Understanding Bone Cancer: Stages
What “Stages” Mean
Staging is a process that tells your doctor whether the cancer has spread and how far. The treatment and prognosis (outlook) for bone cancers depend, to a large extent, on the patient's stage at diagnosis.
The TNM staging system is used for all types of cancer, not just non-Hodgkin lymphoma. The letters TNM describe the amount and spread of cancer in your body.
- T: indicates how far the tumor penetrates.
- N: indicates whether the cancer has spread to surrounding lymph nodes.
- M: indicates metastasis, which means that cancer has spread to other body parts.
- G: indicates the tumor’s grade—how abnormal it looks under a microscope.
The stage is then described in Roman numerals from I to IV (1-4).
The stages of bone cancer are:
- Stage I: All stage I tumors are low grade and have not yet spread outside of the bone.
- Stage II: Stage II tumors have not spread outside the bone (like stage I) but are high grade.
- Stage III: Stage III tumors have not spread outside the bone. However, they are in more than one place on the same bone. They are high grade.
- Stage IV: Stage IV tumors have spread outside of the bone they started in. They can be any grade.
Even though the AJCC staging system is used for most cancers, many bone cancer specialists simplify the stages into localized or metastatic. Localized includes stages I, II, and III, while metastatic is the same as stage IV.