Grading and staging of bone cancer

Grading Back to top

Grading describes the appearance of the cancer cells under a microscope. The grade gives an idea of how quickly the cancer may develop. The most common grading system for bone cancer uses two grades: low-grade and high-grade.

Low-grade means that the cancer cells look very similar to normal bone cells. They are usually slow-growing and are less likely to spread.

In high-grade tumours the cells look very abnormal. They’re likely to grow more quickly and are more likely to spread. All Ewing’s sarcomas| are high-grade.

Staging Back to top

The stage of a cancer describes its size and whether it has spread. The stages of bone cancer are also based on the grade of the cancer.

There are two different staging systems used for bone cancer. This is the Enneking staging system, which is commonly used to stage bone cancers:

 

Stage 1

The cancer is low-grade and hasn’t spread beyond the bone. Stage 1 is further divided into:

• Stage 1A The cancer is low-grade and is still completely inside the bone it started in. The cancer may be pressing on the bone wall and causing a swelling, but it has not grown through it.
• Stage 1B The cancer is low-grade and has grown through the bone wall.

Stage 2

The cancer is high-grade and hasn’t spread beyond the bone. Stage 2 is further divided into:

• Stage 2A The cancer is high-grade and is still completely inside the bone it started in.
• Stage 2B The cancer is high-grade and has grown through the bone wall.

Stage 3

The bone cancer may be any grade and has spread to other parts of the body, such as the lungs.