A comparison of ARMS and direct sequencing for EGFRmutation analysis and Tyrosine Kinase Inhibitors treatment prediction in body fluid samples of Non-Small-Cell Lung Cancer patients

Liu Yi, Liu Bing, Li Xiao-Yan, Li Jian-Jie, Qin Hai-Feng, Tang Chuan-Hao, Guo Wan-Feng, Hu Hai-Xu, Li Sha, Chen Cui-Jing, Gao Hong-Jun, Liu Xiao-Qing

Description

Epidermal growth factor receptor ( EGFR ) mutation is strongly associated with the therapeutic effect of tyrosine kinase inhibitors (TKIs) in patients with non-small-cell lung cancer (NSCLC). Nevertheless, tumor tissue that needed for mutation analysis is frequently unavailable. Body fluid was considered to be a feasible substitute for the analysis, but arising problems in clinical practice such as relatively lower mutation rate and poor clinical correlation are not yet fully resolved. Method In this study, 50 patients (32 pleural fluids and 18 plasmas) with TKIs therapy experience and with direct sequencing results were selected from 220 patients for further analysis. The EGFR mutation status was re-evaluated by Amplification Refractory Mutation System (ARMS), and the clinical outcomes of TKIs were analyzed retrospectively. Results As compared with direct sequencing, 16 positive and 23 negative patients were confirmed by ARMS, and the other 11 former negative patients (6 pleural fluids and 5 plasmas) were redefined as positive, with a fairly well clinical outcome (7 PR, 3 SD, and 1 PD). The objective response rate (ORR) of positive patients was significant, 81.3% (direct sequencing) and 72.7% (ARMS) for pleural fluids, and 80% (ARMS) for plasma. Notably, even reclassified by ARMS, the ORR for negative patients was still relatively high, 60% for pleural fluids and 46.2% for plasma. Conclusions When using body fluids for EGFR mutation analysis, positive result is consistently a good indicator for TKIs therapy, and the predictive effect was no less than that of tumor tissue, no matter what method was employed. However, even reclassified by ARMS, the correlation between negative results and clinical outcome of TKIs was still unsatisfied. The results indicated that false negative mutation still existed, which may be settled by using method with sensitivity to single DNA molecule or by optimizing the extraction procedure with RNA or CTC to ensure adequate amount of tumor-derived nucleic acid for the test.

Sujets

• Body Fluids
• Arms
• Non-small cell lung carcinoma

Informations

• Publié par: biomed
• Publié le: 01 janvier 2011
• Nombre de lectures: 14
• Langue: English

Extrait

Liuet al.Journal of Experimental & Clinical Cancer Research2011,30:111 http://www.jeccr.com/content/30/1/111

R E S E A R C H

Open Access

A comparison of ARMS and direct sequencing for EGFRmutation analysis and Tyrosine Kinase Inhibitors treatment prediction in body fluid samples of NonSmallCell Lung Cancer patients *† † Yi Liu , Bing Liu , XiaoYan Li, JianJie Li, HaiFeng Qin, ChuanHao Tang, WanFeng Guo, HaiXu Hu, Sha Li, * CuiJing Chen, Bing Liu, HongJun Gao and XiaoQing Liu

Abstract Background:Epidermal growth factor receptor (EGFR) mutation is strongly associated with the therapeutic effect of tyrosine kinase inhibitors (TKIs) in patients with nonsmallcell lung cancer (NSCLC). Nevertheless, tumor tissue that needed for mutation analysis is frequently unavailable. Body fluid was considered to be a feasible substitute for the analysis, but arising problems in clinical practice such as relatively lower mutation rate and poor clinical correlation are not yet fully resolved. Method:In this study, 50 patients (32 pleural fluids and 18 plasmas) with TKIs therapy experience and with direct sequencing results were selected from 220 patients for further analysis. TheEGFRmutation status was reevaluated by Amplification Refractory Mutation System (ARMS), and the clinical outcomes of TKIs were analyzed retrospectively. Results:As compared with direct sequencing, 16 positive and 23 negative patients were confirmed by ARMS, and the other 11 former negative patients (6 pleural fluids and 5 plasmas) were redefined as positive, with a fairly well clinical outcome (7 PR, 3 SD, and 1 PD). The objective response rate (ORR) of positive patients was significant, 81.3% (direct sequencing) and 72.7% (ARMS) for pleural fluids, and 80% (ARMS) for plasma. Notably, even reclassified by ARMS, the ORR for negative patients was still relatively high, 60% for pleural fluids and 46.2% for plasma. Conclusions:When using body fluids forEGFRmutation analysis, positive result is consistently a good indicator for TKIs therapy, and the predictive effect was no less than that of tumor tissue, no matter what method was employed. However, even reclassified by ARMS, the correlation between negative results and clinical outcome of TKIs was still unsatisfied. The results indicated that false negative mutation still existed, which may be settled by using method with sensitivity to single DNA molecule or by optimizing the extraction procedure with RNA or CTC to ensure adequate amount of tumorderived nucleic acid for the test. Keywords:Body Fluids,EGFRMutation, Direct Sequencing, ARMS, TKIs, NSCLC

Introduction Lung cancer causes over 1 million deaths per year worldwide, making it the major source of cancerrelated deaths [1].There has been progress made in therapeutic strategies for lung cancer, but the 5year survival rate is

* Correspondence: [e-mail]; [e-mail] †Contributed equally Cancer Center of People’s Liberation Army of China, Affiliated Hospital of Academy of Military Medical Sciences, Beijing 100071, China

still only about 15% [2]. Treatment strategies for lung cancer have changed dramatically with the recent dis covery that a proportion of nonsmall cell lung cancers (NSCLC) harbor activating mutations in the epidermal growth factor receptor (EGFR) gene [3,4], and that the mutatedEGFRproteins are particularly susceptible to inhibition by smallmolecule tyrosine kinase inhibitors (TKIs) Gefitinib and Erlotinib [59].

© 2011 Liu et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.