Author of

• 10743

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  P1.10 - Poster Session 1 - Chemotherapy (ID 204)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10769

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    P1.10-026 - Validation of EGFR Mutation Testing Using Cytology Specimens in Non-small Cell Lung Carcinoma: Multi-institutional study of 128 cases in Korea (ID 1739)

    09:30 - 09:30  |  Author(s): S.H. Jung
    • Abstract

    Background
    EGFR gene mutations are the important factors predicting a patient’s response to EGFR TK inhibitors (EGFR TKIs). The importance of sensitive methods for the EGFR mutant detection is emphasized. The aim of study is to examine the comparative and concordance analyses among application of direct sequencing, pyrosequencing and peptide nucleic acid (PNA) clamping method to detect EGFR gene mutation using archived cytology specimens.

    Methods
    A total of 128 cases, which were diagnosed as adenocarcinoma of the lung at 9 hospitals in Korea between 2006 and 2012, were collected. Based on the above three methods, the concordance rates of EGFR mutations for in exon 18, 19, 20, 21 were analyzed and validated in comparative cytology specimens and formalin-fixed, paraffin-embeded (FFPE) tissues.

    Results
    Comparison of EGFR mutant detection between cytology specimens and concurrent FFPE tissues from the same anatomic site had a concordance rate of 74.7%. The diagnostic performance of pyrosequencing and PNA clamping method in cytology specimen was higher than that of direct sequencing as well as FFPE tissue. In comparison of EGFR mutant detection in cytology specimen and FFPE tissue according to three methods, PNA clamping method showed high concordance rate (93.6%), than other methods. The concordance rate between PNA clamping method and pyrosequencing was high (62.4%) in cytology specimen, whereas direct sequencing and PNA clamping method was as high as 74.5% in FFPE tissue.

    Specimen	Cytology
    	Direct	Pyro	PNA
    Cytology
    Direct	-	-	-
    Pyro	0.381[*]	-	-
    PNA	0.486[*]	0.624[*]	-
    	FFPE
    	Direct	Pyro	PNA
    FFPE
    Direct	-	-	-
    Pyro	0.509[*]	-	-
    PNA	0.745[*]	0.684[*]	-
    	Cytology
    	Direct	Pyro	PNA
    FFPE
    Direct	0.546[*]	0.504[*]	0.743[*]
    Pyro	0.386[*]	0.735[*]	0.626[*]
    PNA	0.491[*]	0.683[*]	0.936[*]
    FFPE, formalin-fixed, paraffin-embeded; Direct, direct sequencing; Pyro, pyrosequencing; PNA, peptide nucleic acid (PNA) clamping method [*]k coefficient

    Conclusion
    Cytology specimens had a diagnostic performance for the detection of EGFR mutations that was comparable to that of FFPE tissues. The high concordance rate among three techniques had good diagnostic performance. Additionally, At least two methods are more likely to improve the detection rate of EGFR mutation than only one.