EGFR mutations in lung carcinomas: Mutation profile and survival analysis.

Abstract

e20518 Background: Epidermal growth factor receptor (EGFR) mutation have been demonstrated to be both predictive and prognostic for patients with metastatic lung cancer. The administration of EGFR tyrosine kinase inhibitors (TKIs) has improved survival in this group of patients. Several generations of EGFR TKIs are currently available. The EGFR mutations have been divided into common and rare. The common mutations include Exon 19 deletion and Exon 21 L858R mutations and rest are grouped as rare. The presence of visceral metastasis in the brain and liver are usually portends a poor prognosis. Methods: We conducted a retrospective analysis of lung cancer patients who attended our hospital outpatient department from 2017 to 2021. The prevalence, demographics and clinical profile of EGFR common and rare mutations were studied using descriptive statistics. Survival of EGFR mutated patients was plotted using Kaplan Meier plots. SPSS was used for statistical analysis. Results: The prevalence of EGFR mutation among metastatic lung cancer was 14.10% (161/1148). The median age of the group was 60 years (23- 104 years). Smokers with EGFR mutations were 11.8% (n = 19). Male to Female ratios was 76:85 (47.2% and 52.8%). Three patients with squamous cell carcinoma exhibited EGFR mutation. Most common EGFR TKI used was Gefitnib. Osimertinib was used in 13 patients (1.4%). The percentage of common mutations were 85.75% (N = 132) and rare mutations were 14.3% (n = 22). The type of mutations could not be identified in 10 patients. The percentage of patients with exon 19 deletion were 63% (n = 97) and L858R were 24.7% (n = 38). Visceral metastasis (brain and liver) was seen in 47 patients (n = 29.2%). Brain progression was seen in 32 patients (n = 19.9%). The survival of patients with EGFR exon 19 deletion and L858R mutation was 16.36 + 8.97 months and 15.97+ 10.93 months, Survival among patients with common mutation was 16.20 + 9.57 months and among rare mutation was 13.43 + 12.19 months. Median Survival period of patients with visceral metastasis was 12 months (0 to 38 months). Conclusions: In our retrospective study, there was no significant difference between survival among common and rare EGFR mutations.