突变特异性免疫组织化学法检测非小细胞肺癌EGFR基因突变

背景与目的：表皮生长因子受体(epidermal growth factor receptor,EGFR)基因的突变状态是非小细胞肺癌(non-small cell lung cancer,NSCLC)患者使用EGFR酪氨酸激酶抑制剂(tyrosine kinase inhibitors, TKIs)的重要疗效预测指标。该研究旨在探讨突变特异性免疫组织化学(immunohistochemistry,IHC)法检测NSCLC标本EGFR基因突变的临床实用价值。方法：同时采用突变特异性IHC法和扩增阻滞突变系统(amplifi-cation refractory mutation system,ARMS)法检测290例NSCLC患者的EGFR基因突变状态,计算突变特异性IHC法检测EGFR基因突变的灵敏度、特异度、阳性预测值(positive predictive value,PPV)和阴性预测值(negative predictive value,NPV);比较ARMS法和突变特异性IHC法检测EGFR突变的一致性。结果：以ARMS法检测结果为金标准,当染色评分≥1+为阳性时,突变特异性IHC法诊断EGFR基因突变的灵敏度为72.92%,特异度为95.20%,PPV为93.75%,NPV为78.08%。突变特异性IHC法诊断不同类型EGFR基因突变的准确性相差明显：诊断19外显子缺失突变的灵敏度只有55.55%,但其特异度在99%以上;当染色评分为1+时,诊断L858R突变的灵敏度为90.27%,特异度为95.86%,当染色评分为2+或3+时,其特异度则为98.63%~100%。突变特异性IHC法与ARMS法检测结果有较好的一致性(P<0.001,Kappa值：0.612~0.864)。突变特异性IHC法能直观判断EGFR基因突变细胞丰度。结论：突变特异性IHC法是EGFR突变分子检测的有效补充。     

Ventana免疫组化检测非小细胞肺癌EML4-ALK融合基因及其结果判读难点分析

目的 分析Ventana免疫组织化学染色（IHC）检测非小细胞肺癌（NSCLC）组织中EML4-ALK融合基因的突变情况。解析Ventana IHC结果 判读的难点和陷阱,为此项检测的开展提供参考。方法 回顾性分析695份Ventana IHC检测NSCLC标本,对部分标本进行了实时定量PCR（qRT-PCR）对照研究。结果 EML4-ALK在腺癌中的突变率为8.78%,鳞状细胞癌中的突变率为4.49%,总突变率为8.48%。10例Ventana IHC为（-）和（+）标本qRT-PCR检测为阴性;5例Ventana IHC染色（+++）标本qRT-PCR检测均为阳性;5例Ventana IHC（++）标本qRT-PCR检测1例阳性。结论 EML4-ALK融合基因主要发生在肺腺癌。Ventana IHC检测结果 存在判读难点和陷阱,判读需要谨慎。EML4-ALK IHC检测阳性（++）的需要qRT-PCR或其它方法 进一步证实。     

高分辨率熔解曲线技术检测非小细胞肺癌患者胸水中EGFR基因突变

目的探讨高分辨率熔解曲线(HRM)技术对非小细胞肺癌(NSCLC)患者胸水标本EGFR基因突变进行检测的可行性及临床意义。方法采用高分辨率熔解曲线技术检测30例非小细胞肺癌患者胸水标本EGFR基因18-21外显子基因突变,并与Sanger测序法检测结果进行对比分析。结果HRM法检测胸水中EGFR基因18-21外显子突变总检出率为26.67%(8/30),Sanger测序法检测突变总检出率为23.33%(7/30)。HRM法与Sanger测序法相比,敏感性为100%,特异性为95.83%,阳性预测值为88.89%,阴性预测值为100%。结论运用HRM技术对非小细胞肺癌患者胸水进行EGFR基因突变检测方法可行,适宜推广。     

变性高效液相色谱技术检测非小细胞肺癌患者表皮生长因子受体基因突变的研究

 目的　探讨采用变性高效液相色谱（DHPLC）技术检测表皮生长因子受体（EGFR）基因突变的优势。方法　应用DHPLC技术检测49例非小细胞肺癌（NSCLC）患者EGFR基因第19与21外显子突变情况,并应用DNA直接测序法验证DHPLC检测基因突变的准确性。结果　49例NSCLC患者中,应用DHPLC检测出13例EGFR基因突变;其中第19外显子缺失突变10例（76.92 %）;第21外显子替代突变3例（23.08 %）。DNA直接测序法突变检测结果与DHPLC一致,DHPLC检测EGFR基因突变灵敏度为100 %。结论　DHPLC技术可以快速、准确、大规模筛选EGFR基因突变。     

