What are soft tissue sarcomas?
Soft tissue sarcomas are rare cancers, accounting for less than 1 in 100 of all adult cancers. They can occur in supporting tissues of the body, such as muscle, fat, blood vessels or nervous tissues.
They are particularly common around the limbs, but also occur within the abdomen, the chest, or in the head or neck region.
There are many different types of soft tissue sarcoma. The treatment a patient receives will vary depending on where their sarcoma is, and which type of sarcoma they have. Soft tissue sarcomas are different from other sarcomas, which occur in bone and cartilage. The information on this page does not cover bone and cartilage sarcomas.
Soft tissue sarcomas can occur at any age, including during childhood and during the teenage and young adult years.
What causes soft tissue sarcomas?
For the vast majority of soft tissue sarcomas, we do not know the cause. Like many other cancers, sarcomas often arise ‘out of the blue’, even in people who lead a healthy lifestyle. However, we are beginning to build up a picture of what might cause soft tissue sarcomas.
- Research suggests that some sarcomas are caused by a ‘spelling mistake’ in the instructions contained within the genes that control the activity of supporting tissues. Sometimes it is possible to identify the damaged gene by performing analysis of the sarcoma cells in a gene research laboratory. It is becoming increasingly common for us to send samples of sarcomas to these laboratories, because identifying the specific gene fault can help to determine exactly which type of sarcoma we are dealing with.
- Sometimes, the genetic damage that can lead to sarcoma is inherited. This is the case with a condition called neurofibromatosis, which is characterised by multiple skin lumps called neurofibromas. People who have this condition have a 1 in 10 chance of developing a sarcoma.
- A rare but important cause of soft tissue sarcoma is damage caused to tissues by previous radiotherapy for another condition.
What types of soft tissue sarcoma are there?
These are the most common types of soft tissue sarcoma
- synovial sarcoma
- malignant peripheral nerve sheath tumour (MPNST)
- epithelioid sarcoma
- GISTs (Gastro-Intestinal Stromal Tumours)
- sarcoma NOS (not otherwise specified)
There are other rarer varieties of sarcomas including:
- desmoid tumours
- dermatofibrosarcoma protuberans (DFSP)
Before any treatment can begin, we need to establish the exact type of sarcoma.
How are soft tissue sarcomas diagnosed?
Sarcomas are usually diagnosed when a patient notices a lump that is changing. In cases where the lump is very small or superficial (close to the skin), it may be possible to proceed straight to surgery. However, in most cases, it is useful to have a specialist scan (CT or MRI scan) before any surgery, followed by a needle biopsy of the lump. This involves placing a needle into the lump (usually under local anaesthetic) to remove a core of tissue for analysis.
When this tissue is examined under the microscope, it is often possible to classify the grade and type of the sarcoma. Low grade sarcomas (grade 1) tend to be easier to treat and have a better prognosis than high grade sarcomas (grades 2 and 3). Some lumps may turn out to be benign (non-cancerous).
Once the diagnosis of sarcoma is confirmed, we usually arrange for the patient to have a CT scan of their lungs, to make sure that the sarcoma has not spread to this area (the most likely part of the body for a sarcoma to spread to).
Questions for your doctor
Whenever treatment is discussed with you, remember that it is always up to you whether you consent to it or not. We will help you make this decision by providing as much information as you require. We encourage you to discuss your diagnosis and proposed treatment options with your family, close friends, GP and your specialist nurse before you decide on your treatment plan. You will always be asked to sign a consent form before starting any treatment.
Before you decide, here are some things you might like to think about and perhaps discuss with your doctor:
- “What are the benefits of this treatment?”
- “What are the short and long term side effects or risks?”
- “Are there any alternatives to this treatment?”
- “What would happen if I did not have this treatment?”
How do we treat soft tissue sarcomas?
To treat soft tissue sarcomas effectively, it may be necessary to involve several different specialists, such as surgeons and oncologists specialising in radiotherapy (treatment with x-rays) and chemotherapy (treatment with drugs).
The treatment we can offer will vary depending on whether the sarcoma is a localised primary sarcoma (one which has not spread elsewhere) or whether it is more advanced.
The treatment offered will vary from patient to patient. This leaflet gives a general overview of treatment. The exact treatment for any sarcoma patient will be discussed with them individually.
Treatment for localised primary soft tissue sarcoma
The recommended treatment is usually a combination of surgery and radiotherapy.
