Predicting Survival in Patients with Advanced Non-squamous Non-small Cell Lung Cancer: Validating the Extent of Metastasis

Purpose A number of factors related to overall survival (OS) have been addressed in advanced non-small cell lung cancer (NSCLC). This study was conducted to determine the impact of whole-body metastatic regions on survival outcome in advanced non-squamous NSCLC. Materials and Methods Between March 2005 and February 2011, 112 eligible patients with newly confirmed stage IV non-squamous NSCLC, available for epidermal growth factor receptor (EGFR) mutation status 18-21 analysis, and accessible for the determination of pretreatment whole-body metastatic regions were enrolled in this retrospective study. The total number of synchronous metastatic regions was scored according to the following disease sites: abdomen/pelvis, lung to lung/pulmonary lymphangitic spread, bone, pleura/pleural effusion/pericardial effusion, neck/axillary lymph nodes, other soft tissue, brain. Results The median age of the cohort was 65 years (range, 31 to 88 years). The median whole-body metastatic score was 2 (range, 1 to 6), and bone and lung to lung were the most common metastatic sites. EGFR mutations were observed in 40 (35.7%) patients with a deletion in exon 19 and Leu858Arg mutation in exon 21 being detected in 16 (40.0%) and 19 (47.5%) patients, respectively. Multivariate analysis for OS revealed that treatment factors (p=0.005), performance status (p=0.006), whole-body metastatic score (p