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Stages of bone cancer
Staging describes or classifies a cancer based on how much cancer there is in the body and where it is when first diagnosed. This is often called the extent of cancer. Information from tests is used to find out the size of the tumour, which parts of the bone have cancer, whether the cancer has spread from where it first started and where the cancer has spread. Your healthcare team uses the stage to plan treatment and estimate the outcome (your prognosis).
The most common staging system for bone cancer is the TNM system. For bone cancer there are 4 stages. Often the stages 1 to 4 are written as the Roman numerals I, II, III and IV. Generally, the higher the stage number, the more the cancer has spread. Talk to your doctor if you have questions about staging.
The stages of bone cancer also depend on the grade. The grade describes how different the cancer cells look from normal cells, how quickly they grow and divide, and how likely they are to spread.
A stage is only given to bone tumours that start in the shoulders, arms, hips and legs (appendicular skeleton), the central part of the body (trunk) and the skull and face bones. There are no stages for bone tumours of the spine and pelvis. They are grouped into one category only (a T category), depending on the size of the tumour, where the tumour is within the spine or pelvis and whether it has grown into nearby areas.
When describing the stage, doctors sometimes use the words localized and metastatic.
Localized bone cancer means the cancer is only in the bone where it started and has not spread to other parts of the body. It includes stages 1, 2 and 3.
Metastatic bone cancer means the cancer has spread to another part of the body, such as the lungs. This is stage 4.
The tumour is 8 cm or smaller and low grade.
The tumour is larger than 8 cm or there are tumours in several different parts of the same bone (called discontinuous tumours). It is low grade.
The tumour is 8 cm or smaller and high grade.
The tumour is larger than 8 cm and high grade.
There are tumours in several different parts of the same bone. The cancer is high grade.
The cancer has spread to other parts of the body, such as to the lungs, the brain, other bones or nearby lymph nodes. This is called metastatic bone cancer. It can be low grade or high grade.
Recurrent bone cancer
Recurrent bone cancer means that the cancer has come back after it has been treated. If it comes back in the same place that the cancer first started, it’s called local recurrence. If it comes back in tissues or lymph nodes close to where it first started, it’s called regional recurrence. It can also recur in another part of the body. This is called distant metastasis or distant recurrence.