因突变患者中,30例患者口服厄洛替尼150mg/d,持续至疾病进展或发生不能耐受的药物不良反应,评价客观有效率（RR）,疾病控制率（DCR）,总生存（OS）,无疾病进展时间（PFS）,一年生存率和药物不良反应。结果：110例NSCLC组织中EGFR基因突变31（28%）例,其中19外显子缺失18（58%）例,21外显子点突变13（42%）例。EGFR基因突变率女性40%、肺腺癌33%、不吸烟者46%,高于男性、非腺癌、吸烟的病人。30例口服厄洛替尼患者,完全缓解（CR）3例,部分缓解（PR）21例,疾病稳定（SD）5例和疾病进展（PD）1例,客观有效率为80%,疾病控制率为97%,截止随访结束,仍有20例患者生存,故中位总生存未获得结果,无疾病进展时间为11.4个月,1年生存率为78%,厄洛替尼治疗晚期NSCLC最常见的不良反应是腹泻和皮疹,多为I-II级。结论：DNA直接测序检测晚期NSCLC患者EGFR基因突变具有高度敏感性,以EGFR基因突变结果为依据,一线应用厄洛替尼治疗晚期NSCLC患者,疗效明显,耐受性好,是治疗晚期NSCLC的最佳选择之一。     

厄洛替尼单药治疗EGFR突变的晚期NSCLC患者试验汇合分析

背景与目的 厄洛替尼被全球多个国家批准用于晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)患者的二、三线治疗.有报道显示EGFR突变的患者应用厄洛替尼治疗疗效更好.本文拟探讨厄洛替尼单药治疗EGFR突变晚期NSCLC患者的疗效.方法 计算机检索MEDLINE(2004-2009)、CBMdjc(2004-2008)、CNKI(2004-2008),互联网检索以及纳入试验的参考文献.纳入相关临床试验,提取并汇总试验结果.结果 共纳入研究7篇,包括晚期非小细胞肺癌患者463例.厄洛替尼单药治疗EGFR突变的晚期非小细胞肺癌患者,有效率达到66%,1年生存率达到73%,2年生存率达到5396,中位生存时间23个月以上,无进展生存时间8.6个月以上.结论 在当前研究的基础上,厄洛替尼单药一线和二线治疗EGFR突变的晚期NSCLC有效率高,无进展生存期和总生存期长,可以推荐作为EGFR突变的晚期NSCLC的首选治疗.尚需要更详尽的证据评价厄洛替尼单药方案或厄洛替尼与化疗联合方案与标准含铂化疗方案在治疗晚期NSCLC中的地位.     

晚期非小细胞肺癌表皮生长因子受体基因突变情况和其对吉非替尼疗效的影响

背景与目的 研究晚期非小细胞肺癌( non-small cell lung cancer,NSCLC)表皮生长因子受体(epidermal growth factor receptor,EGFR)基因突变情况和该基因突变状态对吉非替尼疗效的影响.方法 于2007年1月-2009年12月对160例晚期非鳞癌NSCLC患者进行了EGFR基因检测,EGFR基因外显子19和外显子21突变检测采用突变富集PCR法.其中111例接受了吉非替尼治疗.中位生存期(overall survival,OS)和无疾病进展生存时间(progression free survival,PFS)的比较采用Kaplan-Meier方法计算.结果 晚期非鳞癌NSCLC患者EGFR基因突变率为55％,多因素分析显示只有病理类型与是否突变明显相关.EGFR基因突变型患者的OS为29.0个月(95％CI:24.2-33.8),野生型为21.0个月( 95％CI:14.7-27.3),两者差别无统计学差异.EGFR基因突变患者的PFS为17.0个月(95％CI:5.6-17.6),而野生型为11.6个月(95％CI:8.6-25.4),两者有明显性差别(P=0.022).OS的多因素分析结果显示,OS与ECOG评分、病理类型、EGFR基因突变状态明显相关.PFS多因素分析结果显示,PFS与ECOG评分、既往化疗方案数和EGFR基因突变明显相关.EGFR基因外显子19突变与外显子21突变的OS和PFS无明显差别,客观疗效也无差别.结论 晚期非鳞癌NSCLC EGFR基因突变患者的PFS明显优于野生型患者,OS有延长趋势.EGFR基因不同突变类型的PFS和OS均无差别.     

