Author of

• 11917

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  P2.21 - Poster Session 2 - Diagnosis and Staging (ID 170)

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

  • 11926

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    P2.21-009 - Results of Epidermal Growth Factor Receptor (EGFR) Reflex Testing implementation in the Brazilian National Cancer Institute (INCA) (ID 3337)

    09:30 - 09:30  |  Author(s): D. Herchenhorn
    • Abstract

    Background
    Patients with advanced lung cancer and EGFR mutations can derive significantly benefit by receiving first line EGFR tyrosine kinase inhibitor (TKI) therapy. Multiple trials have showed that clinical selection is not sufficient and that EGFR mutations test should be requested for all non-squamous patients. Moreover there is a suggestion that a lag time between diagnosis and molecular test could harm patients. In this retrospective trial we describe EGFR mutation analysis after the implementation of reflex testing in a cohort of Brazilian patients.

    Methods
    After May 2011 EGFR reflex testing was recommended for all stage IVA and IVB non-squamous lung cancer patients treated at INCA. EGFR exons 18, 19, 20 and 21 were examined using a commercially available Polymerase chain reaction and Sanger sequencing assay. We retrospectively reviewed clinical and EGFR tests characteristics from medical charts of all patients with available results.

    Results
    From May 2011 to May 2013 samples from 189 patients (56.2%) out of 336 were screened for EGFR mutations. Main reason for non-testing was insufficient material. Turn around time for EGFR mutation processing substantially improved over this period, from over three weeks to less than 5 working days. Of those patients tested 58.8% were women and 22% were non-smokers or light smokers. Results were obtained from cytological specimen in 33 cases (17.4%). Most patients had adenocarcinoma (95.2%) with only 6 cases (3.2%) of unspecified carcinoma. EGFR mutations were detected in 52 patients (27.5%). The incidence of mutations was higher in females (58.8%) and non-or light smokers (56%). Of the mutations identified 18 (34.6%) were in frame deletions in exon 19, and 8 (15.3%) were exon 21 L858R. Exon 18 G719A and exon 20 insertions were detected in only 1 (1.9%) and 2 (3.9%) cases respectively. We found a high incidence of atypical mutations (44.3%). All of them were single aminoacidic substitutions in exon 18 (7 cases; 30.5%), exon 19 (5 cases; 21.7%), exon 20 (5 cases; 21.7%), exon 21 (5 cases; 21.7%), and a single case of double mutation (exons 19 and 20). We did not detect any de novo T790M exon 20 mutation.

    Conclusion
    The results of the first 2 years of reflex molecular testing at a single Brazilian institution reported demonstrate the feasibility and potential for a non-clinical selective approach. This high frequency of atypical mutations must be further investigated since to date there are no published data regarding EGFR mutations in the Brazilian population.