Pediatric Osteosarcoma

Osteosarcoma is cancer of the bone. The cancer (malignant) cells make immature bone cells (osteoid). Osteosarcoma is very rare, but it is the most common type of bone cancer in children and teens. It is most common in teens and young adults.

The cancer most often grows in the ends of long bones, especially the bottom of the thigh bone (femur) and the top of the larger shin bone (tibia). The top of the upper arm bone (humerus) is another common place it grows.

The types of osteosarcoma include:

• High-grade. This is fast-growing cancer. Most osteosarcoma in children is high-grade. There are several sub-types of high-grade osteosarcoma.
• Intermediate-grade. This type is uncommon. It is between high- and low-grade.
• Low-grade. This is slow-growing cancer. There are two sub-types of low-grade.

The exact cause is not known. The cancer may be caused by changes in the DNA of the cells. In most cases, these changes are not passed on from parents to children. They happen by chance.

A child with one of certain rare genetic cancer syndromes may be at higher risk of osteosarcoma. Having radiation or chemotherapy treatment for other cancers also increases the risk.

Other risk factors for osteosarcoma include:

• Age between 10 and 30 years
• Tall height
• Male sex
• African-American race
• Certain bone diseases

Symptoms can occur a bit differently in each child. They can include:

• Pain at the site of the tumor
• Swelling at the site of the tumor
• Lump (mass) in the area
• Increased pain with activity or at night
• A bone that breaks for no known reason

The symptoms of osteosarcoma can be like other health conditions. Make sure your child sees a health care provider for a diagnosis.

Your child's health care provider will ask about your child's health history and symptoms. He or she will examine your child. Your child may be referred to a specialist. This may be a bone specialist (orthopedic surgeon) or a bone cancer specialist (orthopedic oncologist). Your child may have tests such as:

• X-ray. An X-ray uses a small amount of radiation to take pictures of bones and other body tissues.
• Blood tests. Some test results may be abnormal with osteosarcoma. For example, liver tests and the erythrocyte sedimentation rate (ESR) may be higher than normal.
• CT scan. This test uses a series of X-rays and a computer to make detailed images of the body.
• MRI. This test uses large magnets, radio waves and a computer to make detailed images of the inside of the body.
• Bone scan. A small amount of radioactive dye is injected into a vein. The whole body is scanned. The dye shows up in areas of bone where there may be cancer.
• Positron emission tomography (PET) scan. For this test, a radioactive sugar is injected into the bloodstream. Cancer cells use more sugar than normal cells, so the sugar will collect in cancer cells. A special camera is used to see where the radioactive sugar is in the body. A PET scan can sometimes spot cancer cells in different areas of the body, even when they can’t be seen by other tests. This test is often used in combination with a CT scan. This is called a PET/CT scan.
• Biopsy of the tumor. A sample of the tumor is taken and checked under a microscope for cancer cells. A biopsy is needed to diagnose osteosarcoma. The biopsy may be done with a needle or with surgery. It’s very important that a biopsy be done by a doctor with experience and knowledge about bone tumors..

After a diagnosis of osteosarcoma, other tests will be done. These help your child's health care providers learn more about the cancer. They will show how much and how far the cancer has spread (metastasized) in your child's body. A stage grouping is then assigned.

The most commonly used system uses stage groupings with a value of 1 to 3. They are written as Roman numerals I, II and III. Some staging systems add a stage 4 (IV). The higher the number, the more advanced the cancer is. Letters and numbers can be used after the Roman numeral to give more details.

Staging for osteosarcoma also takes into account the grade of the cancer. This is a measure of how much the cancer cells look like normal cells. A 1 or 2 is used. In grade 1 tumors, the cancer cells look a lot like normal cells and tend to grow and spread slower than grade 2. This may also be called a low-grade tumor. Grade 2 may be called high grade, and the cells look very different from normal cells.

The stage of a cancer is one of the most important things to know when deciding how to treat the cancer. Be sure to ask your child's health care provider to explain the stage of your child's cancer to you in a way you can understand.

Treatment will depend on the stage and other factors. The cancer can be treated with any of the below:

• Surgery. Surgery may be done to try to save the arm or leg. This is known as limb-salvage or limb-sparing surgery. Or surgery may be done to remove an arm or leg (amputation). Surgery may be done to remove tumors in other parts of the body.
• Chemotherapy. These are medicines that kill cancer cells. They are usually given before surgery. They may also be given after surgery. Your child may have a port or catheter inserted in order to receive the medicines into a vein (IV). Chemotherapy is given in cycles with periods of rest.
• Radiation therapy. These are high-energy X-rays or other types of radiation. Radiation is used to kill cancer cells or stop them from growing. It is not often used to treat osteosarcoma. It may be used when a tumor can’t be fully removed with surgery. Or it may be used to slow the growth of a tumor and control symptoms. Radioactive medicines may also be given into a vein (IV).
• Clinical trials. Ask your child's health care provider if there are any treatments being tested that may work well for your child.
• Supportive care. Growth factor may be given to help the bone marrow make blood cells. Other medicines may be given for side effects of treatment. Pain medicines may also be given.

With any cancer, how well a child is expected to recover (prognosis) varies. Keep in mind:

• Getting medical treatment right away is important for the best prognosis. Cancer that has spread is harder to treat.
• Ongoing follow-up care during and after treatment is needed.
• New treatments are being tested to improve outcome and to lessen side effects.

A child may have complications from the osteosarcoma or from treatment, such as:

• Infection or bleeding from surgery
• Loose or broken grafts or rods from limb-salvage surgery
• Hair loss, mouth sores, nausea, vomiting, diarrhea, increased infections, easy bruising and bleeding and feeling tired from chemotherapy
• Skin irritation, hair loss, nausea, diarrhea, poor bone growth, organ damage and new cancers from radiation
• Emotional and physical challenges from the tumor, surgery or other treatments
• Heart and lung problems
• Problems with growth and development
• Learning problems
• Changes in sexual development
• Problems with the ability to have children (fertility) in the future
• Return of the cancer
• Growth of other cancers

Call the health care provider if your child has:

• Symptoms that get worse
• New symptoms
• Side effects from treatment