What is osteosarcoma?
Osteosarcoma also is referred to as osteogenic sarcoma. It is the name of a specific malignant disease or tumor of the bone. It can develop in any bone but usually occurs in the long bones of the arms and legs. Most cases of osteosarcoma are diagnosed between ten and twenty years of age and occur slightly more often in boys than girls. Osteosarcoma is the most common type of bone tumor and sometimes occurs in a bone that has received very high doses of radiation as treatment for another type of cancer that occurred earlier. In most cases, no one knows what causes this disease. It is not contagious, and nothing you have done or not done is responsible for your child's tumor.
What are the symptoms of osteosarcoma?
It may take some time before the tumor grows large enough to cause symptoms. Injury to the bone is often associated with the development of bone tumors. This injury is not the cause of the tumor, but it brings patients to a medical facility where x-rays reveal the tumor. The most common symptoms include a swollen, painful area that develops over the involved bone. Activity often increases the pain. Other than the pain caused by the tumor, the child usually feels well. The duration of symptoms may be short, although six months or more is not uncommon.
How is osteosarcoma diagnosed?
When a bone tumor is suspected, a thorough history, physical examination, and x-rays are done first. The only way to diagnose osteosarcoma is to obtain a piece of the tumor and examine it under the microscope. Osteosarcoma may spread (metastasize) to other parts of the body by invading the blood stream. It usually spreads to either the lungs or other bones. In order to determine if the tumor has spread, your child will need to undergo various diagnostic tests. The tests may include any or all of the following:
- X-rays. X-rays of the tumor site and surrounding area look at size and extent of the tumor. X-rays of the chest and entire body (skeletal survey) look for spread of the tumor.
- Surgical biopsy. This is the most accurate way of diagnosing and is done in all cases of osteosarcoma. Samples of the tumor will be removed by an orthopaedic (bone) surgeon and then examined closely under a microscope by a pathologist.
- Bone scan. A small amount of radioactive dye is injected into a blood vessel and the body is then scanned to detect any tumor in other bones.
- Computed tomography (CT) scan. A test that produces images of the scanned body part. A scan is used to see the size of the tumor and whether it has spread.
- Magnetic resonance imaging (MRI). A computerized magnetic scan that is used to see the tumor site to help determine the extent of the tumor.
- Blood tests. Complete blood counts and blood chemistries may be ordered. Blood may be tested for serum alkaline phosphatase, which is frequently elevated in the blood of someone with osteosarcoma.
An accurate staging diagnosis is very important to effective treatment of the disease. After all tests are completed and the diagnosis has been made, a group of doctors including oncologists, radiologists, pathologists, and surgeons will determine the state of the disease and the most effective treatment for it. The classifications system is as follows:
- Localized. The cancer cells have not spread beyond the bone or nearby tissue in which the cancer began.
- Metastatic. The cancer cells have spread from the bone in which the cancer started to other parts of the body. The cancer more often spreads to the lungs or to other bones.
How is osteosarcoma treated?
Osteosarcoma is usually best treated by using a combination of chemotherapy and surgery. Most often chemotherapy is given in a large vein using a central venous catheter before surgery to reduce the size of the tumor. Surgery is performed at a later stage to remove the residual tumor tissue.
When doctors must remove affected bone, whenever possible, the orthopedic surgeon performs a "limb sparing procedure" in which diseased bone is removed and replaced with artificial or donor bone. The goal of this technique is to maintain as much normal function of the affected limb as possible. Fewer and fewer children need amputation of the limb as other treatments are developed that require less extensive surgery. In either case, your child will receive physical therapy to aid in recovery.
You will receive much more information about your child's treatment plan for surgery and chemotherapy after all tests and scans are complete. During the course of therapy and after the treatment is completed, various follow-up studies such as x-rays, CT scans, and blood tests will be done to closely monitor your child's disease status.
What research is currently underway?
Current studies are examining how quickly the osteosarcoma responds to treatment as an indicator of the type of ongoing chemotherapy that is needed. Researchers are also evaluating the use of a biologic drug, interferon, with some patients. The drug Herceptin® is being evaluated in patients with metastatic osteosarcoma whose tumor cells express the protein called HER-2.
About treatment for osteosarcoma at Children's
Children's cancer and blood disorders program consistently achieves treatment results ranking it as one of the top 10 programs in the U.S. Children's treats the majority of children with cancer and blood disorders in Minnesota and provides patients with access to a variety of clinical trials of new treatments. Through our renowned solid tumors program, patients experience unparalleled family support, a nationally renowned pain management team, and compassionate, coordinated care.
If you are a family member looking for a Children's hematologist or oncologist or wanting to schedule an appointment, call our clinic at Children's – Minneapolis at (612) 813-5940.
If you are a health professional looking for consultation or referral information, please call Children's Physician Access at 1-866-755-2121 (toll-free) and ask for the on-call hematologist/oncologist.