Lung cancer with epidermal growth factor receptor exon 20 mutations is associated with poor gefitinib treatment response

PURPOSE: Clinical reports about responsiveness to gefitinib treatment in patients of non-small cell lung cancer (NSCLC) with mutations in exon 20 of epidermal growth factor receptor (EGFR) are limited. To increase understanding of the influence of exon 20 mutations on NSCLC treatment with gefitinib, we investigated the clinical features of lung cancer in patients with exon 20 mutations and analyzed the gefitinib treatment response. EXPERIMENTAL DESIGN: We surveyed the clinical data and mutational studies of NSCLC patients with EGFR exon 20 mutations in the National Taiwan University Hospital and reviewed the literature reports about EGFR exon 20 mutations and the gefitinib treatment response. RESULTS: Twenty-three patients with mutations in exon 20 were identified. Nine (39%) had coexisting mutations in EGFR exons other than exon 20. Sixteen patients received gefitinib treatment, and a response was noted in 4 patients. The gefitinib response rate of NSCLC with exon 20 mutations was 25%, far lower than those with deletions in exon 19 and L858R mutations. Interestingly, different exon 20 mutations and coexisting mutations seemed to have a different influence on gefitinib response. CONCLUSIONS: EGFR exon 20 mutations of NSCLC patients result in poorer responsiveness to gefitinib treatment, but variability exists between different individuals.     

晚期非小细胞肺癌表皮生长因子受体基因突变情况和其对吉非替尼疗效的影响

背景与目的 研究晚期非小细胞肺癌( non-small cell lung cancer,NSCLC)表皮生长因子受体(epidermal growth factor receptor,EGFR)基因突变情况和该基因突变状态对吉非替尼疗效的影响.方法 于2007年1月-2009年12月对160例晚期非鳞癌NSCLC患者进行了EGFR基因检测,EGFR基因外显子19和外显子21突变检测采用突变富集PCR法.其中111例接受了吉非替尼治疗.中位生存期(overall survival,OS)和无疾病进展生存时间(progression free survival,PFS)的比较采用Kaplan-Meier方法计算.结果 晚期非鳞癌NSCLC患者EGFR基因突变率为55％,多因素分析显示只有病理类型与是否突变明显相关.EGFR基因突变型患者的OS为29.0个月(95％CI:24.2-33.8),野生型为21.0个月( 95％CI:14.7-27.3),两者差别无统计学差异.EGFR基因突变患者的PFS为17.0个月(95％CI:5.6-17.6),而野生型为11.6个月(95％CI:8.6-25.4),两者有明显性差别(P=0.022).OS的多因素分析结果显示,OS与ECOG评分、病理类型、EGFR基因突变状态明显相关.PFS多因素分析结果显示,PFS与ECOG评分、既往化疗方案数和EGFR基因突变明显相关.EGFR基因外显子19突变与外显子21突变的OS和PFS无明显差别,客观疗效也无差别.结论 晚期非鳞癌NSCLC EGFR基因突变患者的PFS明显优于野生型患者,OS有延长趋势.EGFR基因不同突变类型的PFS和OS均无差别.     

Double mutation and gene copy number of EGFR in gefitinib refractory non-small-cell lung cancer

Mutations of the epidermal growth factor receptor (EGFR) gene have been reported in non-small-cell lung cancer (NSCLC), especially in patients with adenocarcinoma and never smokers. Some common somatic mutations in EGFR, including deletion mutations in exon 19 and leucine-to-arginine substitution at amino acid position 858 (L858R) in exon 21, have been examined for their ability to predict sensitivity to gefitinib or erlotinib, which are selective EGFR tyrosine kinase inhibitors (EGFR-TKIs). On the other hand, reports have shown that the threonine-to-methionine substitution at amino acid position 790 (T790M) in exon 20 is related to gefitinib resistance. Some studies have indicated that high copy numbers of the EGFR gene may be a more effective molecular predictor to responsiveness and prolonged survival in patients treated with EGFR-TKIs. Here, we describe two NSCLC patients with the L858R mutation who did not respond to gefitinib. Case 1 harbored both the T790M and L858R mutations, and fluorescence in situ hybridization showed EGFR gene amplification. Case 2 harbored both the L858R and aspartic acid-to-tyrosine substitution at amino acid position 761 in exon 19 of EGFR mutations and had a high polysomy status for EGFR. In these two cases, tumors showed resistance to gefitinib treatment despite the presence of EGFR L858R mutation and increased copy number. Our findings encourage further molecular analysis to elucidate the relationship between the EGFR status, including mutations and amplifications, and the responsiveness of NSCLC to gefitinib.     

