Detection of epidermal growth factor receptor and human epidermal growth factor receptor 2 activating mutations in lung adenocarcinoma by high-resolution melting amplicon analysis: correlation with gene copy number, protein expression, and hormone receptor expression

Activating mutations in the epidermal growth factor receptor (EGFR) (7p12.3-p12.1) and in the human epidermal growth factor receptor 2 (HER2) (17q21.1) characterize a subset of lung carcinomas. These mutations may relate to the response of the tumor to the tyrosine kinase inhibitors gefitinib and erlotinib. High-resolution melting amplicon analysis is a screening technique that has been shown to be able to detect missense mutations as well as deletions and insertions in tumor DNA isolated from paraffin-embedded tissue sections. In this study, we used high-resolution melting amplicon analysis to screen for EGFR and human HER2 activating mutations in 39 patients with primary lung adenocarcinoma. There were 20 cases that showed bronchioloalveolar histology and 19 cases that did not. The EGFR exons screened were exons 18, 19, 20, and 21, and the HER2 exons screened were exons 19 and 20. Six (15%) of the 39 patients had tumors that contained EGFR activating mutations. Four of the mutations were in adenocarcinomas, which had some bronchioloalveolar features, and 2 mutations were in tumors without bronchioloalveolar features. The EGFR mutations were in exon 19 (2 cases), exon 20 (2 cases), and exon 21 (1 case). One case contained mutations in both exons 18 and 20. One (2.6%) of the 39 patients had a tumor that contained an HER2 activating mutation, and the mutation was located in exon 20. Two of the 6 EGFR mutation-positive cases showed polysomy for chromosome 7, and each one showed overexpression of EGFR as determined by immunohistochemical staining. The other EGFR mutation-positive cases did not show EGFR overexpression and appeared disomic for chromosome 7. The HER2 mutation-positive case was in an adenocarcinoma with bronchioloalveolar features. This tumor did not show overexpression of HER2 and was disomic for chromosome 17. For the non-EGFR mutation-positive cases, 4 (13%) of 32 evaluated cases showed polysomy for chromosome 7 and EGFR. No case showed EGFR gene amplification. Polysomy for chromosome 7 was not related to EGFR overexpression as estimated by immunohistochemistry. Estrogen and progesterone receptor expression was not strong in any of the cases and did not correlate with the presence of EGFR or HER2 mutations.     

Distinctive evaluation of nonmucinous and mucinous subtypes of bronchioloalveolar carcinomas in EGFR and K-ras gene-mutation analyses for Japanese lung adenocarcinomas: confirmation of the correlations with histologic subtypes and gene mutations

Although adenocarcinomas of the lung are associated with epidermal growth factor receptor (EGFR) gene mutations and sensitivity to EGFR tyrosine kinase inhibitors, it remains unclear whether bronchioloalveolar carcinoma (BAC) components and/or subtypes affect these associations. We aimed to clarify correlations between EGFR gene mutations and BAC components and to establish the histologic features as reliable predictors for the mutations. We examined 141 non-small cell lung cancers (NSCLCs), including 118 adenocarcinomas, for mutations in exons 19 and 21 of the EGFR gene together with mutations in codon 12 of the K-ras gene using loop-hybrid mobility shift assays, a highly sensitive polymerase chain reaction-based method. Adenocarcinomas were subdivided into subtypes with a nonmucinous or mucinous BAC component and those without BAC components. In NSCLCs, EGFR mutations were detected in 75 cases (53.2%) and were significantly associated with adenocarcinoma, female sex, and never smoking. Among adenocarcinomas, nonmucinous and mucinous BAC components were significantly associated with EGFR and K-ras gene mutations, respectively. Because EGFR mutations were detected even in most pure nonmucinous BACs, ie, lung adenocarcinoma in situ, EGFR mutation is considered a critical event in the pathogenesis of nonmucinous BAC tumors.     