EGFR-TKI一线治疗EGFR基因突变的晚期非小细胞肺癌临床观察

背景与目的研究表明,一线表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptortyrosine kinase inhibitor,EGFR-TKI)治疗晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)的客观缓解率及无进展生存期明显优于铂二联的化疗,且耐受性更好。本研究旨在分析EGFR-TKI一线治疗晚期EGFR突变阳性的NSCLC患者的疗效与耐受性。方法 54例晚期NSCLC患者肿瘤标本采用直接测序法证实EGFR活化突变(外显子19缺失或外显子21点突变),一线给予EGFR-TKI口服治疗直至疾病进展,观察疗效及不良反应,并进行生存随访。结果 54例患者外显子19缺失33例(61%),外显子21点突变21例(39%)。均一线接受EGFR-TKI治疗,总体缓解率为90%,中位无进展生存期(progression free survival,PFS)为8.3个月,中位生存期为19.5个月;外显子19缺失患者的中位PFS(9.0个月)较21点突变(7.0个月)时间长(P=0.002)。外显子19缺失患者的中位总生存期(overall survival,OS)(25.0个月)较21点突变(16.0个月)时间长(P=0.001);吉非替尼与厄洛替尼疗效相当,但吉非替尼组安全性更好;最常见的不良事件为皮疹和腹泻,有2例患者(4%)出现了3度皮肤毒性反应,2例患者(4%)出现了3度的转氨酶升高,1例患者(1%)出现了3度口腔炎。结论存在EGFR基因突变的晚期NSCLC患者一线接受EGFR-TKI治疗安全有效,且外显子19缺失比L858R突变疗效更优。     

厄洛替尼与西妥昔单抗联合应用治疗吉非替尼耐药NSCLC的疗效

本研究通过EGFR-TKI和EGFR单克隆抗体联合应用探讨治疗EGFR突变阴性和EGFR T790M突变继发性耐药的NSCLC的疗效。方法:应用EGFR突变阴性和EGFR T790M突变继发性耐药的NSCLL细胞原代培养及药敏技术检验EGFR-TKI和EGFR单克隆抗体联合应用的疗效。结果:检测厄洛替尼和西妥昔单抗联合处理对于15例EGFR突变阴性和8例T790M突变阳性的继发性耐药的NSCLC患者原代细胞的影响,应用浓度分别为50 μg/mL西妥昔单抗和1 μM厄洛替尼作用于EGFR突变阴性的NSCLC患者原代细胞,结果显示这三组间T/C值无显著性差异（P>0.05）,对于T790M突变阳性的继发性耐药的NSCLC原代细胞这三组间T/C值有显著性差异（P<0.05）,联合用药组疗效明显高于单药组。结论:进一步验证了厄洛替尼和西妥昔单抗联合应用对于EGFR突变阴性的NSCLC患者无效,但对于T790M突变阳性的继发性耐药的NSCLC患者有效。      

