EGFR Gene In Patients Research Articles

Investigating Common Mutations in Exon 20 and 21 of EGFR Gene in Lung Cancer Tumor Tissue of NSCLC Type

Background: A mutation in the EGFR gene can be a marker for non-small cell lung cancer (NSCLC). The frequency of this mutation is very different in various countries and ethnic groups. Objectives: This study investigated the frequency of mutations in exons 20 and 21 of the EGFR gene in patients with NSCLC in Iran. Methods: Twenty paraffin blocks with an average age of 3 years were prepared from the Tehran Cancer Institute. The samples belonged to 5 women and 15 men aged 61 - 74 years and were confirmed by a pathologist in terms of positivity and type of tumor. After deparaffinization, DNA extraction was performed using a QIAGEN kit. The appropriate probes and primers were designed, and finally, the samples were examined by the real-time TaqMan method, and the data were analyzed. Results: The findings showed that 15% and 10% of patients had mutations in exon 20 and 21 of the EGFR gene, respectively. The T790M mutation of exon 20 was observed in three patients (tumors of adenocarcinoma type and large cell cancer), and L858R and L861Q mutations of exon 21 of the EGFR gene were observed. Conclusions: The frequency of mutation in exon 20 and 21 of the EGFR gene in NSCLC patients among Iranians is close to Middle Eastern and European patients, but it is very different from the frequency of this mutation among East Asian and North Asian patients.

Evaluation of the role of rs2227983 polymorphism of EGFR gene in the development of allergic asthma

The objective of the study: to study rs2227983 polymorphism of EGFR gene in patients with allergic asthma and healthy individuals.Subjects and Methods. 179 patients suffering from allergic asthma were included in the study. The diagnosis and degree of severity were established in accordance with the GINA recommendations. The Control Group included apparently healthy individuals (n = 217). Patients with allergic asthma underwent standard laboratory and instrumental examinations and DNA typing.Results. A statistically significant predominance of AG genotype frequency in the group of patients with allergic asthma, including women, versus the group of healthy individuals, was established. AG rs2227983 genotype of EGFR gene was found to be significantly more common in patients with mild and moderate allergic asthma including women, than in healthy individuals, including women.Conclusion. The association of rs2227983 polymorphism of EGFR gene with allergic asthma has been established. A homozygous GG genotype may play a protective role against the disease.

Mutation Analysis of EGFR Gene in Patients with Non-Small Cell Lung Cancer in Xinjiang

Short Retraction Notice International Journal of Clinical Medicine (IJCM) does not meet authors’ publication requirements. This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused. Please see the article page for more details. The full retraction notice in PDF is preceding the original paper which is marked "RETRACTED".

Multiple mutations in the EGFR gene in patients diagnosed with lung cancer.

e20542 Background: Lung cancer is the most common malignant tumor after breast cancer and is the main cause of cancer mortality. Mutations in the EGFR gene typical of lung cancer lead to constitutive activation of the epidermal growth factor receptor and malignant cell transformation. The purpose of this study was to identify associations between double and triple mutations in EGFR and clinical and pathological characteristics of patients in the South of Russia diagnosed with lung cancer. Methods: DNA was extracted from FFPE samples of 240 patients. Mutations in EGFR were detected using Cobas EGFR Mutation Test detection kit (Roche). Results: The mutant type of EGFR was identified in 24.6% of cases, and the most common activating mutations were ex19del (47.5%) and L858R (30.5%). Insertion in exon 20 was detected in 5.1% of mutation cases, G719X - in 3.4%. We also registered cases of identification of two or three mutations in one tumor: ex19del - L858R, ex19del - T790M, L858R - T790M with a frequency of 3.4% and G719X - ex20ins, ex19del - L858R - ex20ins with a frequency of 1.7%. Similar frequency is characteristic of the Caucasoid population of the USA. Multiple mutations in EGFR are associated with early manifestations of lung cancer and rapid progression of the disease. Two patients with two mutations EGFR T790M and L858R were of particular interest. According to the literature data, T790M is the most common somatic mutation that causes resistance to targeted therapy; however, rare cases could be associated with germinal variation of T790M. The primary T790M mutation is more common in patients with two or three mutations in EGFR. Conclusions: Mutations in the EGFR gene were detected in 24.6% of lung cancer cases in a patient population in the South of Russia. The frequency of two or three mutations in the EGFR gene was 0.33%. The timely detection of these mutations is particularly important for family cases when the risk group can be determined.

ReadMax-a novel reading and scoring approach for EGFR gene copy number to predict therapeutic benefit of erlotinib treatment in EGFR wild-type non-small-cell lung cancer.

