Indeed, a European workshop on MAPK inhibitor EGFR mutation testing in NSCLC recommended testing at diagnosis, or at relapse, whenever possible, although no gold standard testing method

was chosen [2]. Despite their importance in clinical practice, there is often too little selleckchem tissue available to examine EGFR status as most are obtained by small needle biopsy or extracted from body fluids rather than via a more aggressive surgical approach. Many investigators have tried to solve this problem, leading to the development of more sensitive techniques to detect EGFR mutations, such as the scorpion-amplified refractory mutation system (SARMS) and the peptide nucleic acid (PNA)-mediated polymerase chain reaction (PCR) clamping method [3–18]. In addition, it is suggested that the plasma of cancer patients contains circulating free DNA (cfDNA) originating from necrotic tumor cells sloughed from the tumor mass or from circulating tumor cells [19–21]. Attempts to detect EGFR mutations in cfDNA using these sensitive techniques are currently in

progress. If proven feasible and reliable, the cfDNA test may have broad clinical applications because it is non-invasive, convenient and can be performed repeatedly. In addition, the test could help diagnose lung cancer in cases when an adequate tissue sample is difficult to obtain. Over the past several years, many reports have shown promising results and have supported the feasibility of the test [22–33]. However, the optimal methodology for mutation detection from cfDNA and the possibility for the replacement of tumor tissue to blood sample still need check details to be confirmed. In the present study, we examined the status of EGFR mutations in cfDNA isolated from plasma samples by a PNA-mediated PCR clamping method (PNA test) to determine the utility of plasma as a surrogate tissue for EGFR mutation analysis. Methods Patients The prospective multicenter study was conducted to analyze

EGFR mutations in plasma samples. Sixty patients with advanced NSCLC were recruited from 11 hospitals of the Korean Molecular Lung Cancer Group (KMLCG) between May 2010 and March 2011. All participants had histological or cytological confirmation of advanced NSCLC and showed a partial response to gefitinib as a second-line therapy without regard to the mafosfamide EGFR mutation status. Written informed consents for the use of their blood were obtained from all patients. The study protocol was approved by the Ethical Review Committee of 11 institutions (Korea Cancer Center Hospital, Korea University Guro Hospital, Daegu Catholic University Medical Center, Pusan National University Hospital, Inje University Busan Paik Hospital, Asan Medical Center, Wonkwang University Hospital, Chonnam National University Hwasun Hospital, Chonbuk National University Hospital, Chungnam National University Hospital, Hallym University Medical Center, Konkuk University Medical Center).