Causes and Treatment of Bone Cancer

An Uncommon Cancer Most Commonly Seen in Youth

drawing the words bone cancer
What is bone cancer, what are the causes, and how is it treated?. Istockphoto.com/Stock Photo©vitanovski

Bone cancer is a type of malignancy that can affect both children and adults, although it is more common in children and teens. It is categorized based on whether the cancer originated in the bone (primary) or has spread from another location to the bone (secondary).

Understanding Bone Cancer

Primary bone cancer is considered rare. There are several types of primary bone cancer, including:

  • chondrosarcoma (affecting mainly the pelvis, upper leg, and shoulder)
  • Ewing's sarcoma (seen commonly in the backbone, pelvis, arms, and legs)
  • malignant fibrous histiocytoma (mostly affecting the knee and arms)
  • fibrosarcoma chordoma (mainly affecting the skull and bones of the middle face)

Osteosarcoma, chondrosarcoma, and Ewing's sarcoma are the most commonly diagnosed types of primary bone cancer.

Understanding Secondary Bone Cancer

Secondary bone cancer is much more common than primary bone cancer. As a rule, when secondary bone cancer is diagnosed, we refer to the cancer by the site of origin rather than the organ it has affected. For example, if a bone cancer caused by a breast cancer that has spread (metastasized) would not be called bone cancer but rather "breast cancer metastatic to the bones."

Secondary bone cancer is considered serious and classified as stage 4 (metastatic) disease since it, by its very nature, involves multiple organs.

By contrast, primary bone cancer can be classified from stage 1 to stage 4 depending on its size, characteristics, and location.

Causes of Primary Bone Cancer

Although we don’t the exact mechanisms that give rise to primary bone cancer, we do know many of the risk factors associated with the disease.

Chief among these are hereditary conditions that increase not only the risk of bone cancer but other types of cancers, as well. These include:

  • multiple exostoses ( a genetic condition that causes bumps on the bones)
  • Rothmund-Thomson syndrome (a genetic disorder characterized by skin rash, sparse hair, and malformed bones)
  • hereditary retinoblastoma (an inherited form of cancer that affects the retina and can lead to the formation of bone tumors)
  • Li-Fraumeni syndrome (a genetic disorder that predisposes a person to certain types of cancer)
  • Paget’s disease of the bone (a condition that gradually breaks down bone)

Previous radiation therapy has also been cited as a contributing factor to primary bone cancer, particularly if given during childhood. A typical X-ray is not considered dangerous, but higher doses (usually over 60 Gy) can definitely be a factor. This typically happens in a child being treated for another form of cancer who receives a course of radiation therapy.

Symptoms of Bone Cancer

Symptoms of bone cancer vary from person to person, but pain is by far the most common sign. It most often occurs in the long bones of the body, like those of the arms and legs.

Other symptoms can include:

Diagnosing Bone Cancer

If symptoms combined with findings from a physical exam suggest the presence of bone cancer, additional tests will be performed.

Imaging tests, like X-rays, magnetic resonance imaging (MRI), and computerized tomography (CT scans), can help identify bone abnormalities not seen by the naked eye. Another specialized imaging tool called a bone scan enables doctors to see the metabolic activity of the bone. By doing so, they can detect new growth or where bone matter may have broken down.

Ultimately, a bone biopsy will provide the definitive proof of bone cancer. The biopsy involves the removal of a small amount of bone tissue to be examined under a microscope. It usually takes less than an hour and can be done as an outpatient surgical procedure.

Performing a biopsy on someone with primary bone cancer can be tricky since there is a risk of spreading the cancer the site of origin. It requires a skilled surgeon highly experienced in treating patients with bone cancer.

Treatment of Primary Bone Cancer

The key to successful treatment is having a medical team experienced in primary bone cancer. Your team might include medical oncologists, radiation oncologists, radiologists, surgical oncologists, orthopedic oncologists, and specialized pathologists.

There are three standard forms of treatment for primary bone cancer: surgery, radiation therapy, and chemotherapy. Oftentimes, more than one form of treatment is needed.

  • Surgery is the most common treatment for bone cancer. Surgical treatment for non-metastasized bone cancer involves the removal of cancerous bone tissue and a small margin of healthy tissue surrounding it. Radiation or chemotherapy might be performed afterward to clear up any remaining cells.
  • Radiation therapy uses high-dose radiation to either shrink tumors or eliminate cancer cells following a procedure. It can also be used for palliative purposes to reduce pain. Although radiation therapy can damage nearby healthy cells, those cells tend to be more resilient than cancerous ones and are usually able to recover fully.
  • Chemotherapy works by killing rapidly multiplying cells. These include both cancer cells and other cells that are fast replicating, including hair follicles, bone marrow, and cells lining the gastrointestinal tract. As such, chemotherapy can have considerable side effects.

A Word From Verywell

If you or a loved one has been diagnosed with bone cancer, it’s natural to feel overwhelmed and frightened. Reach out to family and friends. Talking to others who have been there, whether through social media or in support groups organized by your clinic or community center, can help enormously.

Take it one day at at time and try to learn as much about your disease as you can. By doing so, you can become an advocate for your own care. This will not only help you cope better, it can give you a stronger sense of control and self-determination in a process that can often be overwhelmed by specialists.

Sources:

American Cancer Society. "Bone Cancer." Atlanta, Georgia; updated January 21, 2016.

National Cancer Institute. "Osteosarcoma and Malignant Fibrous Histiocytoma of Bone Treatment—Health Professional Version (PDQ)." Washington, D.C.; issued March 20, 2016.

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