Gene amplification and protein expression of EGFR and HER2 by chromogenic in situ hybridisation and immunohistochemistry in atypical adenomatous hyperplasia and adenocarcinoma of the lung

AIMS: To investigate the importance of gene amplification and EGFR (epidermal growth factor receptor) and HER2 protein expression during the progression of adenocarcinoma of the lung. METHODS: EGFR and HER2 gene amplification was examined in atypical adenomatous hyperplasia (AAH), bronchioloalveolar carcinoma (BAC), and adenocarcinoma with mixed subtypes (MX) by chromogenic in situ hybridisation (CISH), and protein expression was examined by immunohistochemistry using paraffin wax embedded tissues. RESULTS: EGFR and HER2 gene amplification was found in four and two of 86 cases, respectively, and was detected only in the invasive components of MX. EGFR and HER2 protein expression was seen in 24 and 18 of 86 cases, respectively. EGFR and HER2 proteins were not expressed in AAH but were expressed in one BAC case each. EGFR and HER2 proteins were expressed in 23 and 17 of 55 adenocarcinomas with MX. EGFR and HER2 protein expression was seen more often in the invasive components than in the BAC components of MX, and increased significantly as lesions progressed from AAH to BAC, early MX, and overt MX. Because EGFR and HER2 protein expression was frequently seen without gene amplification, other mechanisms apart from gene amplification may be associated with protein expression. CONCLUSIONS: EGFR and HER2 gene amplification may be a late event and EGFR and HER2 protein expression may be associated with the development of adenocarcinoma of the lung.     

Epidermal growth factor receptor gene mutations in atypical adenomatous hyperplasias of the lung.

Activating epidermal growth factor receptor (EGFR) gene mutations are frequently detected in lung adenocarcinomas, especially adenocarcinomas with a nonmucinous bronchioloalveolar carcinoma component. EGFR-mutated lung adenocarcinomas respond well to EGFR tyrosine kinase inhibitors. We previously found that most (88%) pure nonmucinous bronchioloalveolar carcinomas (adenocarcinoma in situ) already harbor EGFR mutations, indicating that the mutations are an early genetic event in the pathogenesis. We examined 54 atypical adenomatous hyperplasias, precursor lesions of lung adenocarcinomas, obtained from 28 Japanese patients for the hotspot mutations of EGFR exons 19 and 21 and K-ras codon 12. EGFR mutations were observed in 17 of the 54 (32%) atypical adenomatous hyperplasias examined: Ten and seven atypical adenomatous hyperplasias had deletion mutations at exon 19 or point mutations (L858R) at exon 21, respectively. We did not observe apparent histological differences between atypical adenomatous hyperplasias with and without EGFR mutations. K-ras mutation (G12S) was detected in only one atypical adenomatous hyperplasia. As EGFR mutational frequency of atypical adenomatous hyperplasias was much lower than that of nonmucinous bronchioloalveolar carcinomas, we surmise that EGFR-mutated atypical adenomatous hyperplasias, but not atypical adenomatous hyperplasias with wild-type EGFR, are likely to progress to nonmucinous bronchioloalveolar carcinomas.     

