Author of

• 12824

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  P3.21 - Poster Session 3 - Diagnosis and Staging (ID 171)

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

  • 12831

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    P3.21-007 - <em>EGFR</em> mutation analysis in sputum of lung cancer patients: a multicenter multitechnique study (ID 1782)

    09:30 - 09:30  |  Author(s): C. Mayo
    • Abstract

    Background
    Mutations in the epidermal growth factor receptor (EGFR) gene have been identified in lung adenocarcinomas and are associated with a high response to EGFR tyrosine kinase inhibitors. EGFR mutations can be detected in tumour tissue, cytology specimens and blood from lung cancer patients. Thus far, EGFR mutation analysis has not been systematically demonstrated for sputum samples. The aim of the present study was to determine whether EGFR mutation analysis is feasible on sputum samples, employing different assays in a multicenter study.

    Methods
    Sputum samples were collected from 10 lung cancer patients with confirmed EGFR mutation in their tumour tissue, 10 lung cancer patients without evidence of an EGFR mutation, and 10 patients with chronic obstructive pulmonary disease (COPD). DNA was isolated from the sputum and used for mutation analysis by Cycleave PCR, COLD-PCR, PangaeaBiotech SL technology (PST), and High Resolution Melting, respectively. Targeted resequencing (TruSeq Amplicon Cancer Panel) and droplet digital PCR were additionally performed on the 10 samples with EGFR mutation.

    Results
    Dependent on the assay, EGFR mutations could be detected in 30-50% of the sputum samples of patients with EGFR mutations (Table). The different techniques revealed consistent results, with slightly higher sensitivity for PST. Neither the lung cancer patients without EGFR mutation nor the COPD controls tested positive for EGFR mutations in their sputum samples, indicating high clinical specificity of all assays.

    Subject	Gender	Age (years)	Tumour stage	EGFR mutation status of tumour tissue[1]	EGFR mutation analysis on sputum specimens[2]
    					Cycleave PCR	COLD-PCR	PST[3]	HRM-sequencing	Cytology[4]
    A	F	72	IV	Del E746-A750	0	0	0	0	0
    B	M	66	I	Del E746-A750	0	2	0	0	0
    C[6]	F	78	IV	Del E746-A750	1	1	1	1	2
    D	F	46	III	Del E746-A750	0	0	1	0	0
    E[6]	M	54	IV	Del E746-A750	1	1	1	1	0
    F	F	49	III	Del E746-A750 & c.2369C>T [p.T790M]	0	0	0	0	0
    G	F	54	IV	Del E746-A750 & c.2369C>T [p.T790M]	0	0	1[5]	0	1
    H	F	73	IV	c.2753T>G [p.L858R]	0	0	0	0	0
    I	F	61	IV	c.2753T>G [p.L858R]	0	0	0	0	0
    J[6]	M	60	IV	Del E746-A750	1	1	1	1	2

    [1 ]del E746-A750= deletion exon 19 [2] mutation identified: 0=no, 1=yes, 2=dubious [3] exclusively del19 and L858R were assessed [4] tumour cells: 0=no, 1=yes, 2=in related sample of same patient [5 ]only del19 detected [6 ]TSACP and ddPCR both tested EGFR mutation (del19) positive.

    Conclusion
    EGFR mutations can be detected in sputum samples from patients with EGFR-mutated non-small cell lung cancer, which may replace biopsy procedure for some patients.