e- Ab Sensor-based Real-time Detection of Mutant EGFR in Clinical Specimens From Patients of Non-small Cell Lung Cancer
e- Ab Sensor-based Real-time Detection of Mutant EGFR in Clinical Specimens From Patients of Non-small Cell Lung Cancer
The purpose of this study is to develop a real-time diagnostic technique with e- Ab sensor
 for specific EGFR mutation detection in clinical specimens of NSCLC patients, the
 investigators conduct a prospective clinical study. In comparison with results from direct
 sequencing of EGFR, the investigators evaluate the performance of e- Ab sensor, including
 reproducibility, sensitivity, specificity, and cross-reaction (such as detection of EGFR
 mutations other than L858R and DelL746-A750). The potential factors which may interfere with
 the results would be investigated. With such technique, the investigators can obtain EGFR
 mutation information of NSCLC patients in cost-saving and time-saving way and can offer more
 individualized treatment for the investigators patients.
Epidermal growth factor receptor (EGFR) plays an important role in the development of
 non-small cell lung cancer (NSCLC). High EGFR mutation rate is found in certain population,
 including female, non-smoker, East Asian, and adenocarcinoma. Previous studies have shown
 that patients of NSCLC with mutant EGFR would have better survival, which was related to EGFR
 tyrosine kinase inhibitor treatment.1-2 IPASS study has shown that longer progression-free
 survival (PFS) under gefitinib treatment than that under carboplatin-paclitaxel, in patients
 with lung adenocarcinoma and clinical characteristics suggesting high EGFR mutation rate.3
 However, only some EGFR mutations are associated with sensitivity to tyrosine kinase
 inhibitor treatment, especially deletion in exon 19 and L858R mutation in exon 21.4-5 Two
 recent phase III randomized clinical trials evaluated gefitinib treatment and chemotherapy in
 patients of advanced NSCLC with sensitive EGFR mutaions.6-7 In patients with advanced NSCLC
 and sensitive EGFR mutations, PFS under gefitinib was 9.2~10.8 months, longer than that under
 platinum-based chemotherapy. Therefore, to develop individualized treatment for patients with
 NSCLC, it is important to have EGFR mutation status at the time of diagnosis. Current
 techniques available for detection of EGFR mutation need direct sequencing of EGFR tyrosine
 kinase domains, which are costly and time-consuming. 8 For detection for specific EGFR
 mutations, mutation-specific monoclonal antibodies were developed to detect E746-A750
 deletion in exon 19 and L858R in exon 21. In the pilot study, the immunohistochemistry (IHC)
 assay using mutation-specific antibodies showed a sensitivity of 92% and a specificity of
 99%.9 Recent two studies examining the performance of the mutation-specific antibodies
 disclosed inconsistent sensitivity and specificity. In the study by Akhiko Kawahara et al,
 IHC assay of NSCLC tumor specimens with anti-delE746-A750 antibody showed a sensitivity of
 79%, which was 83% by IHC assay with anti-L858R antibody.10 In the other study by Atsuko
 Kitamura et al, IHC assay with anti-delE746-A750 antibody showed high specificity but low
 sensitivity (99% and 40%, respectively). IHC assay with anti-L858R antibody also showed high
 specificity but low sensitivity (97% and 36%, respectively). The overall sensitivity and
 specificity of these two mutation-specific antibodies were 96% and 47%.11 The discrepancy
 between these two studies was currently unknown. Another study conducted in Memorial
 Sloan-Kettering Cancer Center showed the performance of these two mutation-specific
 antibodies would be affected by the cutoff of IHC score.12 For anti-L858R antibody, the
 sensitivity was 76%-95% and the positive predicted value was 99%-100%. For anti-delE746-A750
 antibody, the sensitivity was 85%-67% and the positive predicted value was 99%-100%. It is
 unknown if the performance of these mutation-specific monoclonal antibodies could be enhanced
 with the use of automated quantitative system (AQUA). However, such techinique needs
 equipment and further cost, and couldn't offer immediate information about EGFR mutation to
 clinicians.

 Electrosensing antibody probing system (e- Ab sensor), which was developed for the rapid and
 sensitive detection of hapten, proteins, or viral antigen in medical samples, will be used
 for analyzing the interaction kinetics between mutation specific anti-EGFR and its antigen
 (EGFR with E746-A750 deletion or L858R mutation) present in the specimens of patients with
 lung cancer. The system incorporates the use of engineered semiconducive antibodies or virus
 in vertical and lateral chip (eAbchip) or lateral flow through (eAbsignal) formats. In
 electrosensing antibody probing, semiconductive antibodies are bound as a suitable
 electrosensing probe, which specifically and selectively binds targeted molecules (i.e.
 specific mutant EGFR) in the test specimens. From assessment of the electric signature of
 semiconductive mutation-specific anti-EGFR antibodies, the eABprobe could offer sensitive
 detection and precise quantification of specific mutant EGFR.

 To develop a real-time diagnostic technique with e- Ab sensor for specific EGFR mutation
 detection in clinical specimens of NSCLC patients, we conduct a prospective clinical study.
 In comparison with results from direct sequencing of EGFR, we evaluate the performance of e-
 Ab sensor, including reproducibility, sensitivity, specificity, and cross-reaction (such as
 detection of EGFR mutations other than L858R and DelL746-A750). The potential factors which
 may interfere with the results would be investigated. With such technique, we can obtain EGFR
 mutation information of NSCLC patients in cost-saving and time-saving way and can offer more
 individualized treatment for our patients.
Inclusion Criteria:

 Inclusion: Patients will be enrolled if they fulfill all of the following criteria

 1. With indication for the following interventions:

 Thoracentesis Fine-needle aspiration and biopsy of primary tumor or metastases
 Bronchoalveolar lavage

 2. With enough residual specimens for further study (Patients would be excluded if they
 have only limited amount of clinical specimens, which should all be sent for clinical
 analysis.)

 3. Consent is obtained from the patient

 Exclusion Criteria:

 -  Patients will be excluded if they couldn't sign the consent. Otherwise, no specific
 exclusion criteria were considered.