A genomic strategy to refine prognosis in early stage non-small cell lung carcinoma (NSCLC).

7026 Background. Although stage-specific classification identifies appropriate populations for adjuvant chemotherapy, this is likely an imprecise predictor for the individual patient with early stage NSCLC. METHODS: Using previously-described methodologies that employ DNA microarray data, multiple gene expression profiles ('metagenes') that predict risk of recurrence in patients with stage I disease were identified. This analysis used an initial 'test' cohort of patients with NSCLC (n = 89) that represented an equal mix of squamous cell and adenocarcinoma. Also, each histologic subset had equal number of patients who survived more than 5 years and those who died within 2.5 years of initial diagnosis. The performance of the metagene-based model generated on the training cohort was then evaluated in independent 'validation' sets, including two multi-center cooperative group studies (ACOSOG Z0030 and CALGB 9761). Importantly, the CALGB validation was performed in a blinded fashion. RESULTS: Classification tree analyses that sample multiple gene expression profiles were used to develop a model of recurrence, termed the Lung Metagene Model, that accurately assesses prognosis (risk of recurrence and survival), performing significantly (p<0.001, odds ratio: 16.1, multivariate analysis) better than pathologic stage, T-size, nodal status, age, gender, histologic subtype and smoking history. The accuracy of prognosis using the Lung Metagene Model exceeded 90% (leave-one-out cross validation) in the initial training set (n = 89), 72% in the ACOSOG (n = 25), and 81% in the CALGB (n = 84) datasets. The prognostic accuracy was consistent across histologic subtypes and stages of NSCLC. Importantly, this provides an opportunity to re-classify stage IA patients to identify a subset of 'high risk' patients that may benefit from adjuvant chemotherapy. Further, stage IB and II patients identified as 'low risk' for recurrence, and who present co-morbidities, could potentially be candidates for observation, and those patients predicted to be at 'high risk' may benefit from novel therapeutic trials. CONCLUSIONS: The Lung Metagene Model provides a mechanism to refine the estimation of an individual patient's risk for disease recurrence and thus guide the use of adjuvant chemotherapy in NSCLC. No significant financial relationships to disclose.

Duke Scholars

Author David Harold Harpole Jr. Surgery, Cardiovascular and Thoracic Surgery

Author Michael John Kelley Medicine, Medical Oncology