Bone Cancer Stages
Bone cancer is a malignant tumor that arises from the cells that make up the bones of the body. This is also known as primary bone cancer. Primary bone tumors are tumors that arise in the bone tissue itself, and they may be benign or malignant (bone cancer). Benign (non-cancerous) tumors in the bones are more common than bone cancers.
When cancer is detected in bones, it either originated in the bones (as in primary bone cancer) or has spread to the bone after originating elsewhere (a metastasis or secondary cancer that spread to the bones). In fact, when cancer is detected in bone, it most often is a metastasis that has started in another organ or part of the body and then spread to the bones. This cancer that has metastasized to the bone is named for the site where the original cancer began (for example, metastatic prostate cancer that has spread to the bone). Breast, prostate, and lung cancers are among the types of cancers that commonly spread to the bone in their advanced stages. Less commonly, cancer can begin within the bone as primary cancer of the bone, and this is true bone cancer. Primary and metastatic secondary bone cancers are often treated differently and have a different prognosis.
There are other cancers that may begin in the bone even though they are not considered to be true bone cancers. Lymphoma is a cancer of the cells that are responsible for the immune response of the body. Lymphoma usually begins in the lymph nodes, but it sometimes begins in the bone marrow. Multiple myeloma is another cancer of the immune cells that typically begins in the bone marrow. These tumors are not considered primary bone cancers because they do not arise from the actual bone cells.
What are risk factors for bone cancer?
About 2,300 cases of bone cancer are diagnosed in the U.S. each year. Primary bone cancers are not common and account for far less than 1% of all cancers. Bone cancers are more common in children and younger adults than in older people. Cancer found in the bones of an older adult usually has spread to the bone after originating from another location in the body.
- Previous treatment with radiation therapy
- Previous chemotherapy with drugs known as alkylating agents
- Mutation in a gene known as the retinoblastoma (Rb) gene or other genes
- Associated conditions, such as hereditary retinoblastoma, Paget's disease of bone, Li-Fraumeni syndrome, Rothmund-Thomson syndrome, tuberous sclerosis, and Diamond-Blackfan anemia
- Implantation of metal to repair previous fractures
What causes bone cancer?
As with other cancers, there is no one cause of bone cancer. In general, cancers arise when normal cell growth and proliferation is disrupted, allowing abnormal cells (cancer cells) to divide and grow uncontrollably. A number of hereditary and environmental factors are likely involved in the development of bone cancers.
What are the different types of bone cancer?
Osteosarcoma
Osteosarcoma is the most common type of bone cancer. Osteosarcoma occurs most commonly in older children, teenagers, and young adults (10-19 years of age), and it is more common in males. The cancerous tissue in osteosarcoma in young people tends to develop at the ends of long bones in areas of active bone growth, often around the knee, either at the end of the thighbone (femur) or the shinbone (tibia) near the knee. The next most common location for bone cancer is in the bone of the arm (humerus). Nevertheless, it is possible for an osteosarcoma to develop in any bone. Depending on the appearance of the tumor cells under the microscope, there are also several different subtypes of osteosarcoma
Chondrosarcoma
Chondrosarcoma is the second most common bone cancer. It arises from cartilage cells that are attached to or cover bone. It is more common in people older than 40 years of age, and less than 5% of these cancers occur in people under 20 years of age. It may either grow rapidly and aggressively or grow slowly. Chondrosarcoma is most commonly found in the bones of the hips and pelvis.
Ewing sarcoma
Ewing sarcoma, sometimes referred to as the Ewing sarcoma family of tumors (ESFTs), is an aggressive form of bone cancer that is most common in children 4-15 years of age. It can occur either in the bones or in the soft tissues and is believed to arise from primitive nerve tissue. ESFTs are more common in males than in females. The most common location for Ewing sarcoma is the middle portion of the long bones of the arms and legs.
Pleomorphic sarcoma (malignant fibrous histiocytoma) of bone
Pleomorphic sarcoma is a cancer formerly referred to as malignant fibrous histiocytoma or MFH. This term is still used frequently. Pleomorphic sarcomas are typically not cancers of bone but of soft tissues. However, they may arise in the bone in up to 5% of cases. Pleomorphic sarcomas typically occur in adults and can be found anywhere in the body.
Fibrosarcoma
Fibrosarcoma is an uncommon type of bone cancer. It is most commonly arises behind the knee in adults.
Chordoma
Chordoma is a very rare cancer usually seen in people over 30 years of age. It is most commonly located in either the lower or upper ends of the spinal column.
What is the treatment for bone cancer?
An operation to remove the cancer is the mainstay of treatment for bone cancers. Surgical techniques can remove most bone cancers without requiring amputation of the affected limb. In some cases, amputation may be avoided with limb-sparing surgery. Sometimes, muscles and other tissues that surround the cancer also have to be removed. Reconstructive surgery may be needed, in addition to cancer resection, to help maximize function of the limb.
Is it possible to prevent bone cancer?
Since the exact cause of bone cancer is poorly understood, there are no lifestyle changes or habits that can prevent these uncommon cancers.