NSCLC原发肿瘤和转移瘤中EGFR基因突变、基因扩增及KRAS基因突变的Meta分析

目的：检测NSCLC原发肿瘤和转移瘤中EGFR基因突变、基因扩增及KRAS基因突变情况,为临床靶向治疗提供更多的循证医学证据。方法：计算机文献检索中英文数据库,收集国内外公开发表的有关EG-FR-TKI靶向治疗预测性生物标记的文献研究,采用Cochrane协作网提供Review Manager 5.2软件进行Meta分析。结果：筛选文献,共11篇纳入研究。Meta分析结果显示,EGFR基因突变组、基因扩增组及KRAS基因突变组RR值分别为0.86（0.65-1.15）、0.73（0.44-1.20）及1.39（0.95-2.03）。结论：联合检测EGFR基因和KRAS基因在原发肿瘤中的突变情况,可作为EGFR-TKIs一线治疗较好的预测性生物标记。检测转移瘤中EGFR基因的扩增情况能够帮助进一步筛查哪些患者对靶向治疗更加敏感。     

Response to dual blockade of epidermal growth factor receptor (EGFR) and cycloxygenase-2 in nonsmall cell lung cancer may be dependent on the EGFR mutational status of the tumor

BACKGROUND: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated clinical benefit in patients with nonsmall cell lung cancer (NSCLC), particularly those with tumors that have EGFR-TK domain mutations. Moreover, the EGFR and cyclooxygenase (COX)-2 pathways are known to enhance the procarcinogenic effects of each other in different tumor types. Therefore, it was hypothesized that tumor EGFR mutation status may influence the effectiveness of simultaneous EGFR and COX-2 inhibition in patients with NSCLC. METHODS: Three NSCLC cell lines with varying EGFR mutation status and sensitivities to EGFR-TKIs were selected: H3255 (L858R), H1650 (del E746-A750), and H1781 (wild-type EGFR). Cells were treated with erlotinib, gefitinib, or celecoxib alone, and the combination of both EGFR-TKI inhibitors with celecoxib. Cell survival and apoptosis was assessed and correlated with the expression of COX-2, EGFR, pEGFR, Akt, pAkt, expression, and derived prostaglandin E2 (PGE(2)). RESULTS: Celecoxib by itself was found to have no effects on cell growth or apoptosis in any of the cell lines. Erlotinib and gefitinib inhibited cell growth and induced apoptosis in both mutant cell lines and did so in H1781 cells at 10-fold higher concentrations. Celecoxib when added to erlotinib or gefitinib significantly enhanced the antiproliferative and proapoptotic effects in both mutant cell lines but had no additional effects in H1781 cells. Greater down-regulation of COX-2, EGFR, pEGFR, Akt, pAkt, and PGE(2) was found when H3255 cells were treated with the combination compared with any of the single agents alone. CONCLUSIONS: The results of the current study demonstrate that the effectiveness of the addition of celecoxib to an EGFR-TKI is significantly greater in NSCLC cells with EGFR mutations, which is likely due to more complete inhibition of both pathways.     

Mutations in the epidermal growth factor receptor and in KRAS are predictive and prognostic indicators in patients with non-small-cell lung cancer treated with chemotherapy alone and in combination with erlotinib.

