PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1362206)

Clipboard (0)
None

Related Articles

1.  Clinical investigation of EGFR mutation detection by pyrosequencing in lung cancer patients 
Oncology Letters  2012;5(1):271-276.
Direct sequencing is the standard method for the detection of epidermal growth factor receptor (EGFR) mutations in lung cancer, however, its relatively low sensitivity limits its clinical use. Pyrosequencing is a bioluminometric, real-time non-electrophoretic DNA sequencing technique with a number of advantages compared with direct sequencing, including higher sensitivity, speed, automation and cost-effectiveness. Clinical specimens from 202 lung cancer patients were analyzed for EGFR mutations in exons 18, 19, 20 and 21 using the pyrosequencing method following genomic DNA extraction from paraffin-embedded tissue specimens. All clinical data and tumor specimens were obtained from the Konkuk University Hospital (Korea) between July 2006 and December 2008. The results and clinical responses to EGFR-tyrosine kinase inhibitors (TKIs) were compared. Overall, EGFR mutation-positive rate was 26.7% (54/202). Activating EGFR mutations were observed more frequently in female (52.1 vs. 13.0%), non-smoking (47.8 vs. 15.8%) and adenocarcinoma (35.2 vs. 5.2%) patients. However, significant numbers of EGFR mutation-positive patients were identified as male, former or current smokers and non-adenocarcinoma patients. The combinations of favorable clinicopathological factors, including female, non-smoking and adenocarcinoma, were not identified to significantly increase the positive EGFR mutation rate (female, 52.1%; female and non-smoker, 52.6%; female, non-smoker and adenocarcinoma, 51.9%). The present findings indicate that EGFR mutation analysis is a highly useful method for the prediction of response to EGFR-TKI and the use of favorable clinicopathological factors to perform this analysis is not suitable. Exon 19 deletion was the most common mutation (63.6%) and exon 21 L858R substitution was measured at 32.7%. The exon 20 T790M mutation was identified in 1 patient prior to EGFR-TKI treatment. EGFR mutation status is associated with response to EGFR-TKI and the overall response rate in patients who have the activating EGFR mutation was 82.4 vs. 5.9% in patients with a wild-type EGFR. The present study demonstrates that EGFR mutations analyzed by the pyrosequencing method are well correlated with clinicopathological parameters and that this method may be useful in the clinical practice.
doi:10.3892/ol.2012.950
PMCID: PMC3525462  PMID: 23255934
EGFR mutation; pyrosequencing; lung cancer
2.  EGFR Exon 20 Insertion Mutations in Lung Adenocarcinomas: Prevalence, Molecular Heterogeneity, and Clinicopathologic Characteristics 
Molecular cancer therapeutics  2013;12(2):220-229.
In contrast to other primary EGFR mutations in lung adenocarcinomas, insertions in exon 20 of EGFR have been generally associated with resistance to EGFR tyrosine kinase inhibitors. Their molecular spectrum, clinicopathologic characteristics and prevalence are not well established. Tumors harboring EGFR exon 20 insertions were identified through an algorithmic screen of 1500 lung adenocarcinomas. Cases were first tested for common mutations in EGFR (exons 19 and 21) and KRAS (exon 2) and, if negative, further analyzed for EGFR exon 20 insertions. All samples underwent extended genotyping for other driver mutations in EGFR, KRAS, BRAF, NRAS, PIK3CA, MEK1 and AKT by mass spectrometry; a subset was evaluated for ALK rearrangements. We identified 33 EGFR exon 20 insertion cases (2.2%, 95% CI 1.6 to 3.1%), all mutually exclusive with mutations in the other genes tested (except PIK3CA). They were more common among never-smokers (p<0.0001). There was no association with age, sex, race, or stage. Morphologically, tumors were similar to those with common EGFR mutations, but with frequent solid histology. Insertions were highly variable in position and size, ranging from 3 to 12bp, resulting in 13 different insertions which, by molecular modeling, are predicted to have potentially different effects on erlotinib binding. EGFR exon 20 insertion testing identifies a distinct subset of lung adenocarcinomas, accounting for at least 9% of all EGFR mutated cases, representing the third most common type of EGFR mutation after exon 19 deletions and L858R. Insertions are structurally heterogeneous with potential implications for response to EGFR inhibitors.
doi:10.1158/1535-7163.MCT-12-0620
PMCID: PMC3714231  PMID: 23371856
EGFR exon 20; EGFR; epidermal growth factor receptor; lung adenocarcinoma; driver oncogenes
3.  Mutations within the tyrosine kinase domain of EGFR gene specifically occur in lung adenocarcinoma patients with a low exposure of tobacco smoking 
British Journal of Cancer  2006;94(6):896-903.
Somatically acquired mutations in the epidermal growth factor receptor (EGFR) gene in lung cancer are associated with significant clinical responses to gefitinib, a tyrosine kinase inhibitor that targets EGFR. We screened the EGFR in 469 resected tumours of patients with lung cancer, which included 322 adenocarcinomas, 102 squamous cell carcinomas, 27 large cell carcinomas, 13 small cell carcinomas, and five other cell types. PCR with a specific condition was performed to identify any deletion in exon 19, while mutant-allele-specific amplification was performed to identify a mutation in codon 858 of exon 21. EGFR mutations were found in 136 cases (42.2%) with adenocarcinoma, in one case with large cell carcinoma, and in one case with pleomorphic carcinoma. An in-frame deletion in exon 19 was found in 62 cases while an L858R mutation was found in 77 cases. In the 322 cases with adenocarcinoma, these mutations were more frequently found in women than in men (P=0.0004), in well differentiated tumours than in poorly differentiated tumours (P=0.0014), and in patients who were never smokers than in patients who were current/former smokers (P<0.0001). The mutation was more frequently observed in patients who smoked ⩽20 pack-year, and in patients who quit at least 20 years before the date of diagnosis for lung cancer. The K-ras mutations were more frequently found in smokers than in never smokers, and in high-dose smokers than in low-dose smokers. In conclusion, the mutations within the tyrosine kinase domain of EGFR were found to specifically occur in lung adenocarcinoma patients with a low exposure of tobacco smoking.
doi:10.1038/sj.bjc.6603040
PMCID: PMC3216424  PMID: 16552419
EGFR; mutation; lung cancer; adenocarcinoma; smoking; screening; K-ras
4.  BIM Mediates EGFR Tyrosine Kinase Inhibitor-Induced Apoptosis in Lung Cancers with Oncogenic EGFR Mutations  
PLoS Medicine  2007;4(10):e315.
Background
Epidermal growth factor receptor (EGFR) mutations are present in the majority of patients with non-small cell lung cancer (NSCLC) responsive to the EGFR tyrosine kinase inhibitors (TKIs) gefitinib or erlotinib. These EGFR-dependent tumors eventually become TKI resistant, and the common secondary T790M mutation accounts for half the tumors with acquired resistance to gefitinib. However, the key proapoptotic proteins involved in TKI-induced cell death and other secondary mutations involved in resistance remain unclear. The objective of this study was to identify the mechanism of EGFR TKI-induced apoptosis and secondary resistant mutations that affect this process.
Methods and Findings
To study TKI-induced cell death and mechanisms of resistance, we used lung cancer cell lines (with or without EGFR mutations), Ba/F3 cells stably transfected with EGFR mutation constructs, and tumor samples from a gefitinib-resistant patient. Here we show that up-regulation of the BH3-only polypeptide BIM (also known as BCL2-like 11) correlated with gefitinib-induced apoptosis in gefitinib-sensitive EGFR-mutant lung cancer cells. The T790M mutation blocked gefitinib-induced up-regulation of BIM and apoptosis. This blockade was overcome by the irreversible TKI CL-387,785. Knockdown of BIM by small interfering RNA was able to attenuate apoptosis induced by EGFR TKIs. Furthermore, from a gefitinib-resistant patient carrying the activating L858R mutation, we identified a novel secondary resistant mutation, L747S in cis to the activating mutation, which attenuated the up-regulation of BIM and reduced apoptosis.
Conclusions
Our results provide evidence that BIM is involved in TKI-induced apoptosis in sensitive EGFR-mutant cells and that both attenuation of the up-regulation of BIM and resistance to gefitinib-induced apoptosis are seen in models that contain the common EGFR T790M and the novel L747S secondary resistance mutations. These findings also suggest that induction of BIM may have a role in the treatment of TKI-resistant tumors.
Susumu Kobayashi and colleagues provide evidence that the polypeptide BIM is involved in tyrosine kinase inhibitor (TKI)-induced apoptosis in sensitiveEGFR-mutant cells and suggest that induction of BIM may have a role in the treatment of TKI-resistant tumors.
Editors' Summary
Background.
