Osteogenic Sarcoma
Osteogenic sarcoma, also called osteosarcoma, is the most common type of bone cancer in
children. It arises in the ends of the bones. The bones most frequently involved are the
large bones of the upper arm (humerus) and the leg (femur and tibia). Osteogenic sarcoma
usually occurs between the ages of 10 and 25 and is more common among males than females.
Young people with this type of cancer generally complain of pain and swelling, which
they sometimes blame on an injury. Diagnosis can be difficult, because the disease is
easily confused with local infection, effects of injury, glandular deficiencies,
arthritis, vitamin deficiencies, and benign tumors. Although osteogenic sarcoma may be
suspected by the way the bone looks on x-rays, diagnosis can be confirmed only by biopsy.
Because the disease commonly spreads (metastasizes) to other parts of the body, especially
the lungs, chest x-rays, lung tomograms, CT scans of the chest, and an x-ray skeletal
survey or bone scan may also be done before treatment.
Surgery (amputation or limb-sparing) is the primary method of treatment, followed by a
course of chemotherapy using one or more anticancer drugs. A prosthesis (artificial limb)
and physical rehabilitation may be important parts of therapy.
Causes of Osteogenic Sarcoma
The cause is not known. In some cases, osteosarcoma runs in
families and at least one gene has been linked to increased risk. This gene is also
associated with familial retinoblastoma, a cancer of the
eye which occurs in children and it appears to be a defective tumor inhibitor gene.
Osteosarcoma tends to occur in the bones of the thigh (distal end), upper arm (proximal end), and shin (proximal end). This
cancer occurs most commonly in larger bones and in the area of bone with fastest growth
rate. Osteosarcoma can occur in any bone, however.
The most common symptom initially is pain. As the tumor grows, there may be visible
swelling and limitation of motion. Tumors in the legs cause limping, while those in the
arms cause pain on lifting. Swelling over the tumor may be warm and slightly reddened.
Symptoms of Osteogenic Sarcoma
- Bone pain.
- Tenderness, swelling, or redness at the site of the bone pain.
- The first sign may be a bone fracture. The tumor may cause weakness in the affected area
of the bone. A fracture at the site of the tumor is called a "pathological
fracture" which occurs after what often seems like a routine movement. For example, a
young athlete who breaks an arm during a routine throw should be tested to ensure there is
no underlying bone problem, such as a tumor or cyst.
Diaganosis of Osteogenic Sarcoma
- X-ray of the affected area
- CT scan of the affected area
CT of the chest to see if the cancer has spread to the lungs
Open biopsy
(at time of surgery for diagnosis)
- Bone scan to see if the cancer has spread to other bones
Treatment of Osteogenic Sarcoma
Prior to surgery,
chemotherapy is given. This is strong medication, injected intravenously (into the
vein) to make the tumor shrink. Surgery is then used to remove any remaining tumor, while
attempting to spare the affected limb. Chemotherapy also treats any cancer cells which may
have spread to other parts of the body.
Limb-saving surgery is usually possible, but more radical surgery (such as amputation)
may be necessary for a permanent cure.
Common chemotherapy medicines include:
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