Prognostic features and comprehensive genomic analysis of NF1 mutations in EGFR mutant lung cancer patients.

Abstract

NF1 is a tumor suppressor gene that encodes the neurofibromin protein and negatively regulates Ras signaling. This study was aimed to investigate the molecular, clinical characteristics, and prognostic features of NF1 gene in EGFR mutant lung cancer patients. The next-generation sequencing (NGS) was used to analyze the data from lung cancer patients in the Guangdong Lung Cancer Institute (GLCI) from June 2016 to December 2020. Somatic NF1 mutations were present in 4.2% (135/3220) of Chinese lung cancer patients. NF1 mutations where clearly enriched in older (p < 0.001), male (p < 0.001), and smoking (p < 0.001) patients. Patients with NF1 mutations were more likely to have TP53 (p=0.003), BRAF (p =0.001) and RASA1 (p=0.026) mutations and mutually exclusive with EGFR mutations (p=0.006). TP53 mutation had worsen prognosis in cases of NF1 mutant (p=0.026) or EGFR/NF1 co-mutant (p=0.031) lung adenocarcinomas (LUAD) patients. There was no effect on overall survival (OS) in LUAD patients with and without NF1 mutations, even in LUAD driver-gene negative patients. NF1/EGFR co-mutation patients had a longer OS than a single mutation of either the EGFR gene (median OS: 47.7m vs. 30.2 m, hazard ratio [95% CI], 0.47 [0.30-0.74], p=0.004) or NF1 gene (47.7m vs. 19.0 m, 0.44 [0.27-0.73], p=0.003). Furthermore, NF1 mutations significantly prolonged OS in EGFR mutant/TP53 wild-type LUAD patients (106.5m vs. 25.5 m, 0.28 [0.13-0.59], p=0.003) but not in patients with EGFR/TP53 co-mutations (36.8m vs. 30.2 m, 0.70 [0.39-1.26], p=0.280). Our results indicated NF1 mutations served as a good prognostic factor in EGFR mutant/TP53 wild-type lung cancer patients in this single-center study. TP53 mutation was obviously enriched in NF1 mutant patients and had shorter OS.