Title: Epithelial phenotype as a predictive marker for response to EGFR-TKIs in non-small cell lung cancer patients with wild-type EGFR
Abstract: International Journal of CancerVolume 135, Issue 12 p. 2962-2971 Cancer TherapyFree Access Epithelial phenotype as a predictive marker for response to EGFR-TKIs in non-small cell lung cancer patients with wild-type EGFR Shengxiang Ren, Shengxiang Ren Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of China S.R., C.S. and Z.W. contributed equally to this workSearch for more papers by this authorChunxia Su, Chunxia Su Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of China S.R., C.S. and Z.W. contributed equally to this workSearch for more papers by this authorZhaoye Wang, Zhaoye Wang Department of Cardio-Thoracic Surgery, Zhoushan Hospital of Zhejiang Province, Zhoushan, Zhejiang Province, People's Republic of China S.R., C.S. and Z.W. contributed equally to this workSearch for more papers by this authorJiayu Li, Jiayu Li Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorLihong Fan, Lihong Fan Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorBing Li, Bing Li Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorXuefei Li, Xuefei Li Department of Lung Cancer and Immunology, Shanghai Pulmonary Hospital, Tongji University, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorCao Zhao, Cao Zhao Department of Lung Cancer and Immunology, Shanghai Pulmonary Hospital, Tongji University, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorChunyan Wu, Chunyan Wu Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of ChinaSearch for more papers by this authorLikun Hou, Likun Hou Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of ChinaSearch for more papers by this authorYayi He, Yayi He Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorGuanghui Gao, Guanghui Gao Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorXiaoxia Chen, Xiaoxia Chen Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorJiawei Ren, Jiawei Ren Department of Respiratory Medicine, Shanghai First Hospital Branch, Shanghai, People's Republic of ChinaSearch for more papers by this authorAiwu Li, Aiwu Li Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorGuotong Xu, Guotong Xu Department of Laboratory Medicine, Tongji University School of Medicine, Shanghai, People's Republic of ChinaSearch for more papers by this authorXiao Zhou, Corresponding Author Xiao Zhou Department of Thoracic Surgery, Shanghhai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of ChinaCorrespondence to: Caicun Zhou, MD, PhD, Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] or Xiao Zhou, MD, Department of Thoracic Surgery, Shanghhai Pulmonary Hospital, Tongji University School of Medicine, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] for more papers by this authorCaicun Zhou, Corresponding Author Caicun Zhou Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaCorrespondence to: Caicun Zhou, MD, PhD, Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] or Xiao Zhou, MD, Department of Thoracic Surgery, Shanghhai Pulmonary Hospital, Tongji University School of Medicine, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] for more papers by this authorGerald Schmid-Bindert, Gerald Schmid-Bindert Department of Surgery, University Medical Center Mannheim, Medical Faculty Mannheim of Heidelberg University, Mannheim, GermanySearch for more papers by this author Shengxiang Ren, Shengxiang Ren Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of China S.R., C.S. and Z.W. contributed equally to this workSearch for more papers by this authorChunxia Su, Chunxia Su Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of China S.R., C.S. and Z.W. contributed equally to this workSearch for more papers by this authorZhaoye Wang, Zhaoye Wang Department of Cardio-Thoracic Surgery, Zhoushan Hospital of Zhejiang Province, Zhoushan, Zhejiang Province, People's Republic of China S.R., C.S. and Z.W. contributed equally to this workSearch for more papers by this authorJiayu Li, Jiayu Li Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorLihong