Osteosarcoma
The most common primary bone cancer in young people
Quick Facts
- Type: Primary bone cancer
- Common in: Teens and young adults
- Usual sites: Knee, thigh, upper arm
- Treatment: Chemotherapy and surgery
Overview
Osteosarcoma is a cancer that begins in the cells that build new bone. It is the most common primary bone cancer, meaning a cancer that starts in the bone itself rather than spreading there from elsewhere. It occurs most often in children, teenagers, and young adults, frequently during the growth spurts of adolescence, although it can also affect older adults.
Osteosarcoma usually develops in the long bones, particularly around the knee (the lower thigh bone and upper shin bone) and in the upper arm. It tends to grow quickly and can spread, most often to the lungs. Because of this, prompt diagnosis and specialized treatment are important. With modern combined treatment, many people, especially those whose cancer has not spread, can be successfully treated.
Symptoms
The symptoms of osteosarcoma can be mistaken for ordinary growing pains or sports injuries, which can delay diagnosis. Common signs include:
- Persistent bone or joint pain that may worsen over time or at night
- Swelling or a lump near a bone or joint, often around the knee
- Pain that continues or returns despite rest
- Reduced movement in a nearby joint
- A bone that breaks more easily than expected (after minor injury)
- Less commonly, tiredness, unexplained weight loss, or fever in advanced disease
Because these symptoms overlap with common injuries, any bone pain or swelling that persists, worsens, or wakes a child or teen from sleep should be evaluated.
Causes
The exact cause of osteosarcoma is usually not known. It develops when bone-forming cells acquire changes in their DNA that cause them to grow uncontrollably. Most cases occur in otherwise healthy young people with no identifiable cause. Some factors are linked to a higher risk, including:
- Rapid bone growth during adolescence
- Previous radiation therapy to an area of bone
- Certain inherited cancer syndromes
- Some pre-existing bone conditions, particularly in older adults
Osteosarcoma is not caused by injury, although an injury sometimes draws attention to a bone that already harbors the cancer.
Risk Factors
Recognized risk factors for osteosarcoma include:
- Being a teenager or young adult during a growth spurt
- Being taller than average for age
- Previous treatment with radiation therapy
- Inherited conditions such as hereditary retinoblastoma and Li-Fraumeni syndrome
- Certain bone disorders, such as Paget disease of bone, which raises risk in older adults
Most people who develop osteosarcoma have none of these risk factors, and having a risk factor does not mean a person will develop the disease.
Diagnosis
Diagnosing osteosarcoma involves imaging and a tissue sample. Steps usually include:
- X-ray: Often the first test, which may show a destructive or unusual area of bone.
- MRI: To assess the size of the tumor and its effect on nearby tissues.
- CT scan of the chest: To check whether the cancer has spread to the lungs.
- Bone scan or PET scan: To look for spread to other bones or sites.
- Biopsy: Removing a sample of the tumor to confirm the diagnosis and determine the specific type; this should be done by a specialist team.
- Blood tests: To assess overall health before treatment.
Because the biopsy approach can affect later surgery, evaluation at a center experienced in bone tumors is strongly recommended.
Treatment
Osteosarcoma is treated by a specialized team using a combination of approaches. Treatment commonly includes:
- Chemotherapy: Usually given before surgery to shrink the tumor and treat any microscopic spread, and again afterward.
- Surgery: To remove the tumor. Most people have limb-sparing surgery that removes the cancer while preserving the limb, often with a metal implant or bone graft; amputation is needed only in some cases.
- Treatment of spread: Surgery or other therapy to remove tumors that have spread, especially to the lungs.
- Supportive care: Rehabilitation, physical therapy, pain control, and emotional support throughout treatment.
The outlook depends on factors such as the tumor's location, whether it has spread, and how well it responds to chemotherapy. Many people, particularly those with localized disease, can be cured with prompt, specialized treatment.
When to See a Doctor
See a healthcare provider if you, your child, or a teenager has bone or joint pain that:
- Persists for more than a few weeks or keeps returning
- Worsens over time or occurs at night and disturbs sleep
- Is accompanied by swelling or a lump near a bone or joint
- Comes with a bone breaking after only minor injury
These symptoms are usually due to harmless causes, but persistent or worsening bone pain and swelling should always be evaluated so that serious conditions, including osteosarcoma, can be identified early. Prompt diagnosis improves treatment options and outcomes.
Frequently Asked Questions
What is osteosarcoma?
Osteosarcoma is a cancer that starts in bone-forming cells. It is the most common primary bone cancer, occurs most often in teens and young adults, and usually develops near the knee or in the upper arm.
What are the warning signs?
The main signs are persistent bone or joint pain that may be worse at night, swelling or a lump near a bone, reduced joint movement, and sometimes a bone breaking after minor injury. These can be mistaken for growing pains or sports injuries.
What causes osteosarcoma?
Most cases have no known cause and arise from DNA changes in bone-forming cells. Risk is higher during adolescent growth spurts, after radiation therapy, and with certain inherited cancer syndromes or bone disorders.
How is osteosarcoma treated?
Treatment usually combines chemotherapy with surgery to remove the tumor, often sparing the limb. Tumors that have spread, commonly to the lungs, may also be removed. Care is best provided by a specialized bone-cancer team.
Can osteosarcoma be cured?
Many people, especially those whose cancer has not spread, can be successfully treated with prompt, specialized care. The outlook depends on the tumor's location, whether it has spread, and how well it responds to chemotherapy.
References
- National Cancer Institute (NCI).
- American Cancer Society.
- Mayo Clinic. Osteosarcoma.