Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “EGFR mutation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2005

Mutations in the tyrosine kinase domain of the EGFR gene associated with gefitinib response in non-small-cell lung cancer.

The potential relevance of epidermal growth factor receptor (EGFR) mutations to non-small-cell lung cancer treatment has recently been identified. We have examined the presence of EGFR mutations in Japanese and Spanish gefitinib-treated non-small-cell lung cancer patients. A total of 34 gefitinib-treated patients were screened, 18 from Japan and 16 from Spain. Laser capture microdissection was performed for the accurate procurement of tumor cells. EGFR exons 18, 19 and 21 were amplified from genomic DNA by means of PCR, and the samples were then subjected to bi-directional automatic sequencing. EGFR somatic mutations in the tyrosine kinase domain were found in 8 of 34 patients (23.5%). Gefitinib response was observed in 7 of 8 patients (87.5%) with EGFR mutations and in 3 of 24 (12.5%) with wild-type EGFR (P=0.0003). Five deletion mutations were clustered in the region spanning codons 746 to 750 (ELREA) within exon 19. Three additional tumors had amino acid substitutions within exon 18, at codons 718 and 719. Logistic regression analysis showed that response was primarily linked to the presence of EGFR mutations and secondarily linked to female gender, non-smoker status and a greater number of prior chemotherapy regimens. The presence of EGFR mutations is a major determinant of gefitinib response, and EGFR tyrosine kinase inhibitors should be tested in clinical trials of first-line treatment of lung adenocarcinomas harboring EGFR mutations.

Adult↗
PubMed2005

The relationship between epidermal growth factor receptor mutations and clinicopathologic features in non-small cell lung cancers.

PURPOSE: Recent studies reported that clinical responsiveness to gefitinib was associated with somatic mutation of epidermal growth factor receptor (EGFR) gene in non-small cell lung cancers (NSCLC). Here, we investigated the relationship between EGFR mutation and clinicopathologic features. EXPERIMENTAL DESIGN: EGFR mutational status of 120 NSCLCs was determined mainly in EGFR exons 18 to 21 by direct sequence and correlated with clinicopathologic parameters. RESULTS: EGFR mutations were present in 38 cases (32%) and the majority of mutations were in-frame deletions of exon 19 (19 cases) and a missense mutation in exon 21 (18 cases). EGFR mutations were frequently associated with adenocarcinoma (P < 0.0001), never smoker (P < 0.0001), and female gender (P = 0.0001). Of interest, increasing smoke exposure was inversely related to the rate of EGFR mutation (P < 0.0001). Multivariate analysis showed that smoking and histology were independent variables. Furthermore, gender difference was observed for the mutational location (P = 0.01) dominance of exon 19 for males and exon 21 for females. Twenty-one cases were treated with gefitinib and found that EGFR mutation was significantly related to gefitinib responsiveness (P = 0.002). In addition, median survival times of patients with and without EGFR mutations treated with gefitinib were 25.1 and 14.0 months, respectively. Patients with EGFR mutations had approximately 2-fold survival advantage; however, the difference was not significant. CONCLUSIONS: We show that EGFR mutations were significantly related to histology and smoke exposure and were a strong predictive factor for gefitinib responsiveness in NSCLC.

Adult↗
PubMed2007

Phase II clinical trial of chemotherapy-naive patients > or = 70 years of age treated with erlotinib for advanced non-small-cell lung cancer.

