Original Article
Clinicopathological features of Chinese lung cancer patients with epidermal growth factor receptor mutation Hui Ning1,2*, Ming Liu1*, Lina Wang3*, Yang Yang1, Nan Song1, Xiaoxiong Xu1, Jin Ju4, Gening Jiang1 1
Department of Thoracic Surgery, Shanghai Pulmonary Hospital affiliated Tongji University, Shanghai 200433, China; 2Department of Thoracic
Surgery, Tianjin Haihe Hospital, Tianjin 300350, China; 3Department of Endodontics & Periodontics, College of Stomatology, Dalian Medical University, Dalian 116044, China; 4Department of Thoracic surgery, Weihai Municipal Hospital, Weihai 264200, China Contributions: (I) Conception and design: H Ning, M Liu, J Ju, G Jiang; (II) Administrative support: J Ju, G Jiang; (III) Provision of study materials or patients: H Ning, M Liu, L Wang, Y Yang, N Song, X Xu; (IV) Collection and assembly of data: H Ning, M Liu, L Wang; (V) Data analysis and interpretation: H Ning, M Liu, L Wang; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. *These authors contributed equally to this work. Correspondence to: Gening Jiang. Department of Thoracic Surgery, Shanghai Pulmonary Hospital affiliated Tongji University, 507 Zhengmin Road, Shanghai 200433, China. Email: [email protected]; Jin Ju. Department of Thoracic surgery, Weihai Municipal Hospital, 70 Heping Road, Weihai 264200, China. Email:[email protected].
Background: Epidermal growth factor receptor (EGFR) gene was the major causative gene of lung cancer and also the specific treatment target. It is necessary to analyze the genotype and phenotype characters of patients. Methods: We investigated 1,034 lung cancer patients in this study. The collected clinicopathological parameters included gender, age at diagnosis, smoking status, pathological TNM stage, tumor morphology and location, visceral pleural invasion as well as histological type. Results: Almost 50% participants had EGFR mutations. L858R in exon 21 was the most common type. Concomitant mutation, 19 del and L858R, were detected in 20 patients. Compared to patients with exon 19 del or L858R mutations solely, they were inclined to have small size adenocarcinomas which occurred in bilateral and invaded the visceral pleura. The tyrosine kinases inhibitors (TKIs)-resistant mutation, insertions in exon 20, was detected in 11 patients. Conclusions: The summarized clinicopathological features will help clinicians to implement the feasible treatment plan. Keywords: Lung cancer; epidermal growth factor receptor (EGFR) gene; mutation; phenotype; genotype Submitted Jan 14, 2017. Accepted for publication Feb 16, 2017. doi: 10.21037/jtd.2017.03.13 View this article at: http://dx.doi.org/10.21037/jtd.2017.03.13
Introduction Epidermal growth factor receptor (EGFR) gene locates at chromosome 7 and has 28 exons. Mutations in EGFR gene are associated with different kinds of tumor including lung cancer. The EGFR protein which is a member of the protein kinase superfamily is a transmembrane glycoprotein. It is a cell surface protein receptor that binds to epidermal growth factor (EGF). The ligand and receptor binding induces dimerization and tyrosine autophosphorylation of EGFR (1). EGFR regulates cellular signaling pathways, © Journal of Thoracic Disease. All rights reserved.