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.     

辽宁沈阳地区非小细胞肺癌EGFR基因突变分析

目的:探讨辽宁沈阳地区非小细胞肺癌（NSCLC）患者表皮生长因子受体（EGFR）基因突变情况及其与临床病理特征的关系。方法:采用扩增耐突变系统（Amplification Refractory Mutation System,ARMS）检测辽宁沈阳地区471例NSCLC患者EGFR基因第18,19,20及21外显子突变情况。结果:471例NSCLC患者共检出EGFR突变253例（53.7%）,其中19缺失和L858R突变占总突变数的42.3%,51.8%。女性患者突变率67.9%明显高于男性（37.4%）,两者之间差异有统计学意义（P=0.000）。腺癌患者突变率57.2%明显高于非腺癌患者（18.6%）,差异有统计学意义（P=0.000）。结论:辽宁沈阳地区NSCLC患者EGFR突变多见于女性,腺癌患者,突变类型以19缺失和21外显子的L858R突变为主。     

Study of the Correlation of EGFR and K-RAS Gene Mutations with Its Protein Expression in Non-small Cell Lung Cancer

OBJECTIVE To investigate gene mutations of epidermal growth factor receptor (EGFR) and K-RAS (Kirsten rat sarcoma viral oncogene) in Chinese patients with non-small cell lung cancer (NSCLC), and study the correlation with its protein expression and its clinical significance on gefitinib. METHODS Detect the EGFR and K-RAS gene mutations status by gene sequencing and use the method of Immunohistochemistry to detect EGFR and K-RAS protein expression. RESULTS The frequency of EGFR mutations was 33%, mainly located in exon 19 and exon 21. The frequency of K-RAS mutations was 5.5%, mainly located in codon 12. There was no case which both had EGFR and K-RAS mutations, suggesting a mutually exclusive relationship between the two. EGFR mutations are more common in adenocarcinomas (particularly those with bronchioloalveolar features), nonsmokers and females. 16% were detected EGFR positive expression and had no correlation with EGFR mutation (P > 0.05), but had significant correlation with mutation in exon 19 (P < 0.05). The frequency of K-RAS positive expression was 52.5% and had no correlation with K-RAS mutation (P > 0.05). Twelve (8 cases were protein-negative) out of 15 gefitinib-treated NSCLC patients with disease control carry EGFR mutations. CONCLUSION EGFR protein expression has some correlation with exon 19 mutations. Combined detection of EGFR and K-RAS gene mutations can help clinicians to choose patients who may benefit from EGFR tyrosine kinase inhibitor (EGFR-TKI) and to predict the response and prognosis of gefitinib.     

Response of some head and neck cancers to epidermal growth factor receptor tyrosine kinase inhibitors may be linked to mutation of ERBB2 rather than EGFR.

PURPOSE: Small-molecule tyrosine kinase inhibitors (TKI) of the epidermal growth factor receptor (EGFR) have shown modest yet reproducible response rates in patients with squamous cell carcinoma of the head and neck (SCCHN). Somatic mutations in EGFR have recently been shown to be predictive of a clinical response in patients with non-small cell lung cancer (NSCLC) treated with these inhibitors. The objective of this study was to determine if such mutations, or recently reported mutations in ERBB2, also underlie EGFR-TKI responsiveness in SCCHN patients. EXPERIMENTAL DESIGN: We sequenced the kinase domain of EGFR and exon 20 of ERBB2 in tumor specimens from eight responsive patients. In addition, mutational analysis was done on tumor specimens from nine gefitinib nonresponders and 65 unselected cases of SCCHN. RESULTS: None of eight TKI-responsive specimens had mutations within the kinase domain of EGFR. EGFR amplification was also not associated with drug responsiveness. However, a single responsive case had a somatic missense mutation within exon 20 of ERBB2. CONCLUSION: Our data indicate that unlike NSCLC, EGFR kinase mutations are rare in unselected cases of SCCHN within the United States and are not linked to gefitinib or erlotinib responses in SCCHN. Alternative mechanisms, including ERBB2 mutations, may underlie responsiveness in this tumor type.     

