AB028. Prevalence of EGFR positive samples among Greek patients with lung cancer

Background: The aim of the present study was to evaluate retrospectively the tissue samples of Greek patients with lung cancer (one center) and to determine the frequency of epidermal growth factor receptor (EGFR) mutation positivity. Furthermore, overall survival of EGFR (+) patients till October 2016 was estimated.

Methods: A retrospective analysis in electronic database from 25/02/2011 until 10/10/2016 was performed. Genomic alterations and small amino deletions in the gene that encodes the EGFR identified in the tyrosine kinase domain were assessed (exons 18–21). Genomic DNA was extracted from the sample under investigation (QIAmp DNA FFPE tissue kit, Qiagen/MagCore Genomic DNA FFPE One-Step Kit, RBC Bioscience).

Results: Overall, 503 samples were examined. Fifty nine patients (11.7%) were found to have mutations in the EGFR gene which correlate with clinical responsiveness to the tyrosine kinase inhibitor (TKIs). The mean age of EGFR positive subgroup was 67±15 years, 63% were female and 81% were diagnosed with lung adenocarcinoma. Four patients underwent surgical resection of their tumor while 75% were presented with distant metastases at the time of diagnosis. TKIs that were prescribed included: gefitinib (28%), erlotinib (45%) and afatinib (35%). Five patients received two different TKIs during the study period. The median overall survival of EGFR positive patients was estimated in 19 months.

Conclusions: EGFR mutation frequency in Greek lung cancer population was estimated to be similar to that reported in the literature in Caucasian populations, as well as the overall survival of these patients.

Keywords: Lung cancer; epidermal growth factor receptor mutations (EGFR mutations); tyrosine kinase inhibitor treatment (TKI treatment)