Source:http://linkedlifedata.com/resource/umls/id/C0854988
NCI: Stage IV includes: (Any T, Any N, M1a); (Any T, Any N, M1b). M1a: Lung cancer with separate tumor nodule(s) in a contralateral lobe; tumor with pleural nodules or malignant pleural (or pericardial) effusion. M1b: Distant metastasis. (AJCC 7th ed.)