Epidermal growth factor receptor mutations are associated with gefitinib sensitivity in non-small cell lung cancer in Japanese

The protein-kinase family is the most frequently mutated gene family found in human cancer. Gefitinib, an ATP-competitive inhibitor of epidermal growth factor receptor (EGFR), also appears to be particularly effective in adenocarcinoma of the lung and in patients without smoking history. To determine whether lung tumors sensitive to gefitinib contained mutations within the tyrosine kinase (TK) domain of EGFR, we screened exons 18-23 of EGFR of tumors in 20 patients with non-small cell lung cancer (NSCLC) who had been treated with gefitinib. Nine (45%) tumors had TK domain mutations. All mutations were observed in adenocarcinoma. Seven (77.8%) of 9 cases with mutated types showed sensitivity to gefitinib, while no cases of 11 with wild type showed gefitinib sensitivity. Such mutations were more frequently observed in patients who had never smoked (5/8 or 62.5%) than in smokers (4/12 or 33.3%). The patients with mutations of EGFR to have a more favorable prognosis than those with wild type (p=0.033). These data show that adenocarcinomas from patients who had never smoked comprise a specific subset of patients with NSCLC sensitive to gefitinib treatment.     

Clinical significance of serum hepatocyte growth factor and epidermal growth factor gene somatic mutations in patients with non-squamous non-small cell lung cancer receiving gefitinib or erlotinib

A study of patients with advanced non-squamous non-small cell lung cancer (NSCLC) evaluated epidermal growth factor receptor (EGFR) mutation status and serum hepatocyte growth factor (HGF) for their associations with response to gefitinib therapy and prognostic impact. An enzyme-linked immunosorbent assay was used to determine levels of HGF in serum from 96 Japanese patients with advanced non-squamous NSCLC. The peptic nucleic acid-locked nucleic acid clamp method was used to determine their EGFR somatic mutation status. We evaluated the relationship between each independent clinicopathological variable and the response to gefitinib therapy and risk factors associated with prognosis. HGF-positive serum status (hazard ratio, 1.536; 95% confidence interval, 1.042-2.400; P = 0.0295) had a significant and independent negative effect on progression-free survival among patients with wild-type EGFR. We demonstrate that having HGF-positive serum is predictive of a negative response to gefitinib therapy in patients with advanced NSCLC who harbor wild-type EGFR.     

E-cadherin expression and epidermal growth factor receptor mutation status predict outcome in non-small cell lung cancer patients treated with gefitinib

It is known that an epidermal growth factor receptor (EGFR) gene mutation(s) is present in a percentage of non-small cell lung cancers (NSCLCs). Gefitinib, an inhibitor of the tyrosine kinase activity of EGFR, is effective on most of them. The EGFR mutation status alone cannot fully predict the response to gefitinib and the prognosis for the patients. We hypothesized that information on the expression levels of phosphorylated-EGFR and -Akt, and E-cadherin, alone or in combination with information on the EGFR mutation, may refine our ability of prediction. We investigated 24 NSCLCs that had recurred after surgery and were treated with gefitinib. Specimens resected by surgery were subjected to the peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp reaction to determine the EGFR mutation status, and to immunohistochemical staining of phosphorylated-EGFR and -Akt, and E-cadherin to determine their expression levels. The EGFR mutation status was predictive of responsive disease (complete response: CR + partial response: PR) and controlled disease (CR + PR + stable disease: SD). Positive E-cadherin staining was predictive of longer time to progression (12.4 vs. 5.9 months, p<0.05) and overall survival (OS) (18.4 vs. 13.0 months, p<0.05). Together the patients with an EGFR mutation and the patients with positive E-cadherin staining defined a patient group with a median OS of 18.4 months and excluded the patient group with the median OS of 3.7 months. Neither p-Akt nor p-EGFR staining was associated with the response and survival. In patients with surgically resected NSCLC tumors, the EGFR mutation status and E-cadherin staining can select patients who will benefit from gefitinib therapy.     

Update on epidermal growth factor receptor mutations in non-small cell lung cancer.

In 2004, several investigators reported that somatic mutations in the epidermal growth factor receptor gene were associated with clinical responses to erlotinib and gefitinib in patients with non-small cell lung cancer. Since then, multiple groups have examined the biological properties that such mutations confer as well as the clinical relevance of these mutations in patients with non-small cell lung cancer. Although a tremendous amount of knowledge has been gained in the past 2 years, there remain a number of important epidemiologic, biological, and clinical questions.     

