Author of

• 11946

  +

  P2.24 - Poster Session 2 - Supportive Care (ID 157)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Supportive Care
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11998

    +

    P2.24-052 - A Single Centre Review of Endothelial Growth Factor Receptor (EGFR) Mutation Testing: A Regional Australian Experience. (ID 3204)

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

    Background
    Endothelial Growth Factor Receptor (EGFR) mutation testing is now recommended practice for lung adenocarcinoma. Those patients with EGFR mutations are eligible for targeted agents which offer survival and quality of life advantages with reduced toxicity in some. Several reports have suggested particular samples are more likely to give reliable EGFR mutation results than others. We were interested in investigating the types of samples locally that were viable for testing and to assess the population rate of EGFR mutation positivity in adenocarcinoma for which there is little published data in Australian (mainly Caucasian) populations.

    Methods
    Data was systematically collected for tissue samples sent for EGFR mutation testing over a three year period. Basic demographic data, sample type and test results were recorded. Testing was performed as part of the routine workup for patients with lung adenocarcinoma. Chart review was undertaken to clarify sampling methods and test results if required.

    Results
    214 sequential specimens from patients with proven adenocarcinoma were sent for analysis of the presence of EGFR mutation. 197 specimens were of adequate quality for analysis (>20% of specimen composed of tumour cells). There were 22 positive tests for EGFR mutations (16 female; 11 non- or never-smokers). Table 1 outlines the types and adequacy of specimens collected for testing. There was no association between specimen type and adequacy for analysis. 27 specimens were unable to be analysed. Of these 12 were labelled failed tests and 15 returned incomplete results for at least one of four exons. 17 specimens were labelled inadequate for testing; 9 of those were reported as negative for EGFR mutations despite being reported as having less than 20% tumour cells in the specimen. 6 of 12 failed tests were adequate for testing. 14 of 15 incomplete tests were adequate for testing.

    Specimen Type	Number collected (% of total)	Number of specimens with >20% of tumour cells in specimen (% of number collected)	Number of failed or incomplete tests
    Image guided FNA Bx	27 (12.5)	25 (93)	5
    Image guided core Bx	16 (7.5)	15 (94)	3
    Bronchial Bx/TBNA/EBUS/TBLB (bronchoscopy)	89 (42)	78 (88)	11
    Lung/Pleura/Pericardium/ Mediastinal LN Bx (surgical)	49 (23)	48 (98)	5
    Pleural fluid	9 (4)	8 (89)	0
    Surgical LN Bx	4 (2)	4 (100)	0
    Abdominal/oesophageal node	3 (1.5)	3 (100)	0
    Brain/ cerebellar metastasis	11 (5)	10 (91)	1
    Musculoskeletal metastasis (surgical)	6 (3)	6 (100)	2
    	214 (100)	197 (92)	27 (13%)

    Conclusion
    In our population (majority Australian born Caucasians), the percentage and profile of EGFR positivity is similar to that reported in other studies. Representative samples can be obtained from many different types of tissue, in particular, fine needle aspirates and core biopsies of lung parenchyma and lymph nodes as well as from pleural fluid.