非小细胞肺癌原发灶与脑转移灶EGFR基因突变状况的一致性研究

目的 探讨非小细胞肺癌（NSCLC）原发灶与脑转移灶的表皮生长因子受体（EGFR）基因突变状况,分析两者之间是否存在一致性。方法 收集2003年1月至2011年12月31例NSCLC脑转移患者的肺原发灶和脑转移灶石蜡包埋组织标本,应用DNA直接测序法进行EGFR突变分析,如发现两者突变不一致则进一步采用增殖阻碍突变系统 （ARMS）验证。结果 31例NSCLC肺原发灶中,8例存在19外显子E746-A750缺失突变、4例为21外显子L858R点突变;在31例脑转移灶样本中,8例为19外显子E746-A750缺失突变,3例存在21外显子L858R点突变,EGFR突变类型在脑转移灶和肺原发灶的分布差异无统计学意义 （P=0.793）。共有16.1％ （5／31）的肺原发灶和脑转移灶EGFR突变状况不一致,其中男性4例,女性1例;3例腺癌 （2例脑转移灶19外显子缺失突变而肺原发灶阴性突变,1例肺原发灶21外显子点突变而脑转移灶阴性突变）,1例鳞癌和1例非典型类癌 （均为脑转移灶阴性突变而肺原发灶19外显子缺失突变）。结论 NSCLC原发病灶及脑转移灶EGFR基因突变存在不一致性。     

非小细胞肺癌原发灶与淋巴结转移灶中KRAS和EGFR基因状态的比较及其临床意义

  目的  比较表皮生长因子受体(EGFR)基因和KRAS基因在非小细胞肺癌原发灶及其淋巴结转移灶之间突变状态的差异, 并分析其与吉非替尼治疗非小细胞肺癌(NSCLC)疗效之间的关系。   方法  收集天津医科大学附属肿瘤医院2010年5月至2010年11月间手术切除的80例NSCLC病例标本, 利用直接测序和实时荧光定量PCR的方法分别检测原发灶和相应淋巴结转移灶中EGFR基因第18、19、20、21外显子及KRAS基因第12、13密码子的突变情况; 其中5例在淋巴结转移灶中检出EGFR酪氨酸激酶抑制剂(EGFR-TKI)敏感型基因突变的患者接受了吉非替尼的新辅助靶向治疗。   结果  80例患者中, 检出原发灶携带KRAS和EGFR基因突变分别为1例和21例, 检出转移灶携带KRAS和EGFR基因突变分别为7例和26例; 分别有6例(7.50%)和7例(8.75%)患者其KRAS和EGFR基因状态在原发灶和转移灶之间不一致。直接测序法和实时荧光定量PCR法的检测结果一致。在5例接受吉非替尼治疗的患者中仅1例原发病灶中未检出EGFR-TKI敏感型基因突变, 并表现为疾病进展。   结论  部分NSCLC患者中KRAS和EGFR的基因状态在肿瘤转移过程中会发生改变, 在给予患者靶向治疗时不应忽视这一现象的存在。实时荧光定量PCR法比直接测序法更适用于临床的快速检测工作。      