EGFR, ERBB2, and KRAS mutations in Korean non-small cell lung cancer patients

The epidermal growth factor receptor (EGFR), and its family members play an important role in the development and progression of lung cancers. It has been reported that somatic mutations in the tyrosine kinase domain of the EGFR or ERBB2 genes occur in a subset of patients with lung cancer. We searched for mutations of the EGFR, ERBB2, and KRAS genes in surgically resected non-small cell lung cancers (NSCLCs) to determine the prevalence of these mutations in Korean lung cancer patients. In addition, we examined the relationship between the mutations and clinicopathologic features of lung cancers. Mutations of the EGFR, ERBB2, and KRAS genes were determined by polymerase chain reaction-based direct sequencing in 115 surgically resected non-small cell lung cancers. EGFR mutations were present in 20 patients (17.4%). The EGFR mutations were found only in adenocarcinomas (20 of 55 adenocarcinomas, 36.4%). The ERBB2 mutation was found in 1 adenocarcinoma of the 115 NSCLCs (0.9% overall; 1.8% of the 55 adenocarcinomas). KRAS mutations were found in 6 (5.2%) of the 115 NSCLCs (2 of 60 squamous cell carcinomas, or 3.3%, and 4 of 55 adenocarcinomas, or 7.3%). EGFR mutations in adenocarcinomas were more frequent in women (P = 0.02) and in never-smokers (P = 0.004). EGFR mutations in adenocarcinomas were not associated with pathologic stage in never-smokers, but were more frequent in pathologic stage II-IV than in stage I in ever-smokers (P = 0.01). Of the 55 adenocarcinomas, 25 (45.5%) had mutations of one or another of the three genes; EGFR mutations were never found in adenocarcinomas together with ERBB2 or KRAS mutations. These findings suggest that the EGFR mutation is frequent in Korean lung cancer patients, and that the ERBB2 mutation is rare. Further studies are needed to investigate the role of EGFR mutations in the carcinogenesis of adenocarcinoma among smokers.     

Molecular alterations in atypical adenomatous hyperplasia occurring in benign and cancer-bearing lungs.

Atypical adenomatous hyperplasia (AAH) is considered to be a precursor lesion of the lung adenocarcinoma. Several genetic abnormalities have been reported in AAH associated with adenocarcinoma, but little is known about AAH associated with benign lung lesions. To address this we compared the molecular characteristics of AAH present in benign conditions to those coexisting with carcinoma. Seven cases of AAH from resected non-neoplastic lungs (AAH-B) and 12 cases from lungs resected for primary lung carcinoma (AAH-M) were analyzed for loss of heterozygosity (LOH) using 21 polymorphic microsatellite markers situated in proximity to known tumor suppressor genes on chromosomes 3p, 5q, 7p, 9p, 10q, and 17p. Direct DNA sequencing for K-ras mutation was also performed. There was a broad range of LOH in both groups. No LOH was identified in 3 cases (25%) of AAH-M, but all cases of AAH-B showed LOH (P=0.26). Six cases (50%) of AAH-M and 3 cases (43%) of AAH-B showed loss at 1 marker (P=0.99). LOH at 2 or more markers was identified in 3 (25%) cases of AAH-M and 4 (57%) cases of AAH-B (P=0.32). LOH was most frequently detected on chromosomes 3p and 10q in both groups. The difference in overall fractional allelic loss between the 2 groups did not reach statistical significance. K-ras mutations were not identified in either group. Our results showed a significant overlap in LOH patterns between AAH with or without coexistent lung malignancy. Therefore, AAH may represent a smoking induced low-grade neoplastic lesion that may be a precursor lesion of only a subset of invasive lung adenocarcinoma.     

Disproportionate representation of KRAS gene mutation in atypical adenomatous hyperplasia, but even distribution of EGFR gene mutation from preinvasive to invasive adenocarcinomas

In the resected lung, additional small lesions are occasionally found incidentally, and include the full spectrum of preinvasive to invasive lesions under the current putative schema of the sequential development of lung cancer. In this study, we examined EGFR and KRAS gene mutations in 119 synchronous pulmonary lesions, including 40 precursor lesions (atypical adenomatous hyperplasia, AAH), 26 carcinomas in situ (non-mucinous bronchioloalveolar carcinoma, BAC), 14 minimally invasive adenocarcinomas, 34 overt invasive adenocarcinomas, and five of other subtypes of cancer. Although the mutually exclusive nature of KRAS and EGFR gene mutations was maintained even in preinvasive lesions, the incidences of the lesions along the putative progression schema were quite different. The KRAS gene was mutated in 33% of AAH, 12% of carcinomas in situ, 8% of minimally invasive adenocarcinomas and 0% of well-differentiated adenocarcinomas, whereas the frequencies of EGFR mutation did not fluctuate greatly, at 25%, 51%, 36%, 86% and 67%, respectively. These results are consistent with the findings of a published gene-targeted mouse model; the mice expressing oncogenic KRAS developed AAH but not invasive adenocarcinoma, whereas a spectrum of preinvasive to invasive adenocarcinomas was observed in the mice expressing mutant EGFR. Taking these factors together, it is suggested that AAH could develop by either KRAS or EGFR gene mutation, but AAH harbouring a KRAS gene mutation might not progress further to an invasive cancer.     

