What Is Osteosarcoma?
Osteosarcoma is a type of malignant (cancerous) bone tumor that forms from the cells that make up bones. These bone sarcomas most often occur at the ends of longer bones in body, in locations such as the knees and toward the shoulders. These tumors may also occur in the jaw and pelvis.
Osteosarcoma is the most common childhood cancer starting in bones, but is still fairly rare. Each year, doctors diagnose just 1,000 cases in the U.S. It’s found most often in children and teens between the ages of 10 and 19. When it does occur in adults, people are usually in their 60s, 70s, or 80s.
While highly treatable, osteosarcoma is often aggressive and can metastasize (spread), typically to the lungs or other bones.
The Sarcoma Program at Penn Medicine’s Abramson Cancer Center is home to one of the nation’s most experienced osteosarcoma care teams. Our specialists work closely with the sarcoma program at the Children’s Hospital of Philadelphia to bring children the most effective treatment for osteosarcoma.
Osteosarcoma Symptoms
Osteosarcoma often causes unusual, weak bone growth. It can also destroy existing bone. Sometimes, these tumors form a noticeable lump along the bone. You may also experience:
- Pain in a bone or near a joint that comes and goes, getting worse and more consistent as the tumor grows
- Harder time moving with osteosarcoma in a leg
- Loss of bladder or bowel control, for an osteosarcoma in the pelvis
- Swelling near the tumor
- Broken bone from the cancer causing damage
Types of Osteosarcoma
Osteosarcoma is categorized by grade, based on how the cells appear and how the cancer is likely to behave. Low-grade tumors typically grow slowly, while high-grade tumors act more aggressively. Intermediate-grade tumors fall in between and usually get treated like high-grade tumors. The vast majority of osteosarcoma are high grade.
Doctors also group osteosarcomas by where in the bone they form:
- Medullary (central) osteosarcoma: Most osteosarcomas are this type of tumor, which forms deeper inside bones. Medullary osteosarcomas tend to be aggressive.
- Peripheral (surface) osteosarcoma: Much less often, osteosarcoma forms near the surface of bones. Some of these tumors are high grade. However, one form, parosteal osteosarcoma, is low grade. Another form, periosteal osteosarcoma, is either low grade or intermediate grade.
What Causes Osteosarcoma?
Researchers don’t always know what causes osteosarcomas. Certain medical treatments and conditions can raise your risk of developing one of these bone cancers.
For example, previous radiation therapy and some chemotherapy drugs can increase the chance of developing an osteosarcoma. Two noncancerous bone diseases, Paget disease and fibrous dysplasia, can also rarely increase risk for osteosarcoma because these conditions change the makeup of bones.
Additionally, people with certain rare, inherited syndromes face a higher risk of developing osteosarcoma. These syndromes include:
- Bloom syndrome: People with this condition often have limited growth and develop skin rashes from the sun. They also face a higher cancer risk, including for osteosarcoma.
- Hereditary retinoblastoma: This condition can cause cancer to develop in both eyes. It also raises the risk for cancers such as osteosarcoma, melanoma, a brain cancer called pineoblastoma, and soft tissue sarcomas such as fibrosarcoma, liposarcoma, and leiomyosarcoma.
- Li-Fraumeni syndrome: This condition raises the risk for a range of cancers. These cancers include osteosarcoma and soft tissue sarcomas—rhabdomyosarcoma and, much less frequently, fibrosarcoma, leiomyosarcoma, orbital (near the eyes) liposarcoma, and undifferentiated pleomorphic sarcoma (UPS).
- Rothmund-Thomson syndrome II: People with this condition are usually shorter, with less hair on their head and face. They can develop a particular kind of rash and often have dental and bone problems. They face a higher risk for certain cancers, including osteosarcoma.
- Werner syndrome: This condition causes premature aging and raises the risk of developing osteosarcoma, skin cancer, and thyroid cancer.
Osteosarcoma Diagnosis
If our team suspects osteosarcoma, we will do an evaluation to rule out other reasons for the bone lesion or adjacent mass. These other diagnoses can include osteomyelitis (bone infection), a benign (noncancerous) tumor, or another kind of bone sarcoma.
We start with a discussion of symptoms and a physical exam. Your doctor will feel for any lump or bump and check for tenderness, pain, swelling, and any loss of joint motion.
Traditional X-rays allow doctors to see the area of concern and detect any bone lesions that need a closer look. If we suspect a tumor, we will order additional imaging such as a magnetic resonance imaging (MRI) scan for more information.
In addition to scans, we typically take a small sample of the tumor during an image-guided biopsy procedure. Analyzing the sample helps our team learn more about the cancer, including options for targeted treatments.
Together, the exam, imaging, and biopsy help us better understand a tumor and determine its stage. This process helps us plan the most appropriate and effective treatment.
Learn more about sarcoma diagnosis and staging.
Osteosarcoma Treatment at Penn
The outlook for patients with osteosarcoma depends on the location of the tumor, its size and aggressiveness, and whether cancer has spread. For older patients, doctors also consider overall health. To ensure this comprehensive approach to treatment, it’s best to find a program with a long history of osteosarcoma care.
Whenever possible, surgeons try to surgically remove osteosarcomas. We have extensive experience with the most effective sarcoma surgery approach, which takes out the tumor in one piece. Our surgeons are able to preserve limbs most of the time when tumors are found in arms or legs. We partner with plastic surgeons to ensure an effective surgery that restores tissue, promotes healing, and preserves function.
Less aggressive osteosarcomas can often be cured with surgery alone. For more aggressive disease, we always recommend chemotherapy both before and after the operation. These medications can help shrink the tumor and reduce the chances that cancer spreads to other areas of the body.
If surgery isn’t possible or our surgeons can’t completely remove the tumor, we may recommend palliative radiation therapy to control further growth. Either way, we follow you closely after treatment to monitor for cancer that returns. Detecting recurrent cancer quickly helps us start treatment as soon as possible.
Learn more about the team-based sarcoma treatment and clinical trials for sarcoma at Penn Medicine.
Make an Appointment
Please call 800-789-7366 or make an appointment.
The Penn Sarcoma Program offers same-day appointments to patients who have their imaging available. To learn more, call 215-349-8200.