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。     

非小细胞肺癌原发灶和转移灶EGFR和KRAS状态比较的meta分析

背景与目的非小细胞肺癌EGFR和KRAS基因状态对肺癌一线靶向治疗的选择尤为关键,而原发肿瘤和转移瘤之间可能存在不同的EGFR和KRAS基因状态.本研究旨在系统评价比较配对的原发肺癌灶和转移灶EGFR和KRAS基因状态以指导临床实践.方法通过Pubmed数据库检索所有符合检索条件的文献,末次检索日期2010年5月10日,根据纳入和排除标准进一步筛选.采用meta分析方法比对肺癌原发灶和转移灶中EGFR基因突变、扩增、EGFR蛋白表达和KRAS基因突变状态之间的差异.结果 14篇文献纳入meta分析,具有配对的原发灶和转移灶,598例vs 598例.原发灶中EGFR蛋白表达和KRAS基因的突变频率高于转移灶,RR分别为1.13(95%CI:0.98-1.31,P=0.09)和1.39(95%CI: 0.95-2.03,P=0.09).转移灶中EGFR的基因拷贝数高于原发灶,RR=0.74(95%CI:0.53-1.02,P=0.06).EGFR基因在原发灶和转移灶中的突变频率无统计学差异(P=0.31).原发灶和转移灶基因状态不一致率分别为:EGFR突变率为17.09%;EGFR扩增率为27.07%;EGFR蛋白表达率为27.84%;KRAS突变率为25.91%.结论肺癌原发灶和相应转移灶中EGFR基因突变较KRAS基因状态更为稳定,原发灶中KRAS基因突变更能反映肺癌周身癌灶KRAS基因特征,单独对转移灶做KRAS状态分析可能会引入更多抵抗EGFR酪氨酸激酶抑制剂治疗的患者.联合检测原发灶中EGFR和KRAS基因突变可作为肺癌靶向治疗的疗效预测指标.     

肺癌原发灶与纵隔转移淋巴结中EGFR突变差异的研究

目的 探讨肺癌原发灶和转移纵隔淋巴结中EGFR突变率有无差异.方法 采用PCR扩增ARMS法,分析NSCLC原发灶组织中EGFR基因突变与纵隔转移淋巴结中EGFR基因突变情况,比较两者突变率.结果 37例非小细胞肺癌患者原发灶检测到EGFR基因突变,突变率为37％,34例纵隔转移淋巴结检测到EGFR基因突变,突变率为34％.NSLCL患者原发灶和纵隔转移淋巴结中EGFR均有突变95.77％;均没有突变97.67％.肺癌原发灶与纵隔淋巴结EGFR突变一致率达到97％.肺癌原发灶与纵隔淋巴结EGFR突变率比较无差异P＞0.05.结论 肺癌原发灶与纵隔转移淋巴结EGFR突变率无差异.     

福建省非小细胞肺癌患者EGFR基因突变分析

 目的　检测福建省非小细胞肺癌（NSCLC）患者表皮生长因子受体（EGFR）基因突变情况。方法　提取50例NSCLC患者新鲜癌组织及其对应的正常组织标本的DNA，用EGFR基因巢式聚合酶链反应（PCR）及脱氧核糖核酸（DNA）测序技术分析NSCLC患者EGFR基因突变情况。结果　50例NSCLC患者的正常组织EGFR第19、21外显子均为野生型，而50例NSCLC患者的癌组织EGFR基因突变检出率为26 ％（13／50）。第19外显子缺失突变10例，第21外显子替代突变3例。结论　福建省NSCLC患者EGFR突变以19外显子突变为主。     

EGFR19/21基因突变与NSCLC组织中p53蛋白表达的关系及对预后的影响

目的 探讨表皮生长因子受体19/21(EGFR19/21)基因突变与非小细胞肺癌(NSCLC)患者肿瘤组织中p53蛋白表达的关系及对患者预后的影响.方法 收集98例NSCLC患者的NSCLC组织标本,采用Taqman-ARMS法检测肿瘤组织中EGFR19/21基因的突变情况,采用免疫组化检测p53蛋白的表达情况,并根据EGFR19/21基因检测结果将患者分为突变组(n=44)和野生型组(n=54),分析EGFR19/21基因突变与p53蛋白表达及患者预后的关系.结果 EGFR19/21基因突变组NSCLC患者p53蛋白的阳性表达率为38.64％,低于野生型组NSCLC患者的59.26％,差异有统计学意义(P﹤0.05).不同年龄、性别、肿瘤直径、TNM分期、淋巴结转移情况、分化程度、病理类型、ECOG评分NSCLC患者的EGFR19/21基因突变发生率比较,差异均无统计学意义(P﹥0.05);Cox比例风险回归分析结果显示,TNM分期高、发生淋巴结转移、分化程度为低分化、p53蛋白阳性表达是影响NSCLC患者预后的独立危险因素(P﹤0.05),EGFR19/21突变是影响NSCLC患者预后的保护因素(P﹤0.05).结论 EGFR19/21基因突变的NSCLC患者,其p53蛋白呈现低表达,EGFR19/21野生型患者的预后较突变型差.     

