Epidermal growth factor receptor mutation status in pulmonary adenocarcinoma: Multi-institutional data discussion at national conference of "Lung Cancer Management in Indian context"

Abstract

The presence of activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene in adenocarcinomas of lung confers sensitivity to tyrosine kinase inhibitor therapy. The prevalence of EGFR mutations varies among different ethnicities and demographic profile. This multi-institutional data was compiled to determine the EGFR mutation status in Indians patients with lung adenocarcinoma. Cohorts represented by 4 tertiary care hospitals participated in data discussion at a national conference entitled as 'Lung Cancer Management in Indian Context'. The clinicopathologic data and EGFR mutation rate in the patients of lung adenocarcinoma screened in these cohorts were collected and analyzed. The sample types included both surgical and cytological specimens. A variety of methods were used including immunohistochemistry, polymerase chain reaction, Sanger sequencing and next generation sequencing. A total of 3436 cases of treatment naïve lung adenocarcinoma were tested for EGFR mutations. The overall frequency of EGFR mutations observed was 30.03%. The most common baseline mutation detected was exon 19 deletion followed by L858R point mutation in exon 21. Dual mutations were observed in 6.5% of cases and were predominantly combinations of exon 19 deletion and T790M point mutation in exon 20. Incidence of EGFR mutations was higher among females and non-smokers diagnosed with lung adenocarcinomas. The most common histology in EGFR mutant cases was acinar predominant adenocarcinomas. With nearly one-third of Indian patients with lung adenocarcinoma harboring EGFR mutations, routine testing for these mutations is important to get the benefit of targeted therapy.

Keywords: Cytology; EGFR mutation; Lung adenocarcinoma; Non small cell lung carcinoma; Tyrosine kinase inhibitors.