O2. Frequency of EGFR gene mutations in patients with NSCLC in Czech Republic

Background: Worldwide, lung cancer is the most common cause of cancer-related death, and was responsible for 1.56 million deaths annually, as of 2012. The situation in the Czech Republic is identical, lung cancer is the leading cause of mortality due to malignant tumours, with 5,572 cancer related deaths in 2010. The detection of epidermal growth factor receptor (EGFR) gene mutations can guide targeted therapies for non-small cell lung cancer (NSCLC), because most of these mutations are strongly associated with clinical response to EGFR tyrosine kinase inhibitors. The aim of this study was to verify the frequency of EGFR mutations in a large group of Caucasians patients with advanced stage non-squamous NSCLC.

Methods: Analysed data were collected in the period from November 15, 2011 to June 30, 2013 in three pneumo-oncological centres. Totally, 486 patients diagnosed with adenocarcinoma (459 cases) or NSCLC-NOS (27 cases) were tested for EGFR mutations, consisting of 284 males and 202 females, with median age of 66.5 years.

Results: EGFR mutations were detected in 74 patients (15.2%). Mutations were shown in 25 (8.8%) men vs. 49 (24.3%) women (P<0.001), in 12 (6.7%) smokers vs. 20 (11.2%) ex-smokers vs. 38 (37.3%) non-smokers (P<0.001), and in 32 (15.7%) patients under 65 years of age vs. 42 (14.9%) patients over 65 years of age (P=0.898).

Conclusions: The authors showed that the overall frequency of EGFR mutations in patients with non-squamous NSCLC was 15.2%, most commonly in female patients and non-smokers. The study results are in concordance with recent studies in which the frequency of EGFR mutations varies between 8-23% in Caucasian population. This information can help us to estimate number of patients who will need EGFR tyrosine kinase inhibitors in the first line of treatment.

Keywords: Epidermal growth factor receptor (EGFR); non-small cell lung cancer (NSCLC); gene; mutation