promotes tumor cell differentiation, proliferation, maintenance, invasion and metastasis (2,3). EGFR contains extracellular domain, transmembrane domain and intracellular domain which had tyrosine kinases (TK) domain and autophosphorylation domain. The TK domain which is the functional core of the protein consists of a smaller N-terminal and a larger C-terminal lobe (4). It stretches from exon 18 to exon 24. In lung cancer, the EGFR mutation sites center on exons 18–21 (5). Increasing catalytic activity of TK domain caused by EGFR mutation results in greatly over-expressed EGFR (3,6). Meanwhile jtd.amegroups.com
J Thorac Dis 2017;9(3):796-801
Journal of Thoracic Disease, Vol 9, No 3 March 2017
it also provides a specific therapeutic strategy. Tyrosine kinases inhibitors (TKIs) targeted to TK domain have been approved for the treatment of NSCLC (7,8). Several studies suggest that the application of TKIs improved response rates and progression-free survival of lung cancer patients with EGFR mutations (9,10). The sensitivity of lung cancer patients to TKIs is associated with the mutation type. Patients with deletions in exon 19 and L858R in exon 21 responded positively. In this respect, the detection of EGFR mutations is the premise to the treatment of lung cancer patients. But in clinic the quantity of biopsy samples were not enough to fulfill the entire mutation screening. The phenotypic traits summary could help clinicians make judgement beforehand. Furthermore, most previous studies on EGFR mutations mainly focused on lung adenocarcinoma, few studies have evaluated the EGFR mutations in other lung cancer type in large scale. In the current study, we analyzed the EGFR mutation spectrum in Chinese lung cancer patients and summarized the clinicopathological characters of patients with EGFR gene mutations. Methods Ethical approval This study was approved by the Institutional Review Board (IRB) of Shanghai Pulmonary Hospital affiliated Tongji University (No. 2014-016). Written informed consents were obtained from all participants. The methods were carried out in accordance with the approved guidelines. Patients and specimen collection The consecutive primary lung cancer patients who were admitted into the Shanghai Pulmonary Hospital affiliated Tongji University from Jun. 2014 to Oct. 2015 were recruited. No choose or correct was performed on patients’ collection. None of these patients received any anticancer therapies prior to surgery. The recurrent or metastatic patients were excluded. The samples which contained more than 50% tumor cells were qualified. Fresh primary tumor tissues were collected during the surgery. Clinical and pathological data which was gathered for analysis included gender, age at diagnosis, pathological TNM stage, histological type, tumor morphology and location, visceral pleural invasion as well as smoking status. Tumors were staged pathologically according to the Union
© Journal of Thoracic Disease. All rights reserved.
797
International Contre le Cancer (UICC-7) staging system for lung cancer (11). Candidate gene mutation analysis According to the manufacturer’s instruction, genomic DNA and total RNA were extracted from fresh tumor tissues using QIAamp DNA Tissue Kit and RNeasy Kit (Qiagen, Germany) respectively. EGFR mutations were detected by Amoy Diagnostics kits (Xiamen, China) which were based on amplification refractory mutation system (ARMS) realtime PCR. Twenty-nine mutations in exons 18–21 of EGFR gene were detected including T790M, L858R, L861Q, S768I, G719S, G719A, G719C, three types of insertions in exon 20, and 19 kinds of deletions in exon 19. Statistical analysis χ 2 test was used to analyze the association between the EGFR mutation type and other clinicopathology data. All data were analyzed by the SPSS package for Windows (Version 18.0, Chicago, IL). P value
Clinicopathological features of Chinese lung cancer patients with epidermal growth factor receptor mutation Hui Ning1,2*, Ming Liu1*, Lina Wang3*, Yang Yang1, Nan Song1, Xiaoxiong Xu1, Jin Ju4, Gening Jiang1 1
Department of Thoracic Surgery, Shanghai Pulmonary Hospital affiliated Tongji University, Shanghai 200433, China; 2Department of Thoracic
Surgery, Tianjin Haihe Hospital, Tianjin 300350, China; 3Department of Endodontics & Periodontics, College of Stomatology, Dalian Medical University, Dalian 116044, China; 4Department of Thoracic surgery, Weihai Municipal Hospital, Weihai 264200, China Contributions: (I) Conception and design: H Ning, M Liu, J Ju, G Jiang; (II) Administrative support: J Ju, G Jiang; (III) Provision of study materials or patients: H Ning, M Liu, L Wang, Y Yang, N Song, X Xu; (IV) Collection and assembly of data: H Ning, M Liu, L Wang; (V) Data analysis and interpretation: H Ning, M Liu, L Wang; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors. *These authors contributed equally to this work. Correspondence to: Gening Jiang. Department of Thoracic Surgery, Shanghai Pulmonary Hospital affiliated Tongji University, 507 Zhengmin Road, Shanghai 200433, China. Email: [email protected]; Jin Ju. Department of Thoracic surgery, Weihai Municipal Hospital, 70 Heping Road, Weihai 264200, China. Email:[email protected].
