WHAT IS OSTEOSARCOMA?
Osteosarcoma is a kind of bone cancer that most often affects children and teenagers. It usually begins in a leg bone (either the femur or the tibia) near the knee or in the upper arm bone (the humerus) near the shoulder. Osteosarcoma can metastasize (spread) to other parts of the body, most often to the lungs or to other bones.
WHO GETS OSTEOSARCOMA?
Osteosarcoma occurs most often in children, teenagers, and young adults between the ages of 10 and 20. It is slightly more likely to affect males.
Osteosarcoma is not a common cancer. Only about 400 cases occur in the United States each year. It is the most common bone cancer in children and teenagers.
WHAT CAUSES OSTEOSARCOMA?
Osteosarcoma has no known cause. Some researchers believe that genetics may play a role. In some cases, osteosarcoma can develop as a result of radiation therapy.
WHAT TESTS WILL THE DOCTOR USE TO CHILD HAS OSTEOSARCOMA?
1. Physical exam
The doctor will check for general signs of health as well as examine the place around the swelling, lump or break. The doctor will also ask about any previous health conditions or medical treatments.
An X-ray is usually the first imaging test your doctor will order. If there is a tumor, it will usually show up on the X-ray.
3. MRI and CT
The doctor may also order an MRI scan, a CT scan (also called a CAT scan), or both. MRI scans take pictures that help the doctor see if the tumor has destroyed any of the bone, and a CT scan is useful to look at the chest and belly to see if the disease has spread. Before a CT scan, the doctor may inject or ask you to swallow a special kind of dye. The dye helps the organs or tissues show up more clearly on the scan.
A biopsy is important because other malignant (cancerous) tumors and some infections can look like osteosarcoma on an X-ray. For the biopsy, a doctor with training in the treatment of bone cancer takes a piece of the tumor from the bone, sometimes with a needle, sometimes through an incision. This piece of tissue is looked at under a microscope to see if the tumor is an osteosarcoma.
5. Other tests
he doctor may recommend other tests to see if the cancer has spread to the lungs or other organs. For example, a bone scan will help the doctor see if the cancer has spread to other bones. Other tests may also be needed.
WHAT ARE THE RISK FACTORS FOR OSTEOSARCOMA?
A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors.
Lifestyle-related risk factors such as body weight, physical activity, diet, and tobacco use play a major role in many adult cancers. But these factors usually take many years to influence cancer risk, and they are not thought to play much of a role in childhood cancers, including childhood osteosarcomas. So far, lifestyle-related factors have not been linked to osteosarcomas in adults, either.
The risk of osteosarcoma is highest for those between the ages of 10 and 30, especially during the teenage growth spurt. This suggests there may be a link between rapid bone growth and risk of tumor formation. The risk goes down in middle age, but rises again in older adults (usually over the age of 60). Osteosarcoma in older adults is often linked to another cause, such as a long-standing bone disease.
Children with osteosarcoma are usually tall for their age. This also suggests that osteosarcoma may be related to rapid bone growth.
Osteosarcoma is more common in males than in females. Females tend to develop it at a slightly earlier age, possibly because they tend to have their growth spurts earlier.
Osteosarcoma is slightly more common in African Americans than in whites.
5. Radiation to bones
People who were treated with radiation therapy for another cancer might have a higher risk of later developing osteosarcoma in the area that was treated. Being treated at a younger age and being treated with higher doses of radiation both increase the risk of developing osteosarcoma.
It is not clear if imaging tests that use radiation, such as x-rays, CT scans, and bone scans, raise the risk of developing osteosarcoma. The amount of radiation used for these tests is many times lower than that used for radiation therapy. If there is any increased risk it is likely to be very small, but doctors try to limit the use of these types of tests in children whenever possible, just in case.
INHERITED CANCER SYNDROMES
People with certain rare, inherited cancer syndromes have an increased risk of developing osteosarcoma.
Retinoblastoma is a rare eye cancer of children. Some children have the inherited form of retinoblastoma (hereditary retinoblastoma), in which all the cells of the body have a mutation (change) in the RB1 gene. These children also have an increased risk of developing bone or soft tissue sarcomas, including osteosarcoma. If radiation therapy is used to treat the retinoblastoma, the risk of osteosarcoma in the bones around the eye is even higher.
The Li-Fraumeni syndrome makes people much more likely to develop certain types of cancer, including breast cancer, brain tumors, osteosarcoma, and other types of sarcoma. This syndrome is usually caused by a mutation of the TP53 tumor suppressor gene.
Children with Rothmund-Thomson syndrome are short and tend to have skeletal problems and rashes. They also are more likely to develop osteosarcoma. This syndrome is caused by abnormal changes in the REQL4 gene.
Other rare inherited conditions, including Bloom syndrome, Werner syndrome, and Diamond-Blackfan anemia, have also been linked to an increased risk of osteosarcoma.
Symptoms of childhood osteosarcoma, or bone cancer, vary from child to child. However, the first symptom usually is an aching pain in a bone or joint. At first, the pain may go away and come back. Gradually, it becomes worse and is constant, often getting worse at night.
Other signs of osteosarcoma include:
- Difficulty with normal activities, such as moving, lifting or walking
- Limping, pain, tenderness, swelling or lump close to or in a joint. The area may be warm and red.
- Weight loss
- Broken bone at the site of the tumor; bone may break with routine, normal movement
- Low red blood cell count (anemia)
These symptoms are not always caused by osteosarcoma. In fact, they usually are caused by a less serious condition.
Leg and arm pain are common in growing boys and girls, and usually it is nothing to worry about. But if the pain persists, worsens or if other symptoms are present, you should speak to your child’s doctor.