The Correlation Between Mutation Burden And Disease Free Survival In Patients With Lung Adenocarcinomas.

8550 Background: Lung cancer is one of the leading causes of cancerous deaths globally. High mutation burden is a special character in lung adenocarcinoma patients. Mutation burden is usually based on the number of non-synonymous mutations implying the instability of genome. We hypothesize genome-wide mutation burden indicates mutation degree and is correlated with prognostic in lung adenocarcinoma. Methods: Whole-exome sequencing was performed on 98 Chinese lung adenocarcinoma patients with tumor and normal tissue to a mean depth of 49.6ⅹ. The total number of non-synonymous somatic mutations was calculated from the sequencing data of each patient. Patients were divided into high mutation burden and low mutation burden groups in accordance with the mean mutation burden and Kaplan-Meier analysis was performed for survival analysis between these two groups. The association between mutation burden and age or smoking status was analyzed by Wilcoxon rank-sum test. Results: Among these 98 patients, the values of mutation burden varied from 5 to 1121 with mean value 161.8, 36 (36.7%) patients with smoking history and 34 (34.7%) patients were older than 65 years; the numbers of patients in I, II, III stage were 19 (19.4%), 16 (16.3%) and 63 (64.3%) respectively. 32 patients were classified into high mutation burden group, the other 66 patients classified into low mutation burden group. Survival analysis showed a significantly longer disease free survival (DFS) in low mutation burden group (p-value = 0.0133).Mutation burden was significantly associated with age ( < 65 vs ≥65, p-value = 0.0208) and smoking status (p-value = 8.67ⅹ10-4). Conclusions: The association between mutation burden and age or smoking status suggested the high risk for mutation burden accumulation. The significant difference of DFS between high mutation burden and low mutation burden groups reveals the potential of mutation burden as one of the prognostic factors in patients with lung adenocarcinomas.