Fan, Lihong Fan Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorBing Li, Bing Li Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorXuefei Li, Xuefei Li Department of Lung Cancer and Immunology, Shanghai Pulmonary Hospital, Tongji University, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorCao Zhao, Cao Zhao Department of Lung Cancer and Immunology, Shanghai Pulmonary Hospital, Tongji University, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorChunyan Wu, Chunyan Wu Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of ChinaSearch for more papers by this authorLikun Hou, Likun Hou Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of ChinaSearch for more papers by this authorYayi He, Yayi He Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorGuanghui Gao, Guanghui Gao Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorXiaoxia Chen, Xiaoxia Chen Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorJiawei Ren, Jiawei Ren Department of Respiratory Medicine, Shanghai First Hospital Branch, Shanghai, People's Republic of ChinaSearch for more papers by this authorAiwu Li, Aiwu Li Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaSearch for more papers by this authorGuotong Xu, Guotong Xu Department of Laboratory Medicine, Tongji University School of Medicine, Shanghai, People's Republic of ChinaSearch for more papers by this authorXiao Zhou, Corresponding Author Xiao Zhou Department of Thoracic Surgery, Shanghhai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, People's Republic of ChinaCorrespondence to: Caicun Zhou, MD, PhD, Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] or Xiao Zhou, MD, Department of Thoracic Surgery, Shanghhai Pulmonary Hospital, Tongji University School of Medicine, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] for more papers by this authorCaicun Zhou, Corresponding Author Caicun Zhou Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, Shanghai, People's Republic of ChinaCorrespondence to: Caicun Zhou, MD, PhD, Department of Medical Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Tongji University Medical School Cancer Institute, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] or Xiao Zhou, MD, Department of Thoracic Surgery, Shanghhai Pulmonary Hospital, Tongji University School of Medicine, No. 507 Zheng Min Road, Shanghai 200433, People's Republic of China, Fax: +86-21-55660346, E-mail: [email protected] for more papers by this authorGerald Schmid-Bindert, Gerald Schmid-Bindert Department of Surgery, University Medical Center Mannheim, Medical Faculty Mannheim of Heidelberg University, Mannheim, GermanySearch for more papers by this author First published: 28 April 2014 https://doi.org/10.1002/ijc.28925Citations: 35 Conflicts of interest: Nothing to report AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Epithelial-to-mesenchymal transition (EMT) has profound impacts on cancer progression and also on drug resistance, including epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Nowadays, there is still no predictive biomarker identified for the use of EGFR-TKIs in non-small cell lung cancer (NSCLC) patients with wild-type EGFR. To clarify the role of EMT phenotype as a predictive marker for EGFR-TKI, we performed a retrospective study in 202 stage IV or recurrent NSCLC patients receiving gefitinib or erlotinib therapy from June 2008 to September 2012 in our institute. Clinical data and EGFR mutational status were collected, while epithelial, epithelial to mesenchymal, not specified or mesenchymal phenotype were classified according to EMT markers such as E-cadherin, fibronectin, N-cadherin and vimentin by immunohistochemistry. Epithelial phenotype was more frequently found in patients with EGFR mutation (p = 0.044). Epithelial phenotype was associated with a significantly higher objective response rate (23.5 vs. 11.1 vs. 0.0 vs. 2.4%, p = 0.011), longer progression-free survival (4.4 vs. 1.9 vs. 1.7 vs. 1.0 months, p < 0.001) and longer overall survival (11.5 vs. 8.9 vs. 4.5 vs. 4.9 months, p < 0.001) compared to epithelial to mesenchymal, not specified and mesenchymal