P021 The Impact of TP53 Mutation and Tumor Mutation Number on Outcomes in Patients with Stage I Non Small Cell Lung Cancer

Mutations of the Tumor protein p53 (TP53) gene and Tumor Mutation Number (TMN) have been associated with the formation of tumor especially in non- small lung cancer (NSCLC). However, their prognostic roles in early stage NSCLC were not well defined. In this study we sought to identify the pure prognostic role of TP53 mutation and TMN in patients with completely resected stage I NSCLC. 244 patients of stage I (T1a-cN0) NSCLC who had been completely resected (1991-2014) with TP53 Mutation status and TMB data were collected from TCGA Database. TMB data was analyzed in 119 patients. Disease free survival (DFS) and overall survival (OS) were compared between TP53 mutation and wild-type mutation, higher TMN (>223.5) and lower TMN (<223.5). DFS and OS were estimated using Kaplan Meier methods and Cox regression models. 244 patients were included in this study with 122 (50%) TP53 mutations. Multivariate analysis identified TP53 mutation tumors were associated significantly shorter OS (HR 2.31, 95%-CI 1.34 to 3.87; p=0.002) and DFS (HR 1.80, 95%-CI 1.12 to 2.71;p=0.005) compared to wild-type tumors. The TMN between TP53 mutation and wild-type mutation was significant (mean 332.1 vs 164.1; p=0.001), TMN>223.5was associated with worse OS (HR 2.72, 95% CI 1.25-5.93, p=0.012) and DFS (HR 1.79, 95% CI 1.01-3.15, p=0.045). TMN>223.5 were identified as independent prognostic markers. TP53 and TMN＞223.5 are two independent prognostic factors in resected stage I lung adenocarcinoma. TP53 mutation might increase TMN which impact on the prognosis.