Osteosarcoma is the most common type of bone cancer among children, adolescents, and young adults.
The disease usually occurs in the long bones, such as the arms (humerus), legs (femur and/or tibia), and pelvis. It rarely occurs in the jaw and fingers. It most often occurs at the ends of bones near growth plates, where bones are actively growing, especially around the knees.
Osteosarcoma cancer cells can also spread (metastasize) to other areas of the body. Most commonly, these cells spread to the lungs. However, bones, kidneys, the adrenal gland, the brain, and the heart can also be sites of metastasis.
What causes osteosarcoma?
The exact cause of osteosarcoma is not known, but genetics may play an important role. Children and adults with other hereditary abnormalities, including retinoblastoma, Rothmund-Thompson syndrome, Li-Fraumeni syndrome, multiple hereditary osteochondromas, and Paget disease, have an increased risk for developing osteosarcoma.
This form of cancer has also been linked to exposure to ionizing irradiation associated with radiation therapy for other types of cancer (for example, Hodgkin and non-Hodgkin disease).
What are the symptoms of osteosarcoma?
The following are the most common symptoms of osteosarcoma. However, each child may experience symptoms differently. Symptoms may include, but are not limited to, the following:
- Pain (sharp or dull) at the site of the tumor
- Swelling and/or redness at the site of the tumor
- Increased pain with activity or lifting
- Decreased movement of the affected limb
The symptoms may have occurred over a short period of time or may have been present for 6 months or more. Often, an injury brings a child into a medical facility, where an X-ray may indicate suspicious bone lesions. The injury itself, however, doesn't cause osteosarcoma.
The symptoms of osteosarcoma may resemble other conditions or medical problems. Always consult your child's doctor for a diagnosis.
How is osteosarcoma diagnosed?
In addition to a complete medical history and physical examination of your child, diagnostic procedures for osteosarcoma may include:
- Multiple imaging studies of the tumor and sites of possible metastasis, such as:
- X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film.
- Bone scan. A nuclear imaging method to evaluate any degenerative and/or arthritic changes in the joints; to detect bone diseases and tumors; and/or to determine the cause of bone pain or inflammation.
- Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. This test can be done to better define a mass seen on X-ray, rule out any associated abnormalities of the spinal cord and nerves, and to look for nearby tumors.
- Computed tomography scan (also called a CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.
- Positron emission tomography (PET) scan. Radioactive-tagged glucose (sugar) is injected into the bloodstream. Tissues that use the glucose more than normal tissues (such as tumors) can be detected by a scanning machine. PET scans can be used to find small tumors or to check if treatment for a known tumor is working.
- Complete blood count (CBC). A measurement of size, number, and maturity of different blood cells in a specific volume of blood.
- Other blood tests (including blood chemistries to monitor kidney and liver function)
- Biopsy of the tumor. This is the definitive test required to diagnose osteosarcoma.
What is the treatment for osteosarcoma?
Specific treatment for osteosarcoma will be determined by your child's doctor based on:
- Your child's age, overall health, and medical history
- Extent of the disease
- Your child's tolerance for specific medications, procedures, or therapies
- Expectations for the course of the disease
- Your opinion or preference
Treatment may include, but is not limited to, one or more of the following:
- Surgery (for example, biopsy, tumor resection, bone/skin grafts, limb salvage procedures, reconstructions, amputation)
- Radiation therapy
- Resections of metastases (to treat spread of the tumor to other locations)
- Rehabilitation including physical and occupational therapy and psychosocial adapting
- Prosthesis fitting and training
- Supportive care (for the side effects of treatment)
- Antibiotics (to prevent and treat infections)
- Continued follow-up care (to determine response to treatment, detect recurrent disease, and manage the side effects of treatment)
What is the long-term outlook for a child with osteosarcoma?
Prognosis for osteosarcoma greatly depends on:
- The extent of the disease
- The size and location of the tumor
- Presence or absence of metastasis
- The tumor's response to therapy
- The age and overall health of your child
- Your child's tolerance of specific medications, procedures, or therapies
- New developments in treatment
A person who was treated for bone cancer as a child or adolescent may develop side effects months or years after treatment ends. These effects are called late effects. The kind of late effects one develops depends on the location of the tumor and the way it was treated.
Some types of treatment may later affect fertility. If this side effect is permanent, it will cause infertility, or the inability to have children. Both men and women can be affected.
As with any cancer, prognosis and long-term survival can vary greatly from child to child. Every child is unique, and treatment and prognosis are structured around the child's needs. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for a child diagnosed with osteosarcoma. Side effects of radiation and chemotherapy, as well as second malignancies, can occur in survivors of osteosarcoma.