An introduction to sarcoma
What is sarcoma?
Sarcoma is a cancer that affects the bones and soft tissues. Soft tissues are the ones that support, connect and surround the organs such as muscles, fat cells, blood vessels, nerves, cartilage, tendons and skin. All of these tissues might seem entirely unrelated, but they all develop from the same type of cell, called a mesenchyme cell that forms in the first few days of an embryo’s development.
Sarcomas are a large group of over 100 different types of tumours. Some tumours that are described as sarcomas are benign (non cancerous) and others are cancerous, but grow very slowly but tend not to spread to other parts of the body. Sometimes these tumours can become aggressive. Other sarcomas are fast growing and aggressive from the start.
Doctors usually distinguish between bone sarcomas, also called primary bone cancer where the cancer starts in cells that form part of bones, and soft tissue sarcomas that form in other tissues.
Symptoms of sarcoma
The first sign of a sarcoma is usually a painless lump or lumps somewhere on the body, often on the arms and legs. There are many types of cysts and fatty lumps (lipomas) that people can develop that are generally harmless. A GP will refer any suspicious lumps for further analysis. Diagnosis will usually involve an ultrasound and maybe an MRI scan, CT scan or X-rays, along with a biopsy so an histologist can examine the cells that make up the lump.
Sarcomas will grow over time, some slowly, others much quicker. Many sarcomas are not noticeable until they have become quite large, sarcomas are often more than 10 cm across by the time they are diagnosed. If they become very large they can press on nerves, causing pain. If they block lymph vessels it can lead to swelling. Tumours can also press on nearby organs, affecting their function. Sarcomas in or near the digestive system can cause a feeling of fullness, pain, nausea and blood in poo or vomit.
Bone sarcomas will cause pain in the affected bone, especially at night. There may also be swelling and nearby joints may be stiff. Occasionally the first symptom may be a bone breaking with no significant force or accident involved.
Causes of sarcoma
Cancer is the result of genetic damage, or mutations that lead to cells dividing uncontrollably. For some cancers there are clear risk factors that make these mutations more likely. For most people and most sarcomas there is no clear cause which means there is nothing that can be done to reduce the chance of a sarcoma developing.
There are a few known risks for sarcoma, but these are rare.
Someone who has had radiotherapy for another cancer is at increased risk of developing a sarcoma in the area that was exposed to the radiation. These can develop up to 10 years after the original cancer was treated. This type of sarcoma is getting less common as we get better at controlling the dose and location of radiotherapy.
People with a damaged immune system due to infection with HIV (the AIDS virus) or drugs to protect against organ rejection after a transplant, are at increased risk of Kaposi’s sarcoma when the body is unable to fight off an infection by a common herpes virus (HHV 8).
Some possible links have been made between exposure to certain chemicals and a higher risk of sarcoma. Dioxins, weed killers and chemicals involved in making plastics have been suspected, but the evidence is unclear. They are not thought to be a risk to most people who are not exposed to these chemicals in large amounts.
There are also a few very rare inherited conditions where mutations in particular genes increase the risk of developing a sarcoma, often alongside other health problems. The table below shows these inherited conditions and the genes that are affected.
Li Fraumeni Syndrome
Increased risk of several cancers. Increased chance of sarcoma after radiotherapy
Increased chance of sarcoma after radiotherapy
Many benign tumours, about 5% develop a sarcoma within a neurofibroma tumour
Rapid ageing and increased cancer risk
High risk of basal cell carcinomas, fibrosarcoma and rhabdomyosarcoma
Several health problems, increased risk of rhabdomyosarcoma
Polyps/colon cancer and risk of desmoid tumours
A bone sarcoma can form in very advanced Pagets disease
Types/locations of sarcoma
With such a large number of different sarcomas there are many ways of grouping them. Bone sarcomas, also called primary bone cancers, are usually grouped separately from the soft tissue sarcomas.
Some sarcomas can be found anywhere in the body and are named after either the way they look – spindle cell sarcomas have long, thin cells, or the type of tissue they form in – fibrosarcomas form in the fibrous connective tissue, angiosarcomas form in blood vessels (an angiogram is an X-ray of the blood vessels). A few are named after the scientist who first described them (Ewing, Kaposi).
The diagram shows the places where sarcomas can occur and the approximate numbers of different types that can be found there.
