5 63.0 0.76    Range 51-76 38-84 Gender          Female 7 (70.0%) 32 (64.0%) 1.00    Male 3 (30.0%) 18 (36.0%) Smoking history          Nonsmoker 8 (80.0%) 35 (70.0%) 0.67    Ex-smoker 1 (10.0%)

10 (20.0%)    Current smoker 1 (10.0%) 5 (10.0%) WHO Performance status          Normal activity 4 (40.0%) 19 (38.0%) 0.94    Restricted activity 4 (40.0%) 23 (46.0%)    In bed < 50% of the time 2 (20.0%) 7 (14.0%)    In bed > 50% of the time – 1 (2.0%) Tumor histology          ADC 9 (90.0%) 44 (88.0%) 0.83    SQC GDC-0973 mouse – 3 (6.0%)    LCC – 1 (2.0%)    NSCLC NOS 1 (10.0%) 1 (2.0%)    Others – 1 (2.0%) Stage          IIIA – 3 (6.0%) 0.64    IIIB 1 (10.0%) 3 (6.0%)    IV 9 (90.0%) 44 (88.0%) Central labotory          on-site 5 (50.0%) 16 (32.0%) 0.30    off-site 5 (50.0%) 34 (68.0%)   Abbreviations: ADC adenocarcinoma, SQC squamous cell carcinoma LCC large cell carcinoma, NSCLC NOS non-small cell lung cancer not otherwise specified. Discussion Direct sequencing of amplified DNA products using Sanger’s method is the most popular test

for detecting EGFR mutations. However, this method is limited by low sensitivity (meaning that the mutant DNA must represent greater than 25% of the total DNA), and requires multiple steps to be performed over several days [15]. Furthermore, in patients with advanced NSCLC, tumor tissue is not always available for EGFR Sepantronium research buy mutation testing either because only small amounts of tissue are collected or because the tissues collected Ilomastat have very low, or non-existent, tumor content . For these reasons, new techniques are needed for more sensitive and rapid detection. Several new techniques, including SARMS, Taqman PCR, and denaturing high-performance liquid chromatography (dHPLC) have been introduced, although Tolmetin none have been adopted as a standard method for detecting EGFR mutations [4, 5, 9–11, 13, 14, 16, 22–24, 26–28],[30–33]. Peptide nucleic acid (PNA) is an artificial polymer with the properties of both nucleic acids and proteins. PNA can bind tightly

to complementary sequences in DNA because of a lack of electrostatic repulsion. Therefore, when a PNA oligomer, designed to detect an EGFR mutation and to bind to the antisense strand of the wild-type EGFR gene, is used for real-time PCR, amplification is rapid and sensitive and displays similar sensitivity to SARMS. Several studies using this novel method have been published [8, 17, 34, 35], however, to our knowledge, there are no reports showing detection of EGFR mutations in cfDNA extracted from the plasma of NSCLC patients using PNA-mediated real time PCR clamping. In the present study, the detection rate of EGFR mutations in cfDNA was 16.1%. This is somewhat lower than that reported previously, which ranges from 20% to 73% (Table 5) [16, 24, 26–28, 32].