Most cases of lung cancer—the leading cause of cancer deaths worldwide—are “non-small cell lung cancer” (NSCLC). Many patients with NSCLC die within a year of their diagnosis, but recently, “targeted” therapies have increased the life expectancy of some of them. Like all cancers, NSCLC occurs when cells begin to divide uncontrollably because of changes (mutations) in their genes. Targeted therapies specifically attack these changes and, unlike standard chemotherapy drugs, kill cancer cells without damaging normal cells. The targeted drugs used to treat NSCLC are gefitinib and erlotinib, two epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). In normal cells, messenger proteins bind to EGFR and activate its tyrosine kinase, an enzyme that sticks phosphate groups on tyrosine (an amino acid) in other proteins. These “phosphorylated” proteins then tell the cell to divide. In some NSCLCs, EGFR drives uncontrolled cell division because its tyrosine kinase is mutated and the cancer becomes dependent on or “addicted” to EGFR signaling for its survival. TKI treatment can dramatically shrink this subset of NSCLCs, most of which lack a specific part of EGFR (the gene that encodes EGFR) or have the amino acid leucine instead of arginine at position 858 (an L858R mutation) of EGFR.
Why Was This Study Done?
TKI-sensitive NSCLCs eventually become resistant to TKIs because they acquire additional (secondary) mutations. In half of these TKI-resistant tumors, the additional mutation is replacement of threonine by methionine at position 790 (T790M) in EGFR. However, the mutations responsible for the remaining cases of TKI resistance are not known. In addition, little is known about how TKIs induce cell death other than that they induce a type of cell death called apoptosis. A better understanding of how TKIs kill tumor cells and how secondary mutations block their effects could reveal ways to enhance their action and improve the outcome for patients with NSCLC. In this study, the researchers have studied the mechanism of TKI-induced cell death and of resistance to TKIs.
What Did the Researchers Do and Find?
The researchers first measured the ability of gefitinib to cause apoptosis (genetically programmed cell death) in NSCLC cell lines (tumor cells adapted to grow indefinitely in dishes) that had the EGFR deletion, the L858R mutation, or normal EGFR. Gefitinib caused apoptosis only in cell lines with altered EGFR. Then they asked whether a proapoptotic protein called BIM (a member of the BCL2 family of pro- and antiapoptotic proteins) is involved in TKI-induced cell death—BIM is known to be involved in this process in leukemia (blood cancer) cells. Gefitinib treatment increased the expression of BIM in TKI-sensitive NSCLC cell lines and reduced the phosphorylation of BIM (which makes BIM more active). By contrast, blocking BIM expression using a technique called RNA interference reduced TKI-induced apoptosis in TKI-sensitive NSCLC cells. Furthermore, introduction of the T790M resistance mutation into these cells blocked gefitinib-induced up-regulation of BIM and apoptosis. Finally, the researchers identified a new TKI resistance mutation (L747S, substitution of serine for leucine at position 747) in a patient whose TKI-sensitive NSCLC had become resistant to gefitinib, and showed that this resistance mutation also reduced TKI-induced apoptosis in cells growing in dishes by interfering with BIM up-regulation.
What Do These Findings Mean?
These findings (and those reported by Gong et al. and Cragg et al.) show that BIM is required for TKI-induced apoptosis in EGFR mutant NSCLC cells. They also show that mutations that make TKI-sensitive cells resistant to these drugs reduce TKI-induced apoptosis by preventing the upregulation of BIM. These results were obtained by examining the behavior of established cell lines growing in dishes and need to be confirmed in cells freshly isolated from tumors and in tumors themselves. However, they suggest that the efficacy of TKIs could be increased by finding ways to increase BIM expression or to activate other proteins involved in apoptosis Such approaches might be particularly beneficial for patients with NSCLC whose initially TKI-sensitive tumors have acquired mutations that make them resistant to TKIs.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040315.
Ingo Mellinghoff discusses this paper and two related ones in a perspective article
US National Cancer Institute information for patients and professionals on lung cancer (in English and Spanish)
Information for patients from Cancer Research UK on lung cancer, including information on treatment with TKIs
CancerQuest information on all aspects of cancer from Emory University (in several languages)
Wikipedia pages on apoptosis, epidermal growth factor receptor, and BCL2 proteins (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
Information for patients from Cancerbackup on erlotinib and gefitinib
doi:10.1371/journal.pmed.0040315
PMCID: PMC2043012  PMID: 17973572
5.  Detection of EGFR mutations in circulating free DNA by PNA-mediated PCR clamping 
Background
Epidermal growth factor receptor (EGFR)-activating mutations are major determinants in predicting the tumor response to EGFR tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC). Noninvasive test for the detection of EGFR mutations is required, especially in NSCLC patients from whom tissue is not available. In this study, we assessed the feasibility of detection of EGFR mutations in free DNA circulating in plasma.
Methods
Plasma samples of 60 patients with partial response to gefitinib were analyzed to detect EGFR-activating mutations in exons 19 and 21. Forty (66.7%) of patients had tumor EGFR mutation results. EGFR mutations in plasma were detected using the peptide nucleic acid (PNA)-mediated polymerase chain reaction (PCR) clamping method. All clinical data and plasma samples were obtained from 11 centers of the Korean Molecular Lung Cancer Group (KMLCG).
Results
Of the 60 patients, 39 were female and the median age was 62.5 years. Forty-three patients never smoked, 53 had adenocarcinomas, and seven had other histologic types. EGFR-activating mutation was detected in plasma of 10 cases (exon 19 deletion in seven and exon 21 L858R point mutation in three). It could not be found in plasma after treatment for 2 months. When only patients with confirmed EGFR mutation in tumor were analyzed, 17% (6 of 35) of them showed positive plasma EGFR mutation and the mutation type was completely matched with that in tumor. There was no statistically significant difference in clinical parameters between patients with EGFR mutations in plasma and those without EGFR mutations.
Conclusions
The detection rate of EGFR mutations from plasma was not so high despite highly sensitive EGFR mutation test suggesting that more advances in detection methods and further exploration of characteristics of circulating free DNA are required.
doi:10.1186/1756-9966-32-50
PMCID: PMC3751150  PMID: 23927790
Plasma; EGFR mutation; PNA-mediated PCR clamping method; Non-small cell lung cancer
6.  Epidermal Growth Factor Receptor Mutation (EGFR) Testing for Prediction of Response to EGFR-Targeting Tyrosine Kinase Inhibitor (TKI) Drugs in Patients with Advanced Non-Small-Cell Lung Cancer 
Executive Summary
In February 2010, the Medical Advisory Secretariat (MAS) began work on evidence-based reviews of the literature surrounding three pharmacogenomic tests. This project came about when Cancer Care Ontario (CCO) asked MAS to provide evidence-based analyses on the effectiveness and cost-effectiveness of three oncology pharmacogenomic tests currently in use in Ontario.
Evidence-based analyses have been prepared for each of these technologies. These have been completed in conjunction with internal and external stakeholders, including a Provincial Expert Panel on Pharmacogenetics (PEPP). Within the PEPP, subgroup committees were developed for each disease area. For each technology, an economic analysis was also completed by the Toronto Health Economics and Technology Assessment Collaborative (THETA) and is summarized within the reports.
The following reports can be publicly accessed at the MAS website at: http://www.health.gov.on.ca/mas or at www.health.gov.on.ca/english/providers/program/mas/mas_about.html
Gene Expression Profiling for Guiding Adjuvant Chemotherapy Decisions in Women with Early Breast Cancer: An Evidence-Based Analysis
Epidermal Growth Factor Receptor Mutation (EGFR) Testing for Prediction of Response to EGFR-Targeting Tyrosine Kinase Inhibitor (TKI) Drugs in Patients with Advanced Non-Small-Cell Lung Cancer: an Evidence-Based Analysis
K-RAS testing in Treatment Decisions for Advanced Colorectal Cancer: an Evidence-Based Analysis
Objective
The Medical Advisory Secretariat undertook a systematic review of the evidence on the clinical effectiveness and cost-effectiveness of epidermal growth factor receptor (EGFR) mutation testing compared with no EGFR mutation testing to predict response to tyrosine kinase inhibitors (TKIs), gefitinib (Iressa®) or erlotinib (Tarceva®) in patients with advanced non-small cell lung cancer (NSCLC).
Clinical Need: Target Population and Condition
With an estimated 7,800 new cases and 7,000 deaths last year, lung cancer is the leading cause of cancer deaths in Ontario. Those with unresectable or advanced disease are commonly treated with concurrent chemoradiation or platinum-based combination chemotherapy. Although response rates to cytotoxic chemotherapy for advanced NSCLC are approximately 30 to 40%, all patients eventually develop resistance and have a median survival of only 8 to 10 months. Treatment for refractory or relapsed disease includes single-agent treatment with docetaxel, pemetrexed or EGFR-targeting TKIs (gefitinib, erlotinib). TKIs disrupt EGFR signaling by competing with adenosine triphosphate (ATP) for the binding sites at the tyrosine kinase (TK) domain, thus inhibiting the phosphorylation and activation of EGFRs and the downstream signaling network. Gefitinib and erlotinib have been shown to be either non-inferior or superior to chemotherapy in the first- or second-line setting (gefitinib), or superior to placebo in the second- or third-line setting (erlotinib).