PURPOSE: This is a phase II, multicenter, open-label study of chemotherapy-naïve patients with non-small-cell lung cancer (NSCLC) and age > or = 70 years who were treated with erlotinib and evaluated to determine the median, 1-year, and 2-year survival. The secondary end points include radiographic response rate, time to progression (TTP), toxicity, and symptom improvement. PATIENTS AND METHODS: Eligible patients with NSCLC were treated with erlotinib 150 mg/d until disease progression or significant toxicity. Tumor response was assessed every 8 weeks by computed tomography scan using Response Evaluation Criteria in Solid Tumors. Tumor samples were analyzed for the presence of somatic mutations in EGFR and KRAS. RESULTS: Eighty eligible patients initiated erlotinib therapy between March 2003 and May 2005. There were eight partial responses (10%), and an additional 33 patients (41%) had stable disease for 2 months or longer. The median TTP was 3.5 months (95% CI, 2.0 to 5.5 months). The median survival time was 10.9 months (95% CI, 7.8 to 14.6 months). The 1- and 2- year survival rates were 46% and 19%, respectively. The most common toxicities were acneiform rash (79%) and diarrhea (69%). Four patients developed interstitial lung disease of grade 3 or higher, with one treatment-related death. EGFR mutations were detected in nine of 43 patients studied. The presence of an EGFR mutation was strongly correlated with disease control, prolonged TTP, and survival. CONCLUSION: Erlotinib monotherapy is active and relatively well tolerated in chemotherapy-naïve elderly patients with advanced NSCLC. Erlotinib merits consideration for further investigation as a first-line therapeutic option in elderly patients.

Age Factors↗
PubMed2025

Mismatch-introduced crRNA guided PCR-CRISPR/Cas12a platform improves EGFR point mutation detection in single tumor cell.

Dynamic monitoring of epidermal growth factor receptor (EGFR) mutations is essential for the early identification of resistance and treatment adaptation. Single-cell heterogeneity analysis is crucial for precision cancer medicine, yet sensitive and specific detection methods for individual tumor cells remain challenging. Here, we develop a PCR-CRISPR/Cas12a platform enhanced by the incorporation of mismatched base in crRNA at specific site for single-cell point mutation detection. This platform demonstrated high specificity and sensitivity, detecting point mutation at a frequency of 0.1% and in as low as 1.02&#xa0;ng of genomic DNA, which represents an improvement over the amplification-refractory mutation system PCR (ARMS-PCR). Notably, the accuracy of the platform is highly consistent with next-generation sequencing (NGS), as evidenced by Kappa test values surpassing 0.9. By utilizing a conical-pore membrane with optimized porosity for single circulating tumor cell (CTC) enrichment, our platform enables point mutations detection in individual tumor cells, offering potential enhancements in precision and reliability for EGFR mutation analysis. This novel methodology holds potential for more accurate and personalized cancer treatment strategies.

Humans↗
PubMed2005

Clinicopathologic significance of the mutations of the epidermal growth factor receptor gene in patients with non-small cell lung cancer.

PURPOSE: It has been reported that the mutations of epidermal growth factor receptor (EGFR) are detected in lung cancers. Studies of EGFR mutations in large numbers of patients' tumors with clinical data including response to EGFR tyrosine kinase directed therapy are needed to develop a robust database for clinical use. The purpose of the present study is to gain further insights into the significance of EGFR mutation in non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: We investigated the clinicopathologic significance of tyrosine kinase domain (exons 18-21) EGFR mutations in 120 patients with primary NSCLC and the correlation between EGFR mutation and sensitivity to gefitinib in an additional 20 NSCLC patients treated with gefitinib. In addition, onocogenic KRAS mutations and RASSF1A promoter methylation were determined in the same samples. RESULTS: EGFR mutation was detected in 29 of 120 (24%) tumors. All of the 29 (40%) mutations occurred in 72 adenocarcinomas. EGFR mutation was significantly more frequent in females (47%) than males (12%, P < 0.0001), in younger patients (38%) than older patients (10%, P = 0.0005), in nonsmokers (47%) than smokers (13%, P < 0.0001), and in well-differentiated tumors (39%) than moderately and poorly differentiated tumors (7%, P < 0.0001). Mutation of the EGFR gene was preferentially observed in advanced disease. Furthermore, EGFR mutations were detected in 11 of 14 (79%) responders, whereas none of six (0%) nonresponders had the mutation (P = 0.0022). CONCLUSIONS: These results in Japanese (East Asian) patients indicated that EGFR mutation plays an important role in pathogenesis of lung adenocarcinoma.

Adenocarcinoma↗
PubMed2005

Low incidence of mutations in EGFR kinase domain in Caucasian patients with head and neck squamous cell carcinoma.