EGFR exon 20 insertion mutation in Japanese lung cancer

Mutations of the epidermal growth factor receptor (EGFR) gene have been reported in non-small cell lung cancer (NSCLC), especially in female, never smoker patients with adenocarcinoma. Some common somatic mutations in EGFR, including deletion mutations in exon 19 and leucine to arginine substitution at amino acid position 858 (L858R) in exon 21, have been examined for their ability to predict sensitivity to gefitinib or erlotinib. On the other hand, previous report has shown that the insertion mutation at exon 20 is related to gefitinib resistance. We investigated the exon 20 EGFR mutation statuses in 322 surgically treated non-small cell lung cancer cases. Two hundred and five adenocarcinoma cases were included. The presence or absence of EGFR mutations of kinase domains was analyzed by direct sequences. EGFR insertion mutations at exon 20 were found from 7 of 322 (2.17%) lung cancer patients. We also detected the 18 deletion type mutations in exon 19, and 25 L858R type mutations in exon 21. There was a tendency towards higher exon 20 insertion ratio in never smoker (never smoker 4.4% versus smoker 1.3%, p=0.0996) and female (female 4.5% versus male 1.3%, p=0.0917). Two exon 20 insertion cases were treated with gefitinib and failed to response. EGFR insertion mutation in exon 20 could not be ignored from Japanese lung cancers.     

非小细胞肺癌E GF R基因突变的表现及其与肿瘤标记物的相关性

目的：探讨非小细胞肺癌（NSCLC）EGFR基因突变位点状态,分析其与血清肿瘤标记物NSE、CEA、CYFRA21－1、TSGF间的关系。方法：回顾性分析240例NSCLC患者组织标本中EGFR不同位点基因突变状态,分析基因突变率与患者性别、年龄、吸烟史和组织分型间的关系及NSCLC患者19、21突变位点与肿瘤标记物NSE、CEA、CYFRA21－1、TSGF的相关性。结果：240例标本突变135例,18号外显子突变2例（1．5％）;19号外显子突变47例（34．8％）;20号外显子突变7例（5．2％）;21号外显子突变71例（52．6％）;双突变8例（5．9％）。EGFR突变主要发生在19、21号外显子上,其中19号外显子突变与组织分型有关（P＜0．05）,与年龄、性别、吸烟史无关（P＞0．05）;21号外显子突变与组织分型、吸烟史、性别有关（P＜0．05）,与年龄无关（P＞0．05）。EGFR突变组肿瘤标志物NSE、CEA、CYFRA21－1、TSGF的表达水平与未突变组之间差异无统计学意义（P＞0．05）,19、21号外显子突变的肿瘤标记物NSE、CEA、CYFRA21－1、TSGF之间的差异也无统计学意义（P＞0．05）。结论：NSCLC的EGFR突变中19、21号外显子突变率显著高于其他类型,这对于指导临床合理应用EGFR－TKIs药物治疗有重要的意义。而肿瘤标记物NSE、CEA、CYFRA21－1、TSGF在突变组与未突变组之间、19和21号外显子突变之间的差异均无统计学意义。因此,血清肿瘤标记物可能不足以作为评估EGFR突变的指标。     

The impact of sex and smoking status on the mutational spectrum of epidermal growth factor receptor gene in non small cell lung cancer.