Certain patient characteristics (adenocarcinoma, non-smoking history, Asian ethnicity, female gender) predict for better survival benefit and response to therapy with TKIs. In addition, the current body of evidence shows that somatic mutations in the EGFR gene are the most robust biomarkers for EGFR-targeting therapy selection. Drugs used in this therapy, however, can be costly, up to C$ 2000 to C$ 3000 per month, and they have only approximately a 10% chance of benefiting unselected patients. For these reasons, the predictive value of EGFR mutation testing for TKIs in patients with advanced NSCLC needs to be determined.
The Technology: EGFR mutation testing
The EGFR gene sequencing by polymerase chain reaction (PCR) assays is the most widely used method for EGFR mutation testing. PCR assays can be performed at pathology laboratories across Ontario. According to experts in the province, sequencing is not currently done in Ontario due to lack of adequate measurement sensitivity. A variety of new methods have been introduced to increase the measurement sensitivity of the mutation assay. Some technologies such as single-stranded conformational polymorphism, denaturing high-performance liquid chromatography, and high-resolution melting analysis have the advantage of facilitating rapid mutation screening of large numbers of samples with high measurement sensitivity but require direct sequencing to confirm the identity of the detected mutations. Other techniques have been developed for the simple, but highly sensitive detection of specific EGFR mutations, such as the amplification refractory mutations system (ARMS) and the peptide nucleic acid-locked PCR clamping. Others selectively digest wild-type DNA templates with restriction endonucleases to enrich mutant alleles by PCR. Experts in the province of Ontario have commented that currently PCR fragment analysis for deletion and point mutation conducts in Ontario, with measurement sensitivity of 1% to 5%.
Research Questions
In patients with locally-advanced or metastatic NSCLC, what is the clinical effectiveness of EGFR mutation testing for prediction of response to treatment with TKIs (gefitinib, erlotinib) in terms of progression-free survival (PFS), objective response rates (ORR), overall survival (OS), and quality of life (QoL)?
What is the impact of EGFR mutation testing on overall clinical decision-making for patients with advanced or metastatic NSCLC?
What is the cost-effectiveness of EGFR mutation testing in selecting patients with advanced NSCLC for treatment with gefitinib or erlotinib in the first-line setting?
What is the budget impact of EGFR mutation testing in selecting patients with advanced NSCLC for treatment with gefitinib or erlotinib in the second- or third-line setting?
Methods
A literature search was performed on March 9, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, OVID EMBASE, Wiley Cochrane, CINAHL, Centre for Reviews and Dissemination/International Agency for Health Technology Assessment for studies published from January 1, 2004 until February 28, 2010 using the following terms:
Non-Small-Cell Lung Carcinoma
Epidermal Growth Factor Receptor
An automatic literature update program also extracted all papers published from February 2010 until August 2010. Abstracts were reviewed by a single reviewer and for those studies meeting the eligibility criteria full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, and then a group of epidemiologists, until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology.
The inclusion criteria were as follows:
Population: patients with locally advanced or metastatic NSCLC (stage IIIB or IV)
Procedure: EGFR mutation testing before treatment with gefitinib or erlotinib
Language: publication in English
Published health technology assessments, guidelines, and peer-reviewed literature (abstracts, full text, conference abstract)
Outcomes: progression-free survival (PFS), Objective response rate (ORR), overall survival (OS), quality of life (QoL).
The exclusion criteria were as follows:
Studies lacking outcomes specific to those of interest
Studies focused on erlotinib maintenance therapy
Studies focused on gefitinib or erlotinib use in combination with cytotoxic agents or any other drug
Grey literature, where relevant, was also reviewed.
Outcomes of Interest
PFS
ORR determined by means of the Response Evaluation Criteria in Solid Tumours (RECIST)
OS
QoL
Quality of Evidence
The quality of the Phase II trials and observational studies was based on the method of subject recruitment and sampling, possibility of selection bias, and generalizability to the source population. The overall quality of evidence was assessed as high, moderate, low or very low according to the GRADE Working Group criteria.
Summary of Findings
Since the last published health technology assessment by Blue Cross Blue Shield Association in 2007 there have been a number of phase III trials which provide evidence of predictive value of EGFR mutation testing in patients who were treated with gefitinib compared to chemotherapy in the first- or second-line setting. The Iressa Pan Asian Study (IPASS) trial showed the superiority of gefitinib in terms of PFS in patients with EGFR mutations versus patients with wild-type EGFR (Hazard ratio [HR], 0.48, 95%CI; 0.36-0.64 versus HR, 2.85; 95%CI, 2.05-3.98). Moreover, there was a statistically significant increased ORR in patients who received gefitinib and had EGFR mutations compared to patients with wild-type EGFR (71% versus 1%). The First-SIGNAL trial in patients with similar clinical characteristics as IPASS as well as the NEJ002 and WJTOG3405 trials that included only patients with EGFR mutations, provide confirmation that gefitinib is superior to chemotherapy in terms of improved PFS or higher ORR in patients with EGFR mutations. The INTEREST trial further indicated that patients with EGFR mutations had prolonged PFS and higher ORR when treated with gefitinib compared with docetaxel.
In contrast, there is still a paucity of strong evidence regarding the predictive value of EGFR mutation testing for response to erlotinib in the second- or third-line setting. The BR.21 trial randomized 731 patients with NSCLC who were refractory or intolerant to prior first- or second-line chemotherapy to receive erlotinib or placebo. While the HR of 0.61 (95%CI, 0.51-0.74) favored erlotinib in the overall population, this was not a significant in the subsequent retrospective subgroup analysis. A retrospective evaluation of 116 of the BR.21 tumor samples demonstrated that patients with EGFR mutations had significantly higher ORRs when treated with erlotinib compared with placebo (27% versus 7%; P=0.03). However, erlotinib did not confer a significant survival benefit compared with placebo in patients with EGFR mutations (HR, 0.55; 95%CI, 0.25-1.19) versus wild-type (HR, 0.74; 95%CI, 0.52-1.05). The interaction between EGFR mutation status and erlotinib use was not significant (P=0.47). The lack of significance could be attributable to a type II error since there was a low sample size that was available for subgroup analysis.
A series of phase II studies have examined the clinical effectiveness of erlotinib in patients known to have EGFR mutations. Evidence from these studies has consistently shown that erlotinib yields a very high ORR (typically 70% vs. 4%) and a prolonged PFS (9 months vs. 2 months) in patients with EGFR mutations compared with patients with wild-type EGFR. Although having a prolonged PFS and higher respond in EGFR mutated patients might be due to a better prognostic profile regardless of the treatment received. In the absence of a comparative treatment or placebo control group, it is difficult to determine if the observed differences in survival benefit in patients with EGFR mutation is attributed to prognostic or predictive value of EGFR mutation status.
Conclusions
Based on moderate quality of evidence, patients with locally advanced or metastatic NSCLC with adenocarcinoma histology being treated with gefitinib in the first-line setting are highly likely to benefit from gefitinib if they have EGFR mutations compared to those with wild-type EGFR. This advantage is reflected in improved PFS, ORR and QoL in patients with EGFR mutation who are being treated with gefitinib relative to patients treated with chemotherapy.
Based on low quality of evidence, in patients with locally advanced or metastatic NSCLC who are being treated with erlotinib, the identification of EGFR mutation status selects those who are most likely to benefit from erlotinib relative to patients treated with placebo in the second or third-line setting.
PMCID: PMC3377519  PMID: 23074402
7.  Differences in EGFR and KRAS mutation spectra in lung adenocarcinoma of never and heavy smokers 
Oncology Letters  2013;6(5):1207-1212.
Epidermal growth factor receptor (EGFR) mutations are common in lung adenocarcinomas of never smokers, while KRAS mutations are more frequent among heavy smokers. Different clinicopathological and biological characteristics may, therefore, exist in lung adenocarcinoma according to smoking status. In the present study, a retrospective review was performed using 521 patients with surgically resected lung adenocarcinomas. The clinicopathological factors of age, gender, pathological tumor size, nodal status, lymphatic permeation and blood vessel invasion and the EGFR and KRAS mutation spectra were compared between never and heavy smokers. EGFR mutations were detected in 233 (45%) patients, while KRAS mutations were detected in 56 (11%) patients. EGFR-mutated adenocarcinomas had a higher prevalence of females in the never smokers compared with the heavy smokers (P<0.001). KRAS-mutated adenocarcinomas had a higher prevalence of females (P<0.001) and showed less frequent vascular invasion (P=0.018) in the never smokers compared with the heavy smokers. Minor EGFR mutations, excluding exon 21 L858R and exon 19 deletions, were more common in heavy smokers than never smokers (P=0.055). KRAS G to A transition was more common in never smokers, while KRAS G to T and G to C transversions were more common in heavy smokers (P=0.036). The clinicopathological characteristics and the spectra of the EGFR and KRAS mutations in lung adenocarcinoma were different between the never and heavy smokers. Further large-scale studies are required to evaluate the efficacy of molecular targeting agents with consideration to specific EGFR and KRAS mutations.
doi:10.3892/ol.2013.1551
PMCID: PMC3813793  PMID: 24179496
lung cancer; adenocarcinoma; smoking; epidermal growth factor receptor; KRAS; mutation
8.  EGFR Exon 19 Insertions: A New Family of Sensitizing EGFR Mutations in Lung Adenocarcinoma 
Clinical Cancer Research  2011;18(6):1790-1797.
