What Is Childhood Osteosarcoma?
Sarcomas are cancers that begin in the body's connective tissues. Sarcomas are often divided into two groups:
- Bone cancers, which begin in the hard part of the bone
- Soft tissue sarcomas that start in muscle, fat, fibrous tissue, blood vessels, nerves or other supportive tissues of the body
Osteosarcoma is the most common form of bone cancer in children.
The tumor usually starts in the faster-growing ends of the long bones in the arms and legs. Common places where the tumor is found are the lower end of the thigh bone, the upper end of the shin bone, and the upper end of the long bone of the upper arm. This tumor occurs less often in the jaw, spinal column, shoulder blades and pelvis.
Osteosarcomas are seen more often in boys than girls. It is most often seen in children between the ages of 10 and 20, but it can occur in younger children and adults.
Signs and Symptoms of Osteosarcoma
Symptoms of osteosarcoma include swelling, fractures and bone pain. The pain often worsens over time. Osteosarcoma is suspected when an X-ray shows destruction of the normal bone.
Diagnosis of Osteosarcoma
Diagnosis of osteosarcoma is made by biopsy of the involved bone. This is a surgical procedure done under general anesthesia where medication is given so the patient is not awake and will not feel any pain. A piece of the suspicious bone is removed and looked at under a microscope. Besides the biopsy, CT scan, bone scan, PET scan and MRI are performed to see if the disease has spread.
Treatment for Osteosarcoma
A combination of surgery and chemotherapy is used to treat osteosarcoma. Chemotherapy may be helpful in shrinking the tumor and preventing it from spreading. Radiation treatment is not a standard therapy but may be useful given in high doses in certain situations when a tumor is not easily resected (removed). In some situations, the doctor may recommend proton therapy. Proton therapy is a type of radiation therapy that targets the tumor while avoiding organs and healthy tissue. This means fewer short-term side effects and long-term complications from radiation. Cincinnati Children’s is one of only a few pediatric hospitals in the country that offers proton therapy.
After initial chemotherapy, scans are repeated to see how well the tumor responds. The results will help the doctors decide the type of surgery that will be necessary to save the limb or if amputation is needed.
In the past, amputation was the most common surgery used, but limb-salvage procedures are becoming more common. In this procedure, the cancerous bone and tissue are removed and replaced with artificial material or bone from another part of the body. However, the limb-salvage procedure is not always possible. The decision to perform this procedure will be made only if the X-rays and scans show there is no spread of the tumor, and that the tumor can be completely removed with tumor-free margins.
If these options cannot be done or if the bone is not strong enough, amputation is the only option. If an amputation is performed, an artificial limb is provided when healing is complete. In most cases, artificial limbs work very well.
After surgery, additional chemotherapy is needed. Osteosarcoma can often spread to the lungs. Your child will have chest CT scans to check for tumors in the lungs. The treatment for lung tumors is surgery. Sometimes more than one operation is needed to take out the tumors in the lungs. This treatment can be very effective in improving the survival rate of children whose lungs become involved.
Long-term Outlook
With the combination of surgery and chemotherapy, the 5-year survival rate for children younger than 15 years with osteosarcoma has increased from 40% in the mid 1970s to 76% in 2010 and is now nearly 70% in adolescents aged 15 to 19 years.