EGFR基因突变与EGFR酪氨酸激酶抑制剂近期疗效的关系

背景与目的 多项研究证实表皮生长因子受体(epidermal growth factor receptor,EGFR)突变与EGFR酪氨酸激酶抑制剂(tyrosine kinase inhibitor,TKI)的疗效存在相关性.本研究应用荧光定量PCR技术检测晚期肺癌的EGFR基因突变,分析其与EGFR TKI药物Gefitinib二线治疗晚期非小细胞肺癌(nonsmall cell lung cancer,NSCLC)的近期疗效之间的关系.方法 从63例血浆和胸腔积液标本(其中血浆53例,胸腔积液10例)中提取游离DNA,应用荧光定量PCR技术进行EGFR 18、19、21外显子基因的检测,并结合临床进行分析.结果 在63例血浆和胸腔积液标本中检测到EGFR基因突变17例,突变率为27.0%.EGFR基因突变主要见于女性及非吸烟人群(P＜0.05).存在EGFR基因突变的患者Gefitinib二线治疗的疗效明显优于野生型患者(P＜0.01).结论 晚期NSCLC患者的血浆、胸腔积液游离DNA中存在EGFR基因突变,这类突变可以通过荧光定量PCR技术检测出来.EGFR基因突变患者对Gefitinib的反应率明显高于野生型患者,检测胸腔积液和/或血浆EGFR基因突变有助于选择有效患者接受EGFR TKI治疗.     

中国新疆维吾尔族人群中肺癌驱动基因的表达

背景与目的：肺癌的发病率和肿瘤相关死亡率居当前世界各地恶性肿瘤的首位。肺癌亦存在多种驱动基因。各民族间的差异反映出肺癌的不同基因突变存在差异。该研究旨在探讨新疆维吾尔族患者中肺癌驱动基因的表达状况。方法：收集维吾尔族肺癌患者组织标本43例,采用扩增受阻突变系统(amplification refractory mutation system,ARMS)检测EGFR基因表达,采用实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,RTFQ-PCR)检测K-ras、ALK、ROS1、BRAF及PIK3CA基因表达,分析肺癌驱动基因突变与新疆维吾尔族肺癌患者临床病理特征之间的相关性。结果：43例标本中,EGFR基因突变率为11.63%,其中腺癌及鳞癌EGFR基因突变检出率分别为26.67%和4.76%;大细胞癌、腺鳞癌及小细胞肺癌均未测出EGFR基因突变。肺腺癌患者EGFR基因突变率为26.67%,明显高于非腺癌者的3.57%,差异有统计学意义(P=0.024)。K-ras12/13杂合突变6例,突变检出率为16.28%(6/43);PIK3CA杂合突变2例,突变检出率为4.65%(2/43)。1例发生EGFR基因与K-ras基因同时突变。维吾尔族肺癌患者EGFR基因突变与年龄、性别、吸烟状况、TNM分期、ECOG评分均无关。43例标本中均未见ALK、ROS1融合基因及BRAF基因突变。结论：与亚洲人群相比,新疆维吾尔族肺癌患者EGFR突变率较低,K-ras突变率高,类似于欧美高加索人群的突变特点。     