phenotype in the wild-type EGFR subgroup. In the subgroup with EGFR mutation, the trend remained but without a statistically significant difference. In conclusion, epithelial phenotype was more likely expressed in patients with EGFR mutation and was associated with a better outcome in advanced NSCLC patients with wild-type EGFR, which indicates that the EMT phenotype might be a potential marker to guide EGFR-TKI therapy in this population. Abstract What's new? Although a small number of patients with wild-type status of the epidermal growth factor receptor (EGFR) gene benefit from mutation-targeted EGFR tyrosine kinase inhibitor (TKI) therapy, there are no biomarkers capable of identifying them. Here, wild-type EGFR non-small cell lung cancer (NSCLC) patients treated with EGFR TKIs were found to experience better efficacy outcomes compared with other wild-type EGFR phenotypes, based on epithelial-to-mesenchymal transition (EMT) biomarker immunohistochemistry scoring. The data indicate that EMT biomarkers could be useful in the identification of wild-type EGFR NSCLC patients who are most likely to benefit from the inhibitors. Tailored therapy based on biomarker analysis has entered reality of lung cancer treatment. Patients with EGFR-activated mutation or ALK/ROS1 fusion gain significant benefit from targeted therapy with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) or ALK inhibitors. However, only a minority of patients express these markers, with EGFR mutations detected in ∼30–40% in East Asian population1-3 and EML4-ALK fusions4 in ∼4%. For the majority of patients with wild-type EGFR, a subgroup appears to benefit from EGFR inhibitor treatment,5-7 although there are currently no validated markers for identifying these patients.8 Thus, validated predictive markers are needed to accurately predict likelihood of benefit to EGFR-targeted therapy in the wild-type EGFR subgroup. The epithelial-to-mesenchymal transition (EMT) is a fundamental biological process during which epithelial cells change to a mesenchymal phenotype; it has profound impacts on cancer progression. EMT is characterized by downregulation of epithelial markers, particularly E-cadherin and upregulation of mesenchymal markers, such as N-cadherin, vimentin and fibronectin.9-12 In the EGFR-TKI-sensitive EGFR mutant lung cancer cell line, EMT plays an important role in the primary resistance of erlotinib.13, 14 It was also reported that mesenchymal markers were more frequently expressed in rebiopsy samples of patients with acquired resistance to EGFR-TKI.15, 16 Moreover, in the limited clinical data,17-19 patients with epithelial markers showed a trend to have a higher response rate (RR) or longer progression-free survival (PFS) with EGFR-TKI therapy. Importantly, targeting EMT may reverse or prevent acquisition of therapeutic resistance to EGFR inhibitors, as illustrated by one study in which restoration of an epithelial phenotype in NSCLC cell lines restored sensitivity to gefitinib.20 To better clarify and validate the predictive role of EMT phenotype in the sensitivity of non-small cell lung cancer (NSCLC) to EGFR-TKIs, we investigated the association of EMT phenotype at baseline with the efficacy of EGFR-TKIs in 202 Chinese advanced NSCLC patients. Material and Methods Patient selection All patients had pathologically confirmed advanced or recurrent stage IV NSCLC, an Eastern Cooperative Oncology Group performance status of 0–3, sufficient tumor sample for test of EGFR mutation (based on PCR) and EMT biomarkers [measured by immunohistochemistry (IHC)]. All patients had measurable disease and received EGFR-TKI treatment, either gefitinib or erlotinib, for at least 4 weeks. All patients received erlotinib or gefitinib at a fixed oral dose of 150 or 250 mg daily and concomitant chemotherapeutic agents were not used. Erlotinib or getitinib was administered until disease progression or intolerable toxicity. Dose reduction was permitted according to related guidelines. A total of 202 patients who met the above criteria were identified in the Shanghai Pulmonary Hospital, Tongji