The aim of the surgery is to completely remove all the visible sarcoma mass, as well as a safety margin of normal tissue around the tumour. This may sometimes mean removing an entire muscle group, or an organ such as the kidney, or a section of bowel, depending on where the tumour is.
Radiotherapy is often recommended in addition to surgery to treat any remaining sarcoma cells and help to reduce the chance of the sarcoma coming back in the future. If the sarcoma is a less aggressive one, then surgery on its own may be sufficient and radiotherapy may not be needed.
The different types of surgical operations are as follows:
Wide local excision: this operation involves removing the sarcoma with a margin of normal tissue around it. Radiotherapy is often given as well, either before or after surgery, as there is a risk of sarcoma cells remaining after this particular type of operation.
Marginal Excision: at this operation involves removing the sarcoma but without a margin. This is sometimes done for very low grade sarcomas.
Compartmentectomy: the muscles of the arm and leg are divided into separate anatomical groups or compartments. Surrounding each compartment, there is a dense fibrous sheath, which is relatively resistant to the spread of the sarcoma.
A compartmentectomy is an operation to remove the entire muscle compartment that contains the sarcoma, together with its surrounding fibrous sheath.
In some cases, the surgeon may need to use a technique which brings new skin (skin graft) and muscle (known as a pedicle or free flap) into the area to repair the wound.
Radiotherapy is sometimes given as well, depending on the likelihood of sarcoma cells remaining after the operation.
Amputation: nowadays, this is only done in a small minority of cases, where the tumour comes back after the original treatment, or where removal of the tumour would create such a huge defect as to leave the limb functionless.
Following an amputation, the amputee service at the Disablement Services Centre /Limb Fitting Service will be involved in your care as early as possible. Staff from the appropriate service will follow you through the post-operative and rehabilitation stages, and can offer support and practical advice. Some centres also have a Volunteer Visitor service and established amputees will be happy to talk to you about life following amputation.
This may be given after surgery (post-operative radiotherapy) or before surgery (pre- operative radiotherapy). Very occasionally, when it is not possible to have surgery, radiotherapy will be the only treatment given (radical radiotherapy).
Post-operative radiotherapy: This is given once the wounds from the operation have healed. The oncologist will use information from the surgeon and also from scans carried out before the operation (pre-operative imaging) to determine accurately the area to treat. Normally, the whole site of the operation is treated with a safety margin of approximately 5 cm (2 inches).
Pre-operative radiotherapy: Occasionally it is better to deliver radiotherapy before the operation. We will always discuss the pros and cons of pre-operative radiotherapy with you before a final decision is made.
Radical radiotherapy: Sometimes surgery is not possible and radiotherapy is the best option to treat a sarcoma. This may, for example, occur where sarcomas are close to vital structures. If this is the case, you will receive high doses of radiotherapy over a number of weeks to your sarcoma.
Before a course of radiotherapy can start, a mould is made to prevent the part of the body that needs radiotherapy from moving. After this mould is made, you will have another CT scan to plan your treatment. It usually takes about three weeks to plan radiotherapy. Radiotherapy is usually given daily (excluding weekends) over five to six and a half weeks.
Chemotherapy is rarely given after surgery to remove a sarcoma, as it has not been shown to prevent sarcomas from coming back. However, there are a few rarer sarcomas (such as rhabdomyosarcoma), which may be treated with chemotherapy before and after surgery.
If your specialist team recommends chemotherapy you may need to be admitted to hospital for treatment, or you may receive the chemotherapy on an out-patient basis. This depends on the drugs you are being given.
Many soft tissue sarcomas arise within, or very near to, muscle tissue. An operation to remove the tumour may involve removing some muscle tissue. This may leave your arm or leg stiff and weak. You will be shown specific exercises to re-establish a full range of movement and regain your strength.
Radiotherapy may also cause some soft tissue tightness, swelling or stiffness across a joint. A physiotherapist will show you stretching exercises to minimise the effect of this.
Treatment for advanced soft tissue sarcoma
Advanced disease is when either the sarcoma has spread to other parts of the body, or when it is in one primary site but it is impossible to get rid of it all with surgery and radiotherapy. The terms used for cancer spread are secondaries or metastases. The most common site for the tumour to spread to is the lung, but it may also spread to other parts of the body.
If there are only a few lung metastases, we may advise that these are removed surgically. Otherwise, the recommended treatment for metastases is chemotherapy. The most commonly used drugs are doxorubicin (also known as adriamycin) and ifosfamide, but other drugs may be used, depending on the type of sarcoma. Radiotherapy can also be helpful in controlling symptoms from advanced disease.