EGFR突变对非小细胞肺癌预后的影响

目的 探讨EGFR基因突变对非小细胞肺癌(NSCLC)患者临床特征,预后的价值,揭示总生存期(OS)≥3年的生存特点。方法 回顾性分析2013年1月1日至2018年6月30日南京医科大学附属肿瘤医院接受个体化治疗的349例NSCLC患者临床资料。对应收集石蜡包埋组织标本,采用HRM法,检测组织中EGFR基因第18、19、20、21外显子的突变状态,分析EGFR基因突变与患者临床病理参数的相关性。Kaplan-Meier方法和χ2分析随访资料完整的249例患者EGFR基因突变对生存的影响,揭示OS≥3年生存影响因素。结果 在349例NSCLC肺癌患者中,EGFR基因突变率为50. 4%,EGFR基因主要高突变人群是女性(62. 2%)和腺癌患者(52. 0%),60岁易发生19突变(28. 9%),≥60岁(32. 0%)和女性(37. 8%)易发生21突变,差异具有统计学意义(P0. 05)。EGFR18、20、双突变和临床特征之间无统计学意义(P0. 05)。截至2018年12月15日,249例随访完整的患者中,中位生存时间为23个月。EGFR基因的总突变和21突变,与野生型相比较,能显著提高无进展生存期(PFS)和OS,差异具有统计学意义(P0. 05)。EGFR18、19、20、双突变的PFS生存率,与野生型相比较,差异不具有统计学意义(P0. 05)。OS≥3年和OS≤1年的患者在性别、TNM分期、淋巴结转移、EGFR总突变率、21的突变率及靶向治疗率方面差异有统计学意义(P0. 05)。结论 EGFR基因的总突变和21突变的患者均能明显延长生存期。     

Frequent EGFR mutations in brain metastases of lung adenocarcinoma

Lung adenocarcinomas often metastasize to the brain, and the prognosis of patients with brain metastases is still very poor. The epidermal growth factor receptor (EGFR) gene is mutated in a considerable fraction of primary lung adenocarcinomas, in particular those with drastic response to EGFR tyrosine kinase inhibitors. The present study was designed to elucidate the prevalence of EGFR mutations in brain metastases and the timing of their occurrence during cancer progression. EGFR mutations were detected in 12 of 19 metastatic lung adenocarcinomas to the brain (63%). This frequency was higher than those in previous studies for EGFR mutations at various stages of lung adenocarcinoma in East Asia, including Japan (i.e., 20-55%). In 6 cases with EGFR mutations, the corresponding primary lung tumors were also examined for the mutations, and in all of them, the same types of EGFR mutations were detected also in the primary tumors. In 2 of them, second metastatic brain tumors in addition to the first ones were also available for analysis, and the same types of EGFR mutations were detected in both the first and second ones in both cases. These results indicate that EGFR mutations are present frequently in brain metastases and occur preceding brain metastasis. These findings will be highly informative for treatment of metastatic lung adenocarcinoma to the brain.     

探讨ⅢA-N 2 期NSCLC 原发瘤体与N2 淋巴结及外周血中EGFR基因突变的差异性

目的:探讨ⅢA-N 2 期非小细胞肺癌（non-small cell lung cancer ,NSCLC ）原发瘤体、N 2 淋巴结及外周血中表皮生长因子受体基因（epidermal growth factor receptor ,EGFR）突变状况是否存在差异性,从基因层面为目前所提倡的“个体化医疗”提供一些有价值的参考指标。方法:用突变富集—液相芯片法检测中山大学肿瘤防治中心及延安大学附属医院2014年11月至2015年11月间手术切除并经病理证实49例病理分期为ⅢA-N 2 期的NSCLC 原发瘤体、N 2 淋巴结及外周血中EGFR 基因19号及21号外显子突变状况,并对检测结果整理分析。结果:49例患者中,有18例（36.7%）从原发瘤体中检测出EGFR 基因突变,11例（22.4%）从N 2淋巴结中检测出EGFR 基因突变,而从外周血中仅有2 例（4.1%）检测出EGFR 基因突变;其中9 例仅有原发瘤体中EGFR 基因突变,2 例仅有N 2 淋巴结中EGFR 基因突变;而外周血中检测出EGFR 基因突变的2 例,同时也在原发瘤体及N 2 淋巴结中检测出EGFR 基因突变。结论:在NSCLC 原发瘤体及转移淋巴结中EGFR 基因突变状况存在一定的差异性;在ⅢA-N 2 期NSCLC 患者外周血中,EGFR 基因突变检出率较低。以上结果提示肿瘤在转移过程中从分子水平上可能已经发生改变,存在一定的差异性,为今后EGFR-TKIs 治疗NSCLC 乃至于其他针对基因靶点的个体化治疗提供有价值的思考。      