At RareCan we ask our members to sign up with us using the specific cancer name for some of the better known sarcomas (GIST, Kaposi’s, Ewing’s) or by their typical location for the remainder (for example. soft tissue sarcoma of limbs). The tables and their links at the end of this document follow these groups to make it easier to find information on a particular sarcoma.
What are the treatments for sarcoma?
As the sarcomas are a large group of cancers with many differences in the types of cells or tissues involved, the genetic mutations that occur and the way the disease progresses treatment will be planned to be the most effective for each patient.
This is the main treatment for all sarcomas. Tumours, both primary and secondary if present, will be removed, along with a border of healthy tissue to ensure that all of the cancer cells have been removed. Very rarely it may be necessary to amputate (remove) an affected limb. For bone sarcomas, bone can be removed and replaced with a metal implant.
For soft tissue sarcomas radiation may be used instead of surgery, when a tumour is in a place where it can’t be safely removed. It is also used before surgery to reduce the size of a tumour and afterwards to kill any remaining cancer cells.
Radiotherapy is used less often for bone sarcomas, usually only when surgery is not possible, or the cancer has returned
Chemotherapy is routinely used for bone sarcomas as it can be very effective. Chemotherapy is given before surgery to try and shrink the tumour, and after surgery if the whole tumour was not removed or there is a risk of it coming back. It may also be used to try and reduce the size or symptoms of a tumour that can’t be removed. It is not commonly used for soft tissue sarcomas, but will sometimes be given for the same reasons as for bone sarcomas. The chemotherapy drugs used include Doxorubicin, Ifosfamide (Mitoxana), Cisplatin, Etoposide (Etopophos, Vepesid), Vincristine, Gemcitabine (Gemzar, Docetaxel (Taxotere), Trabectedin (Yondelis) and Paclitaxel.
Targeted drugs are different from chemotherapy because they are designed to destroy cancer cells by taking advantage of the differences they have from normal cells.
Some targeted drugs activate the immune system to improve its ability to attack and destroy cancer cells (mifamurtide). Others switch off faulty signals sent by messengers called tyrosine kinases, that are telling the cancer cells to divide. These drugs are called tyrosine kinase inhibitors or TKIs and will have “nib” at the end of their chemical name, but you will also hear them called by their brand name. They can only be effective if a sarcoma has a mutation where a tyrosine kinase is known to be involved. TKIs include Glivec (Imatinib), Sutent (Sunitinib) and Stivarga (Rigorafenib).
Sarcomas by location and type
The sarcomas in these tables are grouped by their location in the body (e.g. head/neck) or the tissue type they form in (e.g. muscle). These are the most common locations, but they can also occur in other parts of the body.
The bone sarcomas are in a separate group.
For each body area common sarcomas are shown, but rare ones can occur.
The links in these tables are gradually being updated, but will also be available directly to RareCan members according to their cancer type. If you are a member and cannot find links to your particular cancer, please contact RareCan so we can help.
Soft tissue sarcomas
Some sarcomas can be found anywhere in the body, because the original cell type is widespread.
Clear cell sarcoma
Solitary fibrous tumour
Abdomen / retroperitoneum (the space at the back of the abdomen)
Desmoplastic small round cell tumour
Limbs (arms and legs)
N.B. If the cancer you are looking for is not mentioned below it may be because it is a bone sarcoma which is listed separately (further down this page).
Mediastinum (the space between the lungs that contains the heart, thymus, oesophagus (gullet) and trachea and major blood vessels).
Sarcomas of the mediastinum can be of almost any type, other than ones specific to a particular organ. Some of the most common are in the table.
Paraorbit (tissues surrounding the eye)
A sarcoma that affects any type of tissue can develop in this area. The most common are below.
These are usually thought of as being a separate group to the soft tissue sarcomas. They form from the bone-making cells or cartilage cells that are present in bones. These are usually found in the limbs or pelvis.
Support groups and awareness
Main UK group for support and information as well as funding research
Bone Cancer Research Trust
Main UK group for bone cancer specific support and information as well as funding research
GIST Cancer UK
Support, information and research on GIST and PAWS GIST cancers
Bone Sarcoma Peer Support
Linking patients with shared experience
Sarcoma awareness month is held in July. The awareness ribbon for all sarcomas is yellow.