非小细胞肺癌中EGFR和K-ras基因突变检测

目的:探讨不同类型非小细胞肺癌的EGFR和K-ras基因突变情况及其与肺癌相关临床病理特征的关系。方法:用厦门艾德ADxARMS试剂盒进行98例非小细胞肺癌患者肿瘤组织中EGFR（18,19,20,21外显子）基因和K-ras（12,13,61密码子）基因突变的检测。所有患者均未接受过吉非替尼的治疗。结果:98例样本中31例发生了EGFR基因突变,突变率为31.6%（31/98）,其中15例为19外显子缺失,13例为21 L858R外显子点突变,3例为20外显子突变,1例为18外显子突变。其中1例既有19外显子缺失突变,又有20外显子突变。腺癌中EGFR基因突变率较鳞癌、腺鳞癌、大细胞癌高。女性患者EGFR基因突变率较男性高。不吸烟患者EGFR基因突变率较吸烟患者高。低分化腺癌患者EGFR基因突变率较中、高分化患者高。21例发生了K-ras基因突变（21.4%）,其中12、13、61密码子均发现突变。突变率腺癌较鳞癌、腺鳞癌、大细胞癌高,与是否吸烟、患者性别、分化程度均无相关性。结论:非小细胞肺癌患者EGFR基因突变检出率较高,K-ras基因突变率较低,且两者不存在同时突变,EGFR基因突变与肺癌组织学类型、分化程度、性别等相关。K-ras基因突变与组织学类型相关。     

非小细胞肺癌EGFR基因突变及与疗效的相关性研究

目的:研究晚期非小细胞肺癌(NSCLC)患者表皮生长因子受体(EGFR)基因突变情况,探讨其与NSCLC临床病理学特征及吉非替尼疗效的关系。方法:PCR扩增和基因测序的检测60例NSCLC患者EGFR基因第18、19、20和21外显子突变情况。靶向治疗组14例吉非替尼治疗;化疗组46例以GP方案(顺铂联合吉西他滨方案)治疗。结果:60例晚期NSCLC中,EGFR基因突变率30.00%,19外显子突变12例,21外显子突变6例。腺癌、无吸烟史和女性患者EGFR基因突变率分别为36.89%、50.00%和57.14%。14例EGFR突变阳性患者口服吉非替尼组,CR 1例,PR 10例,SD 2例和PD 1例,客观有效率为78.57%,疾病控制率为92.85%;4例EGFR突变阳性患者GP方案化疗组,CR 0例,PR 2例,SD 2例和PD 0例,客观有效率为50.00%。42例EGFR突变阴性GP方案化疗组,客观有效率为38.10%。结论:晚期NSCLC患者EGFR基因突变率较高,EGFR基因的突变与肿瘤的病理类型、性别、年龄、民族、吸烟指数相关。EGFR基因突变KTI治疗,可有效提高患者的疾病缓解率,并较好地预测TKI治疗晚期非小细胞肺癌的疗效。     

非小细胞肺癌患者表皮生长因子受体突变对靶向治疗的疗效影响及生存分析

目的 探讨表皮生长因子受体(EGFR)基因突变对非小细胞肺癌(NSCLC)患者靶向治疗疗效及生存的影响.方法 83例经一线化疗失败的中晚期NSCLC患者,通过基因测序按照是否存在EGFR基因第19或21号外显子突变分为突变型组和野生型组,两组均给予吉非替尼口服治疗,250 mg/次,期间进行其他常规检查和定期随访.分析EG-FR突变与患者疗效及生存的关系.结果 女性、腺癌、不吸烟的NSCLC患者的突变率高于相应的男性、鳞癌、吸烟的NSCLC患者,差异均有统计学意义(P<0.05),而年龄、TNM分期与EGFR突变无明显相关(P>0.05).78例患者获得随访,其中突变型组32例,患者治疗的客观有效率(ORR)和疾病控制率(DCR)分别为64.7%和94.1%;明显高于46例野生型组的38.8%和71.4%,差异均有统计学意义(P<0.05).突变型组患者的无进展生存期(PFS)和中位生存时间分别为7.3个月和16.1个月,均较野生型组患者的3.5个月和8.3个月显著延长(P<0.01).结论 存在EGFR基因第19或21号外显子突变的NSCLC患者对应用吉非替尼治疗较敏感,效果较好,生存时间较长.EGFR基因突变可作为评估NSCLC患者分子靶向治疗疗效及生存的预测因子.     