PURPOSE: Mutation of epidermal growth factor receptor (EGFR) gene has been reported to be present in non-small cell lung cancer (NSCLC) and significantly associated with female sex and never-smoking status. In this study, we extensively investigated the impact of sex and smoking on the EGFR mutation. EXPERIMENTAL DESIGN: We examined EGFR exons 18 to 21 status in 1,467 NSCLC patients by direct sequencing to study the impact of sex and smoking status on the EGFR mutational spectrum. RESULTS: Among 1,467 patients, 197 mutations were found at exon 19, 176 at exon 21, 21 at exon 18, and 24 at exon 20. To examine the independent effect of sex and smoking, the mutational status of each exon was compared between smokers and never smokers in each sex and between males and females stratified by smoking status. In females, exon 19 (P = 0.001) and exon 21 (P < 0.001) mutations were significantly less frequent in ever smokers compared with never smokers. In males, exon 19 (P < 0.001), exon 21 (P < 0.001), and exon 18 (P = 0.003) mutations were significantly less frequent in ever smokers compared with never smokers. In analysis stratified by smoking, there was no difference in sex among never smokers. However, exon 19 mutations were significantly less frequent in males compared with females among ever smokers (P = 0.003). In addition, the interactive effect of male sex and ever smoking status significantly decreased the frequency of exon 19 mutations (P = 0.047) when female never smoker was set as a reference. CONCLUSION: Both sex and smoking status could influence the EGFR mutational spectrum. Our findings suggest that individual EGFR exons may have differing susceptibilities for mutagenesis.     

Exon 19 deletion mutations of epidermal growth factor receptor are associated with prolonged survival in non-small cell lung cancer patients treated with gefitinib or erlotinib.

PURPOSE: Somatic mutations in the epidermal growth factor receptor (EGFR) have been detected in patients with non-small cell lung cancer (NSCLC) and are associated with sensitivity to treatment with gefitinib or erlotinib. Our study explored the relationship between the two most common types of somatic EGFR mutations, exon 19 deletions and the L858R point mutation, and outcomes of patients following treatment with gefitinib or erlotinib. EXPERIMENTAL DESIGN: Tumor specimens obtained before treatment with gefitinib or erlotinib were analyzed for EGFR mutations. Patients with exon 19 deletion or L858R mutations were identified. The response rate, time to progression, and overall survival were determined for the two groups. RESULTS: We identified 36 patients with NSCLC and an EGFR mutation who were treated with gefitinib or erlotinib. Patients with an exon 19 deletion had a significantly longer overall survival compared with patients with an L858R mutation (38 versus 17 months; P = 0.04). There were also trends toward higher response rate (73% versus 50%) and improved time to progression (24 versus 10 months) for the patients with an exon 19 deletion, although these were not independently significant in a multivariate analysis. A difference in response rate for patients treated with gefitinib compared with erlotinib was also noted [18 of 23 (78%) versus 3 of 9 (33%); P = 0.04]. No obvious difference in time to progression or overall survival was noted between gefitinib- and erlotinib-treated patients. CONCLUSIONS: Patients with NSCLC and EGFR exon 19 deletions have a longer survival following treatment with gefitinib or erlotinib compared with those with the L858R mutation. Pooling of greater numbers of patients and completion of prospective trials are needed to further define the predictive and prognostic roles of different EGFR mutations with respect to treatment with gefitinib, erlotinib, and other EGFR inhibitors.     

EGFR-TKI一线治疗EGFR基因突变的晚期非小细胞肺癌临床观察

背景与目的研究表明,一线表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor receptortyrosine kinase inhibitor,EGFR-TKI)治疗晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)的客观缓解率及无进展生存期明显优于铂二联的化疗,且耐受性更好。本研究旨在分析EGFR-TKI一线治疗晚期EGFR突变阳性的NSCLC患者的疗效与耐受性。方法 54例晚期NSCLC患者肿瘤标本采用直接测序法证实EGFR活化突变(外显子19缺失或外显子21点突变),一线给予EGFR-TKI口服治疗直至疾病进展,观察疗效及不良反应,并进行生存随访。结果 54例患者外显子19缺失33例(61%),外显子21点突变21例(39%)。均一线接受EGFR-TKI治疗,总体缓解率为90%,中位无进展生存期(progression free survival,PFS)为8.3个月,中位生存期为19.5个月;外显子19缺失患者的中位PFS(9.0个月)较21点突变(7.0个月)时间长(P=0.002)。外显子19缺失患者的中位总生存期(overall survival,OS)(25.0个月)较21点突变(16.0个月)时间长(P=0.001);吉非替尼与厄洛替尼疗效相当,但吉非替尼组安全性更好;最常见的不良事件为皮疹和腹泻,有2例患者(4%)出现了3度皮肤毒性反应,2例患者(4%)出现了3度的转氨酶升高,1例患者(1%)出现了3度口腔炎。结论存在EGFR基因突变的晚期NSCLC患者一线接受EGFR-TKI治疗安全有效,且外显子19缺失比L858R突变疗效更优。     

