Osteosarcoma
Osteosarcoma is one of the commonest types of bone cancer in children and young people. It can develop in any bone but most often affects either a leg or an arm. Usually it develops from the area of bone where new bone forms as an individual grows. This is called the metaphysis.
Who gets osteosarcoma?
About 30 children develop osteosarcoma in the UK each year. It is more common in teenagers and young adults, and in boys compared to girls. It is rare in children under five years of age.
The cause of osteosarcoma is unknown. However, genetic factors and irradiation may play a part in some individuals. For example, children with retinoblastoma (a rare type of eye tumour) or Li-Fraumeni syndrome (a familial cancer syndrome) have an increased risk of developing osteosarcoma. Long-term survivors of cancer who have previously had radiotherapy also have an increased risk of osteosarcoma, which may develop many years after the original radiotherapy.
Signs and symptoms
The most common symptom is pain in the affected bone. There may be some associated swelling and tenderness. Occasionally, a child may present with a fracture at the site of the tumour. Often, symptoms have been present for several months before a diagnosis is made.
Tests / investigations
We will need to carry out some tests to find out as much as possible about the type, position and size of the tumour. These tests include:
- X-ray of the affected bone to identify the tumour.
- Chest x-ray to see whether the tumour has spread to the lungs.
- CT scan or MRI scan – a scan of the affected bone/tissue and chest will be carried out. This provides more information about the tumour and whether it has spread.
- Biopsy – this is a small operation, usually under general anaesthetic, to remove some tissue.
- Bone scan – this involves injection of a radioactive substance which is taken up by any areas of abnormal bone.
Staging
Staging refers to the size of the tumour and whether it has spread. Knowing the stage of the cancer helps the doctors decide on the most appropriate treatment for your child. For treatment purposes, patients with osteosarcoma are divided in to two groups. These are:
- localised, where the tumour is found in only one part of the body
- metastatic, where the tumour has spread to other parts of the body.