disease staging tumor stage SNOMEDCT:371508000 http://en.wikipedia.org/wiki/TNM_staging_system All child terms imported from RadLex, with Radlex Xrefs. Closest classification to ArrayExpress type data. tumour stage Tumor stage as classified by the TNM system. T describes the size of the tumor and whether it has invaded nearby tissue, N describes regional lymph nodes that are involved, M describes distant metastasis (spread of cancer from one body part to another). Helen Parkinson