166P - Non-small cell lung cancer (NSCLC) patients with rare or complex epidermal growth factor receptor (EGFR) mutations: A single institution series

Date 15 April 2016
Event European Lung Cancer Conference 2016 (ELCC) 2016
Session Poster lunch
Topics Non-small-cell lung cancer
Translational Research
Basic Principles in the Management and Treatment (of cancer)
Presenter Giulia Pasello
Citation Journal of Thoracic Oncology (2016) 11 (supplement 4): S57-S166. S1556-0864(16)X0004-4
Authors G. Pasello1, V. Polo2, S. Frega2, M. Lorenzi3, S. Indraccolo4, M. Fassan5, L. Bonanno1, N. Nannini6, P.F. Conte2, F. Calabrese6
  • 1Medical And Experimental Oncology Department, Medical Oncology 2, Istituto Oncologico Veneto IRCCS, 35128 - Padova/IT
  • 2Surgical Oncological And Gastroenterological Sciences Deparment, University of Padova, 35128 - Padova/IT
  • 3Medicine And Surgery Faculty, University of Padova, Padova/IT
  • 4Immunology And Molecular Oncology, Istituto Oncologico Veneto IRCCS, 35128 - Padova/IT
  • 5Surgical Pathology Unit, Department Of Medicine, University of Padova, 35124 - Padova/IT
  • 6Department Of Cardiothoracic And Vascular Sciences, University of Padova, 35128 - Padova/IT

Abstract

Background

Epidermal Growth Factor Receptor (EGFR) Tyrosine Kinase Inhibitors (TKIs) are first-line treatment of advanced Non-Small Cell Lung Cancer (NSCLC) harboring EGFR mutations. Exon 19 deletion and exon 21L858R are common sensitizing mutations, while exon 20 T790M is an acquired resistance mutation; conflicting data about uncommon mutations have been published while the predictive and prognostic value of rare and complex mutations has not been established. The aim of this study is to describe epidemiology, clinical features and treatment outcome of NSCLC patients with rare and/or complex EGFR mutations at our Center

Methods

Clinical and molecular data of NSCLC patients who referred to our Center between 2010 and 2015 were collected and analyzed. EGFR status was assessed through Sanger sequencing, RT-qPCR or pyrosequencing. Best response to first-line treatment was assessed through RECIST v.1.1.

Results

Among non-squamous NSCLC patients (N = 992), EGFR status was unknown in 228(23%), wild-type in 675(68%) and mutated in 89(9%). We observed 2 rare and complex mutations (exon 18 E709K+exon 21 L833V; exon 18 G719A+ exon 20 V769M), 1 complex mutation (exon 19 del E746-A750+exon 21 L858R) and 21 rare mutations: exon 18 (N = 7); exon 19 (N = 6); exon 20 (N = 8). First-line treatment for advanced NSCLC in 21 patients was: afatinib (A) (N = 2); gefitinib (G) (N = 11); erlotinib (E) (N = 3); chemotherapy (Ctp) (N = 4); clinical trial (CT) (N = 1). In evaluable patients (N = 18) we observed 2 partial response (PR) with A; 1 stable disease (SD) and 2 progressive disease (PD) with E; 2 SD, 3 PD and 3 PR with G; 4 SD with Ctp; 1 PD with CT. PD after EGFR TKIs occurred in cases harboring exon 20 (N = 3) and exon 18 (N = 2) mutations. Of note, one of the two cases responsive to afatinib harbored three EGFR rare complex mutations (exon 18 E709K and exon 21 L833V/H835L). Three cases harboring exon 20 mutation were treated with chemotherapy with SD.

Conclusions

Afatinib seems to be effective in rare and complex mutations; first-line chemotherapy seems to achieve a better outcome compared with EGFR TKIs in exon 20 mutated cases. Complete clinical and molecular data of this patient series will be presented at the conference.

Clinical trial identification

Not applicable

Legal entity responsible for the study

Istituto Oncologico Veneto

Funding

Istituto Oncologico Veneto

Disclosure

All authors have declared no conflicts of interest.