Somatic mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene are associated with increased sensitivity to tyrosine kinase inhibitors (TKIs) and are present in 10-30% of non-small cell lung carcinoma depending on ethnic origin. EGFR protein is also overexpressed in about 90% of squamous cell carcinoma of head and neck (HNSCC), and treatment with TKIs has shown clinical benefit in a subgroup of these patients. Recently, EGFR mutations were described in three Asian patients with larynx cancer. We screened for EGFR tyrosine kinase mutations in tumour DNA of 100 patients of Caucasian origin with HNSCC by direct sequencing of the hotspot regions. Only one patient with larynx cancer displayed a novel, somatic EGFR missense mutation, K745R, affecting a highly conserved residue within the ATP cleft. Similar to reports in lung cancer, EGFR kinase domain mutations in HNSCC patients seem to show a lower incidence in patients of Caucasian origin.

Adult↗
PubMed2006

Impact of EGFR point mutations on the sensitivity to gefitinib: insights from comparative structural analyses and molecular dynamics simulations.

Emergence of resistant mutations in drug targets represents a serious problem in the targeted chemotherapy. One challenging issue is to understand the atomic-detailed effect of the mutation on the target. Another intriguing issue is how to predict specific mutations that would show up in the clinical setting, leading to drug resistance. By computational approaches, we have investigated structural, dynamics and energetic effects of a series of EGFR mutations identified from the lung cancer patients. We demonstrated mutation L858R caused gefitinib move closer to the hinge region, whereas T790M caused the ligand escape from the binding pocket. In particular, the T790M decreased the size of the hydrophobic slot formed by L718 and G796. This suggests that, to be effective against the T790M mutant, the inhibitors should avoid interactions with the hydrophobic slot. Mutations T790M, L858R, and their combinations are found to cause different conformational redistribution and to perturb the electrostatic potential at the ATP-binding pocket. Normal mode analysis revealed the mutations resulted in changes in the correlated movements in the protein. In an attempt to develop a computational descriptor for predicting the functional effect of EGFR mutations, we have developed a Plarm algorithm, and the Plarm score was found to be an excellent predictor of the functional impact of six clinical relevant mutations in EGFR tyrosine kinase domains, including T790M, L858R, G719C, L861Q, T790M + L858R double mutant, and delL747-P753insS. The Plarm algorithm could be readily extended to investigate other drug targets.

Adenosine Triphosphate↗
PubMed2005

Mutations of the epidermal growth factor receptor gene in atypical adenomatous hyperplasia and bronchioloalveolar carcinoma of the lung.

A hypothesis of multistep carcinogenesis of lung adenocarcinoma from atypical adenomatous hyperplasia (AAH) to invasive adenocarcinoma through bronchioloalveolar carcinoma (BAC) has been proposed. However, the genetic alterations that play a role during these processes are not yet clear. Recently, somatic mutations of the epidermal growth factor receptor (EGFR) gene were found in lung adenocarcinoma. We examined the status of EGFR mutations in AAH and BAC to elucidate the role they play during multistage of lung adenocarcinoma. We found somatic EGFR mutations in 3% (1/35) of AAH, 10.8% (4/37) of BAC and 41.9% (13/31) of invasive adenocarcinoma. Sixteen of 18 EGFR mutations were found in exon 19 and two were in exon 21. Among the 16 EGFR mutations in exon 19, 13 were deletions of 15bp and one was an insertion/duplication of 18bp. Mutations of the K-ras gene were detected in 26.7% (8/30) of AAH, 16.7% (5/30) of BAC and 10% (3/30) of invasive adenocarcinoma. None of the tumors with EGFR mutations had K-ras mutation simultaneously. Patients who had invasive adenocarcinoma with EGFR mutations were younger than those without mutations (60.6 versus 67.4 years, p=0.03). These results suggest that tumors with EGFR mutations may progress more rapidly and develop into invasive cancer faster than those without mutations. Alternatively it is also possible that some invasive adenocarcinomas with EGFR mutations may not follow the AAH-adenocarcinoma sequence. We analyzed 24 patients with multiple lung lesions and 13 patients had at least one lesion that had either an EGFR or K-ras mutation. In all cases each lesion had a different mutation status. This finding suggests that the genetic alterations responsible for the development of lung adenocarcinoma occur randomly even under exposure to the same carcinogen.