176例非小细胞肺癌的EGFR基因突变分析

目的 分析非小细胞肺癌（NSCLC）中上皮生长因子受体（EGFR）基因突变的发生率和突变类型。方法 收集123例正常肺组织和176例肺癌组织,采用PCR扩增和基因测序方法,对组织DNA中EGFR外显子19～21基因突变进行分析。结果 正常肺组织中EGFR基因均为野生型,肺癌组织中EGFR基因突变检测率为32．4％（57／176例）,其中,外显子19和21突变分别占突变总数的64．9％（37／57例）和31．6％（18／57例）,外显子20突变少见,仅占3．5％（2／57例）。外显子19突变发生在第746～753位密码子,均为碱基缺失突变,有7种不同类型。外显子20突变发生在第789—793位密码子,为碱基替换突变。外显子21突变全部是第858位密码子碱基替换突变。EGFR基因突变多见于女性,肺腺癌和腺鳞癌。结论 EGFR基因突变是一种肿瘤特异性的体细胞遗传改变,突变发生率约占肺癌总数的1／3,其中以外显子19和21为主。女性、肺腺癌和腺鳞癌中突变多见。     

Double mutation and gene copy number of EGFR in gefitinib refractory non-small-cell lung cancer

Mutations of the epidermal growth factor receptor (EGFR) gene have been reported in non-small-cell lung cancer (NSCLC), especially in patients with adenocarcinoma and never smokers. Some common somatic mutations in EGFR, including deletion mutations in exon 19 and leucine-to-arginine substitution at amino acid position 858 (L858R) in exon 21, have been examined for their ability to predict sensitivity to gefitinib or erlotinib, which are selective EGFR tyrosine kinase inhibitors (EGFR-TKIs). On the other hand, reports have shown that the threonine-to-methionine substitution at amino acid position 790 (T790M) in exon 20 is related to gefitinib resistance. Some studies have indicated that high copy numbers of the EGFR gene may be a more effective molecular predictor to responsiveness and prolonged survival in patients treated with EGFR-TKIs. Here, we describe two NSCLC patients with the L858R mutation who did not respond to gefitinib. Case 1 harbored both the T790M and L858R mutations, and fluorescence in situ hybridization showed EGFR gene amplification. Case 2 harbored both the L858R and aspartic acid-to-tyrosine substitution at amino acid position 761 in exon 19 of EGFR mutations and had a high polysomy status for EGFR. In these two cases, tumors showed resistance to gefitinib treatment despite the presence of EGFR L858R mutation and increased copy number. Our findings encourage further molecular analysis to elucidate the relationship between the EGFR status, including mutations and amplifications, and the responsiveness of NSCLC to gefitinib.     

中国非小细胞肺癌患者K-Ras和EGFR基因突变与临床病理特征的关系

目的 探讨中国非小细胞肺癌（NSCLC）患者中K-Ras和表皮生长因子受体（EGFR）基因突变情况及其与临床病理特征的关系。方法 回顾性分析2011年7月至2013年8月广州医科大学附属第一医院收治的381例NSCLC患者的临床病理特征,并应用扩增突变阻滞系统（ARMS）检测其癌组织中EGFR基因18、19、20、21外显子共21个点突变和K-Ras基因12、13密码子共6个点突变,分析其突变情况及与临床病理特征的相关性。结果 21例（5.5％）存在K-Ras基因突变,其中20例12密码子,1例13密码子Asp突变;146例（38.3％）存在EGFR突变,其中4例18外显子突变（G719S）,52例19号外显子序列缺失突变,3例20外显子序列缺失突变,85例21外显子突变（81例L858R,4例L861Q）,2例双突变。男性患者K-Ras基因突变率高于女性患者,差异有统计学意义（6.8％ vs. 2.5％, P=0.018）。EGFR基因突变与性别、吸烟史、临床分期、全身转移、病理类型均有关（P＜0.05）。二分类Logistic回归分析显示,病理类型和性别与EGFR基因突变密切相关。结论 中国NSCLC患者中EGFR突变常见,该突变与腺癌有关;K-Ras基因突变率较低,多见于男性,其他相关因素尚需进一步研究。     

