EGFR酪氨酸激酶区域基因变异与吉非替尼治疗非小细胞肺癌临床因素相关性研究进展

【指示性摘要】吉非替尼是表皮性生长因子受体（EGFR）酪氨酸激酶抑制剂，在非小细胞肺癌的治疗中受到普遍关注，而EGFR突变有助于筛选针对吉非替尼治疗的受益人群，本文回顾了近期国外对EGFR突变及其与病理类型、种族、性别、生存期等临床因素的相关性。     

晚期NSCLC患者外周血中EGFR突变预测EGFR TKIs一线治疗的疗效的观察

目的:检测NSCLC患者外周血EGFR突变情况,预测EGFR TKIs作为治疗晚期NSCLC的一线疗法的疗效。方法:应用荧光偏振(TDI-FP)法检测51例晚期非小细胞肺癌患者外周血EGFR基因突变情况,口服EGFR TKI进行治疗,分析外周血基因突变结果与EGFR TKI疗效之间的关系。结果:TDI-FP法检测出的外周血EGFR突变率为60.8%(31/51)。经EGFR TKIs一线治疗后,EGFR突变型和EGFR野生型有效率(RR)分别为41.9%和5.0%;疾病控制率(DCR)分别为77.4%和15.0%;中位PFS则分别为13.0和7.0个月。与检测组织中EGFR突变比较,TDI-FP法检测外周血EGFR突变的正确率(π)为84.2%。统计学分析显示,EGFR突变型NSCLC患者应用EGFR TKIs一线治疗能获得更佳疗效。结论:应用荧光偏振法检测NSCLC患者外周血中的EGFR基因突变,对于预测EGFR TKI作为一线治疗的疗效有重要的价值。     

Epidermal growth factor receptor (EGFR) inhibitors in gastrointestinal cancer

Gastrointestinal (GI) cancer continues to be a leading cause of cancer morbidity and mortality worldwide. Over the past decade the treatment options for patients with GI cancers have increased with the advent of newer combination chemotherapy regimes. Despite these clinical advances, new strategies are warranted in order to improve the efficacy as well as the safety. New molecular targets have provided novel opportunities in the treatment of GI cancer. One of the most advanced new approaches to date is the use of targeted inhibitors of the epidermal growth factor receptor (EGFR). In this review we describe the current status of therapeutic strategies based on EGFR inhibitors in the treatment of GI cancer.     

中国非小细胞肺癌患者表皮生长因子受体突变的研究

背景与目的:最近的研究结果表明,表皮生长因子受体(epidermalgrowthfactorreceptor,EGFR)基因酪氨酸激酶域的体细胞突变与非小细胞肺癌(non鄄smallcelllungcancer,NSCLC)患者对酪氨酸激酶抑制剂吉非替尼的敏感性密切相关。这些突变均发生在酪氨酸激酶域的ATP结合域附近,突变为19号外显子上的缺失突变,或18和21号外显子上的替代突变。研究发现,日本患者的突变率高于美国患者的突变率。本研究中我们分析中国NSCLC患者肺癌组织中EGFR突变情况。方法:收集2004年7月到10月间中山大学肿瘤防治中心52例可手术的NSCLC患者的新鲜组织标本,包括肿瘤组织标本和来自同一患者相应的正常肺组织标本。所有患者均未接受过吉非替尼治疗。采用PCR技术扩增EGFR基因的19和21号外显子,从正反两个方向对扩增片段进行DNA测序和分析。结果:52例1NNNSCLC患者中10例(19.2%)患者EGFR基因酪氨酸激酶域存在体细胞突变。10例突变中包括7例(70%)发生于19号外显子上的缺失突变,另外3例(30%)发生于21号外显子上的替代突变。腺癌(6/23,26.1%)、腺鳞癌(2/5,40.0%)和支气管肺泡癌(2/4,50.0%)的突变率高于鳞癌(0/20,0.0%)的突变率(P=0.025);非吸烟者的突变率(7/17,41.8%)高于吸烟者的突变率(3/35,8.6%)(P=0.009);而女性患者突变率(3/13,23.1%)与男性患者突变率(7/39,18.0%)无显著性差异(P=0.697)。结论:中国NSCLC患者EGFR的突变率较高,与日本患者的突变情况相似,明显高于高加索人种。     

