appreciation of the level of development of a cancer, divided into three criteria summarized with the characters TNM

1. T refers to the originating tumor status

  • T1 tumours are small tumors, usually not seen during physical or visual examination
  • T2 tumours are identified tumors that remain inside the original organ (e.g. prostate)
  • T3 tumours have broken through the covering or membrane of the original organ but have not yet spread into other organs
  • T4 tumours have spread into other body organs

2. N refers to the level of invasion of lymph node cells by tumor cells

  • NX – The lymph nodes cannot be checked
  • N0 – There are no cancer cells in lymph nodes close to the primary tumor
  • N1 – Cancer cells have been detected in lymph nodes

3. M provides the status of the metastases distribution

  • M0 – No cancer has spread outside the primary tumor
  • M1 – Cancer has spread outside the primary tumor

Oncologists use also subsclassifications of T2, T3 and M1.