中国肺腺癌患者上皮生长因子受体基因突变的研究

目的:分析我国肺腺癌患者上皮生长因子受体(EGFR)基因突变的发生率和突变类型。方法:在上海、杭州和昆明等地收集61例肺腺癌及其正常肺组织,采用PCR扩增和基因测序方法对组织DNA中EGFR外显子19~21基因突变进行分析。结果:正常肺组织中EGFR基因均为野生型,肺腺癌组织中EGFR基因突变检测率为47.5%(29/61),其中外显子19和21突变分别占突变总数的55.2%(16/29)和44.8%(13/29),外显子20未检测到突变。外显子19突变发生在第746~752位密码子,均为碱基缺失突变,有6种不同类型。外显子21突变全部是第858位密码子碱基替换突变。EGFR基因突变与患者性别和年龄无显著相关性。但昆明和上海等地患者的基因突变存在明显差异。结论:EGFR基因突变是一种肿瘤特异性的体细胞遗传改变,突变发生率约占肺腺癌总数的一半,其中以外显子19和21突变为主。我国EGFR基因突变存在地域差异。     

The use of first-generation tyrosine kinase inhibitors in patients with NSCLC and somatic EGFR mutations

Initial studies with the first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors gefitinib and erlotinib in patients with non-small cell lung cancer (NSCLC) showed that, although most did not have an objective radiographic response, a minority of patients had dramatic and durable clinical and radiographic responses. The discovery of EGFR mutations in tumours from patients with NSCLC and the association of these mutations with clinical response to gefitinib and erlotinib provided an opportunity to tailor treatment to the mutation profile of the tumour. A number of retrospective reviews and prospective trials have established that gefitinib or erlotinib therapy leads to radiographic responses in approximately 75-80% of patients with NSCLC with EGFR mutations. Although a variety of mutations in EGFR have been identified, the two most common somatic activating EGFR mutations are the LREA deletions in exon 19 and the L858R substitution in exon 21. Together, these mutations make up 85-90% of EGFR mutations. At least two retrospective reviews have indicated a difference in the outcome of patients with different EGFR mutations: after treatment with gefitinib or erlotinib, patients with exon 19 deletions have an increased survival compared with those patients whose tumours have an L858R substitution. These findings remain to be confirmed in prospective studies. Improved understanding of the association of EGFR mutations with clinical outcome may improve the ability of physicians to match treatment to mutation status for patients with NSCLC.     

辽宁沈阳地区非小细胞肺癌EGFR基因突变分析

目的:探讨辽宁沈阳地区非小细胞肺癌（NSCLC）患者表皮生长因子受体（EGFR）基因突变情况及其与临床病理特征的关系。方法:采用扩增耐突变系统（Amplification Refractory Mutation System,ARMS）检测辽宁沈阳地区471例NSCLC患者EGFR基因第18,19,20及21外显子突变情况。结果:471例NSCLC患者共检出EGFR突变253例（53.7%）,其中19缺失和L858R突变占总突变数的42.3%,51.8%。女性患者突变率67.9%明显高于男性（37.4%）,两者之间差异有统计学意义（P=0.000）。腺癌患者突变率57.2%明显高于非腺癌患者（18.6%）,差异有统计学意义（P=0.000）。结论:辽宁沈阳地区NSCLC患者EGFR突变多见于女性,腺癌患者,突变类型以19缺失和21外显子的L858R突变为主。     

Subsequent brain metastasis responses to epidermal growth factor receptor tyrosine kinase inhibitors in a patient with non-small-cell lung cancer

