How common is soft tissue sarcoma
Soft tissue sarcoma is a rare condition occurring in approximately 1- 2 people per 100,000 head of population. There is almost an equal risk to males and females.
Soft tissue sarcomas mainly occur in people over the age of 55 years although synovial sarcoma and liposarcoma may occur in patients in their 20s.
Where do soft tissue sarcomas develop?
The most common places where soft tissue sarcomas develop are in the thigh, the shoulder and the pelvis. Occasionally soft tissue sarcomas can also occur in the abdominal cavity and some of these arise from a special type of tumour known as atypical lipomas.
Who is at risk?
Patients with a strong family history of certain cancers and also patients who have received high doses of radiotherapy are at risk.
What are the symptoms
The most important symptom of soft tissue sarcoma is the presence of a painless mass that has developed over a period of months. Occasionally there is a history of a much smaller softer lump in the same area for some years before increasing in size and changing from soft to firm or hard. Frequently, these lumps are misdiagnosed as lipomas (benign fatty lumps) or haematomas (bruises), and delay in appropriate investigation and diagnosis may occur.
Treatment of soft tissue sarcoma
The main treatment of soft tissue sarcoma is surgery to remove the cancer including a proper margin of normal tissue around the tumour. There are different types of surgery including limb sparing surgery and amputation.
Limb sparing surgery is where the sarcoma is cut out including part of or the entire soft tissue or neighbouring bone in which it developed, and if present, the gap in the bone is rebuilt using special metal implants or bone grafts from the patient or the bone bank. The soft tissue defect is usually reconstructed using special plastic surgical techniques. These reconstructions allow the patient to have a functioning limb after the surgery, and in over 85% of cases, limb sparing surgery is possible. This type of surgery is combined with a dedicated programme of physiotherapy afterwards to promote a return to normal functioning of the limb. There will always be some weakness, scarring, deformity or limp associated with surgery to the limbs. Poorly performed surgery may jeorpardise a patient’s life or chance for limb sparing surgery by increasing the risk of spread of tumour cells to nearby areas or even as far away as other bones, lungs or body parts. It is important that this complex surgery is performed at centres by teams who are expert in managing sarcoma.
Amputation – Occasionally, it is not possible to cut out a sarcoma and leave the patient with a normally functioning limb. Sometimes it is dangerous to try and save the limb. Under these circumstances, the surgeon has no choice but to amputate the limb. Amputation has a huge affect on limb function so it is important that a carefully planned programme of rehabilitation be undertaken after surgery to maximise a patient’s independence and mobility.
Radiotherapy is an important part of the treatment of soft tissue sarcoma. Soft tissue sarcomas are generally sensitive to radiotherapy and are known to respond to radiotherapy by shrinking in size which may help to make surgery safer, or developing a thick rind around itself as a reaction of the tissue around the tumour to radiotherapy. Radiotherapy is usually given once a day for 5.5 weeks. Before commencement of radiotherapy, the dose of radiotherapy and the different angles of irradiation are calculated by a process called simulation. Here the patient lies on a bed in a special room and the best position for the patient under the radiotherapy beam is calculated and trialled. Later, the patient will be placed in exactly the same position that was decided after the simulation test in order to receive the most effective radiotherapy. Radiotherapy is provided as an outpatient service and patients may continue working or undertaking normal activities until surgery. Although radiotherapy will not make your cancer worse, it is linked with a higher risk of cancer in that area after along period of time. This risk of a secondary cancer is less than 5%.
Chemotherapy is a programme of drug treatment that patients are given to reduce the risk of spread of the soft tissue sarcoma. This is not commonly given because the overall benefit to patient survival of chemotherapy is disappointingly low. However, if it is prescribed, chemotherapy is usually given to patients through a drip into a main vein in their body before surgery and continued even after the tumour is removed. Chemotherapy can cause the vein it is given into to shrivel up and block off. To reduce the discomfort to patients from multiple stabs that are needed to put drips into them, patients now are treated through a small specialised container (Porta-cath) that is placed under the skin that is temporarily connected to a main vein in their body. The Porta-cath allows chemotherapy to be given safely through the same site regularly. The Porta-cath is permanently removed after completion of chemotherapy or if something has compromised its function such as infection or permanent blockage.
Chemotherapy is given in regular cycles. This means patients under treatment are treated for several days at a time in hospital before being discharged home. The process is repeated again after a few weeks sometimes with the same or additional drugs. It is usual for patients to receive between 3 to 5 cycles before surgery, and for these cycles to be continued after surgery until a total of 10 cycles are given. Each cycle lasts for about 3 weeks. Occasionally, patients do not react well to the harshness of the drugs and the cycles have to be permanently ceased or reduced in intensity. Older patients (usually older than 40 years) do not tolerate chemotherapy well. Sometimes a decision is made to only perform surgery, while other times chemotherapy is given at a lower dose and/or for a shorter time than normal. The tumour is shown to respond by an improvement in symptoms, a reduction in size, or from special tests that are performed after commencement of chemotherapy. Chemotherapy is usually recommended to young patients or very healthy patients who have developed spread of their tumour, usually to the lungs. Sometimes, spread of cancer to the lungs can be treated by surgical removal.