Adenocarcinoma↗
PubMed2006

Relationship between epidermal growth factor receptor gene mutations and the severity of adverse events by gefitinib in patients with advanced non-small cell lung cancer.

PURPOSE: Recent reports have demonstrated that mutation of epidermal growth factor receptor (EGFR) gene is predictive factor for tumor responsiveness to gefitinib suggesting the importance of EGFR status for the treatment of the patients with non-small cell lung cancer (NSCLC). However, the relationship between EGFR mutation and adverse events of gefitinib is still unknown. The aim of this study was to evaluate its correlation. PATIENTS AND METHODS: Twenty-six tumor samples from Japanese NSCLC patients who received gefitinib in Okayama University Hospital between November 2000 and October 2004 were examined exons 18-21 of EGFR using direct sequence method. We retrospectively reviewed the clinical records and compared EGFR mutation status with adverse events during gefitinib treatment. RESULTS: Of all 26 patients, EGFR mutation (exon 19 in-frame deletion, 6; exon 21 L858R, 5), were detected in 11 patients (42.3%). The principal adverse event was skin rash (89%), diarrhea (39%), and liver injury (39%). Grade 3 or more adverse events were not common. EGFR mutation status was correlated with neither its frequency nor severity of adverse events during gefitinib treatment including skin rash, diarrhea, liver injury, and interstitial lung disease. As expected, objective response rate of those with EGFR mutations was significantly higher than those without EGFR mutations (78% versus 21%, P<0.001). CONCLUSION: Our study did not demonstrate the presence of close relationships between EGFR mutation status and adverse events during gefitinib treatment.

Adenocarcinoma↗
PubMed2026

Enozertinib Is a Selective, Brain-Penetrant EGFR Inhibitor for Treating Non-Small Cell Lung Cancers with EGFR Exon 20 and Atypical Mutations.

UNLABELLED: EGFR mutations are common oncogenic drivers in non-small cell lung cancer (NSCLC), and approximately half of patients develop brain metastases over the course of their disease. Patients with nonclassic EGFR mutations, such as insertions in exon 20, are a high unmet need with a worse prognosis compared with patients with classic EGFR mutations. Here, we describe the discovery and development of enozertinib (formerly ORIC-114), a highly brain-penetrant, orally bioavailable, irreversible inhibitor that targets EGFR exon 20 mutations with unparalleled kinome selectivity. Preclinical studies revealed strong potency and tumor regressions driven by enozertinib across a broad range of atypical EGFR-mutant models. In a phase I clinical trial of enozertinib in patients with advanced NSCLC bearing atypical mutations in EGFR, a patient harboring an EGFR exon 20 insertion experienced sustained complete response of all systemic and brain metastases. Together, these findings identify enozertinib as a promising investigational inhibitor to address the unmet need for brain-penetrant therapies in NSCLC with EGFR exon 20 insertions or other atypical mutations. SIGNIFICANCE: Preclinical and initial phase I clinical data demonstrate the potency, kinome selectivity, efficacy, and brain penetration of enozertinib in NSCLC with EGFR exon 20 insertions and atypical mutations, warranting further clinical development.

Carcinoma, Non-Small-Cell Lung↗
PubMed2007

Identical epidermal growth factor receptor mutations in adenocarcinomatous and squamous cell carcinomatous components of adenosquamous carcinoma of the lung.

BACKGROUND: Adenosquamous carcinoma of the lung is composed of adenocarcinomatous and squamous cell carcinomatous components. The epidermal growth factor receptor (EGFR) mutations occur mostly in adenocarcinomas and rarely in squamous cell carcinoma of lung. Attempts to investigate the EGFR mutation status in each component of adenosquamous carcinoma and to characterize the patients according to mutation status may help to understand the histogenesis of adenosquamous carcinoma. METHODS: The mutation status of EGFR kinase domain from exon 18 to 21 was investigated in 25 Korean patients with adenosquamous carcinoma by polymerase chain reaction-single strand conformation polymorphism using the tissues of each component from the adenosquamous carcinoma tumor. Clinicopathologic characteristics of the patients according to the status of EGFR mutations were compared. RESULTS: EGFR mutations were identified in 11 (44%) patients: 9 mutations were in exon 19, 1 in exon 20, and 1 in exon 21. EGFR mutations were significantly more frequent (P = .005) in women (n = 8, 80%) than men (n = 3, 20%). Never-smokers (n = 8, 62%) had EGFR mutations more commonly than smokers (n = 3, 25%; P = .111). Identical EGFR mutations in both components of adenosquamous carcinoma were confirmed by nucleotide sequencing. CONCLUSIONS: The frequency of EGFR mutation and clinicopathologic characteristics of the EGFR mutants in adenosquamous carcinoma are similar to those of Asian patients with adenocarcinomas. Identical EGFR mutations in both components suggest the possibility of monoclonality in the histogenesis of adenosquamous carcinoma.