What will happen once I have finished my treatment?
Following the successful surgical treatment of a primary soft tissue sarcoma, we currently recommend follow-up visits every three months for two years, then every six months for three years, and then annually for a further five years.
The most common site for metastases is the lung. If lung metastases are picked up early, it may be possible to remove them surgically. For this reason you will have regular chest x-rays as part of your follow-up.
If chemotherapy or radiotherapy has been part of the treatment, follow-up visits may be more frequent.
In between follow-up appointments, you should report any new lumps around the site of your initial sarcoma to a member of your sarcoma team as soon as possible.
After you have completed treatment, symptoms such as coughs, chest infections, and pain in the back or abdomen should be reported to your GP. In most cases, these symptoms will be due to everyday illnesses which will get better. However, if they do not respond to treatment, or if they persist for more than two or three weeks, your GP should refer you to the sarcoma team.
We are often involved in trials to try to improve the treatment of patients with soft tissue sarcomas. Your sarcoma specialist will discuss with you any trials that may be relevant. Occasionally we may recommend a trial that is not available in your hospital but is available in one of the other hospitals in the East Midlands Sarcoma Service. Participation in clinical trials is voluntary and if you would prefer not to take part in a trial your treatment will not be affected in any way.
Information about rarer soft tissue tumours
Desmoid tumours (also known as aggressive fibromatosis or musculoaponeurotic fibromatosis).
Desmoid tumours are not true sarcomas and, strictly speaking, they are not malignant either. They do not metastasize but can spread locally and often come back after previous treatment.
They can sometimes occur in young adults who have a condition known as familial adenomatous polyposis (FAP) or Gardner’s syndrome.
In some cases, these tumours appear as distinct round lumps, for example within a muscle. If so, treatment would be very similar to the treatment of a muscle sarcoma – complete surgical removal with a wide safety margin.
In other cases, fibromatosis can produce a mass that spreads through several adjacent tissues. This is a particular problem if it arises within the abdomen, as it makes surgical removal difficult. However, we would still aim to treat it surgically, as this appears to be the most successful form of treatment.
Radiotherapy or chemotherapy may also be considered, either in conjunction with surgery or instead of it. Occasionally drugs like tamoxifen (usually used in breast cancer), and certain pain killers, can be used to treat difficult cases. In some cases, fibromatosis will grow fairly rapidly for a few months, and then stop growing, even without treatment. When this happens, it may be preferable to have a period of observation instead of any treatment.
Dermofibrosarcoma protuberans (DFSP)
DFSP is a tumour arising within the skin. It very rarely metastasises (spreads to other parts of the body), but it can spread through the skin and produce a large and painful tumour or ulcer.
The usual treatment is surgery. It is essential to make sure that there is a wide clearance of unaffected (healthy) tissue around the DFSP. This may mean having a skin graft, which can leave a scar. Sometimes radiotherapy is given after surgery.
Retroperitoneal sarcomas are those that arise within the abdomen or pelvis in a distinct area called the retroperitoneal tissues. The commonest type of sarcoma found in this area is a liposarcoma. These can be difficult to treat because of poor accessibility during surgery, and they are often quite large by the time they are diagnosed.
As with other sarcomas, we will arrange for careful assessments to be made before any treatment is started. This will include appropriate x-rays and scans, and a needle biopsy is often useful.
The usual treatment is surgery to remove the tumour and, possibly, other adjacent organs. Radiotherapy and chemotherapy may also be used.
GISTs (Gastro-Intestinal Stromal Tumours)
GISTs are a rare type of sarcoma found in the digestive system, most often in the wall of the stomach. Some GISTS are benign (not cancerous) but they can become cancerous if not treated. Generally speaking, the larger the GIST, the more likely it is to be cancerous.
The most common treatment used is surgery, and this alone may be a cure for people with small tumours. Larger tumours are less likely to be completely removed and may require treatment with imatinib (Glivec®) tablets first. If the GIST has spread to other parts of the body, it is sometimes possible to remove these secondary tumours too.
NICE (the National Institute for Health and Care Excellence) recommends that imatinib (Glivec®) should be the first choice of treatment for people with GIST that cannot be completely removed with surgery. Some people may take imatanib tablets for many years.
Second line treatment with sunitinib (Sutent®) is available for suitable patients whose GIST is no longer controlled by imatinib. Other treatments may become available in the future.
Post amputation. Rehabilitation for sarcoma patients.