Bone Cancer

Causes, Symptoms, Treatment, and Prevention of Bone Cancer

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

What is bone cancer and how is it different from cancer which has spread to the bones?  What are the symptoms?  What causes it?  And how is it best treated?

What is Bone Cancer?

Bone cancer is a type of cancer 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 whether it spread from another location to the bone (secondary).

Secondary bone cancer, or cancer that has spread to the bone from another part of the body, is much more common than primary bone cancer.   A cancer which has spread to bone from another region of the body is called by the name of the original tumor followed by the words "metastatic to bone."  For example, a breast cancer which has spread to the bones would not be called bone cancer, but rather "breast cancer metastatic to the bones."  Cancer that has spread to the bones is by definition stage 4 (metastatic) whereas cancer that starts in the bones (primary bone cancer) can be any stage depending on size and other characteristics.

Primary bone cancer is considered rare. We'll focus specifically on primary bone cancer here.

Types of Bone Cancer

There are several types of primary bone cancer, including:

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

Other types of cancer can occur in the bone, such as lymphoma and multiple myeloma. Lymphoma most often develops in the lymph nodes, but can begin in the bone. Multiple myeloma affects the cells of the bone marrow, not the actual cells of the bone, so it is not characterized as a true bone cancer.

Causes of Bone Cancer

Although we can't pinpoint exactly why malignant (cancerous) bone tumors form, we do know of some risk factors for the disease.

Researchers have discovered that some hereditary conditions can increase the risk of bone cancer.  Examples of hereditary conditions that may increase the risk of bone cancer include:

Adults with Paget's disease of the bone may also be at an increased risk of developing bone cancer.

Previous radiation therapy treatment has been associated with bone cancer. This correlation is strongest if the radiation therapy was given during childhood. This, however, does not make having radiation therapy as cancer treatment harmful or unsafe. For most people with cancer, the benefit of having radiation therapy far exceeds any risks. This risk does not include radiation exposure from routine x-rays.

Symptoms of Bone Cancer

Symptoms may vary based on the type of bone cancer, but pain is the most commonly experienced symptom. Bone cancer most often occurs in the long bones of the body (arms and legs), so these are the most common sites for pain.

Keep in mind that not all bone tumors are cancerous; some are benign (non-cancerous.) Bone pain is more often related to a benign condition, like an injury, than it is to cancer.

Other symptoms of bone cancer include:

  • Joint tenderness or inflammation
  • Fractures due to bone weakness - Fractures that occur in a bone which is weakened due to a tumor are referred to as pathological fractures.

Non-specific symptoms like fever, unintentional weight loss (weight loss without trying), fatigue, and anemia can also be symptoms of bone cancer, but are also indicators of other less severe conditions.

Diagnosing Bone Cancer

Symptoms combined with other findings during a physical exam may suggest the presence of bone cancer, but additional tests are needed to confirm any suspicion.

Imaging tests, like x-rays, MRIs, and CT scans, help identify any bone abnormalities. Other tests may include a bone scan, a specialized nuclear imaging test that allows doctors to see the metabolic activity of the bone. Bone scans identify areas in the bone that have new growth or have broken down -- signs that suggest the possibility that a cancer is present.

Ultimately, it is a bone biopsy that will rule out or confirm the presence of cancer. A bone 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.

Doing a biopsy on someone with primary bone cancer can be complex because there is a risk of spreading the cancer during the procedure. The procedure should be done by a surgeon who has experience performing bone biopsies on those with primary bone cancer.

If cancer is detected, it is then graded and staged by a pathologist. Grading and staging classifications vary based on the type of bone cancer. Ideally, the pathologist examining the sample will be experienced in diagnosing bone cancer.

Treatment of Bone Cancer

The key to successful treatment is having a treatment team that is experienced in primary bone cancer. Many types of bone cancer are very rare, and having a team that is highly experienced in managing bone cancer is a necessity. Several different types of doctors make up these unique treatment teams and 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. Many times, more than one treatment method. is required, such as surgery along with radiation therapy. Treatment varies based on type of bone cancer, if it has spread (metastasized), and other general health factors.

Getting a second opinion is very important when you have an uncommon tumor such as bone cancer.  Many people choose to get an opinion at one of the larger cancer centers, as these centers are more likely to have physicians who specialize in bone cancer treatment.

Surgery: Bone cancer is most commonly treated with surgery. Surgical treatment for bone cancer that has not spread involves removing the cancerous tissue and a small margin of healthy bone tissue surrounding it. Some tumors may require chemotherapy or radiation therapy in addition to surgical treatment.

Radiation Therapy: Radiation therapy uses specific types high energy beams of radiation to shrink tumors or eliminate cancer cells. Radiation therapy works by damaging a cancer cell's DNA, making it unable to multiply. Although radiation therapy can damage nearby healthy cells, cancer cells are highly sensitive to radiation and typically die when treated. Healthy cells that are damaged during radiation are resilient and are often able to fully recover.

Chemotherapy: Chemotherapy is often prescribed to treat bone cancer. Chemotherapy drugs work by eliminating rapidly multiplying cancer cells. However, there are other healthy cells in the body that multiply just as quickly, such as hair follicle cells, bone marrow cells, and cells lining the gastrointestinal tract.. Unfortunately, the effect of chemotherapy on these normal cells accounts for many of the side effects of chemotherapy.

Coping and Support

If you or a loved one have been diagnosed with bone cancer, you're probably feeling overwhelmed and frightened.  Reach out to family and friends.  Talking to others who have "been there" can be invaluable, and thankfully the internet now allows people with bone cancer to communicate online via social media and bone cancer organizations 24 hours a day.  Take time to learn about your cancer, and check out these tips on how to find good cancer information online.

Sources:

American Cancer Society. Bone Cancer. Updated 01/21/16. http://www.cancer.org/cancer/bonecancer/detailedguide/bone-cancer-what-is-bone-cancer

American Society of Clinical Oncology. Bone Cancer: Symptoms and Signs. Updated 08/2104.

National Cancer Institute. Osteosarcoma and Malignant Fibrous Histiocytoma of Bone Treatment – Health Professional Version (PDQ). Updated 03/20/16. http://www.cancer.gov/types/bone/hp/osteosarcoma-treatment-pdq

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