Bone Cancer

Definition

Cancer that begins in the bone is called primary bone cancer. Primary bone cancer is relatively uncommon in comparison with secondary or metastatic cancer (occurring in another organ and spreading to bone).

Description

The bones in the body serve several purposes. They support and protect internal organs (for example, the skull protects the brain and the ribs protect the lungs). Muscles pull against the bones to make the body move. Bone marrow (the soft, spongy tissue in the center of many bones) makes and stores blood cells.

Cancer that begins is the bone is called primary bone cancer. It is found most often in the arms and legs, but it can occur in any bone in the body. Children and young people are more likely than adults to have bone cancer.

Primary bone cancers are called often called sarcomas. There are several types of sarcoma. Each type begins in a different kind of bone tissue. The most common are osteosarcoma, Ewing's sarcoma and chondrosarcoma.

Osteosarcoma is the most common type of bone cancer in young people. It usually occurs between the ages of 10 and 25. Males are affected more often than females. Osteosarcoma often starts in the ends of bones, where new bone tissue forms as a young person grows. It usually affects the long bones of the arms or legs.

Ewing's sarcoma usually is found in people between 10 and 25 years of age; teenagers are most often affected. This cancer forms in the middle part (shaft) of large bones. It most often affects the hipbones and the long bones in the thigh and upper arm. It also occurs in the ribs.

Chondrosarcoma is found mainly in adults. This type of tumor forms in cartilage, the rubbery tissue around joints.

Cancers that begin in the bone are quite rare. On the other hand, it is not unusual for cancers to spread to the bones from other parts of the body. When this happens, the disease is not called primary bone cancer. Each type of cancer is named for the organ or the tissue in which it begins. Cancer that spreads is the same disease and has the same name as the original (or primary) cancer.

Treatment for cancer that has spread to the bones depends on where the cancer started and the extent of the spread. About 80 percent of these metastatic lesions are from primary carcinomas, particularly of the breast, prostate, lung, kidney, thyroid, pancreas and stomach.

Symptoms

Patients may present with persistent pain, swelling, or tenderness of a bone. They may have unexplained fracture of one or more bones, sometimes without noticeable trauma.

Diagnosis

The presenting symptom is usually pain. Pathologic fracture may be present and is more common in the lower than the upper extremity.

The presenting radiologic finding on X-ray is often destruction of bone. In a patient with a known primary malignant tumor presenting with a painful, destructive lesion of bone, a diagnosis of metastatic cancer can be made with some assurance. However, there are individuals in whom the primary cancer is not yet recognized at the time when the early metastatic lesion in bone becomes painful.

A study called a bone scan or a skeletal survey may be done to pinpoint which bones have been affected.

Treatment

The treatment of cancer of the bone, especially metastatic cancer, has two goals: management of the neoplasm and management of the symptoms produced by the local lesion. Prognosis is affected by a patient's age, the size of the primary tumor, grade and stage, degree of lymphatic and blood vessel invasion, the duration of symptoms and the location of the tumor on the arm, leg or trunk.

Bone tumors are often treated with a combination of surgery, radiation therapy, and chemotherapy to improve the possibility of cure.

Surgery often has to be extensive, with a wide margin of tissue around the tumor being removed. Sarcomas involving muscles require removal of the entire affected muscle group.

Radiation therapy is used to prevent local recurrences of radiosensitive tumors and may be given either before or after surgery.

Chemotherapy - a number of drugs have proven to be effective in treating bone and soft tissue sarcomas. The dosages required to provide a good chance for cure often produce significant side effects. Effective single agents may include doxorubicin (Adriamycin), cyclophosphamide, high-dose methotrexate (with leucovorin rescue), ifosfamide, dacarbazine, vincristine, dactinomycin (Actinomycin D), etoposide and investigational agents. Combinations of these drugs are often used.

Even if a bone or soft tissue sarcoma is appears to be localized and could apparently be completely removed, there is still significant risk that tumor cells too small to detect have already spread to other places in the body. Additional treatment with chemotherapy (adjuvant chemotherapy) attempts to eliminate these tumor deposits.

Questions to Ask Your Doctor

Is it primary or secondary cancer of the bone?

Where has it spread from?

Do you recommend chemotherapy?

What is the prognosis?