TNM Staging System

**Semantic type:** Classification

**Definition:** A system for clinicopathologic evaluation of tumors based on the extent of tumor involvement at the primary site (T, followed by a number indicating size and depth of invasion), and lymph node involvement (N) and metastasis (M) each followed by a number starting at 0 for no evident metastasis; numbers used depend on the organ involved and influence the prognosis and choice of treatment.

**Synonyms:** - AJCC staging system - TNM - TNM Staging - TNM staging system