Sarcomas are rare tumours that develop in the supporting tissues of the body, such as bone, muscle or cartilage. There are two main types of sarcomas:
- Soft tissue sarcomas can develop in muscle, fat, blood vessels, or in any of the other tissues that support, surround and protect the organs of the body
- Bone sarcomas can develop in any of the bones of the skeleton
Rhabdomyosarcoma has muscle-like features and can grow in any part of the body. The most common areas of the body to be affected are around the head and neck, bladder, testes, uterus, or vagina.
Sometimes rhabdomyosarcoma is found in a limb, in the chest or in the abdominal wall. If the tumour is in the head or neck area, it can occasionally spread into the brain.
In children, about 20% of rhabdomyosarcomas have a gene rearrangement involving the PAX and FOXO1 genes (fusion positive), and the remaining tumours do not have the gene fusion (fusion negative).
The genetic information of the tumour is important to help doctors to decide on the best treatment.
Watch our expert Dr Boo Messahel, Consultant Paediatric Oncologist and CCLG member, explain more about rhabdomyosarcoma.
Causes
The causes of rhabdomyosarcoma are unknown but research is going on all the time to try and find out. Children with certain rare genetic disorders, such as Li-Fraumeni syndrome, have a higher risk of developing rhabdomyosarcoma.
Signs and symptoms
The most common sign of rhabdomyosarcoma is a lump or swelling. Other symptoms will depend on the part of the body that’s affected by the rhabdomyosarcoma:
- a tumour in the head or neck area can sometimes cause a blockage (obstruction) and discharge from the nose or throat. Occasionally, an eye may appear swollen and protruding.
- a tumour in the tummy (abdomen) can cause pain or discomfort in the tummy and difficulty going to the toilet (constipation).
- a tumour in the bladder may cause symptoms such as blood in the urine and difficulty being able to wee.
How rhabdomyosarcoma is diagnosed
Different tests are usually needed to diagnose a rhabdomyosarcoma. Your child may need a small operation to remove a sample from the tumour (a biopsy) so that it can be examined under a microscope. This is usually done under a general anaesthetic.
Tests may be done to check the exact size of the tumour, to check whether the tumour is fusion positive or fusion negative and to find out if it has spread to any other part of the body. These may include:
- a chest x-ray to check the lungs
- an ultrasound scan
- CT, PET/CT or MRI scans
- blood and bone marrow tests
- molecular gene testing
Any tests and investigations that your child needs will be explained to you.
Staging
The stage of a cancer is a term used to describe its size and whether it has spread from where it first started. Knowing the stage helps the doctors decide on the most effective treatment for your child.
The staging system for rhabdomyosarcoma is based on:
- where in the body the tumour started
- whether it is in only one part of the body (localised disease), or if it has spread to another part of the body (metastatic disease).
There are different ways of staging rhabdomyosarcoma, and your child’s doctor will explain more about the system they are using.
Treatment
Treatment will depend on the size of the tumour, the type of rhabdomyosarcoma, its position in the body and whether it has spread.
The three main types of treatment for soft tissue sarcomas are chemotherapy, surgery and radiotherapy. Your child may have a combination of treatments.
Chemotherapy
Chemotherapy is the use of anti-cancer drugs to destroy cancer cells. It can be given:
- to shrink the tumour before surgery
- after surgery to reduce the risk of the cancer returning
The drugs used and the length of treatment depends on the type and stage of the rhabdomyosarcoma.
Surgery
If it is possible, your child will have an operation to remove all or as much as possible of the tumour, without damaging surrounding tissue or organs. The operation will depend on the size of the tumour and where it is in your child’s body. The surgeon will explain what is involved.
Chemotherapy is usually given before surgery to shrink the tumour and make it easier to remove. If an operation isn’t possible, both chemotherapy and radiotherapy are given.
Radiotherapy
Radiotherapy treats cancer by using high energy rays, which destroy the cancer cells while doing as little harm as possible to normal cells. It may be given after surgery to the area where the rhabdomyosarcoma started.
Depending on the site of the rhabdomyosarcoma, there are different radiotherapy techniques, and this may mean travelling to a different treatment centre. Examples include brachytherapy and proton beam.
Sometimes patients are offered radiotherapy before surgery, rather than after surgery.
Clinical trials
Many children have their treatment as part of a clinical research trial. Clinical trials are carried out to try to improve our understanding of the best way to treat an illness, usually by comparing the standard treatment with a new or modified version. Clinical trials mean there are now better results for curing children’s cancers compared with just a few years ago.
Your child’s medical team will talk to you about taking part in a clinical trial and will answer any questions you have. Taking part in a research trial is completely voluntary, and you’ll be given plenty of time to decide if it’s right for your child. You may decide not to take part, or you can withdraw from a trial at any stage. You will then receive the best standard treatment available.
National treatment guidelines
Sometimes, clinical trials are not available for your child’s tumour. In these cases, your doctors will offer the most appropriate treatment, using guidelines which have been agreed by experts across the UK. Children’s Cancer and Leukaemia Group (CCLG) is an important organisation which helps to produce these guidelines.
Late side effects
A small number of children may develop long-term side effects many years after treatment for a rhabdomyosarcoma.
Months or years later some children may develop late side effects from the treatment they have had. These may include a reduction in bone growth, a change in the way the heart, lungs and kidneys work, a risk of infertility and a small increase in the risk of developing another cancer in later life. It is important to understand that not all late effects will happen to all patients. You can find more information here (link to www.cclg.org.uk/life-after-childhood-cancer)
Your child’s doctor or nurse will talk to you about any possible late side effects and will keep a close eye on possible long-term side effects in follow-up clinics.
Follow-up care
Once treatment has finished, the doctors will monitor your child closely with regular appointments to be sure that the cancer has not come back and there are no complications. After a while, you will not need to visit the clinic so often.
If you have specific concerns about your child’s condition and treatment, it’s best to discuss them with your child’s doctor, who knows their situation in detail.
This information is about rhabdomyosarcoma in children, aged 0-14 years.
Find out about soft tissue sarcoma in teenagers and young adults (15 - 24 years)