表皮生长因子受体在肺癌诊治中的研究

表皮生长因子受体(EGFR)近年来已成为肿瘤诊断及治疗的一个潜在靶点.本文对肺癌中EGFR的表达及其与肺癌患者的预后关系以及在肺癌诊治方面的研究进展作一概述.     

Association of epidermal growth factor receptor (EGFR) gene mutations with EGFR amplification in advanced non-small cell lung cancer

Somatic mutations in the epidermal growth factor receptor (EGFR) gene are associated with the response to EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). Increased EGFR copy number has also been associated with sensitivity to these drugs. However, given that it is often difficult to obtain sufficient amounts of tumor tissue for genetic analysis from patients with advanced NSCLC, the relationship between these two types of EGFR alterations has remained unclear. We have now evaluated EGFR mutation status both by direct sequencing and with a high-sensitivity assay, the Scorpion-amplification-refractory mutation system, and have determined EGFR copy number by fluorescence in situ hybridization (FISH) analysis in paired tumor specimens obtained from 100 consecutive patients with advanced NSCLC treated with chemotherapy. EGFR mutations or FISH positivity (EGFR amplification or high polysomy) were apparent in 18% (18/100) and 32% (32/100) of patients, respectively. The Scorpion-amplification-refractory mutation system was more sensitive than direct sequencing for the detection of EGFR mutations. Furthermore, EGFR mutations were associated with EGFR amplification (P = 0.009) but not with FISH positivity (P = 0.266). Our results therefore suggest the existence of a significant association between EGFR mutation and EGFR amplification in patients with advanced NSCLC.     

Epidermal growth factor receptor targeted therapy by ZD 1839 (Iressa) in patients with brain metastases from non-small cell lung cancer (NSCLC)

PURPOSE: We report four cases of Brain Metastases (BM) from non-small cell lung cancer (NSCLC) responding to ZD 1839 therapy after standard therapy failure. PATIENTS AND METHODS: Four patients with BM from NSCLC, pretreated with two or more lines of chemotherapy, received ZD 1839 (Iressa), on a compassionate use basis, at the daily dose of 250 mg until disease progression. Three patients received Iressa after whole brain radiotherapy (WBRT) failure. RESULTS: After 3 months of ZD 1839 therapy, one patient had complete response on the brain with stabilization of extracranial disease, while the other three patients had partial response both on the brain and on extracranial sites. At the time of this analysis, two patients discontinued the treatment after 5 and 7 months for disease progression, while two patients are still on treatment with no evidence of treatment failure after 3+ and 12+ months. ZD 1839 was generally well tolerated, with skin toxicity recorded in two patients. CONCLUSION: ZD 1839 may be effective in NSCLC patients with pretreated BM. Large and prospective trials need to clarify the role of ZD 1839 in the treatment of BM from NSCLC.     

Intercalated chemotherapy and erlotinib for non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutations

Among attempts to delay development of resistance to tyrosine kinase inhibitors (TKIs) in patients with advanced non-small cell lung cancer (NSCLC) with activating mutations of epidermal growth factor receptor (EGFR), intercalated therapy has not been properly evaluated. In a phase II trial, 38 patients with EGFR mutated NSCLC in advanced stage were treated with 4 to 6 3-weekly cycles of intercalated schedule with gemcitabine (1250 mg/m2, days 1 and 4), cisplatin (75 mg/m2, day 2) and erlotinib (150 mg, days 5 – 15), followed by continuous erlotinib as maintenance. In addition to standard radiologic evaluation according to RECIST, PET/CT was done prior to treatment and at 6 months, using PERCIST as a method for assessment of response. The primary endpoint was progression-free survival (PFS). In general, tolerance to treatment was good, even among 8 patients with performance status 2–3 and 13 patients with brain metastases; grade 4 toxicity included 2 cases of neutropenia and 4 thrombo-embolic events. Complete response (CR) or partial response (PR) were seen in 15 (39.5%) and 17 (44.7%) cases, respectively. All cases of CR were confirmed also by PET/CT. Median PFS was 23.4 months and median overall survival (OS) was 38.3 months. After a median follow-up of 35 months, 8 patients are still in CR and on maintenance erlotinib. In conclusion, intercalated treatment for treatment-naive patients with EGFR activating mutations leads to excellent response rate and prolonged PFS and survival. Comparison of the intercalated schedule to monotherapy with TKIs in a randomized trial is warranted.     

