Bone tumours

Bone tumours develop when cells in the bone divide without control, forming a mass of tissue. Most bone tumours are benign, which means they are not cancer and cannot spread. However, they may still weaken bone and lead to fractures or cause other problems. Bone cancer destroys normal bone tissue and may spread to other parts of the body (called metastasis).

Benign bone tumours

Benign tumours are more common than cancer of the bones. These are a few common types of benign bone tumours:

• Non-ossifying fibroma is a single bone tumour found mostly in the long bones of children. It does not usually cause symptoms.
• Osteochondroma is a tumour in areas of bone and cartilage, more common in people under age 20.
• Giant cell tumour is a benign tumour, typically affecting the leg (malignant types of this tumour are uncommon).
• Osteoid osteoma is a bone tumour, often occurring in long bones, that occurs commonly in the early 20s.
• Osteoblastoma is a single tumour that occurs in the spine and long bones, mostly in young adults.

Metastatic cancer

When people have cancer in bones, it is often cancer that has spread there from elsewhere in the body. This is metastatic cancer. Even though it spreads to bone, it still acts and looks like the primary cancer.

Cancers that commonly spread to bone include:

• breast cancer
• prostate cancer
• lung cancer

Primary bone cancer

Primary bone cancer is cancer that forms first in bone.  It is less common than metastatic cancer.

There are around 500 cases of primary bone cancer in the UK each year.

The cause of bone cancer is not certain, but heredity may play a role. Also, high-dose radiation therapy or anticancer drugs may increase the risk of this type of cancer. These are some of the most common types of bone cancer:

• Osteosarcoma begins in bone cells and is most common in the thigh, shin and other larger bones. Most of the time, it is found in teenagers and young adults.
• Ewing's sarcoma also shows up in younger people between the ages of 10 and 20. Ribs, pelvis, leg, and upper arm are the most common sites. It usually shows up in bone, but can also start in soft tissue around bones. 
• Chondrosarcoma occurs most often in people between 40 and 70. The ribs, pelvis, leg, arm, and shoulder are more common sites of this cancer, which begins in cartilage cells.
• Chordoma is a tumour of the skull and bones of the spine. More common in adults over age 40, it tends to grow slowly and is less likely than other tumours to spread.

Although almost always found in bone, multiple myeloma is not a primary bone cancer. It is a bone marrow cancer. Bone marrow is the soft tissue inside bones.