Purpose
EGFR genotyping is now standard in the management of advanced lung adenocarcinoma, as this biomarker predicts marked benefit from treatment with EGFR tyrosine kinase inhibitors (TKIs). EGFR exon 19 insertions are a poorly described family of EGFR mutations, and their association with EGFR TKI-sensitivity in lung adenocarcinoma is uncertain.
Experimental Design
Patients with lung cancers harboring EGFR exon 19 insertions were studied. The predicted effects of the insertions on the structure of the EGFR protein were examined, and EGFR exon 19 insertions were introduced into Ba/F3 cells to assess oncogenicity and in vitro sensitivity to EGFR TKIs. In patients receiving TKI, response magnitude was assessed with serial computed tomography (CT) measurement.
Results
Twelve tumors harboring EGFR exon 19 insertions were identified; patients were predominately female (92%) and never-smokers (75%). The 11 specimens available for full sequencing all demonstrated an 18 bp insertion that resulted in the substitution of a Pro for Leu at residue 747. The mutant EGFR transformed the Ba/F3 cells, which were then sensitive to EGFR TKI. Six patients with measurable disease received TKI and 5 had a response on serial CT.
Conclusions
EGFR exon 19 insertions are a newly appreciated family of EGFR TKI-sensitizing mutations, and patients with tumors harboring these mutations should be treated with EGFR-TKI. While these mutations may be missed through the use of some mutation-specific assays, the addition of PCR product size analysis to multi-gene assays allows sensitive detection of both exon 19 insertion and deletion mutations.
doi:10.1158/1078-0432.CCR-11-2361
PMCID: PMC3306520  PMID: 22190593
9.  Epidermal Growth Factor Receptor Mutations and the Clinical Outcome in Male Smokers with Squamous Cell Carcinoma of Lung 
Journal of Korean Medical Science  2009;24(3):448-452.
Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) have been reported to be related to certain clinical characteristics (i.e., female, non-smokers with adenocarcinoma) and gefitinib responsiveness. This exploratory analysis was performed to determine the incidence of EGFR mutations in male smokers with squamous cell carcinoma, who were treated with EGFR tyrosine kinase inhibitor, gefitinib. Sixty-nine Korean NSCLC patients were treated with gefitinib in a prospective study. For a subset of 20 male patients with squamous cell carcinoma and a history of smoking, pretreatment tumor tissue samples were obtained and analyzed for EGFR mutations (exons 18 to 21). EGFR mutations were found in 3 (15%) patients, including in-frame deletions within exon 19 (n=2) and L858R missence mutation in exon 21 (n=1). These 3 patients with EGFR mutations responded to gefitinib, whereas only one of remaining 17 patients with wild-type EGFR achieved clinical response. Trend toward longer progression-free (5.8 vs. 2.4 months; P=0.07) was noted in patients with EGFR mutations compared to those with wild-type EGFR. Although male smokers with squamous cell carcinoma have not been considered ideal candidates for gefitinib treatment, significant incidence of EGFR mutations was observed. The molecular markers should be considered to predict clinical benefits from gefitinib.
doi:10.3346/jkms.2009.24.3.448
PMCID: PMC2698191  PMID: 19543508
Lung Neoplasms; Receptor, Epidermal Growth Factor; Mutation
10.  EGFR Mutation Testing in Patients with Advanced Non-Small Cell Lung Cancer: A Comprehensive Evaluation of Real-World Practice in an East Asian Tertiary Hospital 
PLoS ONE  2013;8(2):e56011.
Introduction
Guidelines for management of non-small cell lung cancer (NSCLC) strongly recommend EGFR mutation testing. These recommendations are particularly relevant in Asians that have higher EGFR mutation prevalence. This study aims to explore current testing practices, logistics of testing, types of EGFR mutation, and prevalence of EGFR mutations in patients with advanced NSCLC in a large comprehensive cancer center in Korea.
Methods
Our retrospective cohort included 1,503 NSCLC patients aged ≥18 years, with stage IIIB/IV disease, who attended the Samsung Medical Center in Seoul, Korea, from January 2007 through July 2010. Trained oncology nurses reviewed and abstracted data from electronic medical records.
Results
This cohort had a mean age (SD) of 59.6 (11.1) years, 62.7% were males, and 52.9% never-smokers. The most common NSCLC histological types were adenocarcinoma (70.5%) and squamous cell carcinoma (18.0%). Overall, 39.5% of patients were tested for EGFR mutations. The proportion of patients undergoing EGFR testing during January 2007 through July 2008, August 2008 through September 2009, and October 2009 through July 2010 were 23.3%, 38.3%, and 63.5%, respectively (P<0.001). The median time elapsed between cancer diagnoses and receiving EGFR testing results was 21 days. EGFR testing was most frequently ordered by oncologists (57.7%), pulmonologists (31.9%), and thoracic surgeons (6.6%). EGFR testing was more commonly requested for women, younger patients, stage IV disease, non-smokers, and adenocarcinoma histology. Of 586 cases successfully tested for EGFR mutations, 209 (35.7%) were positive, including 118 cases with exon 19 deletions and 62 with L858R mutations. EGFR mutation positive patients were more likely to be female, never-smokers, never-drinkers and to have adenocarcinoma.
Conclusions
In a large cancer center in Korea, the proportion of EGFR testing increased from 2007 through 2010. The high frequency of EGFR mutation positive cases warrants the need for generalized testing in Asian NSCLC patients.
doi:10.1371/journal.pone.0056011
PMCID: PMC3585299  PMID: 23468851
11.  Driver mutations among never smoking female lung cancer tissues in China identify unique EGFR and KRAS mutation pattern associated with household coal burning 
Respiratory medicine  2013;107(11):10.1016/j.rmed.2013.08.018.
Lung cancer in never smokers, which has been partially attributed to household solid fuel use (i.e coal), is etiologically and clinically different from lung cancer attributed to tobacco smoking. To explore the spectrum of driver mutations among lung cancer tissues from never smokers, specifically in a population where high lung cancer rates have been attributed to indoor air pollution from domestic coal use, multiplexed assays were used to detect >40 point mutations, insertions, and deletions (EGFR, KRAS, BRAF, HER2, NRAS, PIK3CA, MEK1, AKT1, and PTEN) among the lung tumors of confirmed never smoking females from Xuanwei, China [32 adenocarcinomas (ADCs), 7 squamous cell carcinomas (SCCs), 1 adenosquamous carcinoma (ADSC)]. EGFR mutations were detected in 35% of tumors. 46% of these involved EGFR exon 18 G719X, while 14% were exon 21 L858R mutations. KRAS mutations, all of which were G12C_34G>T, were observed in 15% of tumors. EGFR and KRAS mutations were mutually exclusive, and no mutations were observed in the other tested genes. Most point mutations were transversions and were also found in tumors from patients who used coal in their homes. Our high mutation frequencies in EGFR exon 18 and KRAS and low mutation frequency in EGFR exon 21 are strikingly divergent from those in other smoking and never smoking populations from Asia. Given that our subjects live in a region where coal is typically burned indoors, our findings provide new insights into the pathogenesis of lung cancer among never smoking females exposed to indoor air pollution from coal.
doi:10.1016/j.rmed.2013.08.018
PMCID: PMC3848251  PMID: 24055406
EGFR; KRAS; lung cancer; never smoking; China; driver mutations; tumor tissue
12.  Molecular Epidemiology of EGFR and KRAS Mutations in 3026 Lung Adenocarcinomas: Higher Susceptibility of Women to Smoking-related KRAS-mutant Cancers 
Purpose
The molecular epidemiology of most EGFR and KRAS mutations in lung cancer remains unclear.
Experimental Design
We genotyped 3026 lung adenocarcinomas for the major EGFR (exon 19 deletions and L858R) and KRAS (G12, G13) mutations and examined correlations with demographic, clinical and smoking history data.
Results
EGFR mutations were found in 43% of never smokers (NS) and in 11% of smokers. KRAS mutations occurred in 34% of smokers and in 6% of NS. In patients with smoking histories up to 10 pack-years, EGFR predominated over KRAS. Among former smokers with lung cancer, multivariate analysis showed that, independent of pack-years, increasing smoking-free years raise the likelihood of EGFR mutation. NS were more likely than smokers to have KRAS G>A transition mutation (mostly G12D) (58% vs. 20%, p=0.0001). KRAS G12C, the most common G>T transversion mutation in smokers, was more frequent in women (p=0.007) and these women were younger than men with the same mutation (median 65 vs. 69, p=0.0008) and had smoked less.
Conclusions
The distinct types of KRAS mutations in smokers vs. NS suggest that most KRAS-mutant lung cancers in NS are not due to secondhand smoke exposure. The higher frequency of KRAS G12C in women, their younger age, and lesser smoking history together support a heightened susceptibility to tobacco carcinogens.
doi:10.1158/1078-0432.CCR-11-3265
PMCID: PMC3500422  PMID: 23014527
lung cancer; tobacco; EGFR; KRAS; molecular epidemiology
13.  Induction of BIM Is Essential for Apoptosis Triggered by EGFR Kinase Inhibitors in Mutant EGFR-Dependent Lung Adenocarcinomas 
PLoS Medicine  2007;4(10):e294.
