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. The healthcare team uses information from tests to find out the size of the tumour, where cancer is in the bone, whether the cancer has spread from where it first started and where the cancer has spread. Doctors use the stage to plan treatment and estimate the outcome (prognosis).

The most common staging system for bone cancer is the TNM system. It describes the size of the tumour (T), if cancer is in the lymph nodes (N) and if cancer has spread, or metastasized (M). 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 larger the cancer is or the more the cancer has spread.

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 an arm or leg (appendicular skeleton), the central part of the body (trunk) and the bones of the skull.

There are no stages for tumours in the bones of the spine (vertebrae) or pelvis (hip). They are grouped into one category only (a T category) based on the size of the tumour, where it is in the spine or pelvis and if it has grown into nearby areas.

When describing the stage, doctors 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. Stage 4 tumours are metastatic.

Talk to your doctor if you have questions. Find out more about staging and grading cancer.

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 different parts of the same bone. The cancer is high grade.

The cancer has spread to the lungs. This is called metastatic bone cancer. It can be low grade or high grade.

The cancer has spread to other parts of the body, such as the lungs, brain, other bones or nearby lymph nodes. This is called metastatic bone cancer. It can be low grade or high grade.

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.