How is osteosarcoma found?
Most osteosarcomas are found at an early stage, before they have clearly spread to other parts of the body. Symptoms like bone pain or swelling often prompt a visit to a doctor. The sooner it is found, the better the chance of a cure.
At this time there are no special tests to screen for osteosarcoma in people without symptoms or strong risk factors. The best thing to do is to watch for any symptoms of this disease and see a doctor right away.
Signs and symptoms of osteosarcoma
Pain and swelling
Pain in a bone is the most common symptom. At first, the pain may come and go. It might be worse at night. The pain gets worse with activity and may cause a limp if the tumor is in a leg.
Swelling in the area of the pain may not happen until weeks later. Depending on where the tumor is, you may be able to feel a lump.
Limb pain or swelling is fairly common in normal, active children and teens, so it’s easy to see why this cancer might not be found right away. These symptoms are less common in adults and should be a sign to see a doctor.
Bone fractures (breaks)
Although osteosarcoma may weaken the bone it develops in, the bones often do not break. People with a fracture next to or through an osteosarcoma often describe a limb that was sore for a few months and suddenly became very painful when the fracture occurred.
Medical history and exam
If there are signs or symptoms that suggest a bone tumor, the doctor will want to take a complete medical history. A physical exam will be done to learn more about the tumor, as well as other health problems. If the doctor thinks it may be osteosarcoma or another type of bone tumor, more tests will be done, such as those listed below.
Imaging tests are done to get pictures of the inside of the body to look for problems. These tests can be done:
- To find the cancer
- To figure out how far it has spread
- To see how well treatment is working
- To see if the cancer has come back after treatment
Bone x-rays: This is often the first test done if a doctor suspects a bone tumor. Doctors can often spot a bone tumor like an osteosarcoma on a regular x-ray, but only a biopsy (see below) can show if cancer is really there.
MRI (magnetic resonance imaging): MRI scans use radio waves and strong magnets instead of x-rays to make very detailed pictures. An MRI can help show if a bone tumor has grown into nearby areas. Sometimes the MRI can help find small tumors several inches away from the main tumor. Knowing how far the tumor has grown is important for planning the best type of surgery.
An MRI scan could take up to an hour. You (or your child) have to lie on a table that slides inside a narrow tube, which can be upsetting. Newer, more open MRI machines can help with these feelings, but the test still means staying still for a long time. The machine also makes a thumping noise that may be disturbing. Some places will give you headphones with music to block out the noise. Sometimes, younger children are given medicine to help keep them calm or even asleep during the test.
CT (computed tomography) scan: The CT scan uses x-rays to make detailed pictures of your insides. A CT scan of the bone can show if the tumor has spread into nearby tissues like muscle or fat, although MRI is often better for this. A chest CT scan can show whether the cancer has spread to the lungs or other parts of the body.
A CT scanner has been described as a large donut, with a narrow table in the middle “hole.” During the test, the table slides in and out of the scanner. You (or your child) will need to lie still on the table while the scan is being done. In some cases, children may need to be sedated before the test to stay still and help make sure the pictures come out well.
Before the scan, you (or your child) may be asked to drink a liquid or have a contrast dye put into your vein. This helps better outline places in the body. The dye may cause some a feeling of warmth, especially in the face. Some people are allergic and get hives. Rarely, problems like trouble breathing or low blood pressure can occur. Be sure to tell the doctor if you (or your child) have any allergies or have ever had problem with any contrast dye used for x-rays.
Chest x-ray: An x-ray is sometimes done to see if the cancer has spread to the lungs. A chest x-ray can find larger tumors, but it is not as good as a CT scan for spotting smaller tumors. If a CT scan of the chest is done, a chest x-ray probably won’t be needed.
Bone scan: A bone scan can help show if a cancer has spread to other bones. This test is useful because it can show the whole skeleton at once. a bone scan might not be needed if a PET scan (described below) is being done.
For a bone scan, a small amount of radioactive tracer is put into a vein and travels through the blood. Areas of damaged bone, such as tumors, absorb this tracer. You (or your child) then lie on a table while a special camera makes pictures of the bones that show the radioactive spots. Younger children may be given medicine to help keep them calm or even asleep during the test.
Osteosarcoma will usually look like a darker spot in the bone (called a “hot spot”), showing where there is more radioactivity. Hot spots may suggest cancer, but other bone diseases can also cause the same pattern.
PET scan: For a PET scan, a form of radioactive sugar is put into the blood. The amount of radioactivity used is very low. Any cancer cells in the body will take in a lot of the sugar. A special camera can then make a picture of places of radioactivity in the body. The picture is not detailed like a CT or MRI scan, but it provides useful information about the whole body. PET scans can help show the spread of the cancer to the lungs, other bones, or other parts of the body. Some newer machines can do a PET and CT scan at the same time.
To learn more about these imaging tests, see our document Imaging (Radiology) Tests.
A biopsy involves taking a sample of the tumor to be looked at under a microscope. It is the only way to be sure if a tumor is an osteosarcoma or another type of bone cancer.
If the tumor is in a bone, it is very important that a surgeon with experience in treating bone tumors does the biopsy. This surgeon can plan both the biopsy and surgery to treat the tumor at the same time. This can help prevent later problems and might reduce the amount of surgery needed later on.
The biopsy may be done after the area around the tumor is numbed or with the patient in a deep sleep (under general anesthesia).
There are 2 different types of biopsies, the needle biopsy and the open (surgical) biopsy.
- A needle biopsy is done using a thin, hollow needle to remove a small piece of tumor.
- In an open biopsy, the doctor cuts through the skin, exposes the tumor, and then cuts out a piece of it. This type of biopsy must be done by an expert in bone tumors, or else it could result in problems later on.
Testing the biopsy samples
All biopsy samples are sent to a doctor with special training in lab tests (a pathologist) to be looked at under a microscope. Other lab tests might also be done on the samples. These tests can help tell osteosarcoma from other cancers that look like it under the microscope.
If an osteosarcoma is found, the doctor will give it a grade, which is a measure of how quickly the cancer is likely to grow and spread. Cancer cells that look somewhat like normal bone cells are described as low grade, while those that look very different from normal cells are called high grade.
Blood tests are not used to find osteosarcoma, but they may be helpful after it is found. For instance, high levels of certain chemicals in the blood can suggest that the osteosarcoma might be more advanced than it looks.
Other tests (like blood cell counts) are done before surgery and other treatments to get a sense of a person’s overall health. These tests are also important to keep track of a person’s health while they are getting chemotherapy.
Last Medical Review: 06/13/2014
Last Revised: 01/06/2015