EGFR mutation testing is now well established as a means of selecting the optimal first‐line therapy for patients with advanced non‐small‐cell lung cancer (NSCLC). However, deciding on the correct treatment for EGFR wild‐type NSCLC remains a challenge. EGFR fluorescence in‐situ hybridization (FISH) testing of gene copy number has been a promising marker, but has provided mixed results despite attempts to standardize the reading and scoring process. The novel ReadMax reading and scoring system focuses on the most aberrant cells, to identify oncogene addiction, rather than taking a representative reading as in the Colorado method. The methodology was developed using historical samples from the TRUST and MERIT studies, followed by re‐reading of the samples from the SATURN trial. Analysis of samples using the ReadMax methodology revealed that progression‐free survival (PFS) and overall survival (OS) were improved in patients with ReadMax FISH‐positive (RM FISH+) tumours, compared with those whose tumours were not RM FISH+: PFS hazard ratios (HRs) were 0.52 for RM FISH+ versus 0.93 for not RM FISH+; OS HRs were 0.69 and 0.92, respectively. For PFS, HR for RM FISH+ versus not RM FISH+ in the SATURN erlotinib group was 0.53 (p = 0.003). The PFS and OS results were also similar in the EGFR wild‐type population (PFS HRs were 0.63 and 0.96; OS HRs were 0.61 and 0.84, respectively), although amplification of the EGFR gene in patients with EGFR wild‐type disease was not found to be predictive of treatment outcomes, which was unexpected but not unprecedented. KRAS status was not found to affect outcomes. Further experience is required to refine the ReadMax methodology and fully establish its validity and robustness. In conclusion, the ReadMax scoring system to identify patients with EGFR FISH‐positive NSCLC is a promising technique, which could improve treatment options and outcomes for patients with advanced NSCLC, in particular for EGFR wild‐type tumours.

653: Comparison of direct sequencing and peptide nucleic acid clamping of EGFR gene in patients with non-small cell lung cancer

653: Comparison of direct sequencing and peptide nucleic acid clamping of EGFR gene in patients with non-small cell lung cancer

Abstract C20: Quantitative determination of EGFR gene aberrant methylation in NSCLC: a comparative analysis in tumor tissue, normal lung tissue, peripheral blood, sputum and bronchial aspirate

Abstract Introduction and objective. To evaluate and compare quantitatively aberrant methylation in the promoter area of EGFR gene in patients (p) with in non small cell lung cancer (NSCLC) lung tumor tissue (TT), lung normal tissue (NT), blood (B), bronchial aspirate (BA) and sputum (S). Correlate these methylation patterns with clinical variables. Methods. DNA was extracted from samples of B, S and BA from patients with NSCLC prior to surgery and resected TT and NT. Methylation patterns were analyzed by the bisulfite conversion and subsequent pyrosequencing (QIagen PyroMark System). We analyzed three CpG islands in the promoter region of EGFR gene. Results. 43p were included, median age 66 years (range 46-79), 35 men and 8 women. Histology: 26p adenocarcinoma, 14 squamous and 3 others. 2p had EGFR mutation. Smoking status: 4p never smokers, 21p former smokers, 18p smokers. Significant differences in methylation percentage (%Mth) were observed between TT and S in the following islands: CpG2 (11.8vs7.1, p = 0.008), CpG3 (10vs7.4, p = 0.037) and in overall promoter area (10.6vs7. 6, p = 0.034). The %Mth was higher in women vs men in TT CpG1 island (16.2vs24.9, p = 0.042) and TT CpG2 island (15.8vs26.5, p = 0.013). The %Mth was higher in squamous histology compared to adenocarcinoma in NT CpG2 island (22.6vs14.1, p = 0.017) and S CpG1 island (13.7vs8.2, p = 0.047). However, the %Mth was higher in the overall promoter area of adenocarcinoma respect to squamous histology (19.7vs12.8 TT, p = 0.042). The %Mth was higher in overall promoter area of NT respect Stage I vs II vs III (22.3 vs 13 vs 17.5, p = 0.03). The %Mth was higher in former smokers compared to current smokers and non smokers in NT CpG3 (22.8 vs 13 vs 14.1, p = 0.032). The %Mth in NT CpG3 was higher in never smokers and former smokers > 5 years, respect to current smokers and former smokers <5 years, (23.3 vs 15.8, p = 0.05). Conclusion. EGFR aberrant hypermethylation was higher in tumor tissue respect to sputum, with no correlation with EGFR mutation. The %Mth in normal tissue was higher in never smoker and former smokers > 5 years patients. * This study was funded by the Carlos III Health Institute (PS09/00308), Spain Note: This abstract was not presented at the conference. Citation Format: Rocio Lavado-Valenzuela, Enrique Bermejo, Roberto Mongil, Francisco Páez, Carlos Pagés, Miguel Angel Berciano, Ricardo Arrabal, Dolores Bautista, Jose Luis De la Cruz, Cynthia Robles, Manuel Benavides, Manuel Cobo. Quantitative determination of EGFR gene aberrant methylation in NSCLC: a comparative analysis in tumor tissue, normal lung tissue, peripheral blood, sputum and bronchial aspirate. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr C20.