PURPOSE: Epidermal growth factor receptor (EGFR) mutations have been associated with tumor response to treatment with single-agent EGFR inhibitors in patients with relapsed non-small-cell lung cancer (NSCLC). The implications of EGFR mutations in patients treated with EGFR inhibitors plus first-line chemotherapy are unknown. KRAS is frequently activated in NSCLC. The relationship of KRAS mutations to outcome after EGFR inhibitor treatment has not been described. PATIENTS AND METHODS: Previously untreated patients with advanced NSCLC in the phase III TRIBUTE study who were randomly assigned to carboplatin and paclitaxel with erlotinib or placebo were assessed for survival, response, and time to progression (TTP). EGFR exons 18 through 21 and KRAS exon 2 were sequenced in tumors from 274 patients. Outcomes were correlated with EGFR and KRAS mutations in retrospective subset analyses. RESULTS: EGFR mutations were detected in 13% of tumors and were associated with longer survival, irrespective of treatment (P < .001). Among erlotinib-treated patients, EGFR mutations were associated with improved response rate (P < .05) and there was a trend toward an erlotinib benefit on TTP (P = .092), but not improved survival (P = .96). KRAS mutations (21% of tumors) were associated with significantly decreased TTP and survival in erlotinib plus chemotherapy-treated patients. CONCLUSION: EGFR mutations may be a positive prognostic factor for survival in advanced NSCLC patients treated with chemotherapy with or without erlotinib, and may predict greater likelihood of response. Patients with KRAS-mutant NSCLC showed poorer clinical outcomes when treated with erlotinib and chemotherapy. Further studies are needed to confirm the findings of this retrospective subset analysis.     

Antitumor activity of erlotinib in combination with gemcitabine in in vitro and in vivo models of KRAS-mutated pancreatic cancers

Erlotinib treatment in combination with gemcitabine is a standard therapy for patients with locally advanced pancreatic cancer in many countries, including the US and the EU. Since mutations of the K-ras oncogene (KRAS) occur in approximately 90% of pancreatic cancers, we examined the antitumor activity of erlotinib in combination with gemcitabine in KRAS-mutated pancreatic cancer cell lines, HPAC and Capan-1, which have the KRAS mutation G12D and G12V, respectively. We analyzed the mode of inhibition of in vitro tumor cell proliferation by means of a combination index and found that a combination treatment of erlotinib plus gemcitabine had an additive effect in the two cell lines. We then examined the effect of erlotinib and gemcitabine on the phosphorylation of epidermal growth factor receptor (EGFR). Erlotinib strongly suppressed, while gemcitabine augmented the phosphorylation of EGFR, which was completely blocked by erlotinib in the two cell lines. An in vivo tumor growth inhibition test was then performed using the HPAC tumor xenograft model. The combination therapy of erlotinib and gemcitabine resulted in a significant inhibition of tumor growth compared with erlotinib or gemcitabine monotherapy. To the best of our knowledge, this is the first study to show the combination effect of erlotinib and gemcitabine in vivo using a xenograft model of a KRAS-mutated pancreatic cancer cell line.     

Evodiamine induces apoptosis and enhances apoptotic effects of erlotinib in wild-type EGFR NSCLC cells via S6K1-mediated Mcl-1 inhibition

Erlotinib is effective in NSCLC patients with known drug-sensitizing EGFR mutations, but its clinical efficacy in patients with wild-type EGFR or acquired resistance to erlotinib remains modest. Evodiamine is a chemical extracted from the Evodia rutaecarpa (Juss.) Benth, we showed that evodiamine could induce anti-proliferation and apoptosis in four wild-type EGFR NSCLC cell lines, and combining evodiamine with erlotinib might successfully inhibit cell proliferation and survival in wild-type EGFR NSCLC cells, characterized as erlotinib-resistant. In addition, evodiamine plus erlotinib significantly increased the apoptotic rate of NSCLC cells, as compared to single agent treatment alone. Further investigation of the mechanism underlying these effects revealed that evodiamine plus erlotinib might downregulate Mcl-1 expression through the mTOR/S6K1 control of its translation. Thus, our study has revealed evodiamine as a pertinent sensitizer to erlotinib and the strategy of combining erlotinib with evodiamine appears to be an attractive option for reversing resistance to erlotinib.     