吉非替尼、厄洛替尼与埃克替尼治疗EGFR基因敏感突变晚期NSCLC患者的疗效观察

目的:观察吉非替尼、厄洛替尼与埃克替尼在EGFR基因敏感突变晚期非小细胞肺癌(NSCLC)患者一线治疗中的疗效差异。方法:收集2013年5月—2014年12月间在我院接受治疗的76例EGFR基因突变的晚期NSCLC患者,随机分为三组,A组接受吉非替尼治疗,250 mg,1次/d,空腹口服;B组接受厄洛替尼治疗,150 mg,1次/d,餐前1 h口服;C组接受埃克替尼治疗,125 mg,3次/d,评价疗效及安全性。结果:吉非替尼组、厄洛替尼组和埃克替尼组的客观有效率（ORR）分别为26.9%、34.6%和45.8%;疾病控制率（DCR）分别为61.5%、73.0%和79.2%。三组之间的有效率和疾病控制率差异无统计学意义(P＞0.05）。三组的无进展生存时间（PFS）分别为9.5个月、10个月和9.5个月;19号外显子缺失突变型患者中,三组的PFS分别为8.5个月、12个月和9个月;21号外显子L858R错义突变型患者中,PFS分别为9.5个月、8.5个月和7个月,三组之间无统计学差异(P＞0.05）。结论:吉非替尼、厄洛替尼与埃克替尼治疗EGFR基因突变的晚期NSCLC疗效相似,但在19号外显子缺失突变型患者中,厄洛替尼略显优势。     

Epidermal growth factor receptor mutations in needle biopsy/aspiration samples predict response to gefitinib therapy and survival of patients with advanced nonsmall cell lung cancer

Recently, mutations in the epidermal growth factor receptor (EGFR) gene in nonsmall cell lung cancer (NSCLC) patients were reported to correlate with gefitinib response. Less than 30% of NSCLC patients are surgically resectable; however, molecular analysis has to rely on nonsurgical diagnostic tissue samples. The objective of this study is to investigate EGFR mutation analysis on needle biopsy/aspiration samples and its correlations with gefitinib response and patients' survival. EGFR mutation was assessed from DNA of 63 paraffin-embedded small needle biopsy/aspiration specimens from 62 patients with NSCLC treated with gefitinib. The peripheral blood lymphocyte DNA of the patients was sequenced to verify the EGFR mutation. EGFR mutations were found in 47% of 62 patients (60% of 20 CT-guided biopsies, 44% of 18 ultrasound-guided biopsies, 31% of 16 endoscopic biopsies and 44% of 9 effusion cell blocks). EGFR mutations were frequently present in females (p = 0.006) and never smokers (p = 0.04). Patients with EGFR mutations had a significantly better response rate compared to that of the nonmutation group (p < 0.001). Multivariate analysis showed that EGFR mutation (p < 0.001) and PS 0-1 (p = 0.02) were independently associated with a better response rate. Cox regression analysis showed that EGFR mutation was the independent prognostic factor for progression-free survival (p = 0.008) and overall survival (p = 0.03). In conclusion, EGFR mutation analysis is feasible in needle biopsy/aspiration paraffin-fixed specimens. EGFR mutation is an independent predictor of gefitinib response and survival in patients of advanced NSCLC treated by gefitinib.     