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.     

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

This study aimed to detect mutations in EGFR and KRAS and alterations of c-Met gene copy number (GCN) changes in primary and lymph node-metastatic NSCLCs. The data showed the concordant rate of EGFR genotype in primary and stage N2 lymph node-metastatic tumors was 95.45%. c-Met GCN in stage N2 lymph nodes was significantly higher than that of the primary tumors (P = 0.038). The results suggest both primary and lymph-node metastases have relatively consistent EGFR mutations and EGFR mutations are not relevant to changes in c-Met GCN. c-Met GCN was increased significantly in EGFR TKI-naive patients with lymph node-metastatic tumors.     

EGFR mutations, gene amplification, and protein expression and KRAS mutations in primary and metastatic tumors of nonsmall cell lung cancers and their clinical implications: a meta-analysis

A meta-analysis was performed to determine EGFR mutations, gene amplification, and protein expression and KRAS mutations in primary and metastatic nonsmall cell lung cancer (NSCLC). We found that KRAS gene mutation frequencies were higher in primary than in metastatic tumors. There was no significant difference in EGFR mutation frequency between the primary and metastatic tumors. These results suggest that KRAS mutations in primary NSCLC foci may be a more accurate biomarker than in metastases to reflect KRAS mutation status. Combined detection of EGFR and KRAS mutations in primary NSCLC foci appears to be an optimal approach for first-line EGFR-TKI therapy.     

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 bedifferent in primary tumors (PT) and metastatic lymph nodes (MLN). The aim of this study was to compareEGFR mutations between PT and the corresponding MLN in NSCLC patients, and provide some guidelinesfor clinical treatment using TKI therapy. Materials and Methods: A systematic review and meta-analysis wasperformed with several research databases. Relative risk (RR) with the 95% confidence interval (CI) wereused to investigate the EGFR mutation status between PT and the corresponding MLN. A random-effectsmodel was used. Results: 9 publications involving 707 patients were included in the analysis. It was found thatactivation 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). Therewas no significant heterogeneity between the studies (I2=5%, p=0.003). Conclusions: There exists a considerabledegree of EGFR mutation discrepancy in NSCLC between PT and corresponding MLN, suggesting that tumorheterogeneity might arise at the molecular level during the process of metastasis.     

Quantification of EGFR mutations in primary and metastatic tumors in non-small cell lung cancer

Background

EGFR mutation detection has been widely applied in the prediction of TKIs therapy in Non-Small Cell Lung Cancer (NSCLC). Metastatic tumors rather than primary tumors were usually assayed for those patients in advanced stages. Although the difference of EGFR mutation status in primary and metastatic tumors has been reported, the quantitative difference (ratio of mutated EGFR among total EGFR) in primary and metastatic tumors as well as in different sites of primary tumors was not clear.

Methods

Genomic DNA in Formalin Fixed-Paraffin Embedded samples of primary and metastatic tumors of 50 NSCLC patients was extracted. Real-time fluorescent PCR was performed to quantify the EGFR mutation ratios.

Results

The EGFR mutation ratios detected in different sites of primary tumors were highly concordant, whereas the EGFR mutation ratios in metastatic tumors were lower than those in primary tumors.