Differences in Epidermal Growth Factor Receptor Gene Mutations and Relationship with Clinicopathological Features in NSCLC Between Uygur and Han Ethnic Groups

Objective: To investigate differences in mutations of epidermal growth factor receptor (EGFR) gene andrelationships with clinicopathological features in patients with non-small cell lung cancer (NSCLC) betweenUygur and Han ethnic groups. Methods: The Scorpions amplification refractory mutation system (ScorpionsARMS) was used to measure mutations in exons 18, 19, 20 and 21 of the EGFR gene in paraffin-embedded tumortissue from NSCLC cases, and statistical analysis was performed to investigate links with clinicopathologicalfeatures in different histological types of NSCLC. Results: Results from ARMS testing showed EGFR mutationsin tumor tissues from six (6) of 50 NSCLC patients of Uygur ethnic group, with a positive rate of 12.0%; four ofthem (4) had exon 19 deletion in EGFR, and two (2) had L858R point mutation in exon 21 of EGFR. Statisticallysignificant difference was noted in EGFR genetic mutation between adenocarcinoma and non-adenocarcinoma(P < 0.05), but no differences with gender, age group, smoking status, or stage (P > 0.05). EGFR mutations weredetected in tumor tissues from 27 of 49 NSCLC patients of Han ethnic group , with a positive rate of 55.1%;19 of them had exon 19 deletions, seven (7) had L858R point mutations in exon 21 of EGFR and one (1) hadmutations in both exon 18 G719X and exon 20 T790M of EGFR. Statistically significant differences were notedin EGFR genetic mutations between genders and between adenocarcinoma and non-adenocarcinoma (P<0.05),but not with age group, smoking status, or stage (P > 0.05). Conclusion: Statistically significant differences werenoted in the positive rates of EGFR genetic mutations in NSCLC patients between Uygur and Han ethnic groups,with lower positive rates for the Uygur cases.     

The impact of epidermal growth factor receptor gene status on gefitinib-treated Japanese patients with non-small-cell lung cancer

We investigated the relationships between genetic factors and clinical outcome in Japanese non-small-cell lung cancer (NSCLC) patients treated with gefitinib. Ninety-eight NSCLC patients who had been treated with gefitinib, were screened for mutations in epidermal growth factor receptor (EGFR) exons 18-21, KRAS exon2, and polymorphisms including the CA simple sequence repeat in intron1 (CA-SSR1) and single nucleotide polymorphisms in the promoter region (-216G/T and -191C/A), using a PCR-based assay and direct sequencing. The EGFR copy number status was also evaluated using a fluorescence in situ hybridization assay. EGFR and KRAS mutations were found in 38 (38.8%) and 8 (8.2%) of the 98 patients, respectively. A high EGFR copy number status was identified in 31 (41.3%) of the 75 assessable patients. Drug-sensitive EGFR mutations limited to exon19 deletions and L858R were independent predictive factors of a stronger sensitivity to gefitinib (p = 0.0002), the overall survival (OS) (p = 0.0036), and prolonged progression-free survival (PFS) (p < 0.0001). The EGFR copy number status was not related to a sensitivity to gefitinib and prolonged OS and PFS. Regarding polymorphisms, patients with a short CA-SSR1 showed a prolonged OS as compared with those with a long length in patients with a drug-sensitive EGFR mutation, although this difference was not significant (p = 0.13). Thus, drug-sensitive EGFR mutations predict a favorable clinical outcome and a high EGFR copy number may not be related to clinical benefits in gefitinib-treated Japanese patients with NSCLC. Our findings also suggest that the CA-SSR1 length may influence the clinical outcome in patients with a drug-sensitive EGFR mutation.     

