Osteosarcoma

Medically Reviewed by Jabeen Begum, MD on February 15, 2024
13 min read

Osteosarcoma, also called osteogenic sarcoma, is the most common type of bone cancer. Compared with other cancers, osteosarcoma is rare. About 1,000 new cases are diagnosed in the U.S. each year.

It occurs most often in children and teens. It’s the most common bone cancer in that age group and the eighth most common childhood cancer. Teenage boys are most likely to get it. But osteosarcoma can occur in anyone at any age. About 1 in 10 cases occur in people older than 60 years.

Treatment for osteosarcoma includes chemotherapy and surgery to take the tumor out. The addition of chemotherapy greatly improves survival rates for people with osteosarcoma.

If caught early, before the cancer has spread, the 5-year survival rate is 76%. If you have osteosarcoma that means you are 76% as likely as the overall population to live for at least 5 years after diagnosis. But that figure comes from data on people diagnosed from 2012 to 2018. People diagnosed with osteosarcoma today may face better outcomes as treatment continues to improve.

In the last few decades, there have been many treatment advances in osteosarcoma. Many university hospitals, medical centers, and research institutions worldwide continue to research new ways of treating it. Treatment given today can improve the quality of life for people with osteosarcoma. 

Where does osteosarcoma start?

Osteosarcoma happens when the cells that grow new bone form a cancerous tumor. In children and teens, osteosarcoma often happens at the ends of long bones, where bone grows fastest.

  • Most tumors start around the knee, in either the lower part of the thighbone or the upper part of the shinbone.
  • They also may grow in the upper arm bone close to the shoulder.

But osteosarcoma can happen in any bone, especially in older adults, including your:

  • Pelvis
  • Shoulder
  • Skull

Warning signs of osteosarcoma include:

  • Swelling or lumps around bones or the ends of bones
  • Bone or joint pain or soreness (This pain may come and go for months. Each person can feel different degrees of bone pain, depending on where the cancer is located and if it has spread.)
  • Broken bones without a clear reason
  • Pain at night, often extreme
  • Pain after exercise
  • Limping
  • Respiratory or breathing problems if the cancer has spread to the lungs

Some limb pain and swelling are common in active, growing children. Talk to your doctor if these signs don’t go away in a couple of weeks or if they get worse.

Based on the tumor location, doctors divide osteosarcoma into:

  • Intramedullary or central tumors that occur within the bone.
  • Surface tumors that occur on the surface of the bone.
  • Extraskeletal tumors that occur outside the bone, such as in the soft tissue of the buttocks, thighs, or upper extremities.

Based on what the cells look like under a microscope, osteosarcoma is divided into three subtypes or grades:

High-grade osteosarcoma

This is the fastest-growing type, with cells that don’t look like normal bone cells. Most osteosarcomas in children and teens are high-grade. They include:

  • Osteoblastic
  • Chondroblastic
  • Fibroblastic
  • Malignant fibrous histiocytoma
  • Epithelioid
  • Giant cell
  • Clear cell
  • Telangiectatic
  • Small cell
  • High-grade surface (juxtacortical high grade)
  • Extraskeletal (these tumors start in another part of your body instead of a bone)
  • Pagetoid (these are tumors that grow in someone with Paget’s disease of bone)
  • Post-radiation (these start in a bone with previous exposure to radiation)

Intermediate-grade osteosarcoma

These are the least common and are treated like low-grade osteosarcomas. Periosteal (juxtacortical intermediate grade) is the main type.

Low-grade osteosarcoma 

This subtype grows slowly. The cells look more like regular bone.

  • Fibrous dysplastic
  • Desmoplastic fibroma
  • Parosteal (juxtacortical low grade)
  • Intramedullary or intraosseous well-differentiated (low-grade central)
  • Extraskeletal

It’s still not clear what causes someone to develop osteosarcoma. Possible causes include genetics or DNA changes, environmental factors, and other risk factors.

Genetic risk factors include:

  • Hereditary retinoblastoma, a type of eye cancer that affects children and often occurs around 1 year of age. It increases the risk of osteosarcoma later in life.
  • Li-Fraumeni syndrome, a disorder caused by a mutation in the p53 tumor suppressor gene. Up to 3% of children with osteosarcoma have this disorder. They are also at a high risk of developing several other types of cancer at a very early age.
  • Rothmund-Thomson syndrome, a disorder caused by a mutation in the RECQL4 gene. Along with an increased risk of osteosarcoma, symptoms include a red face rash that develops in infancy and spreads across the body, abnormalities in bones, nails, and teeth, alopecia, premature cataracts, and chronic gastrointestinal problems.
  • Bloom syndrome, a disorder caused by mutations in the BLM gene, which is responsible for maintaining DNA stability during replication. It increases the risk of osteosarcoma and other cancers. Signs include rashes from exposure to ultraviolet light, short stature, and sparse subcutaneous fat (not much fat under the skin that you can pinch).
  • Werner syndrome, or adult progeria, is caused by a faulty WRN gene. It causes premature aging, bilateral cataracts, osteoporosis, short stature, scleroderma-like skin changes, and a risk for osteosarcoma.