University from June 2008 to September 2012. The laboratory data were obtained and recorded independently and blinded from clinical data until analyses by a biostatistician. The study was approved by the Institutional Ethic Committee of Shanghai Pulmonary Hospital. All the patients signed an informed consent for the use of their tumor tissues. Evaluation of treatment response Objective tumor response was determined using the response evaluation criteria in solid tumors (RECIST Version 1.1). The patients had computed tomography scan covering target lesions 4–6 weeks later after the initiating of EGFR-TKI treatment and then every 8 weeks or when the symptom indicated. Brain or bone metastases were evaluated every 6 months by magnetic resonance imaging or bone scintigraphy. According to the Response Evaluation Criteria in Solid Tumors guideline, response to therapy was categorized into four groups: complete response, partial response, stable disease and progression disease. PFS was calculated from the date of the beginning of EGFR-TKI to the date of tumor progression or death. Overall survival (OS) was calculated as the time from the beginning of therapy to death or last follow-up. IHC for E-cadherin, fibronectin, N-cadherin and vimentin IHC was performed on formalin-fixed, paraffin-embedded samples. E-cadherin (E), fibronectin (FN), N-cadherin (N) and vimentin (V) score immunostainings were assessed on whole-tissue sections, and FN, E, N and V immunoreactivities were evaluated in the neoplastic epithelial and mesenchymal component, respectively (epitomics company). Primary antibodies used were rabbit polyclonal to FN (1:250), E (1:500), N (1:500) and V (1:250). Briefly, after deparaffinization, sections were heated in a microwave oven (20 min at 90°C) in citrate buffer for antigen retrieval. Then, they were washed in phosphate-buffered saline for 10 min and incubated overnight at 4°C in the presence of FN, E, N and V. Bound antibodies were visualized by using the SP method according to the supplier's recommendations (SP Kit; kangwei tech com, China). Diaminobenzidine was used as chromogen. All specimens were evaluated independently by two observers to evaluate staining intensity of analyzed cells (on a scale of 0–3) and the fraction of cells staining at each intensity, and interobserver agreement was reached in all cases. We adopted a scoring system21 to calculate the score of intensity times the percentage of the stained tumor cells. For sections with analyzable tumor cells, staining intensity was scored in four categories: no staining (0), weak staining (1+), intermediate staining (2+, between 1+ and 3+) and strong staining (3+). The percentages of tumor cells showing the different staining intensities were assessed visually and then recorded by trained pathologists. We used the prospectively collected IHC data to generate FN, E, N and V IHC scores on a continuous scale of 0–300. By integration of the data relating to the intensity and frequency of staining, the IHC score was calculated with the formula: 1 × (percentage of cells staining weakly [1+]) + 2 × (percentage of cells staining moderately [2+]) + 3 × (percentage of cells staining strongly [3+]). The EMT phenotype was based on the H score of epithelial phenotype biomarker E-cadherin and mesenchymal phenotype biomarkers such as fibronectin, N-cadherin and vimentin. As previous studies17-19 found that mesenchymal markers were associated with the resistance of EGFR-TKI, our study adopted three mesenchymal markers to identify mesenchymal phenotype. H score of mesenchymal biomarker was defined as the highest H score of these three markers, fibronectin, N-cadherin or vimentin. Our data for the cutoff point analysis showed that H score of 100 was the best value to predict both the PFS and OS for E-cadherin. As for mesenchymal phenotype biomarkers, H score of 100 was the best value to predict the PFS and H score of 80 was best for OS (Supporting Information Tables 1 and 2). We choose H score of 100 as a cutoff point both for E-cadherin and for mesenchymal phenotype biomarkers. So, in this study, epithelial