Efficacy of gefitinib for non-adenocarcinoma non-small-cell lung cancer patients harboring epidermal growth factor receptor mutations: a pooled analysis of published reports

The efficacy of gefitinib for patients with non-adenocarcinoma non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations is unclear, because only a small percentage of patients enrolled in the clinical trials to evaluate the efficacy of gefitinib for tumors harboring EGFR mutation were non-adenocarcinoma NSCLC. A pooled analysis was conducted to clarify the efficacy of gefitinib for non-adenocarcinoma NSCLC patients harboring EGFR mutations. A systematic search of the PUBMED databases was conducted to identify all clinical reports that contained advanced non-adenocarcinoma NSCLC patients harboring EGFR mutations and treated with gefitinib. The selected patients were advanced non-adenocarcinoma NSCLC patients harboring EGFR mutations who were treated with gefitinib and described in reports containing the data of the histology, status of EGFR mutations and response to gefitinib. This study selected 33 patients from 15 reports. Twenty-seven and three of the 33 patients were squamous cell carcinoma and adenosquamous cell carcinoma, respectively. One patient each had large-cell carcinoma, pleomorphic carcinoma and spindle cell carcinoma. Twenty-one patients (64%) had sensitive EGFR mutations. The response rate (RR), disease control rate (DCR) and median progression-free survival (mPFS) was 27%, 67-70% and 3.0 months, respectively. These factors were statistically significantly inferior in the non-adenocarcinoma NSCLC patients harboring EGFR mutations to adenocarcinoma patients harboring EGFR mutations selected from the same published reports (RR: 27%vs 66%, P = 0.000028; DCR: 67-70%vs 92-93%, P = 0.000014; mPFS: 3.0 vs 9.4 months, P = 0.0001, respectively). Gefitinib is less effective in non-adenocarcinoma NSCLC harboring EGFR mutations than adenocarcinoma harboring EGFR mutations.     

Usefulness of cumulative smoking dose for identifying the EGFR mutation and patients with non-small-cell lung cancer for gefitinib treatment

We examined the diagnostic accuracy of the cumulative smoking dose for identifying the epidermal growth factor receptor ( EGFR ) exon 19 deletion and L858R mutation among Japanese patients with non-small-cell lung cancer (NSCLC). EGFR mutations in exon 19 and exon 21 were determined in 1001 NSCLC patients. A receiver–operating characteristic (ROC) curve methodology was applied to estimate the diagnostic accuracy. EGFR mutations were detected in 314 patients (31.4%). A cumulative smoking dose of less than 13 pack-years (PY) was the optimal cut-off point for predicting a positive EGFR mutation status, producing a balance between the sensitivity (73.5%) and the specificity (77%). The area under the ROC curve was 0.77, indicating that the smoking dose had a moderate diagnostic accuracy. The median survival time or the median progression-free survival time of patients who had smoked less than 13 pack-years (PY) were 18.6 and 6.3 months, respectively, while those of patients with equal to or more than 13 PY were 9.6 and 2.4 months, respectively. The overall survival (OS) and progression-free survival (PFS) rates were significantly different between the two groups (OS: hazard ratio [HR] = 0.64, 95% confidence interval [CI] = 0.51–0.80, P  = 0.0001) (PFS: HR = 0.58, 95% CI = 0.47–0.71, P  < 0.0001). Our study indicated that the smoking dose predicted EGFR mutations with a moderate diagnostic accuracy. Thus, patients who have smoked less than 13 PY might be candidates for gefitinib treatment when EGFR mutation status cannot be determined. ( Cancer Sci  2009; 100: 1931–1934)     

Gefitinib (ZD1839): therapy in selected patients with non-small cell lung cancer (NSCLC)?