Analysis of multigene detection in patients with advanced lung adenocarcinoma using cytological specimens

ObjectiveTo investigate the mutation status and clinical characteristics of multigene detection in advanced lung adenocarcinoma using cytological specimens.Materials and Methods137 advanced lung adenocarcinoma patients with 10 driver genes detection in the Fourth Hospital Hebei Medical University from January 2019 to November 2019 was analysized. 137 cytological specimens including fine-needle aspiration specimens and maligant serous cavity effusion (pleural effusion, peritoneal and pericardial effusion). Ten driver mutations of EGFR, ALK, ROS1, BRAF, KRAS, NRAS, HER2, RET, PIK3CA and MET were detected by the amplification refractory mutation system (ARMS). Meanwhile, 90 of 137 patients were detected with biopsies for parallel gene detection.Results78.10 % (107/137) of patients with advanced lung adenocarcinoma harbored at least one of 10 driver mutations. The three main mutations were EGFR (69.16 %, 74/137), ALK (6.57 %, 9/137)and ROS1 (3.65 %, 5/137) mutations. Besides, we found 6 cases including two concomitant mutations: EGFR Exon19 del/HER2 (1/137), EGFR Exon21 L858R/PIK3CA (2/137), EGFR Exon21 L858R/RET (1/137), and ALK/KRAS (2/137). Among 137 patients, women aged 64 or older were more likely to have the mutations (P < 0.05). Female patients (P = 0.003) older or equal to 64 years (P = 0.015) with non-smoking habbit (P = 0.027) were more detected with EGFR mutations, while ALK was more detectable in patients yonger than 64 years. Parallel analysis showed that rates of single EGFR, ALK, ROS1, RET, KRAS, NRAS, HER2, MET mutations and concomitant different mutations were not significantly different between cytological specimens and matched histological specimens.ConclusionsIn the study, cytological specimens and biopsy samples have a very high coincidence rate of gene detection. EGFR, ALK and ROS1 mutations were the main driver mutations in patients with advanced lung adenocarcinoma.We speculate that EGFR and ALK are more prone to concomitant mutations respectively and the treatment of advanced lung adenocarcinoma patients with concomitant mutations deserves further study. The rate of KRAS, NRAS, BRAF, PIK3CA, RET and MET exon14 skipping mutation were low but may had a significant impact on the targeted therapy of patients with advanced lung adenocarcinoma.     

Molecular analysis of p53 and K-ras in lung carcinomas of coal miners

Thirty-three cases of non-small cell lung cancers (NSCLC) from the archives of National Coal Workers' Autopsy Study were studied for mutational alterations in p53 and K-ras using PCR-SSCP, DNA sequencing and PCR-oligonucleotide probe hybridization techniques. Mutations of the p53 were observed in 4 smokers (19%) and one in a never smoker (8%). Two polymorphisms in smokers were detected at codon 213, a common site for sequence variation. Among the smokers the p53 mutations were in the heavy smokers. In never smokers there was only a single p53 mutation and two K-ras mutations. In never smokers the frequency of K-ras mutations was similar (17%) in smokers, but one never smoker had two K-ras mutations. Mutations of p53 were more frequent in adenocarcinomas (27%) and they were AT-->GC transitions. Four of 11 (36%) adenocarcinomas were found to have K-ras codon 12 mutations, and one adenocarcinoma had two K-ras mutations. There were two large cell undifferentiated carcinomas with p53 mutation and one with a K-ras mutation. Two of the 16 squamous cell carcinomas were positive for p53 mutation, while no K-ras mutations were found in this group. The results of these preliminary studies indicate a moderately different mutational spectrum of p53 and K-ras in coal miners independent of cigarette smoking. The mutational spectrum observed in this study of coal miners with heavy cigarette smoking history suggest a protective effect of coal mine dust in preventing abnormal mutations induced by chemical carcinogens in cigarette smoke or reactive oxygen species. These limited preliminary studies provide insight into the possibility of accurately measuring changes in etiologic markers to unravel the uncertainties of cancer in coal miners.     

