Bone cancer causes and risk factors

Cancers that start in the bones (known as primary bone cancer) are uncommon, representing fewer than 1 percent of all cancer cases diagnosed, according to the American Cancer Society. In 2023, approximately 3,970 new bone cancers are expected to be diagnosed in the United States.

What causes bone cancer?

The exact causes of bone cancer are unknown, but certain factors may increase a person's risk for developing bone cancer. Some examples are genetic disorders and previous treatments for other conditions.

Bone cancer risk factors

Risk factors for bone cancer may vary, but it's important to remember that not everyone with one of these risk factors will go on to develop cancer. Most people who receive a bone cancer diagnosis don't have any known risk factors.

Is bone cancer hereditary?

Several hereditary syndromes caused by mutations in specific genes are considered risk factors for bone cancer, including:

• Li-Fraumeni syndrome, Rothmund-Thompson syndrome and mutation of the retinoblastoma gene (associated with a rare eye cancer) have been associated with an increased risk in children for developing osteosarcoma.
• Multiple exostoses syndrome (also known as multiple osteochondromas syndrome), an inherited condition associated with bumps of cartilage on the bones, has been associated with an increased risk for chondrosarcoma.
• Some osteosarcomas and chordomas have been found to run in families, but the underlying genetic mutation has not been identified.

Learn more about genetic counseling and genetic testing

Other conditions linked to bone cancer

Paget's disease: This non-cancerous condition causes the bones to become thick and brittle, and to break easily. Paget’s disease has been associated with bone cancer in approximately 1 percent of individuals. (Note: Paget’s disease of the breast, a rare form of breast cancer, is unrelated to Paget’s disease of the bone.)

Multiple enchondromatosis: Patients with many benign cartilage tumors, known as enchondromas, are at increased risk for developing chondrosarcoma.

Previous treatments that may increase risk

Radiation: Exposing bones to high doses of radiation, such as the type of radiation therapy used in cancer treatments, may increase the risk of a primary bone cancer forming in those areas. This risk is higher in young adults. Radioactive minerals such as radium or strontium can build up in the bones and may also cause primary bone cancers.

Bone marrow transplantation: Individuals who have undergone a bone marrow transplant for the treatment of another condition may be at an increased risk for developing osteosarcoma.

Learn more about orthopedic oncology

Next topic: What are the symptoms of bone cancer?