Schedule-dependent apoptosis in K-ras mutant non-small-cell lung cancer cell lines treated with docetaxel and erlotinib: rationale for pharmacodynamic separation

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) given concurrently with chemotherapy in 4 large randomized clinical trials did not improve patient outcomes compared with chemotherapy alone in advanced non-small-cell lung cancer (NSCLC). We hypothesized that the lack of benefit resulted from a negative interaction between chemotherapy and EGFR TKIs. MATERIALS AND METHODS: Herein, we report the cell cycle and apoptotic effects of treatment with erlotinib and docetaxel in the NSCLC cell lines A549 and Calu-1, both of which are mutant for K-ras and wild-type for EGFR. RESULTS: Treatment with erlotinib resulted in accumulation of cells in G(1) phase in A549 cells, with no evidence of apoptosis. Docetaxel treatment led to apoptosis as assessed by increased sub-G1 DNA content and cleavage of caspase 3 and poly (ADP-ribose) polymerase. The sequence of docetaxel followed by erlotinib resulted in significantly enhanced apoptosis compared with single-agent docetaxel in both cell lines. However, in the reverse sequence of erlotinib followed by docetaxel, a reduction of apoptosis was observed. We hypothesize that cell cycle arrest induced by erlotinib accounts for these findings in the presence of wild-type EGFR and that pharmacodynamic separation of the 2 drug classes will ameliorate these effects. CONCLUSION: These studies provide a rationale for intermittent dosing of EGFR TKIs with chemotherapy in order to enhance cytotoxicity.     

KRAS-mutated non-small cell lung cancer cells are responsive to either co-treatment with erlotinib or gefitinib and histone deacetylase inhibitors or single treatment with lapatinib

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors erlotinib and gefitinib provide significant clinical benefit for non-small cell lung cancer (NSCLC) patients whose tumors bear EGFR mutations/amplifications. However, anti-EGFR therapy is largely ineffective in NSCLC with activating KRAS mutations. In this study, we investigated the treatment efficacy of erlotinib and gefitinib in combination with the histone deacetylase inhibitors (HDACi) vorinostat and sodium butyrate in the KRAS-mutated NSCLC cell line A549. For comparison, we tested the combination of HDACi with the dual tyrosine kinase inhibitor lapatinib. A549 cells proved to be resistant to erlotinib and gefitinib, but could be sensitized by cotreatment with HDACi, as assessed by flow cytometric analyses of cell death and mitochondrial depolarization. In contrast, A549 cells were a priori responsive to lapatinib treatment, but responsiveness to lapatinib could not be enhanced by HDACi cotreatment. These divergent effects of the different combination regimens may be explained by dissimilar types of cell death induced by the treatments: The use of the pan-caspase inhibitor z-VAD-fmk in the cell death and mitochondrial depolarization assays as well as fluorescence microscopy analyses indicated that erlotinib or gefitinib combined with HDACi elicited apoptosis, whereas lapatinib treatment induced a non-apoptotic type of cell death. Our study suggests that both HDACi/EGFR inhibitor-combination treatment and lapatinib-single treatment may be effective options for the therapy of NSCLC with KRAS mutations.     

Genotype-driven therapies for non-small cell lung cancer: focus on EGFR, KRAS and ALK gene abnormalities

Non-small cell lung cancers (NSCLCs) are heterogeneous cancers. In 2004, the identification of epidermal growth factor receptor (EGFR) somatic mutations provided the first glimpse of a clinically relevant NSCLC oncogene. Approximately 70% of NSCLCs with EGFR mutations (exon 19 deletions or the exon 21 L858R) attain responses to EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, with improved response rate (RR), progression-free survival (PFS) and in some reports overall survival (OS) when compared with EGFR wildtype (WT) cases. Three randomized trials of gefitinib versus chemotherapy (IPASS, WJTOG3405, NEJ002) in stage IV NSCLC have consistently demonstrated better RR and PFS (hazard ratios of 0.48 [IPASS], 0.49 [WJTOG3405] and 0.30 [NEJ002]) for EGFR-mutated NSCLCs treated with gefitinib. Novel irreversible EGFR TKIs (afatinib, XL647, PF00299804) show similar activity in EGFR-mutated patients. A translocation involving the anaplastic lymphoma kinase (ALK) gene with EML4, identified in 2007, is the most recent oncogene found in NSCLC. Crizotinib (PF02341066), an ALK TKI, has shown impressive activity against ALK translocated NSCLC in an expanded cohort of a phase I trial (NCT00585195). Over 80 patients have been treated and the RR is ～60% with the 6-month PFS rate exceeding 70%. A registration phase III trial of crizotinib versus second-line chemotherapy (pemetrexed/docetaxel) is underway (PROFILE 1007, NCT00932893). KRAS, EGFR mutations and ALK translocations are mutually exclusive and few EGFR WT NSCLCs respond to EGFR TKIs. The promising results of EGFR and ALK TKIs in molecular subgroups of NSCLCs herald a new age of drug and clinical trial development for patients with NSCLC.     

