What is osteosarcoma?

Osteosarcoma is a type of bone cancer. A person with osteosarcoma may feel many symptoms, including pain and swelling. Doctors do not know why some people develop osteosarcoma. The outlook is more favorable when the tumor has not spread.

Osteosarcoma is a relatively rare type of cancer with around 800 to 900 new cases reported in the United States each year. Children and young adults between 10 and 30 years of age are the most commonly affected group.
The bones most likely to be affected by osteosarcoma are:

• the shinbone, or tibia, located below the knee
• the thighbone, or femur, situated above the knee
• the upper arm bone, or humerus, below the shoulder

Osteosarcoma is a rare type of bone cancer in children and usually appears in early adolescence, during growth spurts. Osteosarcoma is slightly more common in African-Americans than in others.

What are the symptoms?

The femur is one of the bones that osteosarcoma most often affects.

The symptoms of osteosarcoma vary from person-to-person and can differ, depending on where the tumor is growing.
Typical symptoms include:

• pain in the bones during movement or rest
• bone fractures
• redness and swelling
• limping due to pain and swelling
• reduced mobility in the joints

Osteosarcoma causes pain that can be a dull, aching sensation or so intense it interferes with sleep. People often mistake these pains for growing pains.
A person should see a doctor if they experience:

• bone pain, particularly if it continues after growth spurts or interferes with daily life
• swelling of an arm or leg
• muscles that look smaller in one arm or leg compared to the other

Causes

While it is not possible to prevent this cancer from occurring, there are several risk factors, such as:

Genetics

Doctors think a mutation of the p53 gene, which they believe affects the development of tumors in young people, might be connected with osteosarcoma.
Osteosarcoma could also be related to the retinoblastoma gene, which experts have linked to eye cancer in children.

Previous radiation therapy

If a person has undergone radiation therapy in the past, they may be at higher risk of developing osteosarcoma, though it could take years for this to occur.

Rapid bone growth

When bones enlarge quickly due to growth spurts, this may leave them more susceptible to tumors.

How is it diagnosed?

A MRI scan can help to identify osteosarcoma.

There are several ways a doctor may diagnose osteosarcoma. These include:

• Asking about symptoms and medical history to see if any risk factors make osteosarcoma more likely.
• A physical examination to see if there are any visible signs, such as swelling and redness.
• A blood test to check for indications that tumors may be growing.

If a doctor suspects that osteosarcoma is causing a person's symptoms, they may recommend further tests. These include:

• X-ray: This allows doctors to see detailed images of tissue, such as bone.
• CT scan: This is imaging that enables doctors to get a more precise look at the bones and organs.
• Magnetic resonance imaging (MRI): This uses a combination of sound waves and powerful magnets to produce detailed images of internal body parts.
• Positron emission tomography (PET) scan: This imaging test uses a dye and shows how well the organs are functioning. It is often used to help doctors detect cancer.
• Bone scan: A bone scan is used to see if there are any abnormalities in a person's bones. It is also known as a radionuclide scan, scintigram, or nuclear medicine test.
• Biopsy: To perform a biopsy a doctor will remove a tissue sample from a person's bone, which they then send to a lab for testing.

If osteosarcoma is present it will be classified in one of two ways:
1. Localized: Where doctors find cancer in one area only, such as the bone where it first developed.
2. Metastatic: Where cancer has spread to other areas of the body.
The stage the cancer is at determines how much disease is present in the body. The Musculoskeletal Tumor Society Staging System and the American Joint Commission on Cancer TNM system provide details of what each stage means.

Treatment options

People diagnosed with osteosarcoma are likely to undergo chemotherapy treatment.
Chemotherapy is a standard cancer treatment where doctors give a patient drugs that destroy cancer cells in the body. People take several cycles of the drugs and may need more extended treatment periods if cancer has spread.
After a course of chemotherapy, a person may then require surgery to remove any tumors that remain. A doctor will try to remove tumors during an operation, as well as the surrounding bone, and will then insert an artificial replacement.

In most cases, surgeons can save the affected limbs. There are, however, instances when they need to amputate the arm or leg that has cancer.
A person may require further rounds of chemotherapy after surgery to destroy any cancer cells that remain.

What are the complications?

It is possible for bone cancer to recur after treatment, and further scans and X-rays will be necessary to check that no new tumors are growing.
There are no guarantees that chemotherapy and surgery will cure cancer. If these treatments fail, amputation may be necessary to stop the cancerous cells from spreading elsewhere.
Chemotherapy is an intense treatment and can cause unpleasant side effects, including:

• nausea
• pain
• vomiting
• tiredness and weakness
• loss of hair
• constipation or diarrhea
• recurrent infections
• fluid retention
• anemia or low red blood cell count

Outlook and takeaway

The prognosis for people with osteosarcoma is dependent on several factors, including:

• the location of the tumor
• how advanced cancer is and how early it is found
• whether cancer has spread to other parts of the body
• the age of the person diagnosed

Some 3 out of 4 people make a full recovery from osteosarcoma if their cancer has not spread.
The survival rate for people whose tumors have spread elsewhere is around 30 percent.