IHC与FISH检测浸润性乳腺癌患者HER2蛋白表达和基因扩增的差异性分析

目的:探讨并比较免疫组织化学法（IHC）与荧光原位杂交法（FISH）检测浸润性乳腺癌人表皮生长因子受体-2（HER2）蛋白表达和基因扩增的差异性。方法:采用IHC法和FISH法分别检测桂西地区120例乳腺癌患者石蜡标本中HER2蛋白表达与基因扩增情况,比较IHC与FISH检测结果一致性并进行结果相关性分析。对检测不一致的病例重新检测及判读,分析差异原因。结果:120例乳腺癌患者中IHC 33例阳性（3+）中FISH检测阳性33例,阳性符合率100%;IHC 61例不确定（2+）中FISH检测阳性24例,阳性符合率39.34%;IHC 26例阴性（0/1+）中FISH检测阴性21例,阴性符合率80.77%。结果显示,除IHC（2+）外,IHC检测HER2蛋白表达与FISH检测HER2基因扩增有较好的一致性（P＜0.05）。造成两种检测方法差异的原因可能有标本固定不及时,抗体浓度偏低等。结论:IHC法检测HER2与FISH法一致性较好。临床实践中可根据实际情况,结合使用,以便指导临床治疗。     

非小细胞肺癌EGFR荧光原位杂交与免疫组化检测的比较

目的探讨荧光原位杂交（FISH）技术和免疫组化（IHC）法检测石蜡标本非小细胞肺癌（NSCLC）EGFR基因扩增及蛋白表达水平的差异性。方法采用FISH和IHC分别检测27例NSCLC患者石蜡标本EGFR基因和蛋白表达,对2种方法的检测结果进行对比分析。结果 14例IHC法EGFR表达（3＋）的标本中有9例FISH显示阳性（64.29%）,其中5例为EGFR基因高多体性扩增（55.56%）,4例为EGFR基因扩增（44.44%）;6例IHC（2＋）的标本中仅1例为高多体性扩增（16.67%）;2例IHC（1＋）及5例IHC（-）标本均无EGFR基因扩增。结论 IHC法初筛（3＋）、（2＋）的标本与FISH检测的符合率较低,提示对IHC检测EGFR表达为（3＋）及（2＋）并选择靶向药物治疗的病例,应采用FISH法对EGFR基因表达作进一步检测。     

免疫组织化学法与Sanger测序法对IDH1基因突变检测的比较分析

目的:采用免疫组织化学法(immunohistochemistry,IHC)、Sanger测序法分别对中枢神经系统肿瘤患者异柠檬酸脱氢酶1(isocitrate dehydrogenase 1,IDH1)基因进行突变检测,并对结果的一致性进行分析,为临床IDH1基因突变检测方法的选择提供指导依据。方法:运用IHC和Sanger测序法检测657例人脑胶质瘤及其他中枢神经系统肿瘤中IDH1基因突变。结果:IHC检测结果:657例样本中,230例发生IDH1基因突变,49例组织为少量阳、弱阳等可疑阳性;Sanger测序法检测发现255例存在IDH1基因突变,11例因DNA质量不佳无法获得可评估结果。IHC与Sanger测序法检测IDH1基因突变具有较好的一致性(Kappa=0.88),差异无统计学意义(P=0.49);IDH1基因突变主要发生在WHOⅡ~Ⅲ级的星形细胞瘤、少突胶质细胞瘤、间变星形细胞瘤、间变少突胶质细胞瘤以及WHOⅣ级的继发性胶质母细胞瘤中。结论:IHC检测IDH1基因突变的结果与Sanger测序法检测结果具有较好的一致性,IHC敏感性低于Sanger测序法,但特异性较高,且操作相对简单,适于临床普遍开展和推广;Sanger测序法敏感性高,可检测未知突变位点,IHC检测突变阴性及不确定的病例应进一步使用Sanger测序法验证。     

晚期肺腺癌患者化疗前后血清EGFR基因突变状态的比较

背景与目的 存在表皮生长因子受体(epidermal growth factor receptor,EGFR)基因突变的非小细胞肺癌(non-small cell lung cancer,NSCLC)作为NSCLC的一个特殊亚群,对于表皮生长因子酪氨酸激酶抑制剂(epidermal growth factor receptor tyrosine kinase inhibitor,EGFR-TKI)的治疗显示出良好的疗效.本研究旨在检测晚期肺腺癌患者化疗前后血清EGFR基因外显子19和外显子21的突变状态,并分析化疗是否对EGFR基因突变状态产生影响.方法 磁珠法提取血清游离DNA后,使用酶切富集巢式PCR分别对血清游离DNA中EGFR外显子19和外显子21进行特异性扩增,应用直接测序法对EGFR基因突变状态进行榆测.结果 33例肺腺癌患者化疗前EGFR基凶突变率为39.4%(13/33),化疗后为54.5%(18/33),化疗前后EGFR基因突变状态的一致率为54.5%(18/33);在不一致的15例患者中,10例由化疗前EGFR基因突变阴性变为阳性,5例由化疗前阳性变为阴性.结论 化疗可能导致血清EGFR基因突变状态的改变.     

