Soft tissue sarcomas are a group of diverse and ubiquitous tumours that originate in tissues such as fat, muscles, nerves, tendons, blood and lymphatic vessels (the soft tissues that connect, support and surround other parts of the body).
Every year approximately 9,200 new cases of soft tissue sarcomas are diagnosed in adults and children in the United States and around 13,000 new cases in Europe. Slightly more than 50% of these new patients die from this disease. The 5-year survival rate for patients with soft tissue sarcoma is around 90% if the cancer is detected in early phases and before it has spread. However, the 5-year survival rate is 10% to 15% for sarcomas with metastasis.
Risk factors
Most soft tissue sarcomas do not have a clearly defined cause; however, various predisposition factors have been associated with their development. There are certain familial syndromes which predispose to suffering sarcoma, such as neurofibromatosis, Gardner syndrome, Li-Fraumeni syndrome and retinoblastoma. Other factors associated with soft tissue sarcoma are previous exposure to radiation, chronic lymphoedema (inflammation of a limb) and, rarely, exposure to certain chemical agents and recent history of traumatism.
Prevention
Most sarcomas develop in people without known risk factors, which means that at this time no way is known of preventing most cases.
Signs and symptoms
People with soft tissue sarcoma at an early stage do not usually notice any symptoms. In fact, symptoms may not appear until more advanced stages. Typical symptoms are:
- A lump in the body which may or may not be painful (usually not).
- Abdominal pain and vomiting.
- Sensation of being full without having eaten very much (early satiation).
These symptoms may be a consequence of a soft tissue sarcoma or other less serious causes.
Diagnosis
There are currently no selective detection tests for soft tissue sarcoma. The most frequent diagnostic tests are:
- Physical examination: It may include an assessment to determine the size and shape of the mass and its effect on the surrounding areas.
- Biopsy: A biopsy is usually carried out on a mass of soft tissue if it is symptomatic or is increasing in size. The three types of biopsies which are most frequently carried out to diagnose soft tissue sarcoma are:
- Percutaneous biopsy, with a tissue sample taken through a needle (fine needle aspiration).
- Open biopsy, with sampling through a surgical procedure.
- Retroperitoneal mass biopsy.
- Image diagnosis of the primary tumour: Magnetic resonance (MR) and computerised tomography (CT).
- Image diagnosis of the metastasic disease: This is performed depending on the size, grade and anatomical location of the primary tumour.
Treatment options
In general, treatment of soft tissue sarcomas depends on the stage of the cancer. The stage is established according to the size and grade of the tumour and if it has spread to the lymph glands or to other parts of the body.
- Surgical resection: It is the most typical treatment for patients with localised disease. The improvement in surgical techniques in the last 20 years has substantially reduced the need to amputate. At present, no more than 10% to 15% of patients with sarcoma undergo an amputation. In most cases, surgery with conservation of the limb is an option to avoid the amputation of the arm or leg, while radiotherapy and/or chemotherapy are administered before surgery to reduce the size of the tumour or after surgery to destroy the remaining cancer cells.
- Radiotherapy: It can be administered before surgery to reduce tumour size (neoadjuvant treatment) or after surgery to destroy any cancer cells remaining in the area (adjuvant treatment). It is also used to treat those soft tissue sarcomas which are not resectable or are inoperable due to medical reasons.
- Chemotherapy: It can be used with radiotherapy before or after surgery to reduce the tumour or to destroy the remaining cancer cells. If the cancer has spread to other areas of the body, chemotherapy can be used to reduce tumours and decrease the pain and discomfort they cause.