Conclusions

Randomly chosen sample may reliably represent the type and ratio of mutations of EGFR in primary tumors. EGFR mutation ratios in primary tumors and metastatic tumors are different. If metastatic tumors are used for the detection of EGFR mutation, the sensitivity of the detection assay must be considered.     

Somatic mutations of the HER2 kinase domain in lung adenocarcinomas

Mutations in the epidermal growth factor receptor gene (EGFR) in lung cancers predict for sensitivity to EGFR kinase inhibitors. HER2 (also known as NEU, EGFR2, or ERBB2) is a member of the EGFR family of receptor tyrosine kinases and plays important roles in the pathogenesis of certain human cancers, and mutations have recently been reported in lung cancers. We sequenced the tyrosine kinase domain of HER2 in 671 primary non-small cell lung cancers (NSCLC), 80 NSCLC cell lines, and 55 SCLCs and other neuroendocrine lung tumors as well as 85 other epithelial cancers (breast, bladder, prostate, and colorectal cancers) and compared the mutational status with clinicopathologic features and the presence of EGFR or KRAS mutations. HER2 mutations were present in 1.6% (11 of 671) of NSCLC and were absent in other types of cancers. Only one adenocarcinoma cell line (NCI-H1781) had a mutation. All HER2 mutations were in-frame insertions in exon 20 and target the identical corresponding region as did EGFR insertions. HER2 mutations were significantly more frequent in never smokers (3.2%, 8 of 248; P=0.02) and adenocarcinoma histology (2.8%, 11 of 394; P=0.003). In 394 adenocarcinoma cases, HER2 mutations preferentially targeted Oriental ethnicity (3.9%) compared with other ethnicities (0.7%), female gender (3.6%) compared with male gender (1.9%) and never smokers (4.1%) compared with smokers (1.4%). Mutations in EGFR, HER2, and KRAS genes were never present together in individual tumors and cell lines. The remarkable similarities of mutations in EGFR and HER2 genes involving tumor type and subtype, mutation type, gene location, and specific patient subpopulations targeted are unprecedented and suggest similar etiologic factors. EGFR, HER2, and KRAS mutations are mutually exclusive, suggesting different pathways to lung cancer in smokers and never smokers.     

Comparison of the epidermal growth factor receptor protein expression between primary non-small cell lung cancer and paired lymph node metastases: implications for targeted nuclide radiotherapy

Background

The knowledge of Epidermal growth factor receptor (EGFR) expression in metastases of NSCLC was limited. In receptor-mediated targeted nuclide radiotherapy, tumor cells are killed with delivered radiation and therapeutic efficiency is mainly dependent on the receptor expression. Thus, the level and stability of receptor expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target. The goal of this study was to evaluate whether EGFR is suitable as target for clinical therapy.

Methods

Expression of EGFR was investigated immunohistochemically in paired samples of lymph node metastases and corresponding NSCLC primary lesions (n = 51). EGFR expression was scored as 0, 1+, 2+ or 3+.

Results

Positive (1+, 2+ or 3+) EGFR immunostaining was evident in 36 of 47 (76.6%) analysed NSCLC primary tumors, and in 78.7% of the corresponding lymph node metastases. When EGFR expression is classified as positive or negative, discordance between the primary tumors and the corresponding metastases was observed in 5 cases (10.6%). EGFR overexpression (2+ or 3+) was found in 53.2% (25/47) of the NSCLC primary tumors and 59.6% of the corresponding metastases. Nine out of the 47 paired samples (19.2%) were discordant: Only three patients who had EGFR overexpression in the primary tumors showed EGFR downregulation (0 or 1+) in lymph node metastases, while six patients changed the other way around.

Conclusions

The EGFR expression in the primary tumor and the corresponding metastasis is discordant in about 10% of the patients. When overexpression is considered, the discordance is observed in about 20% of the cases. However, concerning EGFR overexpression in the primary tumors, similar expression in the metastases could be predicted with a reasonably high probability, which is encouraging for testing of EGFR targeted nuclide radiotherapy.