Physicians use a standardized system called the American Joint Commission on Cancer (AJCC) staging system to describe the significant characteristics of all cancers. This system uses four distinct characteristics based on similar treatment and outcomes data.

These characteristics are:

  • Tumor size (T)
  • Tumor lymph node involvement (N)
  • The presence or absence of tumor spreading or metastasizing (M)
  • The characteristic appearance under the microscope to the pathologist , described as (G)

These characteristics apply to bone and soft-tissue sarcomas as well.

Stages are expressed in numbers, with stage I tumors generally being considered early stage, small and lower grade, while stage IV are advanced cancers that have already spread from the primary site.