Some things may make you more likely to get osteosarcoma, including:

  • Age. Teenagers going through a growth spurt are most likely to get it, especially if the growth is happening quickly. Most cases of primary osteosarcoma happen in children between the ages of 10 and 14. Another group, adults over age 65, are more likely to see osteosarcoma as a secondary cancer related to other diseases. People aged 40 and older have worse outcomes than younger adults.
  • Gender. Osteosarcoma happens more often in people assigned male at birth. Teen males face the highest risk.
  • Height. Taller kids have a higher risk.
  • Treatments such as radiation therapy for other types of cancer or cancer medicines called alkylating agents
  • Health conditions tied to your genes, such as Paget’s disease of the bone, Li-Fraumeni syndrome, Rothmund-Thomson syndrome, Bloom syndrome, Werner syndrome, Diamond-Blackfan anemia, or a type of eye cancer called hereditary retinoblastoma .
  • Race. Black Americans face the highest risk of osteosarcoma among all ethnic groups. Hispanics are a close second.
  • Trauma or injury to the bone, including infection and bone infarction, when there’s a lack of blood supply to your bone, killing cells.

To determine whether your symptoms are related to osteosarcoma, your appointment with your doctor will include:

  • A medical history and physical exam.Your doctor will ask about your personal and family health histories, including any prior exposure to radiation. They’ll check for unusual lumps around your bones.
  • Blood tests. These tests can look for certain biochemical markers that, along with other tests, may help confirm a diagnosis.
  • Diagnostic imaging tests . Imaging can show unusual changes in bones that may be signs of osteosarcoma. They may also show areas where the tumor has spread. These include:
    • X-ray, generally the first imaging test done to diagnose osteosarcoma.
    • MRI, which stands for magnetic resonance imaging. MRIs are considered the gold standard for diagnosing osteosarcomas.
    • CT scan, which stands for computed tomography. CT scans are used for biopsy planning and disease staging.
  • Biopsy. Your doctor will take a small sample of bone or tissue from a painful or swollen area. They may use a needle or make a cut in your skin, called a surgical or open biopsy. A specialist looks at the sample under a microscope. This test may show cancer cells in your bone or cancer cells that have spread to muscles or other areas.

If you are diagnosed with osteosarcoma, your doctor may order other tests to stage your cancer to determine whether it has spread and if it spreads slowly or quickly. This includes:

  • Nuclear imaging:
    • Positron emission tomography or PET scans. These scans are especially used to determine tumor extent and find subtle lesions. During your treatment, PET scans may be used to find cancer recurrence.
    • Radionuclide bone scan. A technetium-99m methylene diphosphonate bone scan can help detect the spread of osteosarcoma and bone cancer. It's a less expensive but less specific alternative to PET scans.
  • Follow-up MRI or CT (both with contrast). These scans are needed if nuclear imaging finds the cancer has metastasized, or spread far outside the bone.
  • Fertility consultation. Treatment for bone cancer can affect fertility.

Treatment depends on several things, including where the tumor is, how fast it's growing, and whether it’s spread. Your age and overall health will also factor in.

Treatment works best when you start before the cancer spreads beyond your bones to other tissues or organs. Most people find tumors early because they cause pain, swelling, or a limp. Let your doctor know about warning signs like these so you can start treatment as soon as possible.

Most people with osteosarcoma need surgery and chemotherapy. Some also get radiation therapy.

Surgery

The goal of surgery is to remove all the cancer. Even a few cells left behind can grow into a new tumor. Depending on your case, your doctor may do one of these procedures:

  • Limb-sparing surgery. Your doctor takes out the tumor in an arm or leg and some of the tissue around it. A medical device, or prosthesis, will fill in part or all of the gap left in the bone. You might also have a bone graft, which uses a piece of bone from another part of your body or from a donor. About 85%-90% of people with osteosarcoma undergo limb-sparing surgery.
  • Amputation. If the tumor is large and has gotten into nerves or blood vessels, your doctor may have to amputate or remove all or part of your leg or arm. You might choose to get fitted for an artificial or prosthetic limb.
  • Rotationplasty. If your doctor has to take off your leg above your knee, they can reattach part of your lower leg and foot to your thigh bone. With the help of a prosthesis, your ankle works as a new knee joint.

Osteosarcoma in your pelvis, jawbone, spine, or skull may be harder to remove completely with surgery. You might also need radiation therapy. If the cancer spreads to your lungs or other parts of your body, your doctor may need to take out those tumors.

Limb-sparing surgery can often leave large, unsightly holes or indentations. Tissue regeneration is a new field of reconstruction to fill in the gaps. This emerging technology uses a patient’s own cells and synthetic materials to build scaffold-like materials to encourage natural bone regeneration at the surgical site.

Chemotherapy

“Chemo” uses strong medications to kill cancer cells or stop them from growing. You usually get them in your vein through an IV. Your doctor may use chemo before surgery (neoadjuvant), after surgery (adjuvant), or both.

Doctors treat most osteosarcomas with chemo. The drugs may shrink the tumor, which can make surgery easier. They also get rid of small clusters of cancer cells that doctors may not be able to see on medical scans.