Terminal respiratory unit type lung adenocarcinoma is associated with distinctive EGFR immunoreactivity and EGFR mutations.

Approximately 10% to 20% of nonsmall cell lung cancer patients respond to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, such as gefitinib. Responders are mostly nonsmokers and women with tumors displaying bronchioloalveolar features. Mutations of the tyrosine kinase domain of the EGFR gene have been associated with a clinical response to gefitinib. A recent study reported that the terminal respiratory unit (TRU)-type adenocarcinoma shares the clinical profile and EGFR mutations of gefitinib responders. EGFR immunoreactivity in this context has not been reported in the literature. We performed a detailed immunohistochemical analysis of EGFR expression on 124 consecutive lung resection specimens for malignancy, to survey the EGFR immunoreactivity in lung cancers in general and to correlate EGFR immunoreactivity with EGFR mutations and TRU-type histology. EGFR positivity was seen most frequently in squamous cell carcinomas (77%), followed by TRU-type adenocarcinomas (63%), large cell carcinomas (23%), and non-TRU-type adenocarcinomas (12%). A distinctive basally oriented cytoplasmic positivity was observed exclusively in TRU-type adenocarcinomas. EGFR mutation was identified in 6 of 54 cases studied and all 6 cases were TRU-type adenocarcinomas. Five of six cases with EGFR mutation were positive for EGFR immunostain with the basal cytoplasmic localization. In conclusion, EGFR immunoreactivity with basal cytoplasmic pattern was exclusively seen in TRU-type adenocarcinoma and a subset of these cases was seen with EGFR mutations in the responders to EGFR inhibitor therapy.     

Diagnostic and therapeutic ERβ, HER2, BRCA biomakers in the histological subtypes of lung adenocarcinoma according to the IASLC/ATS/ERS classification

Several studies revealed that non–small cell lung cancers (NSCLCs) frequently express ER, PR, HER2 and carry BRCA mutation. However, these markers in histological subtypes of lung adenocarcinoma have not been thoroughly investigated. We retrospectively evaluated a total of 640 lung adenocarcinoma samples for ERα, ERβ, PR and HER2 expression by immunohistochemistry and western-blotting, for EGFR and BRCA mutation by real-time PCR and sequencing. Furthermore, HER2 amplification and mutation were explored in samples harboring immunopositivity HER2 using fluorescence in situ hybridization and real-time PCR, respectively. The micropapillary and invasive mucinous predominant adenocarcinoma were frequently detected the higher level of cytoplasmic ERβ (64.9% and 56.6%), HER2 (68.1% and 60.1%) protein expression. But, amplification of HER2 was detected in only three cases (3/110, 2.7%) and 26 HER2 mutations in 110 cases were identified (23.6%) in the HER2 immunopositivity patients. Logistic regression analysis showed that cytoplasmic ERβ (P = 0.032) and HER2 (P = 0.015) expression were independently associated with EGFR mutation. 8 patients (8/640, 1.25%) harbored pathogenic BRCA mutations, 6 with germline BRCA mutations and 2 with somatic BRCA1 mutations were detected with lacking ERβ, PR and HER2 expression. Acinar predominant adenocarcinoma had the higher percentage of BRCA mutations than other subtypes. A systematic examination of ERβ, HER2 and BRCA biomarkers could potentially be useful to diagnosis and identify patients with the histological subtypes of lung adenocarcinoma, who might benefit from the further individualized treatment of anti-hormone, anti-HER2 and/or PARP inhibitors therapeutics.     