不同病理分期肺腺癌EGFR、ALK基因状态与EGFR-TKI靶向治疗的关系

目的：探讨不同病理分期肺腺癌表皮生长因子受体（EGFR）、间变性淋巴瘤激酶（ALK）基因状态与EGFR-TKI靶向治疗的关系。方法选取接受EGFR-TKI靶向治疗的肺腺癌患者87例,检测患者EGFR、ALK基因状态,分析其与临床特征及疗效的关系。结果 EGFR突变患者与非EGFR突变患者年龄、性别及TNM分期比较,差异无统计学意义（P﹥0.05）;EGFR突变患者吸烟比例低于非EGFR突变患者（26.32%vs 48.98%）,差异有统计学意义（P﹤0.05）;ALK阳性与ALK阴性患者的性别、吸烟比例及TNM分期比较,差异均无统计学意义（P﹥0.05）;ALK阳性患者平均年龄低于ALK阴性患者,差异有统计学意义（P﹤0.05）;EGFR突变患者EGFR-TKI治疗的总缓解率优于ALK阳性和WT/WT患者,差异均有统计学意义（P﹤0.05）;ALK阳性患者和WT/WT患者治疗疗效比较,差异无统计学意义（P﹥0.05）。结论肺腺癌患者应首先进行EGFR检测,如有条件可同时检测EGFR突变和ALK重排;EGFR突变患者应首选EGFR-TKI靶向治疗。     

PCR-SSCP检测非小细胞肺癌EGFR基因突变的敏感性分析

目的 探讨分析PCR-SSCP检测非小细胞肺癌EGFR基因突变的敏感性.方法 应用PCR-SSCP检测36例非小细胞肺癌标本的突变情况,阳性结果再进行DNA测序.结果 通过PCR-SSCP分析,11例存在突变,突变率为30.6%(11/36);PCR-SSCP分析阳性的结果通过DNA测序全为序列异常.结论 PCR-SSCP检测肺癌EGFR基因突变具有较高的敏感性.     

Comparison of Polymerase Chain Reaction–Restriction Fragment Length Polymorphism,Immunohistochemistry, and DNA Sequencing for the Detection of IDH1 Mutations in Gliomas

Background: IDH1 mutation shows diagnostic, prognostic, and predictive value in gliomas. Direct Sanger sequencing is considered the gold standard to detect IDH1 mutation. However, this technology is not available in most neuropathological centers in developing countries such as Indonesia. Immunohistochemistry (IHC) and polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) have also been used to detect IDH1 mutation. This study aimed to compare DNA sequencing, IHC, and PCR–RFLP in detecting IDH1 mutations in gliomas. Methods: Research subjects were recruited from Dr. Sardjito Hospital. Genomic DNA was extracted from fresh or formalin-fixed paraffin-embedded samples of tumor tissue. DNA sequencing, PCR–RFLP and IHC were performed to detect IDH1 mutation. Sensitivity, specificity, and accuracy of PCR–RFLP and IHC were calculated by comparing them to DNA sequencing as the gold standard. Results: Among 61 recruited patients, 13 (21.3%) of them carried a mutation in codon 132 of the IDH1 gene, as shown by DNA sequencing. PCR–RFLP and DNA sequencing have a concordance value of 100%. Meanwhile, the concordance value between IDH1 R132H IHC and DNA sequencing was 96.7%. The sensitivity, specificity, positive predictive values, negative predictive values, and accuracy for PCR–RFLP were all 100%. On the other hand, the sensitivity, specificity, and accuracy of IHC were 92.3%, 97.9%, and 96.7%, respectively. Conclusion: This study showed that both PCR–RFLP and IHC have high accuracy in detecting IDH1 mutation. We recommend a combination of PCR–RFLP and IHC to detect IDH1 mutation in resource-limited settings.     

