How common is bone sarcoma?
Bone sarcoma is a rare condition occurring in approximately 2-4 people per 100,000 head of population. There is almost an equal risk to males and females.
The two main age groups where bone sarcomas may arise include:
- The teenage and young adult age group, and
- Later in life in those over the age of 55 years.
It’s thought that sarcoma that develops later in life is usually associated with some prior abnormality of the bone.
Where do bone sarcomas develop?
The most common places where bone sarcomas develop are around the knee, the wrist, the shoulder and the pelvis.
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 of bone sarcoma?
The most important symptom of bone cancer is a painful swelling in a limb or trunk. The pain is usually:
- Poorly responsive to oral painkillers and;
- Is usually much worse at night.
These symptoms usually develop over a number of weeks to months and are sometimes mistaken for growing pains if in a limb or a muscle injury.
Treatment of bone sarcoma
The main treatment of bone 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 or the entire bone in which it developed, and the gap in the bone rebuilt using special metal implants or bone grafts from the patient or the bone bank. 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:
- 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 bone sarcoma.
Amputation – Occasionally, it is not possible to cut out a bone 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.
Chemotherapy is a programme of drug treatment that patients are given to reduce the risk of spread of the bone sarcoma. This 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. Occassionally, 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. Sometimes spread of tumour to the lungs may be treated by surgical removal.
Radiotherapy is not always used for bone sarcomas. If it were required it is usually targeted at Ewing tumours. Ewing tumours are generally very sensitive to radiotherapy and are known to shrink down to very small size after radiotherapy which may help to make surgery safer and combines with chemotherapy to make treatment more effective. 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.
Side effects of treatment
Surgery – The side effects of surgery may be classified as early or late. Although uncommon, the early side effects may include pain, nerve injury, vessel injury, fractures, wound healing problems, swelling, paralysis, deep vein thrombosis and pulmonary embolism, infection, heart attacks, bleeding, kidney failure, stroke and death. The late side effects may include scarring, pain, loss of normal function, limp, weakness, limb swelling and infection.
Chemotherapy – The side effects of chemotherapy may include nausea, vomiting, diarrhoea, bleeding, bruising, infection, tiredness, anaemia, loss of appetite and weight, heart failure, kidney failure, liver failure, hair loss, nerve injury, vessel injury, loss of sensation in feet and fingers, sensitivity to cold, infertility, development of secondary cancers and death. Some of these complications may be so bad as to require chemotherapy to be delayed, stopped or for doses to be reduced.
Radiotherapy – The side effects of radiotherapy may include nausea, tiredness, limb soreness, skin irritation, blistering, swelling, pain, pigmentation of the irradiated part, poor healing after surgery, fractures of the adjacent or underlying bone, and anaemia. Some of these complications may be bad enough to delay or cease further treatment.