Background
Mutations in the epidermal growth factor receptor (EGFR) gene are associated with increased sensitivity of lung cancers to kinase inhibitors like erlotinib. Mechanisms of cell death that occur after kinase inhibition in these oncogene-dependent tumors have not been well delineated. We sought to improve understanding of this process in order to provide insight into mechanisms of sensitivity and/or resistance to tyrosine kinase inhibitors and to uncover new targets for therapy.
Methods and Findings
Using a panel of human lung cancer cell lines that harbor EGFR mutations and a variety of biochemical, molecular, and cellular techniques, we show that EGFR kinase inhibition in drug-sensitive cells provokes apoptosis via the intrinsic pathway of caspase activation. The process requires induction of the proapoptotic BH3-only BCL2 family member BIM (i.e., BCL2-like 11, or BCL2L11); erlotinib dramatically induces BIM levels in sensitive but not in resistant cell lines, and knockdown of BIM expression by RNA interference virtually eliminates drug-induced cell killing in vitro. BIM status is regulated at both transcriptional and posttranscriptional levels and is influenced by the extracellular signal-regulated kinase (ERK) signaling cascade downstream of EGFR. Consistent with these findings, lung tumors and xenografts from mice bearing mutant EGFR-dependent lung adenocarcinomas display increased concentrations of Bim after erlotinib treatment. Moreover, an inhibitor of antiapoptotic proteins, ABT-737, enhances erlotinib-induced cell death in vitro.
Conclusions
In drug-sensitive EGFR mutant lung cancer cells, induction of BIM is essential for apoptosis triggered by EGFR kinase inhibitors. This finding implies that the intrinsic pathway of caspase activation may influence sensitivity and/or resistance of EGFR mutant lung tumor cells to EGFR kinase inhibition. Manipulation of the intrinsic pathway could be a therapeutic strategy to enhance further the clinical outcomes of patients with EGFR mutant lung tumors.
Using a panel of human drug-sensitive EGFR mutant lung cancer cells, William Pao and colleagues show that induction of BIM, a member of the BCL2 family, is essential for apoptosis triggered by EGFR kinase inhibitors.
Editors' Summary
Background.
Lung cancer, a common type of cancer, has a very low cure rate. Like all cancers, it occurs when cells begin to divide uncontrollably because of changes (mutations) in their genes. Chemotherapy drugs kill these rapidly dividing cells but, because some normal tissues are sensitive to these agents, it is hard to destroy the cancer without causing serious side effects. Recently, “targeted” therapies have brought new hope to some patients with cancer. These therapies attack the changes in cancer cells that allow them to divide uncontrollably but leave normal cells unscathed. One of the first molecules for which a targeted therapy was developed was the epidermal growth factor receptor (EGFR). In normal cells, messenger proteins bind to EGFR and activate its “tyrosine kinase,” an enzyme that sticks phosphate groups on tyrosine (an amino acid) in other proteins. These proteins then tell the cell to divide. Alterations to this signaling system drive uncontrolled cell division in some cancers so blocking the EGFR signaling pathway should stop these cancers growing. Indeed, some lung cancers with mutations in the tyrosine kinase of EGFR shrink dramatically when treated with gefitinib or erlotinib, two tyrosine kinase inhibitors (TKIs).
Why Was This Study Done?
TKI-sensitive lung cancers shrink when treated with TKIs because of drug-induced cell death, but what are the molecular mechanisms underlying this death? A better understanding of how TKIs kill cancer cells might provide new insights into why not all cancer cells with mutations in EGFR (the gene from which EGFR is made) are sensitive to TKIs. It might also uncover new targets for therapy. TKIs do not completely kill lung cancers, but if the mechanism of TKI-induced cell death were understood, it might be possible to enhance their effects. In this study, the researchers have investigated how cell death occurs after kinase inhibition in a panel of human lung cancer cell lines (cells isolated from human tumors that grow indefinitely in dishes) that carry EGFR mutations.
What Did the Researchers Do and Find?
The researchers show, first, that erlotinib induces a type of cell death called apoptosis in erlotinib-sensitive cell lines but not in resistant cell lines. Apoptosis can be activated by two major pathways. In this instance, the researchers report, the so-called “intrinsic” pathway activates apoptosis. This pathway is stimulated by proapoptotic members of the BCL2 family of proteins and is blocked by antiapoptotic members, so the researchers examined the effect of erlotinib treatment on the expression of BCL2 family members in the EGFR mutant cell lines. Erlotinib treatment increased the expression of the proapoptotic protein BIM in sensitive but not in resistant cell lines. It also removed phosphate groups from BIM—dephosphorylated BIM is a more potent proapoptotic protein. Conversely, blocking BIM expression using a technique called RNA interference virtually eliminated the ability of erlotinib to kill EGFR mutant cell lines. The researchers also report that erlotinib treatment increased BIM expression in erlotinib-sensitive lung tumors growing in mice and that an inhibitor of the anti-apoptotic protein BCL2 enhanced erlotinib-induced death in drug-sensitive cells growing in dishes.
What Do These Findings Mean?
These findings indicate that BIM activity is essential for the apoptosis triggered by TKIs in drug-sensitive lung cancer cells that carry EGFR mutations, and that treatment of these cells with TKIs induces both the expression and dephosphorylation of BIM. The finding that the intrinsic pathway of apoptosis activation is involved in TKI-induced cell death suggests that changes in this pathway (possibly mutations in some of its components) might influence the sensitivity of EGFR mutant lung cancers to TKIs. Finally, these findings suggest that giving drugs that affect the intrinsic pathway of apoptosis activation at the same time as TKIs might further improve the clinical outcome for patients with EGFR mutant tumors. Such combinations will have to be tested in clinical trials before being used routinely.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040294.
US National Cancer Institute information for patients and professionals on lung cancer (in English and Spanish)
Information for patients from Cancer Research UK on lung cancer including information on treatment with TKIs
Wikipedia pages on apoptosis, epidermal growth factor receptor, and BCL-2 proteins (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
Information for patients from Cancerbackup on erlotinib and gefitinib
doi:10.1371/journal.pmed.0040294
PMCID: PMC2001209  PMID: 17927446
14.  Gefitinib-Induced Killing of NSCLC Cell Lines Expressing Mutant EGFR Requires BIM and Can Be Enhanced by BH3 Mimetics 
PLoS Medicine  2007;4(10):e316.
Background
The epidermal growth factor receptor (EGFR) plays a critical role in the control of cellular proliferation, differentiation, and survival. Abnormalities in EGF-EGFR signaling, such as mutations that render the EGFR hyperactive or cause overexpression of the wild-type receptor, have been found in a broad range of cancers, including carcinomas of the lung, breast, and colon. EGFR inhibitors such as gefitinib have proven successful in the treatment of certain cancers, particularly non-small cell lung cancers (NSCLCs) harboring activating mutations within the EGFR gene, but the molecular mechanisms leading to tumor regression remain unknown. Therefore, we wished to delineate these mechanisms.
Methods and Findings
We performed biochemical and genetic studies to investigate the mechanisms by which inhibitors of EGFR tyrosine kinase activity, such as gefitinib, inhibit the growth of human NSCLCs. We found that gefitinib triggered intrinsic (also called “mitochondrial”) apoptosis signaling, involving the activation of BAX and mitochondrial release of cytochrome c, ultimately unleashing the caspase cascade. Gefitinib caused a rapid increase in the level of the proapoptotic BH3-only protein BIM (also called BCL2-like 11) through both transcriptional and post-translational mechanisms. Experiments with pharmacological inhibitors indicated that blockade of MEK–ERK1/2 (mitogen-activated protein kinase kinase–extracellular signal-regulated protein kinase 1/2) signaling, but not blockade of PI3K (phosphatidylinositol 3-kinase), JNK (c-Jun N-terminal kinase or mitogen-activated protein kinase 8), or AKT (protein kinase B), was critical for BIM activation. Using RNA interference, we demonstrated that BIM is essential for gefitinib-induced killing of NSCLC cells. Moreover, we found that gefitinib-induced apoptosis is enhanced by addition of the BH3 mimetic ABT-737.
Conclusions
Inhibitors of the EGFR tyrosine kinase have proven useful in the therapy of certain cancers, in particular NSCLCs possessing activating mutations in the EGFR kinase domain, but the mechanisms of tumor cell killing are still unclear. In this paper, we demonstrate that activation of the proapoptotic BH3-only protein BIM is essential for tumor cell killing and that shutdown of the EGFR–MEK–ERK signaling cascade is critical for BIM activation. Moreover, we demonstrate that addition of a BH3 mimetic significantly enhances killing of NSCLC cells by the EGFR tyrosine kinase inhibitor gefitinib. It appears likely that this approach represents a paradigm shared by many, and perhaps all, oncogenic tyrosine kinases and suggests a powerful new strategy for cancer therapy.
