True or False. TNM is tissue and cancer specific.

• A. Not sure
• B. Partially
• C. False
• D. True

Answer: (D)

The main idea is that TNM staging is a flexible framework that is tailored to each cancer type. The letters T, N, and M describe tumor size/local spread, lymph node involvement, and distant metastasis, but the specific criteria for what counts as a certain T stage, which nodes are considered regional for N, and what constitutes metastasis M can differ by where the cancer is located. For example, breast cancer uses tumor size and involvement of chest wall or skin to define T, while pancreatic cancer looks at invasion into nearby vessels and organs. The nodal criteria follow the drainage pattern of the organ in question, so what counts as regional lymph nodes varies by cancer site. Distant metastasis is generally noted as absent or present across cancers (M0 vs M1), but the usual sites and implications of metastasis differ by cancer type. Because of these site-specific definitions, the TNM system is indeed tissue and cancer specific.