Epidermal growth factor receptor mutations in patients with non-small cell lung cancer

A year has passed since mutations of the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) were discovered in patients with non-small cell lung cancer (NSCLC) who had dramatic clinical responses to treatment with gefitinib. Additional laboratory and clinical studies have provided further insight into the biological impact of EGFR mutations in cell culture experiments and in patients with NSCLC. In vitro characterizations of NSCLC cell lines and host cell lines transfected with these mutant and wild-type EGFR show that most cell lines with mutated EGFR are growth-inhibited by 10- to 100-fold lower concentrations of gefitinib and erlotinib compared with wild-type EGFR. NSCLC lines with mutations of the EGFR treated with concentrations of gefitinib and erlotinib that are achievable in the plasma undergo apoptosis rather than growth arrest. Retrospective studies of patients with NSCLC-treated gefitinib have reported a close association between EGFR mutations, increased chance of clinical response and longer survival. This review will provide information on the impact of EGFR mutations on gefitinib and erlotinib treatment by in vitro experiments, the outcome of NSCLC patients with these mutations when treated with gefitinib and erlotinib, and the subsets of patients with NSCLC in whom these mutations arise.     

EGFR基因突变及HER2/HER3蛋白表达水平与吉非替尼治疗晚期非小细胞肺癌疗效的关系

背景与目的:吉非替尼治疗非小细胞肺癌(NSCLC)的疗效不一,如何选择对吉非替尼敏感的患者,提高药物的疗效是临床中的难点。本研究探讨了中国人群中表皮生长因子受体(epidermal growth factor receptor,EGFR)的突变及HER2/HER3蛋白表达与吉非替尼治疗局部晚期或转移性NSCLC疗效的关系。方法:2002年5月至2005年2月,符合入组条件的106例患者每日口服250mg吉非替尼一次,直至疾病进展或出现不可耐受的毒副反应。收集吉非替尼治疗前的肿瘤组织。提取基因组DNA后,采用nest PCR技术扩增EGFR基因的18～24外显子,并从正反两个方向进行DNA测序和分析。同时采用免疫组化法检测84例肿瘤组织中的HER2/HER3蛋白的表达。结果:106例肿瘤标本中32例(30.2%)发生了突变。HER2高表达患者的有效率显著高于低表达的患者(36.8%vs.17.4%,P=0.044)。HER2/HER3的表达水平与疾病进展时间(TTP)及总生存期(OS)无关,但HER2/HER3高表达的患者生存期较低表达组略长(9.1个月vs.6.1个月,P=0.725;9.0个月vs.6.1个...     

Complex mutation patterns of epidermal growth factor receptor gene associated with variable responses to gefitinib treatment in patients with non-small cell lung cancer

Mutational analysis was performed in the kinase domain (exons 18-21) of the EGFR gene on tumor tissues of 65 non-small cell lung cancer (NSCLC) patients who had received gefitinib monotherapy. The association between EGFR gene mutation, gefitinib treatment response, and the overall survival were evaluated. In total, EGFR mutations with complex patterns were identified in 32 tumors. The overall mutation rate was 49.2% (32/65). Twenty of the 32 patients were responders, 10 non-responders, and 2 not assessable. The most common mutation in non-responders was L858R. Gefitinib responsiveness was only significantly associated with EGFR mutation and adenocarcinoma. The median survival for responder (15.5 months) was much longer than non-responder (9.23 months), though the difference only had marginal significance (p=0.056). The difference of overall survival between patients with and without EGFR mutation was non-significant (p=0.7819), mainly due to the short survival of the non-responders with EGFR mutations (median survival=6.2 months). Our study revealed that the response to gefitinib treatment in NSCLC patients with EGFR mutations could be quite variable even for the same EGFR mutation type. An analysis of the various EGFR mutations and the response patterns was also performed and compared with recently published reports on EGFR mutation and gefitinib responsiveness.     

中国人非小细胞肺癌表皮生长因子受体EGFR基因突变与血浆纤维蛋白原水平之间的相关性(英文)