phenotype was defined as E-cadherin score no less than 100 and all the mesenchymal phenotype biomarkers score less than 100; mesenchymal phenotype was identified when one of the mesenchymal phenotype biomarkers scores no less than 100 together with E-cadherin score less than 100; epithelial-to-mesenchymal phenotype was defined as both E-cadherin and mesenchymal phenotype biomarker scores were more than 100, while the remains were not specified. The representative IHC figures are shown in Figure 1. Figure 1Open in figure viewerPowerPoint Examples of the four classifications of epithelial marker (E-cadherin) and mesenchyme marker (fibronectin, vimentin and N-cadherin) status in epithelial NSCLC tumor cells based on the criteria described in the results. (a) Epithelial phenotype: E-cadherin+/fibronectin–; (b) mesenchymal phenotype: E-cadherin–/vimentin+; (c) epithelial-to-mesenchymal phenotype: E-cadherin+/N-cadherin+. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] EGFR mutational analyses Genomic DNA was extracted from lung tumors using standard protocols (QiAamp DNA Mini Kit; Qiagen, Hilden, Germany). Cycle sequencing of the purified polymerase chain reaction (PCR) products was carried out with PCR primers using the commercially available ADx Mutation Detection Kits (Amoy Diagnostics Company, Xiamen, China), which is based on the ARMS technology. The assay can identify the 29 most common types of EGFR mutations currently described in lung cancers. All experiments were done by following the manufacturer's protocols. The Ct values that we used to determine whether a sample was positive or negative were based on extensive validation. Briefly, 10 ng genomic DNA was added to 45 μL PCR master mix containing PCR buffer, DNA polymerase, PCR primers and fluorescent Taqman probe specific for each individual EGFR mutation. After 47 amplification cycles, the fluorescent signal was collected from FAM and HEX channels. The details were described in our previous articles.22, 23 Statistical analysis A χ2 test or Fisher exact test was used to analyze the association between EMT phenotype and clinicopathologic variables and RR. For the survival analysis, patients were censored at the last date at which they were known to be alive. All time-to-event outcomes were estimated using the Kaplan–Meier method and compared across groups with the log-rank test or the Cox proportional hazards model. All statistical tests were two-sided, and statistical significance was defined as p < 0.05. We used the SPSS statistical software package (version 13.0; SPSS, Chicago, IL) to perform the statistical analysis. Results Patient characteristics The median age was 59 years (range, 30–80 years). The proportions of males, ever smokers and squamous carcinomas were 54.9, 40.6 and 19.3%, respectively. Patients had received a median of two prior chemotherapy regimens (range, 0–3 regimens) for advanced disease before treatment with EGFR-TKIs. Of the 196 patients available for EGFR mutation status, 97 patients had activated EGFR mutation; 29.7% (n = 60) of the patients received gefitinib treatment and the remaining 70.3% (n = 142) received erlotinib (Table 1). Table 1. Correlations between baseline characteristics and EMT phenotype status in the 202 advanced NSCLC patients EMT phenotype Characteristics Number (%), N = 202 Epithelial (%), n = 70 Mesenchymal (%), n = 66 Epithelial-to-mesenchymal (%), n = 31 Not specified (%), n = 35 p Age (years) >65 54(26.7) 23(11.4) 15(7.4) 5(2.5) 11(5.4) 0.256 ≤65 148(73.3) 47(23.3) 51(25.2) 26(12.9) 24(11.9) Gender Male 111(54.9) 43(21.3) 36(17.8) 15(7.4) 17(8.0) 0.511 Female 91(45.1) 27(13.4) 30(14.9) 16(7.9) 18(8.9) Smoking history Never smoker 120(59.4) 40(19.8) 40(19.8) 19(9.4) 21(10.4) 0.971 Smoker 82(40.6) 30(14.9) 26(12.9) 12(5.9) 14(6.9) Pathology Squamous 39(19.3) 16(7.9) 10(5.0) 6(3.0) 7(3.5) 0.683aa Squ-adno, NSCLC NOS and large cell subgroup were regarded as a combined subgroup when performing the statistical analysis for the limited number in these three subgroups. Adenocarcinoma 134(66.3) 48(23.8) 43(21.3) 21(10.4) 22(10.9) Adeno-squa 17(8.4) 