1187P - The Role of Mutations of EGFR, K-RAS, EML4-ALK, and B-RAF Genes in Resected Pathological Stage I Lung Adenocarcinoma

Abstract

ABSTRACT Background The mutations of EGFR, K-ras, EML4-ALK and B-RAF genes are an early event during oncogenesis of NSCLC. This study retrospectively assessed the mutations of these genes and their clinical significance in resected adenocacinomas. Methods A total of 256 patients with resected stage I lung adenocarcinoma were retrospectively included in this study. The mutations of EGFR and K-ras were determined using PCR-based fragment analysis and direct sequencing. The EML4-ALK fusion gene was assayed by immunohistochemistry and multiplex RT-PCR. The mutation of B-RAF gene was determined using direct sequencing. The DFS for prognostic value and the OS for predictive value of treatment after recurrence were evaluated. Results In 256 tumors, the mutations of EGFR, K-ras, EML4-ALK, and B-RAF genes were detected in 114 (44.5%), 14 (5.5%), 7 (2.7%), and 3 (1.2%). One patient with the EML4-ALK fusion gene harbored the mutation of EGFR, and double mutations of EGFR and B-RAF were also observed in one patient. The incidence of EGFR mutations was significantly higher in females than males (41.2% vs. 54.4%, p Conclusion In patients with stage I adenocarcinoma, the mutation of K-ras gene was a poor prognostic factor for recurrence, and the mutation of EGFR was a predictive factor for EGFR-TKI treatment after recurrence. Disclosure All authors have declared no conflicts of interest.