Sarcomas are a rare group of cancers that develop from bones or soft tissues, such as fat, muscles or nerves – and because these tissues can be found nearly everywhere in the body, a sarcoma can arise in any part of the body. They are relatively uncommon, accounting for about 1% of adult cancers.
Sarcomas are divided into two main groups: bone sarcomas (also known as primary bone cancer) and soft tissue sarcomas. They are further sub-classified based on the presumed cell type of origin.
Soft Tissue Sarcoma
Soft tissue sarcomas (STS) are malignant tumours that develop in the soft tissues of the body. These tissues connect, support and surround other body structures and include muscles, tendons, fat, blood vessels, lymph vessels, nerves and tissue around our joints.
The causes of soft tissue sarcoma are not known, but certain things can affect the chances of developing it. The risk factors include the following.
- Age - Sarcoma can develop at any age, but the risk increases as you get older.
- Genetic conditions - Most types of sarcoma are not caused by an inherited faulty gene that can be passed on to other family members, but people with certain rare inherited genetic conditions are more at risk, including: neurofibromatosis; retinoblastoma, Li-Fraumeni syndrome and familial adenomatous polyposis.
- Previous radiotherapy treatment - Rarely, a soft tissue sarcoma develops in a part of the body that has been treated with radiotherapy for another type of cancer. The sarcoma does not usually develop until at least 5 to 10 years after radiotherapy.
- Lymphoedema (long term swelling in an arm or leg).
- Exposure to certain chemicals.
The symptoms can be non-specific and often go unnoticed until the tumour becomes large. Symptoms may include a painless lump or swelling, pain or soreness caused by compressed nerves or muscles and mobility issues if the tumour is near a joint.
If you think you may have a STS, you would usually start by seeing your GP, who will examine you and may arrange for you to have tests, like an ultrasound scan. If your GP thinks you might have a sarcoma, you would be referred to see a hospital specialist.
Treatment options for STS depend on the size, type, location and stage of the tumour, as well as the individual’s overall health. They may include surgery to remove the tumour, radiation therapy, chemotherapy and in some cases, targeted therapy or immunotherapy. The prognosis for soft tissue sarcoma varies widely based on these factors.
Bone Sarcoma
Bone sarcoma, or primary bone cancer, is a rare type of cancer that forms in the bones. Unlike secondary bone cancer, which has spread to the bones from another part of the body, bone sarcomas originate in the bone itself. The most common types of bone sarcomas include osteosarcoma, chondrosarcoma and Ewing sarcoma.
The exact causes of primary bone cancer are not known and for most people with bone cancer, it is not clear why it has developed. There is some increased risk associated with previous radiotherapy or chemotherapy and rare bone and genetic conditions.
A tumour in a bone can cause symptoms which include pain, tenderness or swelling in the affected area. This may or may not be made worse by exercise, feel worse at night, and potentially result in reduced movement if the tumour is near a joint – for example if the tumour is in the leg it may cause a limp.
Many of these symptoms can be caused by other conditions that are much more common than bone cancer. But always see your GP if you have unexplained bone pain, that does not go away. They might organise further tests, like an x-ray and refer you to a specialist..
The prognosis for bone sarcoma varies, but early detection and prompt treatment, such as surgery, radiotherapy, chemotherapy or targeted treatments, can significantly improve the outlook.
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