The relationship between EGFR mutation status and clinic-pathologic features in pulmonary adenocarcinoma

To detect the relationship of the epidermal growth factor receptor (EGFR) mutation status and the clinicopathologic features. Six hundred thirty-three patients with pathologically confirmed lung adenocarcinoma who underwent lung cancer resection surgery at the Fourth Hospital of Hebei Medical University between April 2012 and April 2015 were selected for the study. The 32 types of mutations in exons 18–21 of the EGFR gene were detected. The total EGFR mutation rate among patients with lung adenocarcinoma was 56.9%. The mutation rates were 71.2% among females and 42.8% among males (P?<?0.05). Among patients with TNM stage I, II, III, and IV disease, the EGFR mutation rates were significant differences (P?<?0.05). Concerning different subtypes of lung adenocarcinoma, the EGFR mutation rates were differences, and these differences were statistically significant (P?<?0.05). Cox multivariate regression model analysis considering EGFR mutation status revealed that differences in TNM stage (P?<?0.01), smoker status, and tumor size were statistically significant predictors. Patients with minimally invasive and lepidic adenocarcinomas were categorized as low-risk group with high EGFR mutation rate; Patients with micro-papillary and solid adenocarcinomas were categorized as high-risk with lower EGFR mutation rate, so there are different mechanisms in different types of adenocarcinomas.     

Epidermal growth factor receptor expression status in lung cancer correlates with its mutation

The molecular mechanisms for frequent epidermal growth factor receptor (EGFR, a tyrosine kinase [TK]) and HER2 (the preferred coreceptor of EGFR) overexpression in lung cancer are poorly understood. Recent studies have shown the mutations of the TK domain in EGFR and HER2 to be present in lung cancer. The purpose of this study was to investigate the relationship between mutation status and expression of EGFR and HER2 in lung cancer. Immunostaining took place for EGFR and HER2, and mutational analyses for EGFR, HER2, and KRAS (a signaling protein) were conducted using 130 resected lung cancer specimens. Thirty-seven EGFR mutations (28%) and 8 HER2 mutations (6%), both of the TK domains, and 5 KRAS (4%) mutations were found, whereas 73 (56%) EGFR and 47 (36%) HER2 overexpressions were found. EGFR overexpression was seen more frequently in tumors with EGFR mutation (28/37, 76%) than in tumors without EGFR mutations (45/93, 48%; P = .0059). No correlation was found between HER2 mutation and HER2 expression. Multivariate regression revealed that EGFR mutation, adenocarcinoma histology, and HER2 expression were associated with EGFR expression, whereas female sex, EGFR mutation, and EGFR expression were associated with HER2 expression. In conclusion, EGFR and HER2 overexpression is frequent in lung cancer, and EGFR overexpression correlates with the EGFR TK domain mutations.     

肺腺癌EGFR基因19、21号外显子突变分析

目的 探讨肺腺癌表皮生长因子受体(EGFR)基因19、21号外显子突变特点及其临床意义.方法 对肺腺癌手术组织提取DNA,采用聚合酶链式反应(PCR)和直接测序法检测EGFR基因19号与21号外显子突变状态,分析与临床病理参数之间的相关性.结果 在54例被测肺腺癌肿瘤中,发现29例患者存在EGFR基因突变,占53.7％ (29/54).其中,19号外显子突变13例(24.1％),均为缺失突变;21号外显子突变病例为16例(29.6％),均为L858R点突变.高、中分化肿瘤的EGFR突变率均达60％以上,明显高于低分化肿瘤突变率44％.结论 肺腺癌存在较高频率的EGFR基因突变,在高、中分化肿瘤的突变率有高于低分化肿瘤的趋势.     