Epidermal growth factor receptor mutation analysis in cytological specimens and responsiveness to gefitinib in advanced non-small cell lung cancer patients

Background

Epidermal growth factor receptor (EGFR) mutation is the key predictor of EGFR tyrosine kinase inhibitors (TKIs) efficacy in non-small cell lung cancer (NSCLC). We conducted this study to verify the feasibility of EGFR mutation analysis in cytological specimens and investigate the responsiveness to gefitinib treatment in patients carrying EGFR mutations.

Methods

A total of 210 cytological specimens were collected for EGFR mutation detection by both direct sequencing and amplification refractory mutation system (ARMS). We analyzed EGFR mutation status by both methods and evaluated the responsiveness to gefitinib treatment in patients harboring EGFR mutations by overall response rate (ORR), disease control rate (DCR) and progression free survival (PFS).

Results

Of all patients, EGFR mutation rate was 28.6% (60/210) by direct sequencing and 45.2% (95/210) by ARMS (P<0.001) respectively. Among the EGFR wild type patients tested by direct sequencing, 26.7% of them were positive by ARMS. For the 72 EGFR mutation positive patients treated with gefitinib, the ORR, DCR and median PFS were 69.4%, 90.2% and 9.3 months respectively. The patients whose EGFR mutation status was negative by direct sequencing but positive by ARMS had lower ORR (48.0% vs. 80.9%, P=0.004) and shorter median PFS (7.4 vs. 10.5 months, P=0.009) as compared with that of EGFR mutation positive patients by both detection methods.

Conclusions

Our study verified the feasibility of EGFR analysis in cytological specimens in advanced NSCLC. ARMS is more sensitive than direct sequencing in EGFR mutation detection. EGFR Mutation status tested on cytological samples is applicable for predicting the response to gefitinib. Abundance of EGFR mutations might have an influence on TKIs efficacy.     

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer harboring uncommon EGFR mutations: Focus on afatinib

The development of first-, second-, and third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of patients with non-small cell lung cancer (NSCLC) harboring mutations in the EGFR. However, limited data are available regarding the activity of available EGFR TKIs against uncommon EGFR mutations. This is an important question because improvements in screening techniques are facilitating the identification of patients with uncommon mutations for whom optimal treatment has not yet been clarified. This uncertainty reflects the fact that most prospective clinical trials of EGFR TKIs have been restricted to patients with tumor harboring common (Del19 or L858R) mutations. In this article, we discuss the nature of EGFR mutation heterogeneity in NSCLC and review recent preclinical and clinical data that have assessed the sensitivity of different mutations to different EGFR TKIs. Recent preclinical data indicate that second-generation ErbB family blockers, such as afatinib, have a broad activity profile across uncommon EGFR mutations. Emerging evidence indicates that the preclinical data for afatinib are reflected in the clinic. Subanalysis of clinical trials, and real-world data, demonstrate that EGFRs with defined, but uncommon mutations such as G719X, S768I, and L861Q are sensitive to afatinib, which is now approved for tumors harboring these mutations. A recent clinical trial has demonstrated that EGFRs harboring some of these less common mutations also appear to be sensitive to the third-generation EGFR TKI, osimertinib. Treatment options for tumors with other uncommon mutations, notably exon 20 insertion, remain an area of unmet need, although osimertinib has shown preclinical activity in this setting, and early clinical activity has been seen with the dual EGFR/HER2 TKIs, poziotinib and TAK-788. Further data are required to help drive appropriate treatment decisions in patients whose tumors harbor these uncommon EGFR mutations. To see an abstract video summarising the content of the paper, please visit http://usscicomms.com/oncology/masood/seminars-in-oncology/.     

