Bone cancer occurs when a tumor, or abnormal mass of tissue, forms in a bone. A tumor may be malignant, that is growing aggressively and spreading to other parts of the body. A malignant tumor is often referred to as cancerous. Cancer that begins in the bones is rare. According to University of Maryland Medical Center, only about 2,000 cases are diagnosed in the U.S. each year.
Primary bone cancers are the most serious of all bone cancers. They form directly in the bones or surrounding tissue such as cartilage. Cancer can also spread (metastasize) from another part of your body to your bones. This known as secondary bone cancer, and this type is more common than primary bone cancer.
Common types of primary bone cancers include:
This is the most common type of bone cancer. It occurs when cancer cells grow in the bone marrow and cause tumors in various bones. Multiple myeloma usually affects older adults.
Osteosarcoma (Osteogenic Sarcoma)
This cancer generally affects children and teenagers but can also occur in adults. It has a tendency to originate at the tips of the long bones in the arms and legs. Osteosarcoma may also start in the hips, shoulders, and other locations. It affects the hard tissue that provides the outer layer of our bones.
This cancer may occur in the pelvis, thigh areas, and shoulders of older adults. It forms in the subchondral tissue, which is the tough connective tissue between the bones.
Ewing’s sarcomas are rare cancers that either begin in the soft tissues surrounding the bones or directly in the bones of children and young adults. The long bones of the body (arms and legs) and the pelvis are commonly affected.
The cause of bone cancer is not exactly known, but there are certain factors that may contribute to or increase a person’s chances of forming abnormal growths in the bone. These include:
Abnormal Cellular Growth
Healthy cells continually divide and replace older cells. After completing this process they die. Abnormal cells, however, continue living. They start forming masses of tissue that turn into tumors.
Radiation therapy, which kills dangerous cancer cells, can be used to treat bone cancer. However, osteosarcoma may form in some people who receive the treatment. The use of high dosages of radiation may be a factor in this development.
The following may be risk factors for bone cancer:
- family history of cancer
- having received radiation treatment or therapy in the past
- having Paget disease, a condition that causes the bones to break down and then grow back abnormally
- having or having had multiple tumors in the cartilage (connective tissue in the bone)
The symptoms of bone cancer are:
- pain and swelling in the affected bone(s)
- feeling tired or fatigued
Less common symptoms include:
- broken bones
- weight loss
Doctors classify bone cancer in stages, and these stages describe where the cancer is, what it is doing, and how much it has affected other parts of the body.
- Stage l: Cancer has not spread from the bone.
- Stage ll: Cancer has not spread but may become invasive (a threat to other tissue).
- Stage lll: Cancer has spread to one or more areas of the bone and is invasive.
- Stage lV: Cancer has spread to the tissues surrounding the bone and to other organs such as the lungs or brain.
The following diagnostic methods may be used to determine the stage of cancers in the bones:
- biopsy (analyzes a small sample of tissue to diagnose cancer)
- bone scans (checks the condition of the bones)
- blood test
- imaging testing that includes magnetic resonance imaging (MRI), X-ray and computed tomography (CT) scan (provides in-depth views of the bones’ structure)
Treatment depends on the stage of cancer, your age and overall health, and the size and location of the tumor.
Medications that treat bone cancer include:
- chemotherapy drugs for multiple myeloma
- pain medications to relieve inflammation and discomfort
- bisphosphonates (drugs that prevent bone loss) to help protect bone structure
- cytotoxic drugs to prohibit or stop the growth of cancerous cells
Your doctor may recommend radiation therapy to kill the cancer cells.
Your doctor may surgically remove tumors or affected tissue. Surgery to remove and replace damaged bone is an option to stop cancers that spread quickly. For extensive bone damage in the arms or legs, amputation may be needed.
Your physician may add alternative therapies that include herbal treatments to your care plan. However, this must be done with careful consideration as some alternative treatments may interfere with chemotherapy and radiation treatments.
The five-year survival rate for bone cancer greatly depends on the location and stage of cancer when first diagnosed. More than 75 percent of people with bone sarcomas survive more than five years.