The favorable prognostic significance of atelectasis in patients with advanced non-small cell lung cancer: results of a prospective observational study.

Purpose: For lung cancer, the TNM staging system included atelectasis (At) as a negative prognostic factor, within the T category. However, according to our clinical experience, we observed the opposite. The aim of the study was to evaluate the influence of At on patient outcome for unresectable stage III and IV non-small cell lung cancer (NSCLC).