Adenocarcinoma↗
PubMed2006

Prospective phase II study of gefitinib for chemotherapy-naive patients with advanced non-small-cell lung cancer with epidermal growth factor receptor gene mutations.

PURPOSE: This study was undertaken to investigate the efficacy and the feasibility of gefitinib for chemotherapy-naïve patients with advanced non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations. PATIENTS AND METHODS: The EGFR gene status in various tumor samples obtained from chemotherapy-naïve advanced NSCLC patients was examined by DNA sequencing of EGFR exons 18 to 23. Patients harboring EGFR mutations received gefitinib (250 mg/d) alone. The response rate, progression-free survival (PFS), and toxicity profile were assessed prospectively. RESULTS: Between June 2004 and October 2005, 75 patients were examined for the EGFR status, and 25 patients (33%) harbored EGFR mutations. EGFR mutations were significantly frequent in females (P < .01) and never or light smokers (P < .001). Sixteen patients with EGFR mutations were enrolled onto the study. The overall response rate in these patients was 75% (95% CI, 54% to 96%), and the disease control rate was 88% (95% CI, 71% to 100%). The median PFS time of these patients was 9.7 months (95% CI, 7.4 to 9.9 months). No life-threatening toxicity was observed. CONCLUSION: Treatment with gefitinib alone for chemotherapy-naïve NSCLC patients with EGFR mutations could achieve a high efficacy with acceptable toxicity. To assess the proper timing of gefitinib in such patients, a subsequent randomized trial comparing gefitinib with standard chemotherapy is warranted.

Adult↗
PubMed2005

Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor are associated with improved survival in gefitinib-treated chemorefractory lung adenocarcinomas.

PURPOSE: Activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) confer a strong sensitivity to gefitinib, a selective tyrosine kinase inhibitor of EGFR. EXPERIMENTAL DESIGN: We examined EGFR mutations at exons 18, 19, and 21 in tumor tissue from 68 gefitinib-treated, chemorefractory, advanced non-small cell lung cancer patients from the United States, Europe, and Asia and in a highly gefitinib-sensitive non-small cell lung cancer cell line and correlated their presence with response and survival. In addition, in a subgroup of 28 patients for whom the remaining tumor tissue was available, we examined the relationship among EGFR mutations, CA repeats in intron 1 of EGFR, EGFR and caveolin-1 mRNA levels, and increased EGFR gene copy numbers. RESULTS: Seventeen patients had EGFR mutations, all of which were in lung adenocarcinomas. Radiographic response was observed in 16 of 17 (94.1%) patients harboring EGFR mutations, in contrast with 6 of 51 (12.6%) with wild-type EGFR (P < 0.0001). Probability of response increased significantly in never smokers, patients receiving a greater number of prior chemotherapy regimens, Asians, and younger patients. Median survival was not reached for patients with EGFR mutations and was 9.9 months for those with wild-type EGFR (P = 0.001). EGFR mutations tended to be associated with increased numbers of CA repeats and increased EGFR gene copy numbers but not with EGFR and caveolin-1 mRNA overexpression (P = not significant). CONCLUSIONS: The presence of EGFR mutations is a major determinant of gefitinib response, and targeting EGFR should be considered in preference to chemotherapy as first-line treatment in lung adenocarcinomas that have demonstrable EGFR mutations.

