Osteosarcoma PDF Print E-mail
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Osteosarcoma is the most common type of bone cancer, and the sixth most common type of cancer in children. Although many different types of cancers, or malignancies, eventually spread to other parts of the skeleton, Osteosarcoma is one of the few cancers that actually begins in bones and sometimes spreads elsewhere. Because osteosarcoma usually develop from osteoblasts (the cells that manufacture growing bone), it most commonly develops in teenagers who are experiencing their adolescent growth spurt. Boys are twice as likely to have Osteosarcoma as girls, and most cases of Osteosarcoma involve the bones around the knee.





Risk for childhood Osteosarcoma

Although Osteosarcoma is most often seen in teenage boys, there is evidence that teens who are taller than average are at special risk for this tumor. Children who have inherited one of the rare cancer syndromes (inherited genetic mutations, or changes, that predispose a child to certain types of cancer) are also at greater risk. These may include Retinoblastoma (a malignant tumor that develops in the retina, usually in children younger than age 2) or Li-Fraumeni syndrome (a genetic condition associated with an unusually high risk of childhood cancer).


Because exposure to radiation is another trigger for DNA mutations, children who have received bone radiation treatments for a prior episode of cancer are also at increased risk for Osteosarcoma. Most Osteosarcomas arise from non-inherited errors in the DNA of growing bone cells. Because these errors occur randomly and unpredictably during intense bone growth, there is currently no effective way to prevent this type of tumor.




The most common symptoms of Osteosarcoma are pain and swelling in a leg or arm. It occurs most often in the longer bones of the body - such as above or below the knee or in the upper arm near the shoulder. Pain may be worse during exercise or during the night, and a lump or swelling may develop in the affected area some time (even several weeks) after the pain starts. In Osteosarcoma of the leg, the child may also develop an unexplained limp.


In some cases, Osteosarcoma may significantly weaken the bone structure of an arm or leg, leading to a broken bone. In some children, this may be the first sign of cancer. Osteosarcoma typically develops during adolescence. If your child or teen has any of the above symptoms of Osteosarcoma, it is important that he be examined by a doctor.




In addition to doing a physical examination, the doctor will ask you about any concerns and symptoms you have, your past health, your family's health, any medications you're taking, any allergies you may have, and other issues. This is called the medical history. After performing a physical examination to check for tenderness and swelling and obtaining a detailed medical history, the doctor will order X-rays of the affected area.


Although changes in bone structure that are typical of Osteosarcoma can be seen in standard bone X-rays, a bone biopsy (the removal and examination of tissue, cells, or fluids from the body) will be needed to confirm the diagnosis. Before a bone biopsy, a computed tomography (CT) scan of the affected area may be done to help determine the best area to biopsy. This scan will also show whether the Osteosarcoma has spread from the bone into nearby muscles and fat. Magnetic resonance imaging (MRI) is also often used.


A type of bone biopsy that may be performed under local anesthesia is a needle biopsy, where a long hollow needle is used to take a sample of the tumor. Alternatively, an open biopsy, in which a portion of the tumor is removed, may be done under general anesthesia. In both types of biopsy, the goal is to obtain a sample of the tumor for laboratory examination. Of all the children who develop Osteosarcoma, about 20% of them are diagnosed with advanced stage Osteosarcoma, which means that the disease has spread to other parts of the body. Cancer cells that have spread beyond the original tumor to other places in the body are called metastases. Most patients with metastases from Osteosarcoma have cancer cells that have spread to their lungs, brain, or to other bones.


If a diagnosis of Osteosarcoma is made, your child's doctor will order CT scans of your the chest, as well as a bone scan, and sometimes additional MRI studies. These will show if there has been any spread of cancerin the body beyond the original bone tumour. These tests will also be repeated after the cancer treatment starts to determine how well treatment is working and whether the cancer is continuing to spread.




The treatment of Osteosarcoma in children includes chemotherapy (the use of medical drugs to kill cancer cells) and surgery (to remove cancerous cells or tumors). In children with Osteosarcoma, surgery can often effectively remove bone cancer, and chemotherapy is used as a complementary or secondary tool to eliminate remaining cancer cells in the body.



Surgical treatment

Surgical treatments for Osteosarcoma consist of either amputation or limb-salvage surgery. Currently, most teens with Osteosarcomas involving an arm or leg can be treated with limb-salvage surgery rather than amputation. In limb-salvage surgery, only the Osteosarcoma is removed, leaving a gap in the bone that is filled by a bone graft that is usually from the patient's own body, taken from the pelvis (hip bone). Amputation (removing part of a limb along with the Osteosarcoma) is often the only choice when the tumor has spread beyond the bone to important surrounding nerves and blood vessels.




Chemotherapy is usually given both prior to and after surgery. A child or teen with Osteosarcoma is given the chemotherapy drugs intravenously (through a vein) or orally (by mouth). The drugs enter the bloodstream and work to kill cancer in parts of the body to which the cancer has spread, such as the lungs or other organs.



Short term and long term side effects

Amputation carries its own special short-term and long-term side effects. It usually takes at least 3 to 6 months until a young person learns to use a prosthetic (or artificial) leg or arm, and this is just the beginning of long-term psychological and social rehabilitation. For teens already experiencing normal adolescent body image struggles, the loss of a limb can be especially difficult.

Many of the medications used in chemotherapy also carry the risk of both short-term and long-term problems. Short-term effects include anemia, abnormal bleeding, and increased risk of infection due to destruction of the bone marrow, as well as kidney damage and menstrual irregularities. Some drugs carry a risk of bladder inflammation and bleeding into the urine, hearing loss, and liver damage. Others may cause heart and skin problems. Years after chemotherapy for Osteosarcoma, patients have increased risk of developing other cancers.


Chances of a cure

Recent studies have reported that survival rates between 60% to 80% are possible for Osteosarcoma that hasn't metastasized, depending on the success of chemotherapy. Osteosarcoma that has metastasized is not always able to be treated as successfully. Also, a child whose Osteosarcoma is located in an arm or leg generally has a better prognosis than one whose Osteosarcoma involves the ribs, shoulder blades, spine, or hip bones.



New treatments

New treatment plans are being developed and researched with new chemotherapy drugs. Other research is looking at the role certain growth factors may play in the development of Osteosarcoma. This research may be used to develop new medications that may slow these growth factors as a means of treating the cancer. For osteosarcomas that cannot be removed surgically, studies are now underway to test treatments involving new combinations of chemotherapy drugs together with localized, high-dose radiation.


More information

Click here for more information from the Bone Cancer Research Trust.