Bone Sarcomas

Bone sarcomas arise from bone or cartilage. Some examples of bone sarcomas are: Osteogenic Sarcoma and Ewing's Sarcoma.

Osteogenic Sarcoma

Osteosarcoma is the most common type of bone cancer. It accounts for about 5% of all childhood cancers. In children, it occurs most commonly in the bones around the knee or in the upper arm. Osteosarcoma most often occurs in adolescents and young adults.

Risk Factors
The known risk factors for osteosarcoma are:

• Prior treatment for childhood cancer with radiation therapy and/or chemotherapy.
• Hereditary retinoblastoma, Li-Fraumeni syndrome, Rothmund Thomson syndrome.

However, most patients do nothave an identifiable risk.

Symptoms

Pain and swelling of the bone or a bone region are the common presenting features. Often, an injury may have occurred earlier in the area, but we do not believe that that type of injury causes osteosarcoma. Instead a minor injury probably felt more painful due to an already growing tumor.

Diagnosis
If your child has symptoms, the doctor may do x-rays or an MRI. If it is suspected that your child may have osteosarcoma, your doctor may recommend seeing an orthopaedic surgeon for a biopsy. A biopsy is removing a piece of tissue from the affected area. This tissue will be examined under a microscope to see if cancer cells are present. It is important that the orthopaedic surgeon has expertise in bone tumors. The biopsy must be planned properly to allow for "limb salvage" surgery later.

Prevention
There is currently no way to prevent osteosarcoma.

Staging
Currently, there is no staging system for osteosarcoma. Most patients are grouped depending on whether the cancer is found in only one part of the body or if it has spread from one part (localized disease) of the body to another (metastatic disease). Additional tests will need to be performed to see how far the disease has spread. The following groups are used to describe how osteosarcoma may spread:

• Localized
  The cancer cells have not spread beyond the bone or nearby tissue where the cancer began
  
  
• Metastatic
  The cancer cells have spread from the bone in which the cancer began to other parts of the body. Osteosarcoma most often spreads to the lungs. It may also spread to other bones.
  
  
• Recurrent
  The cancer has come back after it has been treated. It may come back in the tissues where it first started (local recurrence) or it may come back in another part of the body (metastatic recurrence).

The most common place for metastases to occur are in the lungs and other bones. Progressive disease refers to a tumor that continues to grow despite treatment.

Treatment
Treatment and prognosis depends on the stage of the disease, where it is found, and the patient's age and general health.

The treatments that are used to treat osteosarcoma are:

• surgery (taking out the cancer in an operation)
• chemotherapy (using drugs to kill cancer cells)

Localized Osteosarcoma
Chemotherapy is given initially to shrink the tumor. After 2-3 months, definitive surgery is performed. The goal is to remove all of the tumor, either by amputation or a "limb salvage" procedure. The latter refers to a surgical removal of the affected bones, which is replaced by a metal prosthesis or by bone from elsewhere in the body or from a cadaver. After the surgery, chemotherapy is given for another 3-5 months.

Metastatic Osteosarcoma
With more than one site of disease at diagnosis, a more intensive chemotherapy may be recommended. In addition, surgical removal of all visible tumor is attempted.

Recurrent Osteosarcoma
Treatment depends on where the cancer recurred, what kind of treatment was given before, as well as other factors.

If the cancer has come back only in the lungs, treatment may be surgery to remove the cancer in the lungs with or without chemotherapy. If the cancer has come back in other places besides the lungs, treatment may be combination chemotherapy.

Clinical trials are evaluating new chemotherapy drugs.

Clinical Trials available at Johns Hopkins

• Phase III Pilot Study of Three Intensification Regimens and Phase III Study of Intensification Therapy Plus Dexrazoxane in Patients With Newly Diagnosed, Nonmetastatic Osteosarcoma. (POG 9754)
  
  
• Phase II Study of Irinotecan in Children With Refractory CNS and Solid Tumors. (POG 9761)
  
  
• To open soon -- Phase I trial of Samarium 153 in recurrent or progessive diseases.

Ewing's Sarcoma/Primitive Neuroectodermal Tumor (PNET)

Ewing's Sarcoma/PNET is the second most common malignant bone tumor in children. It accounts for 1% of all childhood cancers. Ewing's Sarcoma can occur in any bone of the body, but most commonly in the pelvis, thigh, lower leg, upper arm and rib.

Risk Factors
Ewing's Sarcoma/PNET is most commonly a disease of white children. Rates in whites are approximately 9 times higher than those in blacks. There are no known environmental risk factors.

Symptoms
Pain, stiffness, or tenderness in the bone are most common.

Diagnosis
If your child has symptoms, the doctor may do x-rays and blood tests. If it is suspected that your child may have Ewing's Sarcoma/PNET, your doctor may do a biopsy. A biopsy is removing a piece of tissue from the affected area. This tissue will be examined under a microscope to see if cancer cells are present.

Prevention
There is currently no way to prevent Ewing's Sarcoma/PNET.

Staging
At present there is no formal staging system for the Ewing's sarcoma.

Most patients are grouped depending on whether the cancer is found in only one part of the body (localized disease) or if it has spread from one part of the body to another (metastatic disease). Additional tests will need to be performed to see how far the disease has spread. The following groups are used for theEwing's family of tumors:

Localized
The cancer cells have not been shown to have spread beyond the bone in which the cancer began and are only found in the bone and nearby tissues.

Metastatic
The cancer cells have spread from the bone in which the cancer began to other parts of the body. The cancer most often spreads to the lung, other bones, and bone marrow. Spread of cancer to the lymph nodes or the central nervous system is less common.

Recurrent
Recurrent disease means that the cancer has come back after it has been treated. It may come back in the tissues where it first started or it may come back in another part of the body. The most common sites for recurrence are lung, bone marrow and bone.

Treatment
Treatment and prognosis depends on the stage of the disease, where it is found, and the patient's age and general health.

The treatments that are used to treat Ewing's are:

• surgery (taking out the cancer in an operation)
• chemotherapy (using drugs to kill cancer cells)
• radiation therapy (using high-dose x-rays to kill cancer cells)

Localized Ewing's/PNET

Treatment may include the following:

• Treatment with chemotherapy is started soon as possible after complete staging is done.
• After 2-3 months, radiation and/or surgery is used to treat the bulk of the tumor. Further chemotherapy is then given.

Metastatic Ewing's

• The approach to metastatic Ewing's Sarcoma/PNET includes chemotherapy and local surgery or radiation. Sites of metastatic disease are also treated with radiation or surgery. Very high dose chemotherapy with stem cell support may further intensify therapy.

Recurrent Ewing's

• Treatment depends on where the cancer recurred, how the cancer was treated before, as well as individual patient factors.
• In general, chemotherapy is chosen that has not been used before. This may include conventional regimen or new agents. Pediatric Phase I trials are available at Hopkins.
• Radiation treatment may be used to treat new metastases. Stem cell transplantation after high dose chemotherapy is offered to appropriate candidates. In conjunction with the NIH, vaccine trials are available to patients with specific types of Ewing's Sarcoma/PNET.

Clinical Trials available at Johns Hopkins

Phase II Study of Irinotecan in Children With Refractory CNS and Solid Tumors. (POG 9761)

Click here for information on Soft Tissue Sarcomas

Click here for more information on The Sarcoma Center at Johns Hopkins