In response to the paper by Popat et al. "Recurrent responses to non-small-cell lung cancer brain metastases with erlotinib", we wish to report a similar case and to provide comments. A 32-year-old Chinese never-smoker female presented a primary lung adenocarcinoma with brain metastasis and three subsequent responses to EGFR tyrosine kinase inhibitors (gefitinib and erlotinib). Direct sequencing of epidermal growth factor receptor (EGFR) gene exons 18 to 21 and K-ras gene was performed on tissue obtained from initial biopsies and post-chemotherapy surgical specimens. An EGFR exon 21 L858R point mutation was identified on pre- and post-chemotherapy samples. K-ras mutations and EGFR exon 20 T790M point mutations were not detected. Moreover, EGFR protein overexpression was observed by immunohistochemistry as well as EGFR gene high polysomy by fluorescent in situ hybridization. These case suggest that re-challenging patients with NSCLC several times with EGFR-TKI should be considered when progressive disease is observed under chemotherapy. However, we do not yet know whether this option should be considered in light of tumor molecular evaluation, or whether it should be proposed to patients who experienced a clinical response after a first administration.     

EGFR exon 20 insertion mutation in Japanese lung cancer

Mutations of the epidermal growth factor receptor (EGFR) gene have been reported in non-small cell lung cancer (NSCLC), especially in female, never smoker patients with adenocarcinoma. Some common somatic mutations in EGFR, including deletion mutations in exon 19 and leucine to arginine substitution at amino acid position 858 (L858R) in exon 21, have been examined for their ability to predict sensitivity to gefitinib or erlotinib. On the other hand, previous report has shown that the insertion mutation at exon 20 is related to gefitinib resistance. We investigated the exon 20 EGFR mutation statuses in 322 surgically treated non-small cell lung cancer cases. Two hundred and five adenocarcinoma cases were included. The presence or absence of EGFR mutations of kinase domains was analyzed by direct sequences. EGFR insertion mutations at exon 20 were found from 7 of 322 (2.17%) lung cancer patients. We also detected the 18 deletion type mutations in exon 19, and 25 L858R type mutations in exon 21. There was a tendency towards higher exon 20 insertion ratio in never smoker (never smoker 4.4% versus smoker 1.3%, p=0.0996) and female (female 4.5% versus male 1.3%, p=0.0917). Two exon 20 insertion cases were treated with gefitinib and failed to response. EGFR insertion mutation in exon 20 could not be ignored from Japanese lung cancers.     

Exon 19 deletion mutations of epidermal growth factor receptor are associated with prolonged survival in non-small cell lung cancer patients treated with gefitinib or erlotinib.

PURPOSE: Somatic mutations in the epidermal growth factor receptor (EGFR) have been detected in patients with non-small cell lung cancer (NSCLC) and are associated with sensitivity to treatment with gefitinib or erlotinib. Our study explored the relationship between the two most common types of somatic EGFR mutations, exon 19 deletions and the L858R point mutation, and outcomes of patients following treatment with gefitinib or erlotinib. EXPERIMENTAL DESIGN: Tumor specimens obtained before treatment with gefitinib or erlotinib were analyzed for EGFR mutations. Patients with exon 19 deletion or L858R mutations were identified. The response rate, time to progression, and overall survival were determined for the two groups. RESULTS: We identified 36 patients with NSCLC and an EGFR mutation who were treated with gefitinib or erlotinib. Patients with an exon 19 deletion had a significantly longer overall survival compared with patients with an L858R mutation (38 versus 17 months; P = 0.04). There were also trends toward higher response rate (73% versus 50%) and improved time to progression (24 versus 10 months) for the patients with an exon 19 deletion, although these were not independently significant in a multivariate analysis. A difference in response rate for patients treated with gefitinib compared with erlotinib was also noted [18 of 23 (78%) versus 3 of 9 (33%); P = 0.04]. No obvious difference in time to progression or overall survival was noted between gefitinib- and erlotinib-treated patients. CONCLUSIONS: Patients with NSCLC and EGFR exon 19 deletions have a longer survival following treatment with gefitinib or erlotinib compared with those with the L858R mutation. Pooling of greater numbers of patients and completion of prospective trials are needed to further define the predictive and prognostic roles of different EGFR mutations with respect to treatment with gefitinib, erlotinib, and other EGFR inhibitors.