Prevalence of EGFR Mutations and Clinico-Pathological Characteristics of Chilean Lung Cancer Patients

Abstract

Background: Lung cancer (LC) is the second leading cause of cancer death in Chile, causing >3,000 deaths every<br />year. Epidemiological LC data in Chile is scarce and scattered. Here, we aimed to quantify the prevalence of Epidermal<br />Growth Factor Receptor (EGFR) gene mutations in a Chilean cancer center. These data may identify individuals that<br />could benefit from targeted therapies such as Tyrosine Kinase Inhibitors (TKIs). Methods: A total of 1,405 Biopsies<br />from 1,381 LC patients were retrospectively analyzed retrieving clinical data from EGFR mutants including age,<br />gender, histological type, smoking habits and type of EGFR mutation. We also analyzed overall survival (OS) rates.<br />Results: From all patients 21.7% had clinically relevant EGFR mutations, and a median age at diagnosis of 65 years.<br />Most were female (64%), classified as adenocarcinomas (94.5%), and non-smokers/light smokers (93.1%). The most<br />prevalent mutation was exon-19 deletions (50.6%) followed by Leucine-to Arginine 858; OS was 15 months. Clinical<br />follow-up information was available for 83 patients. The use of TKIs in these patients significantly improved OS.<br />Conclusion: The prevalence of EGFR mutations in the studied population was 21.7%, comparable to other countries<br />in Latin America. The most frequent EGFR mutation was exon-19 deletion, OS in this group was 15 months, and TKIs<br />significantly improved OS.