The KRAS StripAssay for detection of KRAS mutation in Egyptian patients with colorectal cancer (CRC): A pilot study

BackgroundEpidermal 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.PurposeDetection of KRAS mutation in Egyptian colorectal cancer (CRC) patients by the KRAS StripAssay.MethodsExamination of 20 colorectal cancer (CRC) patients is done to detect KRAS mutations by KRAS StripAssay. For the StripAssay, a mutant-enriched PCR was followed by hybridization to KRAS-specific probes bound to a nitrocellulose strip.ResultsAmong 20 patients, KRAS mutations were identified in 80% of patients by the KRAS StripAssay.ConclusionsOur preliminary results suggest that KRAS StripAssay is an alternative to protocols currently in use for KRAS mutation detection.     

肺腺癌患者EGFR和KRAS基因突变与预后的相关性研究

目的 探讨肺腺癌患者表皮生长因子受体(EGFR)和KRAS基因突变与预后的相关性.方法 选取134例肺腺癌患者的肺腺癌组织标本,应用探针扩增阻滞突变系统在PCR仪上进行EGFR和KRAS基因突变检测,分析EGFR和KRAS基因突变与肺腺癌患者临床病理特征及预后的关系.结果 134例患者中,EGFR基因突变53例,突变率为39.55%,KRAS基因突变6例,突变率为4.48%.肺腺癌患者EGFR基因突变率与年龄、吸烟史有关(P﹤0.01).EGFR基因突变型患者的KRAS基因突变率低于EGFR基因野生型患者(P﹤0.05).EGFR基因突变型患者的无进展生存期(PFS)长于EGFR基因野生型患者(P﹤0.05),KRAS基因野生型患者的PFS长于KRAS基因突变型患者(P﹤0.05).结论 EGFR基因突变的肺腺癌患者KRAS基因更倾向于野生型,EGFR基因突变型或KRAS基因野生型的肺腺癌患者PFS更长.     

Synergistic inhibition of head and neck tumor growth by green tea (-)-epigallocatechin-3-gallate and EGFR tyrosine kinase inhibitor

One of the mechanisms of the antitumor activity of green tea (-)-epigallocatechin-3-gallate (EGCG) is associated with its effect on epidermal growth factor receptor (EGFR)-mediated signaling transduction pathways. We investigated whether combining EGCG with the EGFR-tyrosine kinase inhibitor (EGFR-TKI) erlotinib may augment erlotinib-induced cell growth inhibition of squamous cell carcinoma of the head and neck (SCCHN) in a mouse xenograft model. In vitro studies with 5 head and neck cancer cell lines revealed that synergistic cell growth inhibition by the combination of EGCG and erlotinib was associated with significantly greater inhibition of pEGFR and pAKT, increased activation of caspases 9, 3 and PARP compared to the inhibition induced by EGCG or erlotinib alone. Erlotinib inhibited phosphorylation of EGFR, stabilizing EGFR at the plasma membrane, whereas EGCG induced EGFR internalization and ubiquitin-degradation, ultimately undermining EGFR signaling. The efficacy of the combination treatment was investigated with nude mice (n = 25) orally gavaged with vehicle control, EGCG, erlotinib or the combination at the same doses for 7 days, followed by subcutaneous injection with Tu212 cells. Animals were continuously administered the agents 5 days weekly for 7 weeks. The combined treatment resulted in significantly greater inhibition of tumor growth and delayed tumor progression as a result of increased apoptosis, decreased cell proliferation and reduced pEGFR and pAKT compared to the single agent treatment groups. Our results suggest a synergistic antitumor effect of a combined treatment with EGCG and erlotinib, and provide a promising regimen for future chemoprevention and treatment of SCCHN.     

