A multigene assay is prognostic of survival in patients with early-stage lung adenocarcinoma.

Abstract

Clinical staging does not adequately risk stratify patients with early stage non-small cell lung cancer. We sought to generate a real-time PCR (RT-PCR)-based prognostic model in patients with early stage lung adenocarcinoma, the dominant histology of lung cancer in the United States. We studied gene expression of 61 candidate genes in 107 patients with completely surgically resected lung adenocarcinoma using RT-PCR. We used crossvalidation methods to select and validate a prognostic model based on the expression of a limited number of genes. A risk score was generated based on model coefficients, and survival of patients with high- and low-risk scores were analyzed. We generated a four-gene model based on expression of WNT3a, ERBB3, LCK, and RND3. Risk score predicted mortality better than clinical stage or tumor size (adjusted hazard ratio, 6.7; 95% confidence interval, 1.6-28.9; P=0.001). Among 70 patients with stage I disease, 5-year overall survival was 87% among patients with low-risk scores, and 38% among patients with high-risk scores (P=0.0002). Among all patients, 5-year overall survival was 62% and 41%, respectively (P=0.0054). Disease-free survival was also significantly different among low- and high-risk score patients. This multigene assay predicts overall and disease-free survival significantly better than clinical stage and tumor size in patients with early stage lung adenocarcinoma and performs especially well in patients with stage I disease. Prospective clinical trials are needed to determine whether high-risk patients with stage I disease benefit from adjuvant chemotherapy.