Objective:The plasma fibrinogen levels had not only been used as an independent prognostic parameter for the patients with non-small cell lung cancer (NSCLC), but also as a promising biomarker for evaluating the efficacy of chemotherapy. This study aimed to investigate the correlation between the plasma fibrinogen levels and epidermal growth factor receptor (EGFR) gene mutation and clinical-pathological characteristics of Chinese patients with NSCLC. Methods:In this retrospective study, NSCLC specimens collected from 352 patients between November 2009 and November 2011 were selected to detect EGFR gene mutation with real-time polymerase chain reaction (RT-PCR). In these specimens, 308 ones were also detected EGFR gene copy number with fluorescence in situ hybridization (FISH). Coagulation makers were examined prior to the operations. The association between the plasma fibrinogen levels and EGFR gene mutation and clinical-pathological characteristics were analyzed using SPSS 16.0 software. Results:The median pre-operation plasma fibrinogen level was 3.55 g/L (109/352) patients with higher plasma fibrinogen level (> 4.0 g/L). The lower plasma fibrinogen levels correlated significantly with EGFR gene mutations (P < 0.001), the similar result was seen in platelet counts (P = 0.026). A linear correlation was found between the plasma fibrinogen levels and the platelet counts in NSCLC patients (R 2 = 0.209, P < 0.001). Pre-operation plasma fibrinogen levels correlated with gender (P < 0.001), smoking status (P < 0.001), and histology (P < 0.001). There were significant link between the above clinical-pathological characteristics and EGFR gene mutations. In addition, EGFR gene mutation was correlated with FISH-positive status (P < 0.001). Moreover, both plasma fibrinogen level (P = 0.024) and the EGFR gene copy number (P = 0.040) had significant relationships with the pathological TNM stage. Conclusion:This study showed that a significant relevance between plasma fibrinogen levels and EGFR gene mutations. The plasma fibrinogen level might be as a clinical decision parameter for evaluating the efficacy of anti-EGFR tyrosine kinase inhibitors (TKIs) in NSCLC. The patients of NSCLC had higher indicate have poor benefits from anti-EFGR TKIs. In addition, pre-operation plasma fibrinogen level could be used as an indepedent prognostic biomarker for the patients with NSCLC.     

二线吉非替尼对不同表皮生长因子受体突变点位晚期非小细胞肺癌患者疗效及生存情况的影响

目的 探讨二线吉非替尼对不同表皮生长因子受体(EGFR)突变点位晚期非小细胞肺癌(NSCLC)患者疗效及生存情况的影响.方法 选取72例晚期NSCLC患者,按照不同EGFR突变点位分为两组,EGFR19外显子缺失35例为观察组,EGFR21外显子缺失37例为对照组,比较两组患者二线吉非替尼治疗的临床疗效、不良反应及生存...     

Analysis of epidermal growth factor receptor gene mutation in patients with non-small cell lung cancer and acquired resistance to gefitinib.

PURPOSE: Non-small cell lung cancers carrying activating mutations in the gene for the epidermal growth factor receptor (EGFR) are highly sensitive to EGFR-specific tyrosine kinase inhibitors. However, most patients who initially respond subsequently experience disease progression while still on treatment. Part of this "acquired resistance" is attributable to a secondary mutation resulting in threonine to methionine at codon 790 (T790M) of EGFR. EXPERIMENTAL DESIGN: We sequenced exons 18 to 21 of the EGFR gene to look for secondary mutations in tumors with acquired resistance to gefitinib in 14 patients with adenocarcinomas. Subcloning or cycleave PCR was used in addition to normal sequencing to increase the sensitivity of the assay. We also looked for T790M in pretreatment samples from 52 patients who were treated with gefitinib. We also looked for secondary KRAS gene mutations because tumors with KRAS mutations are generally resistant to tyrosine kinase inhibitors. RESULTS: Seven of 14 tumors had a secondary T790M mutation. There were no other novel secondary mutations. We detected no T790M mutations in pretreatment specimens from available five tumors among these seven tumors. Patients with T790M tended to be women, never smokers, and carrying deletion mutations, but the T790M was not associated with the duration of gefitinib administration. None of the tumors had an acquired mutation in the KRAS gene. CONCLUSIONS: A secondary T790M mutation of EGFR accounted for half the tumors with acquired resistance to gefitinib in Japanese patients. Other drug-resistant secondary mutations are uncommon in the EGFR gene.     

A phase II trial of gefitinib as first-line therapy for advanced non-small cell lung cancer with epidermal growth factor receptor mutations

Retrospective analysis has shown that activating mutations in exons 18–21 of the epidermal growth factor receptor (EGFR) gene are a predictor of response to gefitinib. We conducted a phase II trial to evaluate the efficacy and safety of gefitinib as first-line therapy for advanced non-small cell lung cancer (NSCLC) with EGFR mutations. Patients with stage IIIB or IV chemotherapy-naïve NSCLC with EGFR mutation were treated with 250 mg gefitinib daily. For mutational analysis, DNA was extracted from paraffin-embedded tissues and EGFR mutations were analysed by direct sequence of PCR products. Twenty (24%) of the 82 patients analysed had EGFR mutations (deletions in or near E746-A750, n=16; L858R, n=4). Sixteen patients were enrolled and treated with gefitinib. Twelve patients had objective response and response rate was 75% (95% CI, 48–93%). After a median follow-up of 12.7 months (range, 3.1–16.8 months), 10 patients demonstrated disease progression, with median progression-free survival of 8.9 months (95% CI, 6.7–11.1 months). The median overall survival time has not yet been reached. Most of the toxicities were mild. This study showed that gefitinib is very active and well tolerated as first-line therapy for advanced NSCLC with EGFR mutations.     