Background: Epidermal growth factor receptor (EGFR) gene was the major causative gene of lung cancer and also the specific treatment target. It is necessary to analyze the genotype and phenotype characters of patients. Methods: We investigated 1,034 lung cancer patients in this study. The collected clinicopathological parameters included gender, age at diagnosis, smoking status, pathological TNM stage, tumor morphology and location, visceral pleural invasion as well as histological type. Results: Almost 50% participants had EGFR mutations. L858R in exon 21 was the most common type. Concomitant mutation, 19 del and L858R, were detected in 20 patients. Compared to patients with exon 19 del or L858R mutations solely, they were inclined to have small size adenocarcinomas which occurred in bilateral and invaded the visceral pleura. The tyrosine kinases inhibitors (TKIs)-resistant mutation, insertions in exon 20, was detected in 11 patients. Conclusions: The summarized clinicopathological features will help clinicians to implement the feasible treatment plan. Keywords: Lung cancer; epidermal growth factor receptor (EGFR) gene; mutation; phenotype; genotype Submitted Jan 14, 2017. Accepted for publication Feb 16, 2017. doi: 10.21037/jtd.2017.03.13 View this article at: http://dx.doi.org/10.21037/jtd.2017.03.13
Introduction Epidermal growth factor receptor (EGFR) gene locates at chromosome 7 and has 28 exons. Mutations in EGFR gene are associated with different kinds of tumor including lung cancer. The EGFR protein which is a member of the protein kinase superfamily is a transmembrane glycoprotein. It is a cell surface protein receptor that binds to epidermal growth factor (EGF). The ligand and receptor binding induces dimerization and tyrosine autophosphorylation of EGFR (1). EGFR regulates cellular signaling pathways, © Journal of Thoracic Disease. All rights reserved.
promotes tumor cell differentiation, proliferation, maintenance, invasion and metastasis (2,3). EGFR contains extracellular domain, transmembrane domain and intracellular domain which had tyrosine kinases (TK) domain and autophosphorylation domain. The TK domain which is the functional core of the protein consists of a smaller N-terminal and a larger C-terminal lobe (4). It stretches from exon 18 to exon 24. In lung cancer, the EGFR mutation sites center on exons 18–21 (5). Increasing catalytic activity of TK domain caused by EGFR mutation results in greatly over-expressed EGFR (3,6). Meanwhile jtd.amegroups.com
J Thorac Dis 2017;9(3):796-801
Journal of Thoracic Disease, Vol 9, No 3 March 2017
it also provides a specific therapeutic strategy. Tyrosine kinases inhibitors (TKIs) targeted to TK domain have been approved for the treatment of NSCLC (7,8). Several studies suggest that the application of TKIs improved response rates and progression-free survival of lung cancer patients with EGFR mutations (9,10). The sensitivity of lung cancer patients to TKIs is associated with the mutation type. Patients with deletions in exon 19 and L858R in exon 21 responded positively. In this respect, the detection of EGFR mutations is the premise to the treatment of lung cancer patients. But in clinic the quantity of biopsy samples were not enough to fulfill the entire mutation screening. The phenotypic traits summary could help clinicians make judgement beforehand. Furthermore, most previous studies on EGFR mutations mainly focused on lung adenocarcinoma, few studies have evaluated the EGFR mutations in other lung cancer type in large scale. In the current study, we analyzed the EGFR mutation spectrum in Chinese lung cancer patients and summarized the clinicopathological characters of patients with EGFR gene mutations. Methods Ethical approval This study was approved by the Institutional Review Board (IRB) of Shanghai Pulmonary Hospital affiliated Tongji University (No. 2014-016). Written informed consents were obtained from all participants. The methods were carried out in accordance with the approved guidelines. Patients and specimen collection The consecutive primary lung cancer patients who were admitted into the Shanghai Pulmonary Hospital affiliated Tongji University from Jun. 2014 to Oct. 2015 were recruited. No choose or correct was performed on patients’ collection. None of these patients received any anticancer therapies prior to surgery. The recurrent or metastatic patients were excluded. The samples which contained more than 50% tumor cells were qualified. Fresh primary tumor tissues were collected during the surgery. Clinical and pathological data which was gathered for analysis included gender, age at diagnosis, pathological TNM stage, histological type, tumor morphology and location, visceral pleural invasion as well as smoking status. Tumors were staged pathologically according to the Union
© Journal of Thoracic Disease. All rights reserved.
797
International Contre le Cancer (UICC-7) staging system for lung cancer (11). Candidate gene mutation analysis According to the manufacturer’s instruction, genomic DNA and total RNA were extracted from fresh tumor tissues using QIAamp DNA Tissue Kit and RNeasy Kit (Qiagen, Germany) respectively. EGFR mutations were detected by Amoy Diagnostics kits (Xiamen, China) which were based on amplification refractory mutation system (ARMS) realtime PCR. Twenty-nine mutations in exons 18–21 of EGFR gene were detected including T790M, L858R, L861Q, S768I, G719S, G719A, G719C, three types of insertions in exon 20, and 19 kinds of deletions in exon 19. Statistical analysis χ 2 test was used to analyze the association between the EGFR mutation type and other clinicopathology data. All data were analyzed by the SPSS package for Windows (Version 18.0, Chicago, IL). P value
