Frequency of EGFR mutation and EML4-ALK fusion genes in patients with non-small cell lung carcinoma

Abstract

Lung cancer ranks among the top causes of mortality worldwide. Non-small cell lung cancer (NSCLC) accounts for the majority of cases. Advances in genomics have identified potential biomarkers to predict therapeutic strategies in lung cancer. Despite the availability of targeted drugs such as tyrosine kinase inhibitors, a substantial proportion of patients still experience problems such as drug resistance. Mutations in genes like epidermal growth factor receptor (EGFR) and EML4ALK have already been established with altered clinical outcomes in NSCLC patients. With a focus on non-small cell lung cancer (NSCLC),the study was conducted at indraprastha apollo hospital in new delhi. With their informed agreement, 90 patients who were admitted between january 2012 and december 2015 and who had been diagnosed with fine-needle aspiration cytology (FNAC)/biopsy utilizing computed tomography (CT) guidance were included in the study. Excluded from the study were those receiving radiation therapy or chemotherapy concurrently. Information on age, gender, a thorough medical history, a history of smoking, and any additional co-morbidities were taken from medical records. Investigation of EGFR mutation and EML4-ALK gene fusion in NSCLC patients was done. Eleven (11% ) were positive and (89%) were negative for EGFR mutations. The positive cases were analyzed for exon 19 deletion and exon 21 (L858R) substitution and found positive for (60%) and (40%) of cases, respectively. Amongst 90 EGFR-negative patients, 4 (4.4%) had the EML4-ALK fusion gene, while 86 (95.5%) were negative for EML4-ALK. This study’s EML4-ALK fusion gene incidence was only (4%). Females have a higher occurrence of EGFR mutations than males (p=0.003) and the frequency of EGFR mutation was higher in non-smokers. The overall incidence of the EML4-ALK fusion gene was (4.44%) and was higher in patients below 60 years of age.