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.     

Mutations of epidermal growth factor receptor of non-small cell lung cancer were associated with sensitivity to gefitinib in recurrence after surgery

The epidermal growth factor receptor (EGFR) gene has recently been reported to be mutated in a subset of non-small cell lung cancers (NSCLC), with the mutations being correlated with the patients’ drug sensitivity to gefitinib, an EGFR kinase inhibitor. In this study, we searched for EGFR mutations in patients with lung cancer using primary tumor specimens obtained at initial surgery and examined whether their recurrent tumors showed a response to gefitinib depending on the presence of the activating mutation. Among 12 lung cancers that were treated with gefitinib after recurrence, we found that all four tumors which showed a response to gefitinib had an activating mutation in EGFR, whereas none of the remaining eight tumors had a mutation. Southern blot analysis showed that two of the four responsive tumors had the EGFR gene amplification. We also examined another 73 NSCLC specimens (47 males and 26 females; 53 adenocarcinomas and 20 non-adenocarcinomas) which were not treated with gefitinib to determine whether NSCLCs with an EGFR mutation have different clinicopathological properties and/or unique genetic alterations of the other cancer-associated genes. We found that 13 (18%) of 73 tumors had a mutation of the EGFR gene, with the most being detected in female adenocarcinomas. Comparing the alterations in KRAS and P53 with the EGFR mutation, we found that 10 tumors with the KRAS mutation did not have an EGFR mutation, suggesting that each mutation occurs exclusively during the development of lung cancer. These results suggest that the mutation analysis of the EGFR gene using the specimens obtained at surgery might be useful in selecting the appropriate treatment(s) for recurrent lung cancer patients.     

Long-term survival in three patients with metastatic non-small cell lung cancer treated with gefitinib

Gefitinib, a tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR), produces radiographic regression and symptom relief in patients with refractory advanced non-small cell lung cancer. However, it remains controversial whether gefitinib improves patient survival. We report three cases of refractory metastatic non-small cell lung cancer who have survived approximately 3 years since they first started gefitinib. These long-term survivors were Japanese female non-smokers with adenocarcinoma, who often had multiple lung metastases and were effectively re-treated with gefitinib. One patient had a surgical specimen available for DNA extraction and showed deletions in exon 19 of EGFR. Our experience suggests that gefitinib may improve long-term survival in selected patients. Further studies are required to identify biomarkers downstream of the EGFR mutations that are involved in multiple lung metastases and which could identify those patients who may benefit from gefitinib re-treatment.     

非小细胞肺癌组织表皮生长因子受体基因突变的临床意义

目的探讨非小细胞肺癌(NSCLC)肿瘤组织表皮生长因子受体(EGFR)基因突变及其相关因素.方法抽取80例手术切除肿瘤组织DNA,采用巢式PCR方法对编码EGFR基因的第18、19和21外显子片段进行扩增和测序,用Chromas软件分析基因突变或缺失.结果21例肿瘤组织存在EGFR基因突变或缺失,发生率为26.25%,其中13例为EGFR第19外显子阅读框内多核苷酸的缺失,8例为第21外显子2 573位核苷酸点突变.这些突变均为杂合子型.肺腺癌突变率为42.10%(16/38),显著高于鳞癌的9.68%(3/31)和鳞腺混合癌的18.2%(2/11)(χ2=9.702,P ＜0.01);女性患者突变率为48.28%(14/29),显著高于男性患者的13.73%(7/51)(χ2=11.4,P＜0.01);不吸烟者突变率为40%(16/40),显著高于吸烟者的12.50%(5/40)(χ2=7.812,P＜0.01).EGFR基因突变与患者年龄、TNM分期等因素无关.Logistic回归分析提示患者性别和组织类型是影响EGFR突变的2个主要因素.结论NSCLC存在EGFR基因的突变或缺失,其中以女性、腺癌和不吸烟患者突变率较高.