Loss of Heterozygosity on Chromosomes 9q and 16p in Atypical Adenomatous Hyperplasia Concomitant with Adenocarcinoma of the Lung

Atypical adenomatous hyperplasia (AAH) has recently been implicated as a precursor to lung adenocarcinoma. We previously reported loss of heterozygosity (LOH) in tuberous sclerosis (TSC) gene-associated regions to frequently be observed in lung adenocarcinoma with multiple AAHs. In this study, we analyzed LOH in four microsatellite loci on 9q, including the TSC1 gene-associated region, and four loci on 16p, including the TSC2 gene-associated region, in both 18 AAHs and 17 concomitant lung adenocarcinomas from 11 patients. Seven of 18 (39%) AAHs and 9 of 17 (53%) adenocarcinomas displayed LOH on 9q. Five (28%) AAHs and seven (41%) adenocarcinomas harbored LOH at loci adjacent to the TSC1 gene. Four of 18 (22%) AAHs and 6 of 17 (35%) adenocarcinomas displayed LOH on 16p. One (6%) AAH and five (29%) adenocarcinomas harbored LOH at loci adjacent to the TSC2 gene. These findings may indicate a causal relationship of LOH on 9q and 16p in a fraction of AAH lesions and adenocarcinomas of the lung. Especially, the frequencies of LOH on 9q and at the TSC1 gene-associated region were high. The TSC1 gene or another neighboring tumor suppressor gene on 9q might be involved in an early stage of the pathogenesis of lung adenocarcinoma.     

非小细胞肺癌表皮生长因子受体基因突变检测及其与临床病理特征的相关性

目的探讨中国非小细胞肺癌(NSCLC)患者表皮生长因子受体(EGFR)基因突变特点及与临床病理特征的相关性。方法采用优化寡核苷酸探针聚合酶链反应(PCR)法检测309例甲醛固定、石蜡包埋NSCLC组织中EGFR基因第18 ～21号外显子突变情况,分析EGFR突变与临床病理特征的关系。结果受检309例NSCLC样本中,E...     

非小细胞肺癌患者ALK,EGFR及KRAS基因的检测及临床病理特征

目的:研究汉族非小细胞肺癌患者中间变性淋巴瘤激酶(anaplastic lymphoma kinase,ALK)、表皮生长因子受体(epidermal growth factor receptor,EGFR)及Kirsten鼠肉瘤基因(Kirstenrat sarcoma,KRAS)突变的阳性率及其与临床病理特征的关系.方法:采用免疫组织化学(immunohistochemistry,IHC)的方法检测ALK融合基因异常表达,采用PCR检测EGFR基因和KRAS基因突变,采用x2检验及Fisher精确概率法进行数据分析.结果:共2 267例进行了ALK融合基因检测,其中1 655例同时进行了EGFR突变检测,951例同时进行了KRAS检测.ALK融合基因、EGFR基因及KRAS基因突变阳性率分别为7.28％(165/2 267)、48.58％(804/1 655)、11.40％(108/947).ALK基因突变多见于年轻、腺癌患者;EGFR基因突变多见于女性、腺癌患者;KRAS基因突变多见于老年、男性、腺癌患者.1 655例同时进行了ALK与EGFR检测的病例中,共6例存在双基因突变(0.36％);947例同时进行了ALK与KRAS检测,共4例存在双基因突变(0.42％);943例同时进行了EGFR与KRAS突变检测,未发现双突变病例.结论:非小细胞肺癌患者ALK,EGFR和KRAS基因的突变与患者的年龄、性别、组织学类型均存在相应的联系,个别病例可以出现ALK融合基因与EGFR或KRAS突变共存.     

