Spectrum of EGFR mutations associated with non-small cell lung cancer in an Asian Chinese population

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 20055-20055
Author(s):  
C. Wong ◽  
W. Chan ◽  
H. Lam ◽  
W. Chan ◽  
L. Wang ◽  
...  

20055 Background: Somatic mutations in tyrosine kinase (TK) domain of the EGFR gene, predicting for sensitivity to TK inhibition therapy, are over-represented in lung cancer with adenocarcinoma or bronchioloalveolar histology, non-smokers, female gender and East Asian ethnicity. Methods: We prospectively screened for EGFR mutations at exons 19–21 on micro-dissected specimen enriched for tumor cells by direct nucleotide sequencing in Hong Kong Chinese patients. Results: From May 2005 onwards, a total of 27 patients were analyzed. They comprised 11 males and 16 females with a median age of 67 years. Histological diagnoses were adenocarcinoma (n = 22), bronchioloalveolar carcinoma (n = 4) and squamous cell carcinoma (n = 1). Samples included primary tumor (n = 20) as well as metastatic lesions (n = 7). EGFR mutations were detected in 17 patients (63%), the most common being L858R at exon 21 (n = 7) followed by exon 19 deletions (del(746–750) = 3, del(747–751) = 1, del(747–753) = 3) and G719C at exon 18 (n = 1). Two patients showed novel EGFR mutations, namely 4-base pair insertion deletion at exon 19 leading to substitution of Glu746-Leu747 by Val746-Pro747 and three base pair deletion at exon 18 leading to replacement of Glu709-Thr710 by Asp. Furthermore, two patients showed double mutations, including novel S768I at exon 20 in combination with G719C, and novel K860I at exon 21 in combination with L858R. Finally, one patient showed homozygous del(747–753) as detected by sequencing in both primary lung tumor and brain secondary, which might represent loss of heterozygosity. Conclusions: Similar to other series, two hotspots i.e. exon 19 deletion and L858 account for the majority (82%) of detectable EGFR mutations in our patient population. For the rare and novel variants, it would be of interest to document the clinical responsiveness to TK inhibitors gefitinib and erlotinib, so that a more complete picture of cancer genotype phenotype correlation can be achieved. No significant financial relationships to disclose.

2021 ◽  
Vol 62 (4) ◽  
pp. 28-34
Author(s):  
S. Yermekova ◽  
M. Orazgaliyeva ◽  
T. Goncharova ◽  
F. Rakhimbekova ◽  
E. Serik

Relevance: Increased incidence of lung cancer globally and in Kazakhstan, lack of screening in hereditary cases, high mortality, and low survival of patients necessitate the study of the molecular genetic causes of the disease. At present, gene mutation studies for lung cancer diagnostics are expanding. However, many gene mutations revealed remain undercovered in the scientific literature, and there is not enough data on their prognostic and diagnostic value. The purpose of the study was to discover the specifics of the р53 gene mutations and reveal the EGFR exon 19 deletions and exon 21 L858R mutations in malignant tumors of the lung of various histogenesis. Methods: The mutations were studied in tumors (200 samples) and adjacent tissue (200 samples) of patients with lung cancer (squamous cell carcinoma (SCC) and adenocarcinoma (ADC) of the lung) by polymerase chain reaction (PCR), electrophoresis, and EcoR1- and Pst1-restriction of samples after p53 gene fragments and cDNA amplification and mRNA revertase treatment. Another 263 lung cancer samples were evaluated by real-time PCR for EGFR exon 19 deletions and EGFR exon 21 L858R mutations. Results: The p53 gene was not expressed in 50% of SCC and adenocarcinoma of the lung samples. Restriction revealed p53 mRNA mutations in 100% of SCC and 75% of ADC samples. p53 exon-intron 5-6 was mutated in 50% of ADC and 70% of SCC samples, exon-intron 7-9 – in 60% of SCC cases. EGFR exons 19 and 21 mutations found in 65 of 263 lung tumor samples were associated with increased sensitivity to EGFR tyrosine kinase inhibitors. Conclusion: The p53 gene mutations revealed in most samples of SCC and ADC of the lung could be used to diagnose lung cancer and predict its severity. The identified EGFR mutations allow predicting the effectiveness of targeted therapy


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 7633-7633
Author(s):  
Y. Lee ◽  
B. Cho ◽  
H. Choi ◽  
J. Sohn ◽  
S. Kang ◽  
...  

