EGFR Mutation Status Among Patients in Lithuania: A Single Institution Expierence

Abstract

Background: Activating mutations within the tyrosine kinase domain of Epidermal Growth Factor Receptor (EGFR) are found in approximately 10- 20% of non-small cell lung cancer (NSCLC) patients and are associated with response to EGFR tyrosine kinase inhibitors (TKIs). The aim of this study is to examine the prevalence of EGFR 18-21 among patients with histologically confirmed non-squamous NSCLC treated in our institution. Methods: We report the data of NSCLC patients of a single institution experience enrolled from April 2010 to January 2011. We examined the mutation status of EGFR patients with newly diagnosed nonsquamous NSCLC. The formalin fixed, paraffin embedded tissue samples were obtained from tumor biopsy. These were sequenced to look for mutations in exons 18 - 21 of EGFR. Results: 67 patients were examined for EGFR mutations: 13 (19.4%) patients with stage IIIB and 54 (80.6%) patients with stage IV. Age median was 63 years (range 34-80); male/female: 51/16; smokers/ex-smokers/never-smokers: 41/13/13; adenocarcinoma/large cell carcinoma/no otherwise specified NSCLC: 44/19/4. The EGFR mutations (L858R in Exon21) were found in 5 patients (7.5%): female 12.5% (2/16), male 5.9% (3/51); adenocarcinoma 9.1% (3/44), large cell carcinoma 10.5% (2/19); never-smokers 23.1% (3/13), smokers 4.9% (2/41) (p>0.05). First-line treatment with EGFR-TKI was started for these patients. Conclusion: In comparison with literature data the frequency of EGFR gene mutations among nonsquamous NSCLC patients was very low.