Secondary T790M mutation and novel G796A mutation in exon20 of EGFR gene in patients with non-small cell lung cancer who show resistance to gefitinib

7703 Background: Somatically acquired mutations in the EGFR gene in non-small cell lung cancer are associated with a significant clinical response to a tyrosine kinase inhibitor (TKI). EGFR mutations occur predominantly in exon19 and/or exon21, namely, an in-frame deletion in exon19 or a missense mutation in exon21 (L858R), which have been found to be related to the sensitivity to TKI. However, most patients with such sensitive mutations in their tumor show progression during the TKI treatment. In such resistant tumors, a secondary threonine- to-methionine mutation at codon 790 (T790M) in exon20 has been reported to be related the resistance to either gefitinib or erlotinib. Methods: EGFR mutations in exons19–21 were examined by sequencing in 37 pretreatment tumors obtained from patients with NSCLC, who were treated by gefitinib. Of the 22 cases having sensitive EGFR mutations (19del or L858R), 15 showed CR/PR and 7 showed SD/PD. Of the 15 patients with CR/PR, 4 tumor samples (2 lung, 1 liver, and 1 pleural effusion) that became refractory to gefitinib, were obtained. In pretreatment tumor samples from 4 patients, an in-frame deletion of exon19 was observed in 3 tumors and a L858R mutation of exon21 was in 1 tumor. We next examined whether a secondary mutation occurred in a tumor with acquired resistance to gefitinib in 4 patients by the sequencing of exons 19–21, with informed consent. Results: Three of 4 tumor samples had a secondary T790M mutation, which was not detected in the pretreatment tumor samples. These 3 samples also had an in-frame deletion in exon19. There were no other novel secondary mutations in exons 19,20,21. In 7 cases showing resistance to gefitinib (SD/PD) in spite of the existence of sensitive mutations, 1 tumor demonstrated the co-existence of a missense mutation (G796A) in exon20. In vitro, a stable clone of cells bearing the G796A mutation was approximately 50,000-fold less sensitive to gefitinib in comparison to the cells carrying exon19 deletion. Conclusions: The T790M mutation is common in patients with acquired resistance to gefitinb. Our results suggest that screening tumor samples for a range of EGFR mutations may therefore improve our ability to identify the patients most likely to benefit from treatment with TKI. No significant financial relationships to disclose.

Epidermal growth factor receptor (EGFR) mutations in breast and cervical cancer

20101 Background: EGFR is a tyrosine kinase receptor in the HER family which is widely expressed in a number of epithelial tumors and is believed to play a key role in cell proliferation. Molecular analysis of the EGFR gene in patients with non-small-cell lung cancer have identified a distinct subset of tumors that possess specific point mutations in the tyrosine kinase region of the EGFR gene, which correlate to response to tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib. Clinical trials involving TKIs are currently under way for patients with breast and cervical cancer. While responses thus far may have been modest it is unclear whether specific EGFR mutations are present in breast and cervical cancers which identify patients with improved prognosis and better response to therapy in these cancers. Using clinical samples with 5 years of follow-up clinical data, we have set out to determine whether EGFR mutations exist in breast and cervical cancers, and how these mutations, if any, correlate with the clinical data. Methods: We plan to perform sequence analysis of the tyrosine kinase domain of the EGFR gene (exons 18–24) in 50 archival breast and 44 cervical cancer specimens using PCR amplification and sequencing of genomic DNA. Clinical information has been extracted from patient charts on samples and will be correlated with the presence of any EGFR mutations identified. Results: To date we have collected 50 breast and 44 cervical tumor blocks and have isolated genomic DNA from the specimens. Sequencing for point mutations in exons 18–24 is underway. Clinical data on the cervical cancer specimens revealed a mean age at diagnosis of 48.2 years, tumor grades that were mostly intermediate (50%) and high (45%), and all FICO stages at diagnosis (43% stage I, 30% stage II, 5% stage III, 5% stage IV). In addition the rate of recurrence was 32%, and survival rate was 82% with an average time of follow-up for the set of 4.9 years. Conclusions: Our data will further elucidate the role of point mutations in EGFR gene in breast and cervical cancer prognosis and response to therapy, and will complement data currently being collected in clinical trials using TKIs. No significant financial relationships to disclose.