血清循环DNA的EGFR基因突变与肺癌选择性靶向治疗研究

目的:通过血清循环DNA的基因突变检测,筛选EGFR突变型肺癌患者并评估靶向性药物吉非替尼对其的临床疗效。方法:从肺癌患者血清中提取DNA,采用PCR扩增和基因测序检测EGFR突变。结果:116例肺癌血样中检出EGFR突变46例,突变率为39.7%,其中外显子19和21突变分别占65.2%(30/46例)和34.8%(16/46例),EGFR基因突变多见于女性患者和肺腺癌(包括腺鳞癌)患者。对20例肺癌的进一步分析证明,血清EGFR基因突变类型与患者自身肿瘤的突变类型相同。另外通过血清循环DNA基因检测法筛选了19例化疗失败的突变型晚期肺癌进行吉非替尼靶向治疗,客观有效率为52.6%,病情控制率为89.5%,中位无进展生存时间为8个月,中位生存时间为12个月,2年生存率达到33.3%。结论:证实血清循环DNA与肿瘤组织DNA的EGFR基因突变一致;以血清循环EGFR突变检测结果为依据选择分子靶向性药物吉非替尼治疗,对晚期肺癌患者疗效明显。     

Epidermal growth factor receptor mutations in small cell lung cancer

PURPOSE: The vast majority of epidermal growth factor receptor (EGFR) mutations occur in lung adenocarcinoma, and even rare cases of other subtypes with this mutation, such as adenosquamous cell carcinoma, are associated with adenocarcinoma histology. According to this adenocarcinoma-specific nature of EGFR mutation, analysis of EGFR mutations with small cell lung cancers (SCLC) may provide a clue to its histogenesis. EXPERIMENTAL DESIGN: The mutational status of the EGFR gene was accessed in a cohort of 122 patients with SCLC; all patients were from a single institute. When the EGFR mutated, its gene copy number was also examined. RESULTS: EGFR mutations were detected in five SCLCs (4%). The patients were mainly in the light smoker and histologic combined subtype. All but one of the tumors harbored gene amplifications. Notably, in three tumors of the combined SCLC subtype, both components of adenocarcinoma and SCLC harbored an EGFR mutation, whereas gene amplification was detected only in the adenocarcinoma component. A partial response was achieved in a patient (with an EGFR mutation) who was treated with gefitinib. CONCLUSIONS: Although EGFR mutations are rare in SCLC, a combined subtype of SCLC with adenocarcinoma in light smokers may have a chance of harboring EGFR mutations. For patients with an EGFR mutation, EGFR tyrosine kinase inhibitor can be a treatment option. In terms of molecular pathogenesis, it is suggested that some SCLCs may have developed from pre-existing adenocarcinomas with EGFR mutations, but the development may not be simply linear, taking into consideration the discordant distribution of EGFR amplification.     

Epidermal growth factor receptor (EGFR) status and K-Ras mutations in colorectal cancer

Background: In advanced colorectal cancer, K-Ras somatic mutations predict resistance to mAbs targeting epidermal growth factor receptor (EGFR). Relationships between K-Ras mutations and EGFR status have not been examined so far. We analyzed relationships between K-Ras mutations and EGFR tumoral status based on EGFR germinal polymorphisms, gene copy number and expression.Methods: Eighty colorectal tumors (stage 0–IV) and 39 normal mucosas were analyzed. K-Ras mutations at codons 12 and 13 were detected by a sensitive enrichment double PCR–restriction fragment length polymorphism (RFLP) assay. EGFR gene polymorphisms at positions -216G>T, -191C>A and 497Arg>Lys were analyzed (PCR–RFLP), along with CA repeat polymorphism in intron 1 (fluorescent genotyping) and EGFR gene copy number (PCR amplification). EGFR expression was quantified by Scatchard binding assay.Results: The number of EGFR high-affinity sites, dissociation constant (Kd), gene copy number, intron 1, -216G>T, -191C>A or 497Lys>Arg genotypes was not different between K-Ras-mutated or K-Ras-non-mutated tumors. No relationship was observed between any of the analyzed EGFR genotypes and EGFR expression. EGFR expression was not related to gene copy number. EGFR gene copy number in tumor and normal tissue was not correlated. The mean value of the tumor/normal mucosa gene copy number ratio was 1.16.Conclusions: Present data clearly show that EGFR status is independent of K-Ras mutations in colorectal tumors.     