Andreas Strasser and colleagues demonstrate that activation of the proapoptotic BH3-only protein BIM is essential for tumor cell killing and that shutdown of the EGFR−MEK−ERK signaling cascade is critical for BIM activation.
Editors' Summary
Background.
Normally, cell division (which produces new cells) and cell death are finely balanced to keep the human body in good working order. But sometimes cells acquire changes (mutations) in their genetic material that allow them to divide uncontrollably to form cancers—life-threatening, disorganized masses of cells. One protein with a critical role in cell division that is often mutated in tumors is the epidermal growth factor receptor (EGFR). In normal cells, protein messengers bind to EGFR and activate its tyrosine kinase. This enzyme then adds phosphate groups to tyrosine (an amino acid) in proteins that form part of signaling cascades (for example, the MEK–ERK signaling cascade) that tell the cell to divide. In cancers that have mutations in EGFR, signaling is overactive so the cancer cells divide much more than they should. Some non-small cell lung cancers (NSCLC, the commonest type of lung cancer), for example, have activating mutations within the EGFR tyrosine kinase. Treatment with EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib induces the cells in these tumors to stop growing and die. This cell death causes tumor shrinkage (regression) and increases the life expectancy of patients with this type of NSCLC.
Why Was This Study Done?
Unfortunately, treatment with TKIs rarely cures NSCLC, so it would be useful to find a way to augment the effect that TKIs have on cancer cells. To do this, the molecular mechanisms that cause cancer-cell death and tumor regression in response to these drugs need to be fully understood. In this study, the researchers have used a combination of biochemical and genetic approaches to investigate how gefitinib kills NSCLC cells with mutated EGFR.
What Did the Researchers Do and Find?
The researchers first measured the sensitivity of NSCLC cell lines (tumor cells that grow indefinitely in dishes) to gefitinib-induced apoptosis. Gefitinib caused extensive apoptosis in two cell lines expressing mutant EGFR but not in one expressing normal EGFR. Next, they investigated the mechanism of gefitinib-induced apoptosis in the most sensitive cell line (H3255). Apoptosis is activated via two major pathways. Hallmarks of the “intrinsic” pathway include activation of a protein called BAX and cytochrome c release from subcellular compartments known as mitochondria. Gefitinib treatment induced both these events in H3255 cells. BAX (a proapoptotic member of the BCL-2 family of proteins) is activated when proapoptotic BH3-only BCL-2 proteins (for example, BIM; “BH3-only” describes the structure of these proteins) bind to antiapoptotic BCL2 proteins. Gefitinib treatment rapidly increased BIM activity in H3255 and HCC827 cells (but not in gefitinib-resistant cells) by increasing the production of BIM protein and the removal of phosphate groups from it, which increases BIM activity. Pharmacological blockade of the MEK–ERK signaling cascade, but not of other EGFR signaling cascades, also caused the accumulation of BIM. By contrast, blocking BIM expression using a technique called RNA interference reduced gefitinib-induced apoptosis. Finally, a combination of gefitinib and a BH3-mimicking compound called ABT-737 (which, like BIM, binds to antiapoptotic BCL-2 proteins) caused more apoptosis than gefitinib alone.
What Do These Findings Mean?
These findings (and those reported by Gong et al. and Costa et al.) indicate that activation of the proapoptotic BH3-only protein BIM is essential for gefitinib-induced killing of NSCLC cells that carry EGFR tyrosine kinase mutations. They also show that inhibition of the EGFR–MEK–ERK signaling cascade by gefitinib is essential for BIM activation. Because these findings come from studies on NSCLC cell lines, they need confirming in freshly isolated tumor cells and in tumors growing in people. However, the demonstration that a compound that mimics BH3 action enhances gefitinib-induced killing of NSCLC cells suggests that combinations of TKIs and drugs that affect the intrinsic pathway of apoptosis activation might provide a powerful strategy for treating cancers in which tyrosine kinase mutations drive tumor growth.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040316.
A perspective by Ingo Mellinghoff discusses this article and two related research articles
Wikipedia pages on epidermal growth factor receptor, apoptosis, and BCL2 proteins (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
CancerQuest provides information on all aspects of cancer from Emory University (in several languages)
US National Cancer Institute information for patients and professionals on lung cancer (in English and Spanish)
Information for patients from Cancer Research UK on lung cancer including information on treatment with TKIs
Information for patients from Cancerbackup on erlotinib and gefitinib
doi:10.1371/journal.pmed.0040316
PMCID: PMC2043013  PMID: 17973573
15.  The Impact of Cigarette Smoking on the Frequency of and Qualitative Differences in KRAS Mutations in Korean Patients with Lung Adenocarcinoma 
Yonsei Medical Journal  2013;54(4):865-874.
Purpose
This study was designed to determine the relationship of cigarette smoking to the frequency and qualitative differences among KRAS mutations in lung adenocarcinomas from Korean patients.
Materials and Methods
Detailed smoking histories were obtained from 200 consecutively enrolled patients with lung adenocarcinoma according to a standard protocol. EGFR (exons 18 to 21) and KRAS (codons 12/13) mutations were determined via direct-sequencing.
Results
The incidence of KRAS mutations was 8% (16 of 200) in patients with lung adenocarcinoma. KRAS mutations were found in 5.8% (7 of 120) of tumors from never-smokers, 15% (6 of 40) from former-smokers, and 7.5% (3 of 40) from current-smokers. The frequency of KRAS mutations did not differ significantly according to smoking history (p=0.435). Never-smokers were significantly more likely than former or current smokers to have a transition mutation (G→A or C→T) rather than a transversion mutation (G→T or G→C) that is known to be smoking-related (p=0.011). In a Cox regression model, the adjusted hazard ratios for the risk of progression with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) were 0.24 (95% CI, 0.14-0.42; p<0.001) for the EGFR mutation and 1.27 (95% CI, 0.58-2.79; p=0.537) for the KRAS mutation.
Conclusion
Cigarette smoking did not influence the frequency of KRAS mutations in lung adenocarcinomas in Korean patients, but influenced qualitative differences in the KRAS mutations.
doi:10.3349/ymj.2013.54.4.865
PMCID: PMC3663229  PMID: 23709419
EGFR; KRAS; pulmonary adenocarcinoma; cigarette smoking; EGFR-tyrosine kinase inhibitors
16.  Mutations in the epidermal growth factor receptor gene are linked to smoking-independent, lung adenocarcinoma 
British Journal of Cancer  2005;93(3):355-363.
Epidermal growth factor receptor (EGFR) mutations are a potential predictor of the effectiveness of EGFR inhibitors for the treatment of lung cancer. Although EGFR mutations were reported to occur with high frequency in nonsmoking Japanese adenocarcinoma patients, the exact nature has not been fully elucidated. We examined EGFR gene mutations within exons 18–21 and their correlations to clinico-pathological factors and other genetic alterations in tumour specimens from 154 patients who underwent resection for lung cancer at Kyoto University Hospital. Epidermal growth factor receptor mutations were observed in 60 tumours (39.0%), all of which were adenocarcinoma. Among the patients with adenocarcinoma (n=108), EGFR mutations were more frequently observed in nonsmokers than former smokers or current smokers (83.0, 50.0, 15.2%, respectively), in women than men (76.3 vs 34.0%), in tumours with bronchio-alveolar component than those without bronchio-alveolar component (78.9 vs 42.9%), and in well or moderately differentiated tumours than poorly differentiated tumours (72.0, 64.4, 34.2%). No tumours with EGFR mutations had any K-ras codon 12 mutations, which were well-known smoking-related gene mutations. In conclusion, adenocarcinomas with EGFR mutation had a distinctive clinico-pathological feature unrelated to smoking. Epidermal growth factor receptor mutations may play a key role in the development of smoking-independent adenocarcinoma.
doi:10.1038/sj.bjc.6602707
PMCID: PMC2361570  PMID: 16052218
epidermal growth factor receptor; lung adenocarcinoma; smoking; p53; K-ras; single-strand conformation polymorphism
17.  Erlotinib has better efficacy than gefitinib in adenocarcinoma patients without EGFR-activating mutations, but similar efficacy in patients with EGFR-activating mutations 
Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are an effective treatment for advanced non-small cell lung cancer. The objective of the present study was to compare the efficacy of gefitinib and erlotinib in patients with pulmonary adenocarcinoma, whose tumor EGFR mutation status was known. Pulmonary adenocarcinoma patients who began receiving gefitinib or erlotinib treatment from January 2005 to December 2010, and whose tumor EGFR mutation status had been determined, were included. Clinical data, type of treatment response and survival time data were collected. Of the 224 patients enrolled, 124 received gefitinib treatment and 100 received erlotinib treatment. Of these patients, 146 individuals had tumors with EGFR-activating mutations (exon 19 deletions and/point mutation of L858R in exon 21) and 78 did not. There was no difference in treatment response whether or not the patients had tumors with EGFR-activating mutations at the time they received gefitinib or erlotinib treatment. The median progression-free survival (PFS) of the gefitinib and erlotinib groups was 7.6 and 7.9 months, respectively (p=0.4731). PFS was significantly longer for patients without EGFR-activating mutations who received erlotinib treatment (n=48; median, 4.5 months) than for those who received gefitinib treatment (n=30; median, 2.3 months), with a hazard ratio of 0.58 (95% CI, 0.35–0.96; p=0.0339). Patients whose tumors had EGFR-activating mutations displayed no difference in PFS with either gefitinib (n=94; median, 10.5 months) or erlotinib treatment (n=52; median, 10.4 months). In conclusion, PFS showed no difference with either agent in patients whose tumors had EGFR-activating mutations, but was significantly longer in patients whose tumors did not have EGFR-activating mutations when receiving erlotinib treatment.
doi:10.3892/etm.2011.383
PMCID: PMC3438713  PMID: 22969870
epidermal growth factor receptor; tyrosine kinase inhibitors; non-small cell lung cancer
18.  Plasma epidermal growth factor receptor mutation analysis and possible clinical applications in pulmonary adenocarcinoma patients treated with erlotinib 
Oncology Letters  2011;3(3):713-717.
