What is secondary bone cancer?

Bone cancer can start as either a primary or secondary cancer. The two types are different, and this page is only about secondary bone cancer.

Primary bone cancer – This means that the cancer starts in the bone.

See Bone Cancer (primary) for more information.

Secondary bone cancer – This means the cancer started in another part of the body but has now spread (metastasised) to the bone. It may also be called metastatic bone cancer, bone metastases or bone mets.

Cancer cells can spread from the original cancer (the primary cancer), through the bloodstream or lymph vessels, to any of the bones in the body. Bones commonly affected by secondary bone cancer include the spine, ribs, pelvis, and upper bones of the arms (humerus) and legs (femur).

Secondary cancer in the bone keeps the name of the original cancer. Because the cancer has spread, it is considered advanced or stage 4 cancer.

Which cancers spread to the bone?

Any type of cancer can spread to the bone. The cancers most likely to spread to the bone include:

• prostate cancer
• breast cancer
• lung cancer
• kidney cancer
• thyroid cancer
• myeloma (a type of blood cancer)
• melanoma.

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What types of secondary bone cancer are there?

Secondary bone cancer is described as two main types: osteolytic and osteoblastic.

Osteolytic – In this type, bone is broken down without new bone being made. In some cases, holes form in the bone. These are known as lytic lesions. They can weaken the bone and increase the risk of breakage or other problems.

Osteoblastic – In this type, new bone is formed in some areas, but it grows abnormally. These areas are called osteoblastic lesions. The lesions are very hard (dense) but they make the bone weak and deformed.

Most people with secondary bone cancer develop either osteolytic or osteoblastic changes, but some have both.

How common is it?

Secondary bone cancer is much more common than primary bone cancer in Australia. It is more common in adults than children. The bone is one of the most common sites cancer may spread to, along with the lymph nodes, liver, lungs and brain.