Background to sarcoma

Sarcomas are cancers of connective tissue - bone, muscle, nerves, fatty tissue, cartilage etc. They are rare, accounting for about 1% of all cancer diagnoses, or around 2000 cases in the UK each year.

The causes of sarcoma are generally unknown. There are some hereditary syndromes which have a pre-disposition to sarcoma but the number of cases is very small. Some patients who have had radiotherapy for another cancer are diagnosed with sarcoma, usually many years after the treatment. Patients who had retinoblastoma (an eye cancer) as a child also have a pre-disposition to sarcoma in later life.

Accurate data about the incidence of sarcoma is hard to find because cancer is reported against 'site of origin'. Sarcomas can appear almost anywhere on or in the body and many are only found following investigations for a condition which seems unconnected with cancer.

Most sarcomas (about 55%) affect limbs, most frequently the leg, about 15% affect the head and neck area or are found externally on the trunk, while the remainder are internal in the retro-peritoneum or abdominal area.

Sarcomas fall into three broad categories - soft tissue, primary bone cancers and gastro-intestinal stromal tumours (or GIST). There are many sub-types of sarcoma within these broad categories, determined by the tissue of origin (the histological sub-type) or by other molecular analysis undertaken by expert pathologists.

If you have just been diagnosed it will help you build your understanding of your disease as you read websites and other information to know:

• the sub-type (or histo-type) you have (for example; leiomyosarcoma, liposarcoma, osteosarcoma, chondrosarcoma)

• the 'grade' of the tumour - this is an indicator for how aggressive the cancer may be

• the 'stage' the disease has reached (this is a process undertaken by the doctors to help decide the best treatment plan for you) - this information might not be available immediately

• after surgery, whether margins were 'negative' (this means that the tumour has been completely removed and there is no evidence of disease left in you)

Despite the many different sub-types the general pattern of treatment is similar. Surgery is the surest route to a cure and although chemotherapy will usually be used with bone sarcomas before surgery it is less often used with soft tissue sarcoma. The case for chemotherapy following surgery is uncertain with soft tissue sarcoma but now well accepted with bone sarcomas. There are circumstances when radiotherapy offers benefits, usually after surgery but occasionally at other times too.  Gastrointestinal stromal tumours respond poorly to traditional chemo- or radiotherapies but can be treated with the new drug Glivec.

The treatment plan developed by your doctors will be specific for you. You may meet other patients with a similar diagnosis but who are having different treatment. This is not a matter for concern.