EGFR mutations, gene amplification, and protein expression and KRAS mutations in primary and metastatic tumors of nonsmall cell lung cancers and their clinical implications: a meta-analysis

A meta-analysis was performed to determine EGFR mutations, gene amplification, and protein expression and KRAS mutations in primary and metastatic nonsmall cell lung cancer (NSCLC). We found that KRAS gene mutation frequencies were higher in primary than in metastatic tumors. There was no significant difference in EGFR mutation frequency between the primary and metastatic tumors. These results suggest that KRAS mutations in primary NSCLC foci may be a more accurate biomarker than in metastases to reflect KRAS mutation status. Combined detection of EGFR and KRAS mutations in primary NSCLC foci appears to be an optimal approach for first-line EGFR-TKI therapy.     

厄洛替尼与西妥昔单抗联合应用治疗吉非替尼耐药NSCLC的疗效

本研究通过EGFR-TKI和EGFR单克隆抗体联合应用探讨治疗EGFR突变阴性和EGFR T790M突变继发性耐药的NSCLC的疗效。方法：应用EGFR突变阴性和EGFR T790M突变继发性耐药的NSCLL细胞原代培养及药敏技术检验EGFR-TKI和EGFR单克隆抗体联合应用的疗效。结果：检测厄洛替尼和西妥昔单抗联合处理对于15例EGFR突变阴性和8例T790M突变阳性的继发性耐药的NSCLC患者原代细胞的影响,应用浓度分别为50 μg/mL西妥昔单抗和1 μM厄洛替尼作用于EGFR突变阴性的NSCLC患者原代细胞,结果显示这三组间T/C值无显著性差异（P>0.05）,对于T790M突变阳性的继发性耐药的NSCLC原代细胞这三组间T/C值有显著性差异（P<0.05）,联合用药组疗效明显高于单药组。结论：进一步验证了厄洛替尼和西妥昔单抗联合应用对于EGFR突变阴性的NSCLC患者无效,但对于T790M突变阳性的继发性耐药的NSCLC患者有效。     

EGFR and KRAS mutations as criteria for treatment with tyrosine kinase inhibitors: retro- and prospective observations in non-small-cell lung cancer.

Results of individualized therapy guided by mutational tumor profile of patients with non-small-cell lung cancer are presented. After confirming the importance of epidermal growth factor receptor (EGFR) and KRAS mutations for (non)response on gefitinib in a retrospective series of patients, EGFR mutations were looked for before--and were a condition for--treatment with gefitinib or erlotinib. To increase the chance to find such a mutation, we selected patients on the basis of smoking status, gender and histopathology. Out of 41 patients selected, 13 (32%) were found to harbor an EGFR mutation. In nine of them it concerned deletions in exon 19 and in none of them KRAS mutations were detected. All nine patients with an exon 19 deletion had a favorable and continuing response to tyrosine kinase inhibitors (TKIs), while four other patients with point mutations responded less favorably: stable disease or a response of short duration. These observations confirm the potential role of EGFR and KRAS mutations in predicting (non)response to TKIs. Exon 19 deletions that are associated with the best responses might be used for first-line treatment selection, while KRAS mutations could play a role in excluding patients from treatment with TKIs.     

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.     

Extraordinary response to erlotinib therapy in a patient with lung adenocarcinoma exhibiting KRAS mutation and EGFR amplification

Case reports on the co-incidence of Kirsten rat sarcoma (KRAS) mutation and epidermal growth factor receptor (EGFR) amplification in patients with NSCLC are very rare. This combination is usually considered a negative prognostic factor, despite EGFR amplification alone having positive predictive value. The whole course of treatment of a patient with both EGFR amplification and KRAS mutation present is decribed. The patient in question was a smoker for whom both first- and second-line chemotherapy had been unsuccessful. In stage IV disease biological therapy was administered and proved highly beneficial. Today, 38 months since commencing the treatment, the patient still has no signs of progression and the therapy is still in progress.     