3(1.5) 8(4.0) 3(1.5) 3(1.5) NSCLC NOS 10(5.0) 3(1.5) 4(2.0) 0(0.0) 3(1.5) Large cell 2(1.0) 0(0.0) 1(0.5) 1(0.5) 0(0.0) ECOG PS 0–1 172(85.1) 62(30.7) 52(25.7) 26(12.9) 32(15.8) 0.273 2–3 30(14.9) 8(3.9) 14(6.9) 5(2.5) 3(1.5) No. of previous chemotherapy 0 18(8.9) 10(4.9) 3(1.5) 2(1.0) 3(1.5) 0.233 1 or more 184(91.1) 60(29.7) 63(31.2) 29(14.4) 32(15.8) EGFR-TKI Gefitinib 60(29.7) 17(8.4) 19(9.4) 9(4.5) 15(7.4) 0.271 Erlotinib 142(70.3) 53(26.2) 47(23.3) 22(10.9) 20(9.9) Site of biopsy Primary tumor 169(83.7) 56(27.7) 57(28.2) 29(14.4) 27(13.4) 0.227 Metastatic sizes 33(16.3) 14(6.9) 9(4.5) 2(1.0) 8(4.0) Tissue specimen Resection 49(24.3) 16(7.9) 16(7.9) 9(4.5) 8(4.0) 0.920 Biopsy 153(75.7) 54(26.7) 50(24.8) 22(10.9) 27(13.4) EGFR mutation Activated 97(48.0) 36(17.8) 25(12.4) 20(10.0) 16(7.9) 0.044bb EGFR unknown patients were not included in the statistical analysis for the limited number. Wild type 99(49.0) 34(16.8) 41(20.3) 9(4.5) 15(7.4) Unknown 6(3.0) 0(0.0) 1(0.5) 4(2.0) 1(0.5) a Squ-adno, NSCLC NOS and large cell subgroup were regarded as a combined subgroup when performing the statistical analysis for the limited number in these three subgroups. b EGFR unknown patients were not included in the statistical analysis for the limited number. Abbreviations: Adeno-squa: adeno-squamous carcinoma; NSCLC NOS: non-small-cell lung cancer (not otherwise specified). EMT phenotypes and their relations with baseline characteristics A total of 202 samples were used to classify the EMT phenotype according to our defined criteria. Among them, 70 have epithelial phenotype, 66 have mesenchymal, 31 have epithelial to mesenchymal, while 35 have not specified phenotype. Mesenchymal phenotypes were more likely found in patients with wild-type EGFR than in mutated EGFR (p = 0.044). However, there were no significant associations found between the EMT phenotypes and the other characteristics such as gender, age, smoking status and histological type (Table 1). Tumor response Of the 201 patients available for response evaluation, 76 patients had partial response, 54 had stable disease and 71 had progressive disease as their best tumor response. Therefore, the objective RR (ORR) was 37.8% and the disease control rate (DCR) was 64.7%. EGFR mutation status and EMT phenotype were the main factors identified as predicting the response to EGFR-TKI treatment. The ORR was 64.1% in the patients with activated EGFR mutation, which is significantly higher than 10.1% in patients with wild-type EGFR (p < 0.001). Patients with epithelial phenotype respectively showed a significantly higher RR than those with mesenchymal phenotype, epithelial-to-mesenchymal phenotype and not specified phenotype (52.9 vs. 23.1 vs. 41.9 vs. 31.4%, respectively; p = 0.004). When the analysis was limited to the 99 patients with wild-type EGFR, the difference in RR among the four groups remained unchanged (23.5 vs. 2.4 vs. 11.1 vs. 0.0%, respectively; p = 0.011) and EMT phenotype was the only predictive factor of the response to EGFR-TKI treatment (Fig. 2). However, no statistically significant difference was observed when patients with activated EGFR mutation were analyzed (80.6 vs. 58.3 vs. 54.5 vs. 55.0%, respectively; p = 0.114). Survival outcomes Survival analyses were performed in all the patients who received EGFR-TKIs therapy with a median follow-up time of 13.1 months [95% confidence interval (CI), 13.47–16.64]. Among them, 24 patients (11.9%) were still on EGFR-TKIs and 45 (22.3%) were still alive at the last follow-up data of February 15, 2013. The median PFS and OS for the evaluable patients in this study were 5.6 months (95% CI, 4.31–6.89 months) and 12.6 months (95% CI, 9.27–15.93 months), respectively. The subgroup analysis of PFS showed that EGFR mutation status, EMT phenotype and ECOG PS were the main predictors of PFS with EGFR-TKI in the whole population (Table 2). In the univariate analysis, female patients, never smokers, ECO
Publication Year: 2014
Publication Date: 2014-04-28
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 45
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot