What is sarcoma?
Sarcoma is the name for tumours that start in the connective tissues of the body. Connective tissues include bone, muscle, fat or cartilage.
To better understand bone cancer (sarcoma), you need to first know a bit more about your bones.
What are bones?
Bones are hard tissue that make up the skeleton and hold you up. Here are some facts about bones:
- Adults have 206 bones in their body.
- Bones protect our important organs such as our brain and heart.
- Bones meet at joints like our elbows and knees. Our bones and joints let us move around.
- Blood cells are made inside the marrow, the soft tissue inside our bones.
- Bones store calcium and release it when we need it.
One of the most surprising things about bones is they are alive. Bones are made of many types of living cells and, as in other parts of your body, these cells reproduce, die and have specific jobs. There are two main types of cells in your bones.
- Osteoblasts (say: OS-tee-oh-blasts) build the matrix in your bones. The matrix is the hard part of your bones that makes them strong.
- Osteoclasts (say: OS-tee-oh-clasts) break down the matrix so that your bones keep their proper shape.
These cells are always busy. New bone is always being made and old bone is always being broken down.
What are bone tumours?
A bone tumour is a tumour that starts in your bone. Remember that a tumour starts with a mistake in your DNA called a mutation. This mutation causes the cell to divide out of control and not die when it is supposed to. It also stops it from doing the job of a normal bone cell. This mutation can happen in any of the cells in your bones. When the mutated cell continues to divide it forms a mass of mutated cells called a tumour.
The two most common types of bone tumours in teenagers are osteosarcoma and Ewing sarcoma.
Osteosarcoma is usually found close to the knee joint in the lower part of the thigh bone, but it can occur in almost any bone in the body.
Ewing sarcoma starts in the bone but is usually also found in the tissue around the bone. This tumour is most common in the spine, hip bones, legs and arms.
What are the symptoms of bone tumours?
Common symptoms of bone cancer include:
- pain in the bone with the tumour (the most common symptom)
- swelling in the area of the tumour
- difficulty moving around – for example a tumour in your spine can make it hard to use your legs and arms
- losing weight
- feeling tired
Cancer stage
Your doctor might talk to you and your family about the stage of your cancer. This depends mainly on whether the cancer is only in one spot or whether it has metastasized (spread). The lungs are the most common location for bone tumours to spread. Sometimes, the cancer can also spread to other bones in the body.
Why are bone tumours more common in teenagers?
Bone cancer is most common in teens and young adults, which suggests there might be a link between fast bone growth and the formation of a tumour.
When you are a teenager, you typically go through a growth spurt where you grow quickly to reach your adult height. During a growth spurt, your bones are making many more bone cells. Some scientists suggest that as the cells divide quickly, there is a chance the cells will make a mistake copying the DNA. This mistake can then lead to a bone tumour.
How is bone cancer diagnosed?
Doctors learn what type of bone tumour you have through a process called diagnosis.
Diagnosis of a bone tumour usually starts with a doctor examining you and asking you lots of questions about how you are feeling and why you came to the clinic or the hospital. The doctor will probably do an X-ray and then an MRI to get a picture of your bone. The doctor will also do a biopsy to get a sample of the cells in the tumour. The doctor will look at this sample under a microscope to check for cancerous cells. The doctor will also order some other scans to get a picture of the inside of your body (especially your other bones and the lungs). These scans are called a CT scan of the chest and a bone scan. Together these scans can help the doctor see if the cancer has spread.
How is bone cancer treated?
Doctors use the information they gather to diagnose what type of bone tumour you have, the stage of the tumour (whether it has spread) and to plan your treatment. The main types of treatment for bone tumours are surgery and chemotherapy. Radiation may also be used for people with Ewing sarcoma.
Most of the time, you will meet a bone surgeon (orthopedic surgeon) who will decide whether they can operate to remove the whole tumour from your body. There are different ways of doing this. Talk to your surgeon about these options.
The goal of treatment is to remove or kill all of the cancerous cells in your body. You will learn more about different types of treatment in the sections on cancer medications and cancer treatments and support therapies.
Prognosis for bone cancer
Your doctor will tell you and your family the prognosis for your bone cancer. A prognosis means the likelihood or chance that treatment will work and that you will recover from cancer. Each type of bone cancer has a different prognosis depending on:
- the type of bone tumour
- the stage of the cancer (whether it has spread)
- whether a surgeon can remove all of it
Your best source of information about your bone tumour is your health-care team. If you have any questions or there is anything you don’t understand about your bone tumour, ask your doctors and nurses. Your doctors and nurses want to help you understand your cancer.
If you are nervous about asking the doctors or nurses yourself, you can talk to your parent/caregiver. They parents may be able to answer your questions or they can help you ask questions.