Epidermal growth factor ligand/receptor loop and downstream signaling activation pattern in completely resected nonsmall cell lung cancer

BACKGROUND: In recent years, molecular insights shed light on the role of the epidermal growth factor receptor (EGFR) in nonsmall cell lung cancer (NSCLC), and new therapeutic agents, such as the EGFR tyrosine kinase inhibitors, were tested successfully, with responsiveness to those agents more likely in those patients with specific EGFR gene alterations. The objective of the current study was to investigate the protein profiles of EGFR, c-erb-B2, transforming growth factor alpha (TGF-alpha) (one of the EGFR ligands commonly expressed in NSCLC), and some downstream molecules, potentially to detect a subset of tumors with an activated autocrine loop that is responsible for higher intracellular signaling. METHODS: One hundred twelve consecutive patients with resected NSCLC were analyzed by immunohistochemistry for EGFR, the c-erb-B2 receptor, TGF-alpha, and pivotal molecules downstream from EGFR activation. Statistical correlations between the investigated molecular expression profiles and clinicopathologic data were performed. RESULTS: EGFR, c-erb-B2, TGF-alpha and downstream molecule expression, per se, was not correlated significantly with any clinicopathologic variables, with the exception of a significant correlation between squamous histology and EGFR and between adenocarcinoma and TGF-alpha. However, nearly 30% of NSCLCs demonstrated coexpression of both TGF-alpha and EGFR, and this molecular status was associated positively with a statistically significant expression of phosphatidylinositol 3 kinase and an inversely with mitogen-activated protein kinase expression. CONCLUSIONS: The presence of a subgroup of NSCLCs with an activated autocrine loop may help to explain the mechanisms that lead to the relative ineffectiveness of the EGFR tyrosine kinase inhibitor and may support new clinical trials to define whether the subgroup of patients with these tumors reasonably may benefit from higher doses of such inhibitors or from the simultaneous inhibition of EGFR downstream signaling targets.     

Epidermal growth factor receptor mutations detected by denaturing high‐performance liquid chromatography in nonsmall cell lung cancer

BACKGROUND:

Somatic mutations in the epidermal growth factor receptor (EGFR) kinase domain are associated with sensitivity to EGFR‐tyrosine kinase inhibitors (EGFR‐TKI) in patients with nonsmall cell lung cancer (NSCLC).

METHODS:

The authors tested the possibility that nucleotide sequencing may be poorly suited for detection of mutations in tumor samples and found that denaturing high‐performance liquid chromatography (dHPLC) was an efficient and more sensitive method for screening.

RESULTS:

These results suggested that some reports based on standard DNA sequencing techniques may have underestimated mutation rates. In the present report, the authors examined the relationship between the presence and type of EGFR mutations detected by dHPLC and various clinicopathologic features of NSCLC, including response to therapy with EGFR‐TKI. Among 251 patients with advanced disease, 100 individuals received EGFR‐TKI. Those whose tumors harbored a detectable EGFR kinase mutation were much more likely to have a partial response (PR) or stable disease (SD) with EGFR‐TKI therapy than patients whose tumor contained no mutation (80% vs 35%; P = .001). Among the individual genotype subgroups, the frequency of a PR or SD was significantly different between patients with an exon 19 deletion compared with those with no detectable mutation (86% vs 35%; P < .001). Furthermore, patients whose tumors expressed an exon 19 mutant EGFR isoform exhibited a trend toward better EGFR‐TKI response (86% vs 67%; P = .171) and improved survival compared with patients whose tumors expressed an exon 21 mutation.

CONCLUSIONS:

Our findings warrant confirmation in large prospective trials and exploration of the biological mechanisms of the differences between mutation types. Cancer 2010. © 2010 American Cancer Society.