Types Of Bone Cancer - Osteosarcoma (osteogenic sarcoma)This is the most common type of primary bone cancer and develops in new tissue, in growing bones. Although it can occur at any age, osteosarcoma is most commonly found in teenagers and young adults, and is slightly more common in males. Any bone in the body can be affected but the most common sites are the arms or legs, particularly around the knee joint. There are several different types of osteosarcoma. Most osteosarcomas occur in the centre of the bone. There are also rare subtypes, such as parosteal, intraosseous, periosteal, telangiectatic, small cell and conventional central osteosarcoma. Causes of osteosarcoma The exact causes of primary bone cancer are unknown. It is thought to be related in some way, to periods of rapid bone growth, such as adolescence. 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. Signs and symptoms Pain is the most common symptom of bone cancer. However, symptoms may vary depending on the location and size of the cancer. Tumours that occur in or near joints may cause swelling or tenderness in the affected area. 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 at night 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 other investigations and decide if you need to be referred to a specialist hospital or bone tumour centre for further tests. Many of the specific tests for diagnosing bone tumours, such as the biopsy, require experience and 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. 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 slowly 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. Osteosarcomas are graded from 1 to 3. Grade 1 is a low-grade cancer and grades 2 and 3 are high-grade cancer. Most osteosarcomas are high grade, but a type known as a parosteal osteosarcoma is usually low grade. A further subtype (periosteal osteosarcoma) is often defined as a grade 2, however, it is usually treated as though it was high grade. 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, which is known as 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 completely found within the hard coating of 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 completely 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 extending outside the bone. The cancer has 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. Treatment The type of treatment 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 osteosarcomas 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. Most people with an osteosarcoma will need to have a combination of different treatments. The treatments that may be used are surgery, chemotherapy and radiotherapy. Surgery is a very important part of treatment and is used to remove the tumour in the bone. If surgery is not possible, radiotherapy may be used instead. Chemotherapy is used for most people with an osteosarcoma. It is often given to shrink the tumour before surgery. SurgeryMajor improvements have been made in surgery for bone cancer. In the past, it was often necessary to remove the limb if cancer was found. 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 sometimes removing the whole of the affected limb amputation may be the only way to treat the cancer. This is often due to the cancer spreading 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 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. ChemotherapyChemotherapyis the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. This is an important treatment for most people with osteosarcoma as it can greatly improve the results of surgical treatment. It is often given before surgery and may shrink large tumours enough to avoid the need for amputation. The course of chemotherapy continues after surgery in order to destroy any remaining cancer cells and stop the sarcoma from spreading outside the bone – this is known as adjuvant chemotherapy. 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. RadiotherapyRadiotherapy treats cancer by using high-energy rays, which destroy the cancer cells, while doing as little harm as possible to normal cells. Osteosarcomas are not very sensitive to radiation treatment, so radiotherapy is not often used to treat this type of tumour. However, it may be given after surgery to destroy any remaining cancer cells or if a limb has fractured and the risk of the cancer spreading is increased, especially into the surrounding tissues. Radiotherapy can cause general side 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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