Tumor epidermal growth factor receptor (EGFR) mutation analysis is significant for making treatment decisions for metastatic pulmonary adenocarcinoma. However, less than half of patients have adequate tumor samples for mutation analysis. Patients with adenocarcinoma of the lungs who were due to receive erlotinib treatment were included in the present study. Tumor EGFR mutation status was analyzed using DNA sequencing. Plasma specimens from the patients were collected prior to erlotinib treatment. The plasma-free DNA EGFR mutation status was analyzed using the PCR clamp method. A total of 54 consecutive patients were included in the study. The plasma-free DNA EGFR mutation status of the 54 patients was analyzed. Only 30 patients had adequate tumor samples for EGFR analysis, including 15 with activating mutations (exon 19 deletions or L858R). EGFR-activating mutations were detected in the plasma-free DNA in 25 of 54 patients. The response rate was 86.7 and 33.3% in patients with and without tumor activating mutations, respectively (p=0.002). The response rate was 68 and 31% based on the patients’ plasma-free DNA EGFR mutation status, respectively (p=0.013). No significant difference in progression-free survival (PFS) was observed between patients with and without EGFR-activating mutations, according to data from tumor tissue or plasma-free DNA analysis, although the median PFS time was longer for those patients with EGFR-activating mutations in plasma samples. Plasma EGFR mutation analysis is useful for adenocarcinoma patients who have no or inadequate tumor samples available for EGFR examination. Patients with plasma EGFR-activating mutations had an improved response rate and a statistically insignificant longer PFS.
doi:10.3892/ol.2011.534
PMCID: PMC3362392  PMID: 22740981
epidermal growth factor receptor; erlotinib; targeted therapy; adenocarcinoma
19.  BRIEF REPORT: Compound EGFR mutations and response to EGFR tyrosine kinase inhibitors 
INTRODUCTION
Non-small-cell lung cancers (NSCLCs) containing epidermal growth factor receptor (EGFR) mutations are exquisitely sensitive to EGFR tyrosine kinase inhibitors (TKIs). This is the case of the most common EGFR mutations affecting exon 18 (G719X), 19 (inframe deletions) and 21 (L858R and L861Q). However, the frequency of compound (i.e., double or complex) EGFR mutations - where an EGFR TKI sensitizing or other mutation is identified together with a mutation of unknown clinical significance – and their pattern of response/resistance to EGFR TKIs are less well described.
METHODS
We analyzed the EGFR mutation pattern of 79 cases of NSCLC harboring EGFR mutations, and compiled the genotype-response data for patients with NSCLCs with compound EGFR mutations treated with EGFR TKIs.
RESULTS
Out of the 79 EGFR mutated tumors identified, 11 (14%) had compound mutations. Most involved the EGFR TKI-sensitizing G719X (n=3, plus S768I or E709A), L858R (n=4, plus L747V, R776H, T790M or A871G), L861Q (n=1, plus E709V) and delL747_T751 (n=1, plus R776H). 8 patients received an EGFR TKI: 3 cases with G719X plus another mutation had partial responses (PR) to erlotinib; out of 3 cases with L858R plus another mutation, 2 displayed PRs and 1 (with EGFR-L858R+A871G) progressive disease to erlotinib; 1 NSCLC with EGFR-L861Q+E709A and 1 with delL747_T51+R776S had PRs to EGFR TKIs.
CONCLUSIONS
Compound EGFR mutations comprised 14% of all mutations identified during routine sequencing of exons 18–21 of EGFR in our cohort. Most patients with an EGFR TKI sensitizing mutation (G719X, exon 19 deletion, L858R and L861Q) in addition to an atypical mutation responded to EGFR TKIs. Reporting of the genotype-response pattern of NSCLCs with EGFR compound and other rare mutations, and the addition of this information to searchable databases will be helpful to select the appropriate therapy for EGFR mutated NSCLC.
doi:10.1097/JTO.0b013e3182781e35
PMCID: PMC3531043  PMID: 23242437
lung cancer; non-small-cell lung cancer; EGFR; EGFR mutation; erlotinib; gefitinib; tyrosine kinase inhibitor; L858R; L861Q; G719X; exon 19 deletion: compound; double; complex
20.  Lungs don’t forget: Comparison of the KRAS and EGFR mutation profile and survival of “collegiate smokers” and never smokers with advanced lung cancers 
HYPOTHESIS
We hypothesize that among patients with lung cancers the KRAS/EGFR mutation profile and overall survival of “collegiate smokers” (former smokers who smoked between 101 lifetime cigarettes and 5 pack years) are distinct from those of never smokers and former smokers with ≥ 15 pack years.
METHODS
We collected age, sex, stage, survival, and smoking history for patients evaluated from 2004 to 2009 with advanced stage lung cancers and known KRAS/EGFR status. Mutation profile and overall survival were compared using Fisher’s exact test and log-rank test, respectively.
RESULTS
Data were available for 852 patients with advanced stage lung cancers with known KRAS/EGFR status. 6% were “collegiate smokers”, 36% were never smokers, and 30% were former smokers with ≥ 15 pack years. The mutation profile of “collegiate smokers” (15% KRAS mutations, 27% EGFR mutations) was distinct from those of never smokers (p < .001) and former smokers with ≥ 15 pack years (p < .001)and not significantly different from those of former smokers with 5 to 15 pack years (p = 0.9). Median overall survival for “collegiate smokers” was 25 months, compared to 32 months for never smokers (p = 0.4), 33 months for former smokers with 5–15 pack years (p = 0.48),and 21 months for former smokers with ≥ 15 pack years (p = 0.63).
CONCLUSIONS
“Collegiate smokers” with advanced stage lung cancers represent a distinct subgroup of patients with a higher frequency of KRAS mutations and lower frequency of EGFR mutations compared to never smokers. These observations reinforce the recommendation for routine mutation testing for all patients with lung cancers and that no degree of tobacco exposure is safe.
doi:10.1097/JTO.0b013e31827914ea
PMCID: PMC3534987  PMID: 23242442
Collegiate Smokers; non-small cell lung cancers; epidermal growth factor receptor mutation; KRAS mutation
21.  Epidermal Growth Factor Receptor Kinase Domain Mutations in Esophageal and Pancreatic Adenocarcinomas 
Purpose
Specific activating mutations within the epidermal growth factor receptor (EGFR) identify a subset of non – small cell lung cancers with dramatic sensitivity to the specific tyrosine kinase inhibitors (TKI), gefitinib and erlotinib. Despite the abundant expression of EGFR protein in a broad range of epithelial cancers, EGFR mutations have not been reported in a substantial fraction of other cancers. Given recent reports of TKI-responsive cases of esophageal and pancreatic cancer, this study was designed to determine the prevalence of EGFR mutations in these gastrointestinal cancers.
Experimental Design
We sequenced exons 18 to 21 of EGFR from 21cases of Barrett's esophagus, 5 cases of high-grade esophageal dysplasia, 17 cases of esophageal adenocarcinoma, and 55 cases of pancreatic adenocarcinoma. Subsets of esophageal (n = 7) and pancreatic cancer cases (n = 5) were obtained from patients who were subsequently treated with gefitinib or erlotinib-capecitabine, respectively.
Results
Mutations of EGFR were identified in two esophageal cancers (11.7%), three cases of Barrett's esophagus (14.2%), and two pancreatic cancers (3.6%). The mutations consisted of the recurrent missense L858R and in-frame deletion delE746-A750, previously characterized as activating EGFR mutations in non – small cell lung cancer. We also identified the TKI drug resistance – associated EGFR T790M mutation in an untreated case of Barrett's esophagus and the corresponding adenocarcinoma.
Conclusion
The presence of activating mutations within EGFR in both esophageal and pancreatic adenocarcinomas defines a previously unrecognized subset of gastrointestinal tumors in which EGFR signaling may play an important biological role. EGFR mutations in premalignant lesions of Barrett's esophagus also point to these as an early event in transformation of the esophageal epithelium. The role of genotype-directed TKI therapy should be tested in prospective clinical trials.
doi:10.1158/1078-0432.CCR-06-0189
PMCID: PMC3807136  PMID: 16857803
22.  Clinical pharmacogenomic testing of KRAS, BRAF and EGFR mutations by high resolution melting analysis and ultra-deep pyrosequencing 
BMC Cancer  2011;11:406.