Novel EGFR mutation-specific antibodies for lung adenocarcinoma: Highly specific but not sensitive detection of an E746_A750 deletion in exon 19 and an L858R mutation in exon 21 by immunohistochemistry

Objectives

Activating mutations in the epidermal growth factor receptor (EGFR) kinase domain are correlated with dramatic clinical responses in non-small cell lung cancer patients treated with EGFR-tyrosine kinase inhibitors (TKIs). The two most common EGFR mutations, representing 85–90% of EGFR mutations, are the E746_A750 deletion in exon 19 and the L858R point mutation in exon 21. We conducted this study to evaluate the suitability of mutation-specific antibodies that can detect E746_A750 deletion and L858R mutant EGFR proteins by immunohistochemistry (IHC).

Materials and methods

In a cohort of consecutive patients with surgically resected lung adenocarcinomas (n = 240), mutant EGFR protein expression was assessed by IHC using specific antibodies (clone SP111 and SP125) to the 2 major forms of EGFR mutations. Immunoreactivity was scored as 0–3, and the results were compared with the EGFR-mutational status.

Results

With a cutoff value of IHC 2+ for SP 111 (anti-EGFR E746_A750 del antibody) and SP 125 (anti-EGFR L858R antibody), both antibodies showed high specificity (99.0% and 89.7%, respectively) and sensitivity (70.6% and 80.4%, respectively). While cases with IHC scores of 3 using these 2 antibodies positively correlated with the EGFR-mutational status, cases with IHC scores lower than 3+ showed variable results regarding EGFR-mutational status.

Conclusion

Although each antibody showed relatively high specificity, some EGFR-mutant cases were not detected by the mutation-specific antibodies. Various forms of exon 19 deletions, except E746_A750, were rarely detected by the mutant-specific antibody. Therefore, IHC-negative cases require further molecular analysis to confirm the presence of EGFR mutations.     

EGFR High Copy Number Together With High EGFR Protein Expression Predicts Improved Outcome for Cetuximab-based Therapy in Squamous Cell Lung Cancer: Analysis From SWOG S0819, a Phase III Trial of Chemotherapy With or Without Cetuximab in Advanced NSCLC

BackgroundThe phase III S0819 trial investigated addition of cetuximab to first-line chemotherapy (CT) in NSCLC. Subgroup analyses suggested an OS benefit among patients with EGFR copy number gain in squamous cell carcinomas (SCC), (HR = 0.58 [0.39-0.86], P = .0071). A more detailed model based on EGFR FISH, EGFR IHC and KRAS mutation status was evaluated to yield a more precise predictive paradigm of cetuximab-based therapy in advanced NSCLC.MethodsFISH was performed using the Colorado Scoring Criteria; H-Score was used to quantify EGFR IHC expression (cut-off ≥ 200). A Cox model was used to assess treatment effects for OS and PFS within biomarker and clinical subgroups. KRAS mutation was analyzed using Therascreen. The false discovery rate controlled for multiple comparisons. S0819 ClinicalTrials.gov Identifier: NCT00946712.ResultsOf 1,313 eligible patients, assay results were obtained for FISH on 976 patients (41% positive), for IHC on 945 patients (31% positive), and KRAS mutation status on 627 patients (26% positive). In SCC patients, OS was significantly improved with addition of cetuximab when both EGFR FISH and EGFR IHC were positive (N = 58), (OS HR: 0.32 [95% CI 0.18-0.59]; P = .0002, q = 0.08), median 12.6 versus 4.6 months. The results were independent of KRAS mutation status. In Non-SCC, no predictive value of EGFR IHC, EGFR FISH status and/or KRAS status was seen.ConclusionsIn NSCLC SCC, a combination index of EGFR FISH plus EGFR IHC results was associated with improved OS when cetuximab was added to CT, representing a potential predictive molecular paradigm for patients suitable for EGFR-antibody therapy.     

Epidermal Growth Factor Receptor Gene Mutation Detection in Histology and Cytology Specimens of Primary Lung Adenocarcinoma: Immunohistochemistry Versus the Molecular Method