7633 Background: The presence of EGFR mutations in NSCLC has strongly associated with never-smoking history. SHS exposure is associated with higher risk of lung cancer. We have conducted this study to evaluate the association between SHS exposure and likelihood of mutations in EGFR gene in NSCLC patients who had never smoked. Methods: SHS exposure information from a total of 93 never smokers (<100 lifetime cigarettes) with newly diagnosed primary NSCLC was obtained using a standardized questionnaire. Patients were asked whether they were regularly exposed to SHS at home or work places, respectively. Nucleotide sequencing of the kinase domain of EGFR (exons 18 to 21) was performed using nested PCR amplification of individual exons. Results: Patient characteristics (n=93) included median age 57 years; female (n= 81); adenocarcinoma ± bronchoalveolar carcinoma (n= 82); EGFR mutation (1 mutation in exon 18 G719, 31 in-frame deletions in exon 19, 10 mutations in codon 858 in exon 21). Fifty-two (55.9%) of the patients reported having been exposed to SHS, including 46 (49.5%) exposed at home and 13 (14.0%) exposed at work. The incidence of EGFR mutations was not associated with female gender and adenocarcinoma histology. Patients with SHS exposure showed a trend towards lower incidence of EGFR mutations (36.5% vs. 56.1%, P= 0.060) and a significantly lower incidence of deletion mutations in exon 19 (57.9% vs. 87.0%, P= 0.033). When the incidence of EGFR mutations was compared, no difference between SHS exposure at home and work places was found. No significant differences were found for other clinicopathological factors according to SHS exposure. Conclusions: Our results indicate weak evidence of relationship between likelihood of mutation in EGFR gene and SHS exposure. The deletion mutations in exon 19 were significantly less common in patients with SHS exposure. No significant financial relationships to disclose.


2021 ◽  
pp. 107815522110191
Author(s):  
Pinar Gursoy

Introduction Most patients with non-small-cell lung cancer tumors that have epidermal growth factor receptor (EGFR) mutations have deletion mutations in exon 19 or exon 21, or both.In recent years, targeted therapies in lung cancer have increased survival, but the development of resistance to these drugs poses a major problem. Thesubstitution of methionineforthreonine at position 790 (T790M) mutation,is primarily responsible for this resistance. However, after osimertinib used in T790M positivepatients treatment options are generally limited to chemotherapy. Case report We reported the efficacy of erlotinib, which we reapplied due to the disappearance of the resistance mutation after osimertinib in a 68-year-old patient using osimertinib after erlotinib. Management and outcome: In the patient using erlotinib due to exon 19 deletion when progression was observed and T790M positivity was detected, osimertinib treatment was initiated. However, when T790M was found to be negative with rebiopsy in progression after osimertinib, a complete response was achieved by restarting erlotinib. Discussion The strategy of restarting erlotinib treatment with negative T790M mutation detected in biopsies of patients with osimertinib resistance may be an acceptable treatment option.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 7667-7667
Author(s):  
T. Mok ◽  
P. Lui ◽  
K. C. Lam ◽  
A. Yim ◽  
I. Wan ◽  
...  

7667 Background: EGFR mutation is a diverse and complex phenomenon. Shigematsu et al (JNCI 97:339,2005), analyzing NSCLC samples from multiple ethnicities and histologic cell types, reported 11 types of in-frame deletions in exon 19 (46%), 9 missense mutation in exons 18, 20, 21 (45%) and 8 in-frame insertion in exons 20 (9%). 3/130 tumors (2.3%) had multiple mutations. Here we report the incidence, mutation pattern and novel finding of EGFR mutation in a homogenous ethnic group with adenocarcinoma of lung. Methods: Between 2004 and 2006 we isolated genomic DNA from 194 (archival 53, prospective 141) primary lung adenocarinoma for PCR amplification of EGFR exon 18–21. We isolated tumor cell by micro-dissection. PCR products were purified and sequenced using the BigDye Terminator Cycly Sequencing Ready Reaction Kit (Applied Biosystem) and run on Applied Biosystem 3100 Genetic Analyzer. Results: We found 79 EGFR mutations in 73 tumors (37.6%). Six (8.2%) had double mutations. IN-FRAME DEL: 10 types in exon 19 (39 cases, 49.4%); 1 type in exon 18 (1 case). MISSENSE MUTATION: 2 types in exon 18 (2 cases); 4 types in exon 20 (5 cases) and 2 types in exon 21 (29 cases, 36.7%) IN-FRAME INSERTION: 3 types in exon 20 (3 cases). Typical exon 19 E746-A750del and exon 21 L858R mutations accounted for 31% and 34%, respectively. We found 11 types of mutations not previously described.( Table ) Four pts with novel mutations received EGFR TKI and 3 attained PR (all with exon 19 del). Two pts have T790M mutations without prior exposure to EGFR TKI and both with double mutations. Conclusion: Mutation pattern of EGFR gene in Chinese pts with adenocarcinoma is similar to the Shigematsu report. The overall incidence of EGFR mutation and multiple mutations are higher but in-frame insertion in exon 20 is less common. Majority of the novel mutations are rare mutations involving exon 18 and 20. No significant financial relationships to disclose. [Table: see text]


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22066-e22066
Author(s):  
G. Speranza ◽  
V. Cohen ◽  
J. S. Agulnik ◽  
G. Chong ◽  
F. Meilleur ◽  
...  

