Osteosarcoma is the most common type of bone cancer, and accounts for about 3%
of cancers that happen in children. Although other types of cancer can eventually
spread to parts of the skeleton, osteosarcoma is one of the few that actually begin
in bones and sometimes spread (or metastasize) elsewhere, usually to the lungs or
Because osteosarcoma usually develops from osteoblasts (the cells
that make growing bone), it most commonly affects teens who are having a growth spurt.
Boys are more likely to have osteosarcoma than girls, and most cases of osteosarcoma
involve the knee.
Most osteosarcomas arise from random and unpredictable errors in the DNA of growing
bone cells during times of intense bone growth. There currently isn't an effective
way to prevent this type of cancer. But with the proper diagnosis and treatment, most
kids with osteosarcoma recover.
Risk for Childhood Osteosarcoma
Osteosarcoma is most often seen in teenage boys. Teens diagnosed with osteosarcoma
tend to be tall for their age, suggesting that rapid bone growth may lead to the disease.
Kids who have inherited one of the rare cancer syndromes also
are at higher risk for osteosarcoma. These syndromes include retinoblastoma
(a malignant tumor that develops in the retina, a part of the eye, usually in children
younger than age 2) and Li-Fraumeni syndrome (a kind of inherited
genetic mutation, or change in a person's genes).
Because exposure to radiation is another trigger for DNA mutations, children who
have received radiation treatments
for an earlier cancer are also at increased risk for osteosarcoma.
Symptoms of Osteosarcoma
The most common symptoms of osteosarcoma are pain and swelling in the leg or arm.
It happens 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 at night, and a lump or swelling may form
in the affected area up to several weeks after the pain starts. Pain that often wakes
the child up at night or pain at rest are of particular concern.
In osteosarcoma of the leg, a child also may develop an unexplained limp. In some
cases, the first sign of the disease is a broken arm or leg, which happens because
the cancer has weakened the bone and made it vulnerable to a break.
If your child or teen has any of these symptoms, it's important to see a doctor.
To diagnose osteosarcoma, a doctor will do a physical exam, take a detailed medical history, and order X-rays
to detect any changes in bone structure.
The doctor might order a CT scan or magnetic
scan of the affected area, which will find the best area to biopsy
and show whether osteosarcoma has spread from the bone into nearby muscles and fat.
The biopsy can be done by cutting or scraping a small piece of the tissue or by withdrawing
a sample of tissue with a needle and syringe.
In a needle biopsy, doctors use a long hollow needle to take a sample of the tumor.
Local anesthesia (medicine that numbs the area so the person won't feel pain) usually
is used. Or the doctor may order an open biopsy, in which a portion of the tumor is
removed in the operating room by a surgeon while the child is asleep during the procedure
under general anesthesia.
If a diagnosis of osteosarcoma is made, the doctor
will order CT chest scans as well as a bone scan and,
sometimes, more MRI studies. After treatment starts, repeating these tests will help
doctors see how well treatment is working and whether the cancer is continuing to
Treatment of osteosarcoma in children includes chemotherapy
(the use of medical drugs to kill cancer cells and shrink the cancer), followed by
surgery (to remove cancerous cells or tumors), and then more chemo (to kill any remaining
cancer cells and minimize chances of the cancer coming back).
Surgery often can effectively remove bone cancer, while chemo can help eliminate
remaining cancer cells in the body.
Surgical treatments for osteosarcoma include either amputation or limb-salvage
Currently, most teens with osteosarcomas involving an arm or leg can be treated
with limb-salvage surgery instead of amputation. In limb-salvage surgery, the
bone and muscle affected by the osteosarcoma are removed, leaving a gap in the bone
that is filled by either a bone graft (usually from a bone bank) or more often a special
metal prosthesis (artificial part). These can be matched to the size of the bone defect.
The risk of infection and fracture is higher with bank bone replacement and therefore
metal prostheses are more commonly used to reconstruct the bone after removal of the
If the cancer has spread to the nerves and blood vessels surrounding the original
tumor on the bone, amputation (removing part of a limb along with the osteosarcoma)
is often the only choice.
When osteosarcoma has spread to the lungs or elsewhere, surgery might be done to
remove tumors in these distant locations.
Chemotherapy is usually given both before and after surgery. Chemo makes the tumor
smaller, which makes surgery easier. It also gets rid of small pockets of cancer cells
in the body, even cancer cells too small to appear on medical scans.
A child or teen with osteosarcoma is given the chemotherapy drugs intravenously
(through a vein). The drugs enter the bloodstream and work to kill cancer in parts
of the body where the disease has spread, such as the lungs or other organs.
Short-Term and Long-Term Side Effects
Amputation carries its own 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 (artificial)
leg or arm, and this is just the beginning of long-term psychological and social rehabilitation.
With limb salvage surgery, a person usually starts bending the knee or the
affected body part almost immediately. A continuous passive motion (CPM) machine that
continuously bends and straightens the knee may be used to improve motion for children
with tumors around the knee.
Physical therapy and
rehabilitation for 6 to 12 months after surgery helps a child walk, initially
with a walker or crutches, then without any assistive devices.
Early complications after surgery include infection and slow healing of the surgical
wound. Also, the metal prosthetic device or the bank bone may need to be replaced
as the body grows, although some prosthetics can be adjusted to fit as a child grows.
Other late problems might include fracture of the bank bone or failure of the bank
bone to heal to the child's bone, which might require more surgery.
Many of the medicines 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 chemo
for osteosarcoma, patients have an increased risk of developing other cancers.
Chances for a Cure
Survival rates of 60% to 80% are possible for osteosarcoma that hasn't spread beyond
the tumor, depending on the success of chemotherapy.
Osteosarcoma that has spread cannot always be treated as successfully. Also, a
child whose osteosarcoma is in an arm or leg generally has a better prognosis than
one whose disease involves the ribs, shoulder blades, spine, or pelvic bones.
Treatments are being developed and researched with new chemotherapy drugs. Other
research is focused on the role certain growth factors might play in the development
of osteosarcoma. This research may be used to develop new medicines to slow these
growth factors as a way to treat the cancer.
For osteosarcomas that cannot be removed surgically, studies are underway on treatments
that use new combinations of chemotherapy and localized radiation that
focuses more specifically on the tumor cells.