Types Of Bone Cancer - ChondrosarcomaChondrosarcoma is a cancer of the cartilage. Cartilage is the tough covering found on the ends of the bones. Chondrosarcoma usually grows within a bone or on its surface. This type of cancer can occur at any age and is slightly more common in males. Chondrosarcoma is usually a slow-growing tumour and the most common sites are the pelvic bones, shoulder bones and the upper part of the arms and legs. There are several different sub-types of chondrosarcoma. These include the following chondrosarcomas: central peripheral de-differentiated clear cell mesenchymal juxtacortical CausesThe exact causes of primary bone cancer are unknown. However, adults who have a bone condition known as Paget’s disease, or who have been exposed to high doses of radiotherapy may have a slightly increased risk of developing bone cancer. Rarely, some bone cancers may occur in people from families where there is an inherited faulty gene that increases the risk of developing particular types of cancer. People who have had a rare type of noncancerous (benign) bone tumour called a chondroma or an osteochondroma have a very small risk of developing a chondrosarcoma. Another rare condition called Ollier’s disease (also called enchondromatosis) can also increase the risk of developing this type of primary bone cancer. Patients with rare genetic conditions called hereditary multiple exostoses (HME) and Maffucci’s syndrome can also develop a chondrosarcoma. Signs and symptomsPain is the most common symptom of bone cancer. However, symptoms may vary depending on the position of the cancer in the body and its size. There may be some swelling in the affected area and it may become tender to touch. Primary bone cancer is sometimes discovered when a bone that has been weakened by cancer, breaks after the person has had a minor fall or accident. Many of the symptoms described above are common to conditions other than cancer. However any persistent bone pain, particularly if it occurs at night, or any swelling should be checked by your doctor. How it is diagnosed Usually you begin by seeing your family doctor (GP), who will examine you and may arrange any tests or x-rays, which may be necessary. Your GP will probably refer you to a specialist surgeon (called an orthopaedic surgeon) who can carry out further investigations and decided whether you need to be referred to a specialist hospital or bone tumour centre for tests. Many of the specific tests for diagnosing bone tumours, such as a bone biopsy, need to be done by an experienced surgeon using specialist techniques. The doctor at the hospital will take your full medical history before doing a physical examination. This will include an examination of the painful bone to check for any swelling or tenderness. You will probably have a blood test done to check your general health. Further tests Bone x-ray This involves the use of x-rays to build up a picture of the bone. MRI (magnetic resonance imaging) scan This is a specialist type of scan that uses magnetism to build up cross-sectional pictures of your body. Some people are given an injection of dye into a vein in the arm to improve the image. During the test you will be asked to lie very still on a couch inside a long chamber for up to an hour. This can be unpleasant if you don’t like enclosed spaces, so it may help to mention this to the person working the machine. The machine is also very noisy and you will be given earplugs or headphones to wear. Needle biopsyFor this test, a small sample of the tumour is taken from the affected bone. The doctor looks at the sample under a microscope to identify the exact type of tumour that you may have. Open biopsyThis type of biopsy is not often used, as the needle biopsy is much quicker and simpler. In an open biopsy a small piece of bone is removed during a minor operation while you are under a general anaesthetic. It may be necessary to do this if a needle biopsy can’t be done or doesn’t give a clear diagnosis. Bone scanThis is a more sensitive test than the simple x-ray and shows up any abnormal areas of bone more clearly. For this test, a small amount of a mildly radioactive substance is injected into a vein, usually in your arm. Abnormal bone absorbs more radioactivity than normal bone so these areas are highlighted and picked up by the scanner as `hot spots’. CT (computerised tomography) scan A CT scan is a specialised type of x-ray. A number of x-rays are taken and fed into a computer to shows the structures inside the body. A CT scan can show whether the cancer has spread to other parts of the body. The scan is painless and takes from 10–30 minutes. Chest x-rayIn some people with chondrosarcomas the cancer may spread to the lungs. A chest x-ray is usually done to check for this. Grading and staging GradingGrading refers to the appearance of the cancer cells under the microscope and gives an idea of how quickly the cancer may develop. Low grade means that the cancer cells look very like the normal cells and they are usually slow-growing and are less likely to spread. In high-grade tumours the cells look very abnormal and are likely to grow more quickly and are more likely to spread. Chondrosarcomas are graded from 1 to 3. Grade 1 is a low-grade cancer and grades 2 and 3 are high-grade cancer. StagingThe stage of a cancer is a term used to describe its size and whether it has spread beyond its original site. Knowing the particular type and the stage of the cancer helps the doctors to decide on the most appropriate treatment. Most patients are grouped depending on whether cancer is found in only one part of the body (localised disease) or whether the cancer has spread from one part of the body to another (metastatic disease). - Stage 1A The cancer is low grade and is contained within the bone.
- Stage 1B A low-grade cancer extending outside the bone into the soft tissue spaces, which contain nerves and blood vessels.
- Stage 2A The cancer is high grade and is contained within the hard coating of the bone.
- Stage 2B A high-grade cancer extending outside the bone into the soft tissue spaces, which contain nerves and blood vessels.
- Stage 3 The cancer can be low grade or high grade and it is found either within the bone or outside it. The cancer has also spread to other parts of the body, or to other bones not directly connected to the bone where the tumour started.
If the cancer comes back after initial treatment, this is known as recurrent cancer. TreatmentThe type of treatment that you are given will depend on a number of things, including the position and size of the cancer, whether it has spread, the grade of the cancer and your general health. As chondrosarcomas are very uncommon they are usually treated at specialist hospitals by a team of doctors and other health professionals. This means that you may have to travel some distance to have your treatment. Some people with a chondrosarcoma will need to have a combination of different treatments. The treatments that might be used are surgery (where this is possible), chemotherapy and radiotherapy. However, chemotherapy or radiotherapy are not very effective for most chondrosarcomas and therefore surgery is the main form of treatment. SurgeryMajor improvements have been made in surgery for bone cancer. In the past, if chondrosarcoma was found in a limb (arm or leg) it was often necessary to remove (amputate) the affected limb. Now, however, it is often possible just to remove the affected part of the bone and some of the healthy tissue around it. The bone is then replaced with a specially designed metal replacement (prosthesis) or a bone graft (bone taken from another part of the body). If the cancer affects a bone in or near a joint the whole joint can often be replaced with an artificial one. These operations are known as limb-sparing surgery. Unfortunately, it is not always possible to use limb-sparing surgery and occasionally an amputation may be the only way to treat the cancer. This is often the case when the cancer cells have spread from the bone into the nerves and blood vessels around it. The type of surgery you have will depend on a number of factors. Your surgeon will discuss the different types of surgery with you in more detail before any decision is made about your treatment. It is often helpful to talk to someone who has had the same operation as you are going to have. The medical and nursing staff will be able to arrange this for you. On some wards a special counsellor may be available to discuss any worries you may have. ChemotherapyChemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. This type of treatment is not commonly used for chondrosarcoma. However, it may be helpful in certain situations. Chemotherapy can make you feel better by relieving the symptoms of the cancer, but it can sometimes have unpleasant side effects. Any side effects that do occur can often be well controlled with medicines. RadiotherapyRadiotherapytreats cancer by using high-energy rays, which destroy the cancer cells, while doing as little harm as possible to normal cells. Radiotherapy is rarely used to treat chondrosarcomas, although, it is sometimes helpful in certain situations. Radiotherapy can cause generalside effects such as feeling sick (nausea) and tiredness. These side effects can be mild or more troublesome, depending on the strength of the radiotherapy dose and the length of your treatment. The radiotherapist will be able to advise you what to expect.
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