Background: Epidermal growth factor receptor (EGFR) gene in lung adenocarcinoma is associated with good clinical response to EGFR-tyrosine kinase therapy. The two most common EGFR gene mutations, representing 80 to 90%, are the E746-A750 deletion in exon 19 and the L858R point mutation in exon 21. Materials and Methods: We have conducted the study to evaluate immunohistochemistry’s performance in detecting the E746-A750 deletion in exon 19 of the EGFR gene in primary lung adenocarcinoma cases. This study examined 133 cases of primary lung adenocarcinoma for three years duration. The selected cases were tested for EGFR gene mutations by real-time PCR by a reference laboratory. Most cases (124) were diagnosed by tissue biopsy, though nine used cell block cytology. We performed an immunohistochemistry test on 75 cases that contained adequate diagnostic material in the paraffin block. Results: The test result was scored as 0 to 3+, based on the staining intensity and percentage of positive tumor cells. We evaluated the immunohistochemistry test’s sensitivity and specificity compared to the EGFR gene mutations by real-time PCR. There was a significant association between gender, smoking status, and the EGFR gene mutations (P < 0.001). The overall sensitivity and specificity of the immunohistochemistry test were 40% and 100%, respectively. The positive predictive value and negative predictive values were 100% and 76.9%, each. Conclusions: The immunohistochemistry has high specificity but low sensitivity in the detection of E746-A750 deletion in exon 19 of the EGFR gene. The mutation-specific antibody used in this study was unable to detect other uncommon variants of exon 19 deletions. With high specificity value, immunohistochemistry may provide an adjunct to molecular testing for detecting the most common EGFR gene mutations in cases of a low cellularity sample, financially-limited situations, or in critically ill cases where urgent targeted therapy is needed.     

Unmet needs in squamous cell carcinoma of the lung: potential role for immunotherapy

The relationship between epidermal growth factor receptor (EGFR) mutation status and EGFR-tyrosine kinase inhibitors (TKI) efficacy in non-small cell lung cancer (NSCLC) patients has been well established. However, there is no available standard to define the optimal testing method and specimen type required for the detection of EGFR mutations. In this study, we compare results of ADx-amplification refractory mutation system (ARMS) and direct sequencing for the detection of EGFR mutation and prediction of EGFR-TKI efficacy for surgery and biopsy tumor tissues in 158 NSCLC patients. For 71 surgery samples, there were 13 and 17 positive samples detected by direct sequencing and ARMS, respectively. For 87 biopsy samples, direct sequencing and ADx-ARMS found 15 and 32 positive samples, respectively. For surgery samples, sensitivity of direct sequencing and ARMS was 72.2 % (13/18) and 94.4 % (17/18), respectively. For the biopsy samples, sensitivity of direct sequencing and ARMS was 44.1 % (15/34) and 94.1 % (32/34), respectively. For the biopsy and surgery samples, the ORRs for EGFR positive and negative patients detected by direct sequencing were 46.1 versus 16.7 and 66.7 versus 1.1 %, respectively. For ADx-ARMS, the ORR for EGFR positive patients was significantly higher than for negative patients (55.6 vs. 5.6 %). The median progression-free survival time of patients with EGFR wild type detected by direct sequencing (4.2 months) was significantly longer than that of patients with wild type detected by ARMS (1.7 months). ARMS has a higher sensitivity and specificity than direct sequencing for EGFR detection of mutation in both surgical and biopsy samples, and the results from ARMS are more consistent with the efficacy of EGFR-TKIs treatment.     

Epidermal growth factor receptor analyses in colorectal cancer: a comparison of methods

EGFR immunohistochemistry (IHC) status is not a reliable predictive marker for response to EGFR-targeted therapies. The present study compares the EGFR status at DNA, RNA and protein level. Blood samples, corresponding normal colon and colorectal cancer tissue were collected from 199 colorectal cancer (CRC) patients. EGFR status was evaluated by FISH analysis, real-time RT-PCR, ELISA and IHC. A polymorphism in the EGFR promoter was evaluated by PCR analysis. The EGFR levels by different methods were mutually compared. Seventy-eight percent of primary tumours and corresponding lymph nodes had equivalent EGFR status (28/34). There was a tendency to higher median protein level (by ELISA) in IHC positive patients compared to IHC negative patients (p=0.086). The median EGFR gene expression level was significantly lower in tumours than in the normal colon with no difference according to IHC status. No tumours had increased gene copy number by FISH. EGFR Sp1-216 polymorphism analysis showed a tendency for different EGFR tumour protein levels and gene expression levels according to the different genotypes. The results show a poor correlation between EGFR status at DNA, RNA and protein level. The predictive value of a combination of methods needs further evaluation in the clinical setting.     

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.     

Immunohistochemistry for EGFR Mutation Detection in Non–Small-Cell Lung Cancer

Introduction

The sensitivity and specificity of immunohistochemistry (IHC) was compared with the standard polymerase chain reaction (PCR)-based method for detecting common activating epidermal growth factor receptor (EGFR) mutations in non–small-cell lung cancer (NSCLC). Additionally, we evaluated predictive value of IHC EGFR mutation–positive status for EGFR tyrosine kinase inhibitor (TKI) treatment outcome and estimated cost-effectiveness for the upfront IHC testing.