Epidermal Growth Factor Receptor Mutations in Non-Small Cell Lung Cancers in a Multiethnic Malaysian Patient Population

Background: Mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) in nonsmallcell lung cancer (NSCLC) are predictive of response to EGFR-targeted therapy in advanced stages of disease.This study aimed to determine the frequency of EGFR mutations in NSCLCs and to correlate their presencewith clinical characteristics in multiethnic Malaysian patients. Materials and
Methods: In this prospective study,EGFR mutations in exons 18, 19, 20 and 21 in formalin-fixed paraffin-embedded biopsy specimens of consecutiveNSCLC patients were asessed by real-time polymerase chain reaction.
Results: EGFR mutations were detected inNSCLCs from 55 (36.4%) of a total of 151 patients, being significantly more common in females (62.5%) than inmales (17.2%) [odds ratio (OR), 8.00; 95% confidence interval (CI), 3.77-16.98; p<0.001] and in never smokers(62.5%) than in ever smokers (12.7%) (OR, 11.50; 95%CI, 5.08-26.03; p<0.001). Mutations were more commonin adenocarcinoma (39.4%) compared to non-adenocarcinoma NSCLCs (15.8%) (p=0.072). The mutation ratesin patients of different ethnicities were not significantly different (p=0.08). Never smoking status was the onlyclinical feature that independently predicted the presence of EGFR mutations (adjusted OR, 5.94; 95%CI, 1.94-18.17; p=0.002).
Conclusions: In Malaysian patients with NSCLC, the EGFR mutation rate was similar to thatin other Asian populations. EGFR mutations were significantly more common in female patients and in neversmokers. Never smoking status was the only independent predictor for the presence of EGFR mutations.