Bone Cancer

Bone cancer is a rare cancer that occurs in the bone and destroys normal bone tissue. Although it may afflict any bone in the body, bone cancer typically affects long bones such as those found in the arms and legs. Approximately, 2,800 cases of bone cancer are diagnosed in United States every year, which accounts for less than one percent of all cancers. Bone cancers are classified into three main types, based on the type of cell the cancer first affects. Although symptoms of bone cancer may vary between individuals, pain is typically the most common symptom.  Treatment options usually include surgery, chemotherapy, radiation, or a combination of these treatments. A treatment regimen is usually tailored to the specific type of bone cancer.

Symptoms

Symptoms of bone cancer include:

• Bone fracture (especially as a result of a minimal injury)
• Bone pain
• Fatigue
• Swelling in the affected area
• Weight loss
• The presence of a mass or lump in the affected area

Causes And Risk Factors

The primary cause of bone cancer is currently unknown. However, the following factors may put you at a greater risk for developing bone cancer:

• Inherited genetic syndromes. Certain inherited rare genetic disorders such as Li-Fraumeni syndrome or hereditary retinoblastoma may increase the risk of developing bone cancer.
• Paget's disease of the bone. This condition affects the rate at which old bone is degraded and new bone is formed. This precancerous condition primarily affects older adults.
• Radiation therapy for cancer. Exposure to large doses of radiation may increase the risk of developing bone cancer.

Types Of Bone Cancer

Bone cancers are classified into three main types, based on which type of cell in the bone is affected by cancer. The most common types of bone cancer include:

• Osteosarcoma: usually develops in osteoblasts (cells that are responsible for bone formation) during the period of rapid growth that occurs in adolescence. The average age of diagnosis is 15.

• Chondrosarcoma: typically begins in cells that produce cartilage and are commonly found on the ends of bones. This type of bone cancer most often affects older adults.
• Ewing's sarcoma: is a rare type of bone cancer ,which affects the bone or soft tissue around it. It's not clear where in bone Ewing's sarcoma begins. Ewing's sarcoma occurs most often in children and young adults.

Diagnosis

In order to diagnose bone cancer your doctor will initially perform a physical exam and take a comprehensive medical history. Your doctor may order the following tests in order to confirm a bone cancer:

• X-rays.
• Bone Scan. This test is administered by injecting a small amount of radioactive material that accumulates in the bones and is detected by a scanner.
• Computed tomography (CT) Scan.
• A magnetic resonance imaging (MRI).
• Biopsy. A surgeon may perform a needle or incisional biopsy. In a needle biopsy, a surgeon will make a small hole in the bone and a remove a sample of the tissue with a needle like instrument. In an incisional biopsy, the surgeon cuts directly into the tumor and removes a sample.
• Alkaline phosphatase blood test. Alkaline phosphatase is an enzyme that is present in large amounts in the blood when the cells that form bone tissue are very active. However, high levels of alkaline phosphatase are normal in growing children and adolescents. Therefore this test may not be a reliable indicator of bone cancer on its own.

If you are diagnosed with bone cancer, your doctor will then determine the size and stage of your cancer. Stages of bone cancer include:

• Stage I.  This stage indicates that the bone cancer is limited to the bone and is not considered as aggressive.
• Stage II. This stage indicates that the bone cancer is limited to the bone but is considered high grade and aggressive.
• Stage III. This stage indicates that the bone cancer is present in two or more places on the same bone. This stage of bone cancer is considered high grade and aggressive.
• Stage IV. This stage of bone cancer indicates that cancer has spread beyond the bone to distant areas of the body.

Treatment

There is a vast array of treatment options available for patients with bone cancer. The extensiveness of treatment is most often determined by the stage of bone cancer. Some standard treatments include:

Surgery.This is the most common treatment for bone cancer. The goal of surgery is to remove all of the bone cancer. There are two basic types of surgery for bone cancer:

• Removal of cancer but not the limb. A surgeon may remove the entire tumor and some surrounding healthy tissue. Since some of the bone is removed with the cancer, the surgeon will replace the lost bone with some bone from another area of your body or with a special metal prosthesis.
• Removal of the limb. If the bone tumor is expansive or in a complicated part of the bone, a surgeon may be required to amputate the limb. However, vast improvements have been made to alternate surgical procedures and preoperative treatments that is procedure is becoming increasingly less common.

Chemotherapy. Chemotherapy is a cancer treatment that uses drugs to kill rapidly dividing cells. However, chemotherapy is not currently used to treat chondrosarcoma.

Radiation therapy. This type of therapy utilizes high-energy x-rays or other types of radiation to kill cancer cells.  It is often used in combination with surgery or to treat chondrosarcoma (which cannot be treated with chemotherapy).

Cryosurgery. This technique utilizes liquid nitrogen to freeze and kill cancer cells. It may be used as an alternative to conventional surgery.

Sources:

• Cancer.gov
• American Cancer Society
• Mayo Clinic