Objective: The current staging system for lung cancer is not sufficient to accurately identify those patients with early-stage tumors who would benefit from postsurgery chemotherapy. The objective of this study was to validate a prognostic signature based on the expression of 5 RNA (ribonucleic acid) metabolism-related genes.
Methods: Five lung cancer microarray datasets, 3 from adenocarcinomas and 2 from squamous cell carcinomas, were analyzed. Kaplan-Meier survival curves and Cox proportional hazards models were used to evaluate the relationship between the classifier and recurrence and survival.
Results: Statistically significant differences in relapse-free survival and overall survival were observed when lung adenocarcinoma patients were divided into 3 risk groups. The prognostic information provided by the signature was independent from other demographic and disease variables, including stage. Significant differences in survival were observed between low-and high-risk groups in stage-IB patients: 5-year survival rates ranged from 83% to 100% in the low-risk groups, and from 30% to 71% in the high-risk groups, depending on the dataset. The RNA metabolism score additionally displayed an association with the benefit of adjuvant chemotherapy (P<. 001), suggesting that those patients in the low-risk group are not good candidates for this treatment.
Conclusions: The RNA metabolism signature is a prognostic marker that may be useful for predicting survival and optimizing the benefit of adjuvant chemotherapy in patients with lung adenocarcinoma.