About secondary bone cancer

This section helps you understand more about secondary bone cancer – cancer that has spread to the bone from another part of the body. It includes general information about how secondary bone cancer is diagnosed and treated.

Learn more about:

• What is secondary bone cancer?
• Which cancers spread to the bone?
• The bones
• What types are there?
• Who gets secondary bone cancer?
• What are the causes?

What is secondary bone cancer?

Bone cancer can start as either a primary or secondary cancer. The two types are different, and here we only talk about about secondary bone cancer.

Primary bone cancer

This means that the cancer starts in the bone.

For more on this, see Primary bone cancer.

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. You may find it useful to look at information about the primary cancer type.

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.

The bones

A typical healthy adult has over 200 bones in their body.

Bones have a number of important functions:

• support the body
• protect internal organs
• are attached to muscles to allow movement
• contain bone marrow, which produces and stores new blood cells
• store proteins, minerals and nutrients, such as calcium.

Bones are made up of different parts, including a hard, outer layer (known as cortical or compact bone) and a spongy inner core (known as  trabecular or cancellous bone). The bone marrow is found in this spongy core.

Cartilage is the tough material at the end of each bone that allows one bone to move against another. The meeting point of two bones is called a joint.

Bones have two types of cells – osteoblasts and osteoclasts.

Osteoblasts create new bone and osteoclasts break down old bone. Normal bone is constantly going through a process called  remodelling, in which old bone is broken down and replaced with new bone.

Bones of the body

Cancer can spread to any bone in the body. Bones commonly affected include the spine, ribs, pelvis and upper bones of the arms and legs.

Body structure

What types of secondary bone cancer are there?

There are two main types of secondary bone cancer:

• 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.

Who gets secondary bone cancer?

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.

What are the causes?

Secondary bone cancer is always caused by cancer cells spreading to the bone from a primary cancer. It is not fully understood why some people develop secondary bone cancer and others don’t.

Listen to our podcast series for people affected by advanced cancer