PURPOSE: To evaluate response rate, toxicity and epidermal growth factor (EGFR) mutations and gene copy number as outcome predictive factors in Italian patients with non-small cell lung cancer (NSCLC) treated with gefitinib (Iressa) in an expanded access program (EAP). PATIENTS AND METHODS: A total of 137 patients with advanced NSCLC received gefitinib as first line treatment or after failure of chemotherapy. In 43 cases, tissue specimens were available for EGFR status evaluation: immunohistochemical (IHC) for EGFR, fluorescence in situ hybridisation (FISH) or Chromogenic in situ hybridisation (CISH)-(ISH) analysis for EGFR and HER2 gene copy number, and PCR-DNA sequencing for mutational analysis of EGFR were performed. RESULTS: In the study population, response rate (PR) was 13%; disease stabilization (DS) 26%; overall disease control rate 39%; median survival 6.3 months and time to progression 2.7 months. Toxicity was mild (G3 skin toxicity in 3% and G3 liver toxicity in 4% of patients). An EGFR-mutation was detected in 9/43 patients: Eight deletions in exon 19 and 1 missense mutation in exon 21. Increased gene copy number for EGFR and/or HER2 was detected in 17/43 patients. Response rate was significantly higher in women, non-smokers, in mutation carriers than in wild type carriers, in EGFR-trisomy/polysomy carriers and HER2-trisomy/polysomy carriers. CONCLUSIONS: In this study, response rate and toxicity to gefitinib treatment were consistent with previously reported data for whites. Female gender, absence of smoking history, EGFR-mutations, EGFR and HER2-polysomy were significantly associated with response to gefitinib therapy in NSCLC patients.     

中国非小细胞肺癌患者K-Ras和EGFR基因突变与临床病理特征的关系

目的 探讨中国非小细胞肺癌（NSCLC）患者中K-Ras和表皮生长因子受体（EGFR）基因突变情况及其与临床病理特征的关系。方法 回顾性分析2011年7月至2013年8月广州医科大学附属第一医院收治的381例NSCLC患者的临床病理特征,并应用扩增突变阻滞系统（ARMS）检测其癌组织中EGFR基因18、19、20、21外显子共21个点突变和K-Ras基因12、13密码子共6个点突变,分析其突变情况及与临床病理特征的相关性。结果 21例（5.5％）存在K-Ras基因突变,其中20例12密码子,1例13密码子Asp突变;146例（38.3％）存在EGFR突变,其中4例18外显子突变（G719S）,52例19号外显子序列缺失突变,3例20外显子序列缺失突变,85例21外显子突变（81例L858R,4例L861Q）,2例双突变。男性患者K-Ras基因突变率高于女性患者,差异有统计学意义（6.8％ vs. 2.5％, P=0.018）。EGFR基因突变与性别、吸烟史、临床分期、全身转移、病理类型均有关（P＜0.05）。二分类Logistic回归分析显示,病理类型和性别与EGFR基因突变密切相关。结论 中国NSCLC患者中EGFR突变常见,该突变与腺癌有关;K-Ras基因突变率较低,多见于男性,其他相关因素尚需进一步研究。     

非小细胞肺癌EGFR基因突变的临床意义研究

  目的   探讨非小细胞肺癌EGFR基因外显子突变与其临床病理特征的关系。   方法   利用ADx-ARMS?EGFR基因突变检测试剂盒,检测214例未接受过Gefitinib治疗的非小细胞肺癌患者组织中EGFR基因外显子18、19、20和21突变。   结果   非小细胞肺癌组织中EGFR基因总突变率为45.8%（98/214）,外显子18、19、20和21的突变率分别为0.93%（2/214）、22.0%（47/214）、2.3%（5/ 214）和20.6%（44/214）。另有2例19和21外显子双重突变。EGFR基因在肺腺癌组织中的总突变率为50.3%（93/185）明显高于肺鳞状细胞癌17.2%（5/29）（P=0.001）。EGFR基因在女性患者中的突变率57.0%（57/100）高于男性36.0%（41/114）（P=0.002）,EGFR基因在NSCLC淋巴结转移患者中的突变率（66.7%）显著高于无淋巴结转移患者（39.5%）（P < 0.05）,但EGFR基因突变率与肺癌患者的年龄、肿瘤分级和临床分期均无显著性差异（P>0.05）。   结论   中国肺癌尤其是肺腺癌患者存在EGFR基因的较高突变率,EGFR外显子19、21突变结合肺癌的临床病理特征有望成为评估TKI治疗非小细胞肺癌疗效的分子标志。