Adenocarcinoma↗
PubMed2004

The tumor-specific de2-7 epidermal growth factor receptor (EGFR) promotes cells survival and heterodimerizes with the wild-type EGFR.

Mutations of the epidermal growth factor receptor (EGFR) gene are found at a relatively high frequency in glioma, with the most common being the de2-7 EGFR (or EGFRvIII). This mutation arises from an in-frame deletion of exons 2-7, which removes 267 amino acids from the extracellular domain of the receptor. Despite being unable to bind ligand, the de2-7 EGFR is constitutively active and imparts a significant in vivo growth advantage to glioma cells. In order to examine the signalling pathways activated by the de2-7 EGFR and its biological effects in an in vitro system, the de2-7 EGFR gene was transfected into the murine IL-3-dependent pro-B-cell line BaF/3. Expression of the de2-7 EGFR enhanced the survival of BaF/3 cells in the absence of IL-3 by reducing apoptosis in a phosphatidylinositol 3-kinase (PI3-K)-dependent manner. Interestingly, while de2-7 EGFR also enhanced proliferation of BaF/3 cells in low levels of IL-3, this effect was independent of PI3-K. Survival and proliferation were further enhanced when BaF/3 cells were cotransfected with the de2-7 and wt EGFR. This was due to heterodimerization between the de2-7 and wt EGFR leading to trans-phosphorylation of the wt EGFR. This observation is directly relevant to glioma where de2-7 and wt EGFR appear to be coexpressed. Thus, expression of de2-7 EGFR in BaF/3 cells provides an in vitro model for evaluating the signalling pathways activated by this receptor.

Animals↗
PubMed2004

Mutations of the epidermal growth factor receptor gene in lung cancer: biological and clinical implications.

Recently it has been reported that mutations in the tyrosine kinase domain of the epidermal growth factor receptor(EGFR) gene occur in a subset of patients with lung cancer showing a dramatic response to EGFR tyrosine kinase inhibitors. To gain further insights in the role of EGFR in lung carcinogenesis, we sequenced exons 18-21 of the tyrosine kinase domain using total RNA extracted from unselected 277 patients with lung cancer who underwent surgical resection and correlated the results with clinical and pathologic features. EGFR mutations were present in 111 patients (40%). Fifty-two were in-frame deletions around codons 746-750 in exon 19, 54 were point mutations including 49 at codon 858 in exon 21 and 4 at codon 719 in exon 18, and 5 were duplications/insertions mainly in exon 20. They were significantly more frequent in female (P < 0.001), adenocarcinomas (P = 0.0013), and in never-smokers (P < 0.001). Multivariate analysis suggested EGFR mutations were independently associated with adenocarcinoma histology (P = 0.0012) and smoking status (P < 0.001), but not with female gender (P = 0.9917). In adenocarcinomas, EGFR mutations were more frequent in well to moderately differentiated tumors (P < 0.001) but were independent of patient age, disease stages, or patient survival. KRAS and TP53 mutations were present in 13 and 41%, respectively. EGFR mutations never occurred in tumors with KRAS mutations, whereas EGFR mutations were independent of TP53 mutations. EGFR mutations define a distinct subset of pulmonary adenocarcinoma without KRAS mutations, which is not caused by tobacco carcinogens.

Adenocarcinoma↗
PubMed2005

Mutations of the epidermal growth factor receptor gene predict prolonged survival after gefitinib treatment in patients with non-small-cell lung cancer with postoperative recurrence.