276例手术切除肺腺癌亚型与EGFR/ALK基因状态

目的:探讨手术切除肺腺癌各亚型EGFR和ALK基因状态分布.方法:应用ARMS方法检测手术切除肺腺癌石蜡组织中EGFR基因突变和ALK融合基因情况.结果:276例肺腺癌手术样本中,EGFR基因突变率为54.71％(151/276),其中19del为28.99％(80/276),L858R为23.19％(64/276),20-ins为0.72％(2/276),L861Q为0.72％(2/276),G719X为1.09％(3/276),S768I为0.36％(1/276)和T790M为0.72％(2/276),其中包含G719X+S768I,19del+T790M,L858R+T790M各1例,ALK基因融合阳性率为5.80％(12/207),在肺腺癌各亚型中EGFR基因突变附壁状腺癌,腺泡状腺癌,乳头状腺癌,实体状腺癌和浸润性黏液腺癌之间差异有统计学意义(P＜0.001,P=0.009,P=0.023,P＜0.001和P=0.030),与其他类型之间差异均无统计学意义(P＞0.05);在肺腺癌各亚型中ALK融合基因突变各亚型之间差异均无统计学意义(P＞0.05).结论:肺腺癌组织学亚型与EGFR基因突变有关,附壁状腺癌、腺泡状腺癌和乳头状腺癌出现EGFR基因突变比其他亚型更加明显.     

Adenosquamous carcinoma of the lung: a microdissection study of KRAS and EGFR mutational and amplification status in a western patient population

Molecular testing of pulmonary adenocarcinomas for EGFR and KRAS mutations is becoming more common as tyrosine kinase inhibitor therapy is used for EGFR-mutated adenocarcinomas. Adenosquamous carcinomas represent a hybrid carcinoma, and there is no literature addressing the frequency of EGFR and KRAS mutations in this subset of lung carcinomas in Western populations. For this study, 23 adenosquamous carcinomas were microdissected with the glandular and squamous components analyzed for EGFR and KRAS mutations and EGFR amplification. In 3 cases (13%), there were EGFR mutations, with 2 having the identical mutation in the glandular and squamous elements. In 3 cases (13%), there were KRAS mutations in both histologic elements. Great heterogeneity existed in the rates of EGFR amplification in the 2 histologic components. Amplification was most common in both glandular and squamous components (11/23 [48%]). EGFR mutations occur in adenosquamous carcinoma in the same percentages as in conventional adenocarcinoma in the Western population. KRAS mutations are less common.     

Epidermal growth factor receptor domain II, IV, and kinase domain mutations in human solid tumors

Mutations that may predict response to adenosine 5-triphosphate (ATP)-mimetic epidermal growth factor receptor (EGFR) inhibitors occur in the EGFR kinase domain in lung adenocarcinomas and bronchioloalveolar carcinomas (BACs). Data on the frequency of EGFR mutations are sparse in other human tumors. Apart from the deletion mutant EGFRvIII, little is known about the frequency of mutations that encode for the EGFR extracellular domains II and IV that participate in receptor dimerization and formation of the tethered (autoinhibited) receptor conformation. We investigated 566 human neoplasms consisting of various histological types for mutations in exons 6, 7 (encode domain II), 14, 15 (domain IV), 18, 19, and 21 (the kinase domain) using denaturing high-performance liquid chromatography (DHPLC). Approximately 4,500 EGFR exons were screened for the presence of a mutation, and samples with an abnormal finding in DHPLC were sequenced. Only one mutation was found in the extracellular domain IV (glioblastoma), and none in domain II. Eight (11%) out of the 40 lung adenocarcinomas, or 33 BACs, investigated had exon 19 or 21 mutation in the kinase domain, but no mutations were found in other tumor types. Most of the lung cancers with mutated EGFR had three to six copies of the mutated gene in fluorescence in situ hybridization. We conclude that mutations of the EGFR kinase domain and the cysteine-rich extracellular domains are infrequent in most types of human cancer apart from lung adenocarcinoma. Mutated EGFR is usually not amplified in lung cancer.