By Dr. Columba Quigley
Osteosarcoma is a rare type of bone cancer that mainly affects teenagers and young adults.
What happens in osteosarcoma?
The human body is made up of millions of cells. Each cell has its own specific job. Osteoblasts, for example, are bone-building cells.
Your body makes new healthy cells all the time, to replace old worn out ones. Sometimes a cell misbehaves and produces lots of badly behaved cells instead of healthy ones.
These badly behaved cells join together to form a lump called a tumour. The tumour gets in the way of healthy cells and stops them working properly. When this happens, it's called cancer.
When osteoblasts start behaving badly, the cancer is called an osteosarcoma.
Osteosarcomas usually begin at the ends of long bones, where osteoblasts are normally busiest making new bone. They usually involve the long bones of arms or legs, particularly around the knee or shoulder joints.
Sometimes the tumour spreads outside the bone to other parts of your body, for example to your lungs or to other bones.
How do you know it is osteosarcoma?
As the tumour starts to grow, it pushes against your muscles and joints, causing pain and swelling, which is usually the first thing you notice. The tumour can also make moving joints difficult and painful.
The doctors will then do some tests. These include an X-ray and a biopsy. The biopsy involves using a very thin needle to take a small sample of cells from the tumour and looking at them closely under the microscope.
To check whether the tumour has spread to other parts of the body, you'll need a CT scan or MRI, as well as a bone scan. These scans take detailed pictures of the inside of your body.
How is osteosarcoma treated?
Treatment takes place in a specialist osteosarcoma centre. The first thing is to take the tumour out, so surgery is necessary. The type of operation depends on where the tumour is, and how big it is. Mostly, just the affected bit of bone is removed. This is called 'limb-sparing surgery'. The gap where the tumour was is filled in with a specially designed artificial part, or with bone taken from another part of your body.
Less commonly, the limb where the osteosarcoma is needs to be removed. This is called an amputation. After an amputation, an artificial limb can be fitted.
Artificial arms and legs are so advanced these days, that once they are fitted you can pretty much do anything you want, including sports.
As well as surgery, treatment also includes chemotherapy, which means anti-cancer medicines. These can be given before the operation to shrink the tumour down, as well as afterwards to help stop the osteosarcoma coming back.
Usually chemotherapy includes a few different types of medicines, and the treatment can go on for many months.
Sometimes radiotherapy, which uses very powerful energy beams to zap and kill the cancer cells, is also needed.
Doctors and scientists are working hard to develop new treatments for osteosarcoma.
Even when all the treatment has finished, you will still need regular check ups for a long time, to make sure the tumour does not cause problems again.
About Dr. Columba Quigley
Dr. Columba Quigley is a medical writer and managing editor at Medikidz, an organisation that provides children with informative, accessible and fun comics to help them understand health and illness.