Types of bone cancer

A primary bone cancer is one that starts in the bones. The cancer cells are bone cells that have become cancerous. All the information in this section is about primary bone cancer.

A secondary cancer in the bones has spread from somewhere else in the body. The cancer cells are like the cells of the original tumour. So if you have had breast cancer and it spreads to the bones, the cancer cells in the bones will actually be breast cancer cells.

We keep stressing this because it is very important when you are looking for information on cancer. If you have a secondary cancer, you need to look in the section for your original cancer type. The behaviour of the cancer, including the treatment that it will respond to, depends on where the cancer starts in the body.

The most common type of primary bone cancer is osteosarcoma. It is most often diagnosed in teenagers and young adults but can occur at any age. Osteosarcomas can grow anywhere in the skeleton. But the most common sites are the

• Lower thigh (femur)
• Shin bone (tibia)
• Upper arm (humerus)

This is named after the surgeon who first described it. This bone cancer is also most often diagnosed in teenagers.

Ewing's sarcoma most often starts in the pelvis (hips), thigh (femur) or shin (tibia) bones. It is also possible to get a Ewing's tumour in the soft tissues of the body. Soft connective tissue tumours are called soft tissue sarcomas. If you have a soft tissue Ewing's tumour, you will have the type of treatment described in this section. These tumours respond to the same treatment as Ewing's bone tumours.

This is a type of primary bone cancer most often diagnosed in adults over the age of 40. It is relatively rare – about as common as Ewing's sarcoma. Chrondrosarcoma is a cancer of cartilage cells. The cancer produces cartilage (chondroid) which makes abnormal bone or abnormal cartilage growth. Cartilage is the shiny, smooth substance that normally covers the ends of bones in the joints. It provides support for the joint and allows bones to move smoothly over one another. Chondrosarcoma can grow inside a bone or on the bone surface. So islands of cartilage can be found inside the bone or on the surface in an area where it wouldn't normally grow. This bone tumour is usually slow growing. The most common sites for chondrosarcoma are the

• Pelvis (hips)
• Thigh bone (femur)
• Upper arm (humerus)
• Shoulder blade (scapula)
• Ribs

Spindle cell sarcomas are very similar to osteosarcomas but do not produce a bony substance called osteoid (whereas osteosarcomas do). They tend to occur in adults over the age of 40. There are several types of spindle cell sarcoma including

• Undifferentiated sarcoma of bone
• Malignant fibrous histiocytoma
• Fibrosarcoma
• Leiomyosarcoma

The term spindle cell sarcoma is used to describe any sarcoma that is not an osteosarcoma. But they behave and are treated in a similar way to osteosarcoma.

Undifferentiated sarcoma of bone means that the cells are not specialised. They are quite primitive (immature) and it isn't possible to tell what type of normal cells they started from within the bones. When the cells are more specialised in spindle cell sarcoma, your specialist will classify it as histiocytoma, fibrosarcoma or leiomyosarcoma, according to the appearance of the cells under a microscope.

Malignant fibrous histiocytoma is a very rare type of spindle cell sarcoma that tends to be found in middle aged adults. The arms and legs are the most common sites.

Fibrosarcoma is also very rare and most often diagnosed in middle aged adults. The most common site for fibrosarcoma is the thigh bone (femur).

Leiomyosarcoma of bone is extremely rare and very little is known about it.

Chordomas are a very rare, slow growing type of bone cancer. They are most common in people between 40 and 60 years of age. They tend to occur more often in women than men. There are around 20 cases in the UK each year.

Chordomas develop from the notochord. The notochord forms the early spinal tissue in a foetus developing in the womb. After about six months, this tissue is replaced by the bone. But sometimes small areas of the notochord may remain.

About 2 out of 5 chordomas (35 to 40%) occur in the skull or the bones in the middle area of the face. The rest develop in the bones of the spine (the vertebrae). About half of these are in the lower part of the spine. Chordomas do not usually spread, but if they do the most common places are the lungs, nearby lymph nodes, the liver, and skin.

We have detailed information about chordomas and their treatment in our question and answer section.