Side effects of chemotherapy include nausea and vomiting, diarrhea, and a loss of appetite. Children tend to have less severe side effects than adults, so they might get higher doses of medication.

Radiation therapy

High-energy X-rays can kill cancer cells.

Radiation doesn't work as well on osteosarcoma cells as it may with other cancers. But your doctor might use a procedure called external beam radiation therapy if they can’t take out all of the cancer through surgery. That often happens when a tumor is in your hip or jawbone.

This type of therapy uses a machine to focus high-energy beams on the tumor to kill the remaining cancer cells.

New therapies

Scientists are studying the best mix of chemo medications to treat osteosarcoma and testing newer types of drugs. They’re also working on stronger and more targeted radiation therapies.

You may want to ask your doctor about clinical trials. These are how experts test new treatments before they’re made widely available. Your doctor can help you find one that might be a good match and help you understand what’s involved.

Osteosarcoma and its treatment can lead to short-term and long-term complications, including:

  • Bone fractures
  • Wound infection and slow healing
  • Problems with a donor bone graft or prosthesis, including infection and implant failure
  • Chemotherapy side effects such as anemia, bleeding, kidney , liver, or heart damage, hearing loss, and a higher risk of other cancers. Cancer treatment can also affect your fertility, or your ability to have children, later in life.
  • Radiation side effects, such as itchy and peeling, and sometimes burning skin. For radiation to the pelvic area, complications include erectile dysfunction, menstrual changes, and infertility. Radiation to the chest and abdomen can cause diarrhea, incontinence, nausea, vomiting, dysphagia, pneumonitis, fibrosis, rectal bleeding, and dry mouth.
  • A small risk of a secondary tumor later on, caused by chemotherapy or radiation.

If you or your child develop osteosarcoma, your cancer outlook depends on:

  • The stage of your cancer -- how early it was found and how far it's spread
  • In what bone the cancer was found
  • Your age
  • Your other health conditions

Doctors determine your prognosis using a 5-year relative survival rate that compares people having the same type and stage of cancer with people in the overall population. The data comes from the Surveillance, Epidemiology, and End Results (SEER) database, maintained by the National Cancer Institute (NCI) that tracks survival rates for cancer, including osteosarcoma, in the U.S.

Osteosarcoma survival rate

According to estimates, 76% of people who are diagnosed while the cancer is only in the bone and has not spread (localized stage) live at least 5 more years. The same is true of 64% of people whose tumors spread to nearby areas in the body (regional stage) and for 24% of those whose cancer has spread farther (distant stage).

After treatment, you’ll need regular checkups with your doctor to watch for any long-term side effects and to make sure the cancer doesn’t come back.

A cancer diagnosis can be hard to handle, especially if it affects your child. You may want to consider joining a support group. Counseling is also a good option if the emotions are taking a toll.

Let your family and friends know how they can support you. Chances are, they want to help but may not know how.

Osteosarcoma is the most common type of bone cancer in children, teens, and young adults. But all adults can develop it, too. Knowing the risk factors and symptoms can help you catch osteosarcoma early before it has spread, helping make treatment more effective. Talk to your doctor if you or your child have any symptoms of osteosarcoma.

What is the survival rate for osteosarcoma?

If you have osteosarcoma, your 5-year survival rate will depend on the stage of your cancer -- how far the cancer has spread. Other factors that contribute to the survival rate include your age and other health conditions. Based on the stage, this is how likely you are to live at least 5 years after diagnosis:

  • Localized, meaning the cancer is only in the bone. The survival rate is 76%.
  • Regional, meaning it has spread to nearby structures and lymph nodes. The survival rate is 64%.
  • Distant (also called metastatic), meaning it has spread to distant parts of the body, most often the lungs, or other bones in other parts of the body. The survival rate is 24%. Chemotherapy greatly improves outcomes for people with distant or metastatic osteosarcoma.

What are the warning signs of osteosarcoma?

Warning signs include:

  • Swelling or lumps around bones or the ends of bones
  • Bone or joint pain or soreness. This pain may come and go for months.
  • Broken bones without a clear reason
  • Pain at night or after exercise
  • Limping

Can osteosarcoma be fatal?

Survival rates are based on the stage of the cancer at the time of first diagnosis. The earlier the cancer is found, the more likely you will survive for at least 5 years after diagnosis. For people with localized osteosarcoma, 76% will still be alive, but 24% may not be within 5 years. For people with distant, or metastatic osteosarcoma, 76% aren’t expected to survive 5 years after diagnosis.

Is osteosarcoma curable?

After treatment you may have a partial remission, meaning signs and symptoms of your cancer are reduced. Or you may have a complete remission, meaning there are no signs or symptoms of your cancer. Instead of complete remission (CR), your cancer doctor, or oncologist, may use no evidence of disease (NED). If you are in complete remission, or NED for 5 years or more, some oncologists say you are “cured.” But some oncologists won’t use that term. That’s because even though there may be no visible traces of cancer, some cancer cells can stay in your body years after treatment, and the cancer can return. Doctors cannot guarantee that you are cured. After your treatment, your doctor will continue to follow you closely for many years to look for signs that the cancer has come back.