KRAS mutation status in primary nonsmall cell lung cancer and matched metastases

BACKGROUND:

The objective of this study was to determine whether the mutation status of the v‐Ki‐ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and epidermal growth factor receptor (EGFR) differed between primary tumors and matched distant metastases in nonsmall cell lung cancer (NSCLC).

METHODS:

Patients who underwent resection for both primary NSCLC and matched distant metastases were included in the study. KRAS and EGFR mutation status were assessed by polymerase chain reaction (PCR) amplification and direct sequencing on both primary tumors and metastases. For KRAS analysis, mutant‐enriched PCR (ME‐PCR) was performed in case of discordance between a primary tumor and its matched metastasis.

RESULTS:

Twenty‐one patients were included. No EGFR mutations were detected. KRAS mutations were detected in 6 patients (28%). In all patients, the mutations identified by direct sequencing were discordant between the primary tumor and the matched metastasis. The use of ME‐PCR allowed a resolution of the discordance in 3 of the 6 cases by demonstrating the presence of low levels of mutant KRAS in lesions that were negative by direct sequencing.

CONCLUSIONS:

Highly sensitive tools are required to identify biomarkers. The KRAS mutation status mostly was concordant between primary tumors and matched distant metastases. In a few patients, KRAS mutation status differed between different tumor sites. Cancer 2010. © 2010 American Cancer Society.     

The use of first-generation tyrosine kinase inhibitors in patients with NSCLC and somatic EGFR mutations

Initial studies with the first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors gefitinib and erlotinib in patients with non-small cell lung cancer (NSCLC) showed that, although most did not have an objective radiographic response, a minority of patients had dramatic and durable clinical and radiographic responses. The discovery of EGFR mutations in tumours from patients with NSCLC and the association of these mutations with clinical response to gefitinib and erlotinib provided an opportunity to tailor treatment to the mutation profile of the tumour. A number of retrospective reviews and prospective trials have established that gefitinib or erlotinib therapy leads to radiographic responses in approximately 75-80% of patients with NSCLC with EGFR mutations. Although a variety of mutations in EGFR have been identified, the two most common somatic activating EGFR mutations are the LREA deletions in exon 19 and the L858R substitution in exon 21. Together, these mutations make up 85-90% of EGFR mutations. At least two retrospective reviews have indicated a difference in the outcome of patients with different EGFR mutations: after treatment with gefitinib or erlotinib, patients with exon 19 deletions have an increased survival compared with those patients whose tumours have an L858R substitution. These findings remain to be confirmed in prospective studies. Improved understanding of the association of EGFR mutations with clinical outcome may improve the ability of physicians to match treatment to mutation status for patients with NSCLC.     

Long-Term Treatment with Erlotinib for EGFR Wild-Type Non-Small Cell Lung Cancer: A Case Report

The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib are known to have greater efficacy in EGFR mutation-positive non-small cell lung cancer (NSCLC), although erlotinib also has activity in wild-type disease. We report the successful long-term maintenance treatment of a patient with EGFR wild-type NSCLC with gefitinib and later erlotinib. The patient (male; 44 years old; smoker) was diagnosed with EGFR wild-type NSCLC after computer tomography had revealed a mediastinal mass, and histology and mutation testing had identified the tumor as an EGFR wild-type grade 3 adenocarcinoma. The patient received multiple rounds of chemotherapy, followed by gefitinib maintenance (3 years). Later on, he received erlotinib maintenance and developed a persistent rash (grade 1/2) that lasted throughout the treatment. The patient''s condition has remained stable on erlotinib for more than 5 years, with no evidence of progression. We describe the patient''s disease course and treatment in the context of EGFR TKI therapy and the prognostic factors for long-term clinical outcomes of NSCLC, including the development of erlotinib-induced rash.Key words: Erlotinib, Gefitinib, Epidermal growth factor receptor, Tyrosine kinase inhibitors, Wild-type non-small cell lung cancer, Long-term maintenance treatment