What is Soft tissue Sarcomas

Sarcoma is a term used to describe malignant tumours arising from mesenchymal or supportive tissue.

Mesenchymal tissue includes connective tissues (e.g. bone, cartilage), blood vessels, lymph vessels, synovium (the lining of joint spaces), meninges (brain coverings) and muscle. Malignant tumours are cancers which have the ability to metastasise, which means the tumour can seed and spread to a different part of the body away from its site of origin.

The information here will broadly cover the soft tissue sarcomas as a group. Further information is available on individual sarcoma types. (i.e. Rhabdomyosarcoma and Ewings sarcoma).

Statistics on Soft tissue Sarcomas

Soft tissue tumours represent 0.7% of all malignant lesions in adults and 6.5% of lesions in children (the 4th most common malignancy in children). Males are affected more frequently than females. The incidence increases with age, with specific sarcomas being more prevalent in certain age groups (i.e. Rhadbomyosarcoma in children, synovial sarcoma in young adults).

Risk Factors for Soft tissue Sarcomas

The cause of sarcomas in most cases is unknown.

Predisposing factors may include:

 

  • Scar tissue arising from burns, fractures, foreign bodies or operations.
  • Chemical carcinogens (polycyclic hydrocarbons and asbestos)
  • Irradiation, with sarcomas arising in the area of irradiation.
  • Human Herpes Virus 8 (HHV 8) is associated with Kaposis sarcoma.
  • Immunosuppression, congenital or therapeutic.
  • Familial predisposition.Benign soft tissue lesions rarely predispose to malignant lesions. With the exception of neurofibromas.

    Progression of Soft tissue Sarcomas

    Sarcomas grow as a mass that exerts pressure on its surrounding structures. 5% of all sarcomas metastasize to the lymph nodes, however this varies on the type of sarcoma. The lungs are a common site for sarcomas to travel after lymph node metastases.

    How is Soft tissue Sarcomas Diagnosed?

    A biopsy is recommended for all new or growing masses. This can be done via a core needle biopsy or incision.

     

  • A plain X-ray and/or MRI are performed for masses of the extremities or the head and neck.
  • A CT Scan is performed for masses of the chest or abdomen.
  • Lung imaging should be performed to rule out lung metastases.

    Prognosis of Soft tissue Sarcomas

    Prognosis depends on the grade, stage, classification and location (e.g. superficial better than deep) of sarcoma. Grade and stage are determined by the size, depth, and aggressiveness of the sarcoma.

    How is Soft tissue Sarcomas Treated?

    Treatment is dictated by the stage of the sarcoma. Low stage sarcoma are treated with surgery plus/minus adjuvant radiation therapy. Later stage sarcomas may also receive adjuvant chemotherapy.

    Chemotherapeutic agents that may be used to treat sarcomas include: anthracycline, doxorubicin and ifosfamide.