e22066 Background: EGFR mutations predict sensitivity and clinical outcome to tyrosine kinase inhibitors (TKI) in NSCLC. The two most commonly described mutations are Exon 19 deletion and Exon 21 L858R missense mutations. Genetic alterations over time have been described in other tumour types, but studies assessing EGFR genotypic changes with lung cancer progression are lacking. We sought to compare EGFR mutational status from lung tumors at time of recurrence or progression with the primary tumor. Methods: Using the Jewish General Hospital lung cancer database, of all patients diagnosed with NSCLC since 1999, those with biopsies at two different points in time were identified. All tumour samples were genotyped for EGFR exons 19 and 21 mutations using denaturing high performance liquid chromatography (dHPLC). Results: 29 patients were identified. Data for 12 patients, whose time of recurrence or progression varied between 4 months and 6 years, are available at this time. Of 12 patients, one had EGFR exon 19 mutation at time of diagnosis. One patient who initially displayed no EGFR mutation was found to have an exon 19 deletion at time of recurrence. The one with exon 19 at time of initial diagnosis continued to express exon 19 in the second biopsy. Conclusions: To our knowledge, this is the only study assessing changes in molecular genotype using dHPLC between primary and recurrent or progressive lung cancer biopsy specimens. Although sample size is small, it is evident that changes in EGFR mutational status can occur. Further prospective studies are required to determine how commonly molecular changes occur. No significant financial relationships to disclose.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e20565-e20565 ◽  
Author(s):  
Ruben Salanova ◽  
Julio C Calderazzo Pereyra ◽  
Laura Leguina ◽  
Asuncion Bena ◽  
Mariana Barberis ◽  
...  

e20565 Background: Until now, the results of the correlation between PD-L1, ALK expression and EGFR mutations remain controversial. We prospectively evaluated patterns among EGFR mutant, ALK positive and PD-L1 positive lung cancer patients. Methods: PD-L1 and ALK expression was evaluated in 342 adenocarcinomas (AD) of the lung using inmunohistochemestry (anti-PD-L1 22C3, anti-ALK D5F3), and EGFR mutations using real time PCR (therascreen EGFR RGQ PCR Kit version 2). PD-L1 was also evaluated in 36 squamous (SQ) cell carcinomas. Results: 181 of 342 patients with AD were positive for PD-L1. 108 were positive with a TPS value between 1 and 49, and 73 were positive with a TPS value higher than 50 (p = 0.002). 25 of 36 patients with SQ were positive for PD-L1. 17 were positive with a TPS value between 1 and 49, and 8 were positive with a TPS value higher than 50. 133 samples with AD PD-L1 positive and 97 PD-L1 negative were tested for EGFR and ALK, 33 and 14 respectively were positive for EGFR mutations (p = 0.15), with 45% for exon 19 deletions (p = 0.003), 5 and 0 respectively were positive for ALK translocations (p = 0.053). 210 of 342 patients were men and 132 were women, 117 and 64 were positive for PD-L1 expression respectively (p > 0.1). Conclusions: NSCLC with EGFR mutation showed a trend for higher frequency of positive PD-L1 expression and NSCLC harboring ALK rearrangement was significantly associated with PD-L1 expression. These findings might contribute to the understanding of the regulation of PD-L1 expression in lung cancer and its relation to ALK expression and EGFR mutation.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13527-e13527
Author(s):  
Minghui Wang ◽  
Shuben Li ◽  
Hongbiao Wang ◽  
Jianjiang Xie ◽  
Junhang Zhang ◽  
...  

e13527 Background: Exon 19 deletions and exon 21 L858R substitutions are the most common mutations of epidermal growth factor receptor (EGFR) in cancers, and the remaining other mutations are called uncommon mutations. Recent studies have shown the clinical relevance of EGFR uncommon mutations with tyrosine kinase inhibitors (TKI) therapies and immunotherapies. Therefore, understanding the distribution and characteristics of EGFR uncommon mutations in cancers would provide evidence for future design of trials and drug development. Methods: Next-generation sequencing data were obtained from 3,026 Chinese tumor samples which have been identified with EGFR mutations. Single nucleotide variations (SNV), short and long insertions/deletions (indel), copy number variations and gene rearrangements were assessed. All tests were carried out in a College of American Pathologists (CAP) accredited and Clinical Laboratory Improvement Amendments (CLIA) certified laboratory in Shanghai, China. Results: EGFR mutations including 32% L858R substitutions, 28% exon 19 deletions, and 40% uncommon mutations were detected in this cohort. EGFR uncommon mutations were most frequently detected in lung cancers, followed by esophageal and gastric cancers. The uncommon mutations of EGFR including 54% SNVs, 30% amplifications, and 9% rare types of mutations such as rearrangement, long indels and complex mutations were detected. The SNVs in exon 18 to 21 which encode the tyrosine kinase domain of EGFR consisted of 16% EGFR mutations. Among them, the mostly frequently SNV was G719X in exon 18 and had 3% EGFR mutations. Mutations in other function domain of EGFR, including extracellular EGF binding domain (0.8%), transmembrane domain (0.03%) and intracellular autophosphorylation domain (0.7%) were also detected. Conclusions: Our data indicated that EGFR uncommon mutations were widely distributed in a variety of cancer types in Chinese patients, mostly in lung cancers. SNVs in the tyrosine kinase domain were the most frequent uncommon mutations. These data will provide clues for future clinical studies.


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