Background
Epidermal growth factor receptor (EGFR) and its downstream factors KRAS and BRAF are mutated in several types of cancer, affecting the clinical response to EGFR inhibitors. Mutations in the EGFR kinase domain predict sensitivity to the tyrosine kinase inhibitors gefitinib and erlotinib in lung adenocarcinoma, while activating point mutations in KRAS and BRAF confer resistance to the anti-EGFR monoclonal antibody cetuximab in colorectal cancer. The development of new generation methods for systematic mutation screening of these genes will allow more appropriate therapeutic choices.
Methods
We describe a high resolution melting (HRM) assay for mutation detection in EGFR exons 19-21, KRAS codon 12/13 and BRAF V600 using formalin-fixed paraffin-embedded samples. Somatic variation of KRAS exon 2 was also analysed by massively parallel pyrosequencing of amplicons with the GS Junior 454 platform.
Results
We tested 120 routine diagnostic specimens from patients with colorectal or lung cancer. Mutations in KRAS, BRAF and EGFR were observed in 41.9%, 13.0% and 11.1% of the overall samples, respectively, being mutually exclusive. For KRAS, six types of substitutions were detected (17 G12D, 9 G13D, 7 G12C, 2 G12A, 2 G12V, 2 G12S), while V600E accounted for all the BRAF activating mutations. Regarding EGFR, two cases showed exon 19 deletions (delE746-A750 and delE746-T751insA) and another two substitutions in exon 21 (one showed L858R with the resistance mutation T590M in exon 20, and the other had P848L mutation). Consistent with earlier reports, our results show that KRAS and BRAF mutation frequencies in colorectal cancer were 44.3% and 13.0%, respectively, while EGFR mutations were detected in 11.1% of the lung cancer specimens. Ultra-deep amplicon pyrosequencing successfully validated the HRM results and allowed detection and quantitation of KRAS somatic mutations.
Conclusions
HRM is a rapid and sensitive method for moderate-throughput cost-effective screening of oncogene mutations in clinical samples. Rather than Sanger sequence validation, next-generation sequencing technology results in more accurate quantitative results in somatic variation and can be achieved at a higher throughput scale.
doi:10.1186/1471-2407-11-406
PMCID: PMC3192787  PMID: 21943394
23.  Detection of EGFR mutations in plasma DNA from lung cancer patients by mass spectrometry genotyping is predictive of tumor EGFR status and response to EGFR inhibitors 
Aims
EGFR mutations now guide the clinical use of EGFR-targeted therapy in lung cancer. However, standard EGFR mutation analysis requires a minimum amount of tumor tissue, which may not be available in certain situations. In this study, we combined a mass spectrometry genotyping assay (Sequenom) with a mutant-enriched PCR (ME-PCR) to detect EGFR mutations in free plasma DNA from patients with lung cancer.
Method
DNAs were extracted from 31 plasma samples from 31 patients and analyzed by both methods for EGFR exon 19 deletion and EGFR L858R mutation. Results in plasma DNA samples were compared with EGFR mutation status obtained in tumor DNA (18/31 EGFR mutant). The relationship of EGFR mutation status in tumor and/or plasma samples to overall survival was assessed.
Results
The EGFR mutation status in plasma DNA was identical to the primary tumor in 61% of patients (19/31). By mass spectrometry genotyping, the plasma samples contained mutant DNA corresponding to 5/14 EGFR exon 19 deletions and 3/4 EGFR L858R mutations previously diagnosed in the matched tumors. Two samples were positive in plasma DNA but negative in primary tumor tissue. Results were similar for ME-PCR. For patients treated with erlotinib, overall survival was correlated with the presence of EGFR mutation in plasma and/or tumor tissue (p=0.002), with the two patients positive only in plasma DNA showing responses and favorable outcomes.
Conclusion
The detection of EGFR mutations in plasma DNA samples by mass spectrometry genotyping and ME-PCR is feasible. A positive EGFR result in plasma DNA has a high predictive value for tumor EGFR status and for favorable clinical course on EGFR-targeted therapy and could therefore be useful in guiding clinical decisions in patients with insufficient or unavailable tumor specimens.
doi:10.1016/j.lungcan.2010.10.014
PMCID: PMC3282180  PMID: 21130517
Lung cancer; EGFR; Plasma; Mass spectrometry; Mutant-enriched PCR; Adenocarcinoma
24.  EGFR Mutations in Surgically Resected Fresh Specimens from 697 Consecutive Chinese Patients with Non-Small Cell Lung Cancer and Their Relationships with Clinical Features 
We aimed to reveal the true status of epidermal growth factor receptor (EGFR) mutations in Chinese patients with non-small cell lung cancer (NSCLC) after lung resections. EGFR mutations of surgically resected fresh tumor samples from 697 Chinese NSCLC patients were analyzed by Amplification Refractory Mutation System (ARMS). Correlations between EGFR mutation hotspots and clinical features were also explored. Of the 697 NSCLC patients, 235 (33.7%) patients had tyrosine kinase inhibitor (TKIs) sensitive EGFR mutations in 41 (14.5%) of the 282 squamous carcinomas, 155 (52.9%) of the 293 adenocarcinomas, 34 (39.5%) of the 86 adenosquamous carcinomas, one (9.1%) of the 11 large-cell carcinomas, 2 (11.1%) of the 18 sarcomatoid carcinomas, and 2 (28.6%) of the 7 mucoepidermoid carcinomas. TKIs sensitive EGFR mutations were more frequently found in female patients (p < 0.001), non-smokers (p = 0.047) and adenocarcinomas (p < 0.001). The rates of exon 19 deletion mutation (19-del), exon 21 L858R point mutation (L858R), exon 21 L861Q point mutation (L861Q), exon 18 G719X point mutations (G719X, including G719C, G719S, G719A) were 43.4%, 48.1%, 1.7% and 6.8%, respectively. Exon 20 T790M point mutation (T790M) was detected in 3 squamous carcinomas and 3 adenocarcinomas and exon 20 insertion mutation (20-ins) was detected in 2 patients with adenocarcinoma. Our results show the rates of EGFR mutations are higher in all types of NSCLC in Chinese patients. 19-del and L858R are two of the more frequent mutations. EGFR mutation detection should be performed as a routine postoperative examination in Chinese NSCLC patients.
doi:10.3390/ijms141224549
PMCID: PMC3876127  PMID: 24351833
EGFR mutations; NSCLC; targeted therapy; ARMS; surgery; fresh tumor specimens
25.  Primary concomitant EGFR T790M mutation predicted worse prognosis in non-small cell lung cancer patients 
OncoTargets and therapy  2014;7:513-524.
Purpose
We performed this analysis to improve the understanding of the clinicopathological characteristics and clinical outcome of non-small cell lung cancer (NSCLC) patients harboring the primary epidermal growth factor receptor (EGFR) T790M mutation along with activating EGFR mutation.
Methods
Resected tumors from 1903 NSCLC patients were analyzed for mutation in EGFR, as well as KRAS (Kirsten rat sarcoma viral oncogene homolog), BRAF (v-raf murine sarcoma viral oncogene homolog B), HER2 (human epidermal growth factor 2), PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha), and EML4 (echinoderm microtubule associated protein like 4)–ALK (anaplastic lymphoma receptor tyrosine kinase) fusion. Fluorescence in situ hybridization was performed to define EGFR and c-MET (met proto-oncogene gene amplification. Expression of PIK3CA and p-Akt (phosphorylated protein kinase B) were tested using immunohistochemistry. Clinical and pathological data, including sex, age at diagnosis, stage, tumor differentiation, smoking history, histological subtype, relapse-free and overall survival, were further analyzed.
Results
In all, 16 NSCLC patients were found to harbor primary EGFR T790M mutation, including 14 adenocarcinomas and two adenosquamous carcinomas, accounting for 2.04% of all the EGFR mutant cases and 0.84% of the total. No c-MET amplification was found to coexist with primary EGFR T790M. Fewer EGFR copy-number variations were found in samples harboring EGFR T790M mutations compared with those in patients with exon 19 deletions and L858R. Overall survival was significantly shorter for patients harboring EGFR T790M mutation than it was for patients with exon 19 deletions (logrank P=0.008). When taking patients harboring EGFR L858R or exon 19 deletions as one group, the overall survival was also significantly longer than that in patients with T790M mutation (logrank P=0.012). There was no significant difference in relapse-free survival among three subgroups of patients.
Conclusion
Our study described the clinicopathological and molecular characteristics of NSCLC patients harboring primary EGFR T790M mutations. Its value of being a predictor for worse prognosis was established. Primary EGFR T790M mutation is a rare event in NSCLC cases, but the therapeutic strategies for this subtype of patients should be precisely considered.
doi:10.2147/OTT.S60122
PMCID: PMC3979794  PMID: 24729716
driver mutation; survival; clinicopathological profile; EGFR tyrosine kinase inhibitor; acquired resistance

Results 1-25 (1362206)