PURPOSE: To evaluate the relationship between mutations of the epidermal growth factor receptor (EGFR) gene and the effectiveness of gefitinib treatment in patients with recurrent lung cancer after pulmonary resection. PATIENTS AND METHODS: We sequenced exons 18-21 of the EGFR gene using total RNA extracted from 59 patients with lung cancer who were treated with gefitinib for recurrent lung cancer. Gefitinib effectiveness was evaluated by both imaging studies and change in serum carcinoembryonic antigen (CEA) levels. RESULTS: EGFR mutations were found in 33 patients (56%). Of these mutations, 17 were deletions around codons 746-750 and 15 were point mutations (12 at codon 858, three at other codons), and one was an insertion. EGFR mutations were significantly more prevalent in females, adenocarcinoma, and never-smokers. Gefitinib treatment resulted in tumor shrinkage and/or CEA decrease to less than half of the baseline level in 26 patients, tumor growth and/or CEA elevation in 24 patients, and gefitinib effect was not assessable in nine patients. Female, never-smoking patients with adenocarcinoma tended to respond better to gefitinib treatment. Gefitinib was effective in 24 of 29 patients with EGFR mutations, compared with two of 21 patients without mutations (P < .0001). Of note, del746-750 might be superior to L858R mutations for prediction of gefitinib response. Patients with EGFR mutations survived for a longer period than those without the mutations after initiation of gefitinib treatment (P = .0053). CONCLUSION: EGFR mutations were a good predictor of clinical benefit of gefitinib in this setting.

Adult↗
PubMed2005

Predictive and prognostic impact of epidermal growth factor receptor mutation in non-small-cell lung cancer patients treated with gefitinib.

PURPOSE: This study was undertaken to investigate the effects of epidermal growth factor receptor (EGFR) mutation and its downstream signaling on response and survival in non-small-cell lung cancer (NSCLC) patients treated with gefitinib. PATIENTS AND METHODS: For 90 consecutive NSCLC patients who had received gefitinib, EGFR mutation was analyzed by DNA sequencing of exons 18, 19, 21, and 23 in the EGFR tyrosine kinase domain. Expressions of phosphorylated (p) -Akt and p-Erk were determined via immunohistochemistry. Response rate, time to progression (TTP), and overall survival were compared between each group according to EGFR mutation, as well as p-Akt and p-Erk expression. RESULTS: Seventeen patients (18.9%; 95% CI, 10.8 to 27.0) harbored EGFR mutations. These mutations include deletions in exon 19 in seven patients, L858R in six patients, G719A in three patients, and a novel A859T in one patient. Response rate in patients with EGFR mutation was 64.7% (11 of 17 patients; 95% CI, 42.0 to 87.4), in contrast to 13.7% (10 of 73 patients; 95% CI, 5.8 to 21.6) in patients without mutation (P < .001). Moreover, these 17 patients with EGFR mutation had significantly prolonged TTP (21.7 v 1.8 months; P < .001) and overall survival (30.5 v 6.6 months; P < .001) compared with the remaining 73 patients without mutation. Although no significant correlation was detected between EGFR mutation and expressions of p-Akt or p-Erk, p-Akt overexpression was associated with prolonged TTP in patients with EGFR mutation. CONCLUSION: Our data further support the importance of EGFR mutation with regard to gefitinib sensitivity. In addition to its predictive role, EGFR mutation confers significant survival benefits on NSCLC patients treated with gefitinib.

Adult↗
PubMedDate not supplied

Epidermal growth factor receptor mutations in cells from non-small cell lung cancer malignant pleural effusions.

BACKGROUND: The prevalence of epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients is about 40-50% in Taiwan, and there are significant correlations between EGFR mutations and clinical responses after gefitinib treatment. For most patients with advanced disease, surgical intervention for tissue sampling is not feasible. We therefore conducted this study to survey EGFR mutations in cells from NSCLC malignant pleural effusions and to evaluate the clinical significance. METHODS: In the present study, malignant pleural effusion cells from 29 NSCLC patients were studied for EGFR mutations. Exons 18, 19, 20, 21 of the EGFR gene were analyzed by polymerase chain reaction (PCR) and automated sequencing. For 11 patients who had received gefitinib therapy, correlations between gefitinib effect and EGFR mutations were also evaluated. RESULTS: EGFR mutations were detected in 12 of 29 specimens (41%). In-frame deletion mutations in exon 19 (8 of 12 specimens, 67%) and missense mutations in exon 21 (3 of 12 specimens, 25%) were the most frequent mutations detected. The frequency of EGFR mutations was significantly higher in gefitinib responders (4/4) than non-responders (1/7) (p = 0.015). CONCLUSION: Our results suggest that detecting EGFR mutations in cells from malignant pleural effusions is a feasible adjunct method to finding the subgroup with favorable response to gefitinib therapy among patients with advanced NSCLC.

Adult↗