Osteosarcoma
What is osteosarcoma?
Osteosarcoma is a type of bone cancer that develops in the osteoblast cells
that form the outer covering of bone. It occurs most often in children, adolescents,
and young adults. Approximately 900 new cases of osteosarcoma are reported each
year in the US. It occurs nearly twice as often in males than in females, and
represents 5 percent of all childhood cancers.
Osteosarcoma most commonly occurs in the long bones around the knee. Other
sites for osteosarcoma include the upper leg, or thighbone, the lower leg, upper
arm bone, or any bone in the body, including those in the pelvis, shoulder,
and skull.
Osteosarcoma may metastasize, or spread, into nearby tissues of the foot, or
into tendons or muscles.It may also metastasize through the bloodstream to other
organs or bones in the body.
What causes osteosarcoma?
The exact cause of osteosarcoma is not known, but it is believed to be due to
DNA mutations - either inherited or acquired after birth. Other theories and
associations have been suggested as risk factors.
What are the risk factors for osteosarcoma?
Suggested risk factors for osteosarcoma include the following:
- teenage growth spurts
- being tall for a specific age
- previous treatment with radiation for another cancer, especially at a young
age or with high doses of radiation
- presence of a benign (non-cancerous) bone disease
- presence of certain rare, inherited cancers, such as the following:
- Li-Fraumeni syndrome - a rare family predisposition to multiple
types of cancers (such as soft tissue sarcomas, breast cancer, brain tumors,
osteosarcoma, leukemia, melanoma, cancer of the adrenal cortex, and others)
caused by a mutation in a gene - the p53 tumor-suppressor gene that normally
curbs cancer.
- retinoblastoma - a malignant tumor of the retina that usually
occurs in children younger than 5 years old.
Suggested risk factors for osteosarcoma in adults include lifestyle factors
such as the following:
- high-fat diets
- lack of exercise
- smoking
- drinking alcohol
What are the symptoms of osteosarcoma?
The following are the most common symptoms for osteosarcoma. However, each individual
may experience symptoms differently. Symptoms may include:
- pain in the affected bone
- swelling around the affected site
- increased pain with activity or lifting
- limping
- decreased movement of the affected limb
The symptoms of osteosarcoma may resemble other medical conditions problems,
such as Ewing's sarcoma, or medical conditions. Always consult your physician
for a diagnosis.
How is osteosarcoma diagnosed?
In addition to a complete medical history and physical examination, diagnostic
procedures for osteosarcoma may include the following:
-
multiple imaging studies of the tumor and sites of possible metastasis,
such as:
-
x-rays - a diagnostic test which uses invisible electromagnetic
energy beams to produce images of internal tissues, bones, and organs
onto film.
-
radionuclide bone scans - a nuclear imaging method to evaluate
any degenerative and/or arthritic changes in the joints; to detect bone
diseases and tumors; to determine the cause of bone pain or inflammation.
This test is to rule out any infection or fractures.
-
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 is done to rule out any associated abnormalities of the spinal
cord and nerves.
-
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 cross-sectional images (often called slices),
both horizontally and vertically, 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.
-
complete blood count (CBC) - a measurement of size, number, and
maturity of different blood cells in a specific volume of blood.
-
blood tests (including blood chemistries)
-
biopsy of the tumor - a procedure in which tissue samples are removed
(with a needle or during surgery) from the body for examination under a
microscope; to determine if cancer or other abnormal cells are present;
to remove tissue from the affected bone.
Treatment for Osteosarcoma
Specific treatment for osteosarcoma will be determined by your physician based
on:
- your age, overall health, and medical history
- extent of the disease
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
Treatment may include:
-
surgery (i.e., biopsy, resections, bone/skin grafts, limb salvage procedures,
reconstructions)
-
amputation
-
chemotherapy
-
radiation therapy
-
resections of metastases (spreading 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)
Long-term outlook for an individual with osteogenic sarcoma
Prognosis for osteogenic sarcoma greatly depends on:
As with any cancer, prognosis and long-term survival can vary greatly from
person to person. Every individual is unique and treatment and prognosis is
structured around your needs. Prompt medical attention and aggressive therapy
are important for the best prognosis. Continuous follow-up care is essential
for a person diagnosed with osteogenic sarcoma. Side effects of radiation and
chemotherapy, as well as second malignancies, can occur in survivors of osteogenic
sarcoma. New methods are continually being discovered to improve treatment and
to decrease side effects.
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