Primary bone cancers are cancers that happen to the main bones. They are rare, with only about “580 new cases each year in the UK” (according to MacMillan Research). There are several different types of bone cancer, with osteosarcoma being one of the more common ones. It is a type of cancer that produces immature bone tumours. It is the most common in lengthy bones, and it is usually found in knees, thigh bones, shin bones or upper arms.
Causes of osteosarcoma: The exact causes of primary bone cancer are unknown but it is thought to be linked to periods of rapid bone growth, such as puberty. Adults who have had a bone condition called Paget’s disease or have been previously treated with radiotherapy have an increased risk of developing osteosarcoma. Sometimes, osteosarcomas may be inherited from past generations in the family; there is an inherited faulty gene that increases the risk of developing several other types of inherited cancers.
Symptoms of Osteosarcoma: Pain is the most common symptom of osteosarcoma. However, symptoms may vary depending on where the cancer is and how large it is. Tumours that occur in or near joints may cause swelling in the affected area and restricted movement in the joint. Often the pain is thought to be related to muscle soreness but it does not go away with rest and keeps accumulating.
Diagnostics: The doctor may perform a bone x-ray to check for any visual impacts of the cancer. Then a biopsy is needed so that the rate of cancer growth can be identified, and what type of cancer it is. A bone scan is needed to locate the exact area of the bone cancer. This process involves a radioactive substance to be injected into the bloodstream, so the tumour can be detected by a GM machine. PET (positron emission tomography) scan is then used pinpoint the location of the cancer cells.
Grading of bone sarcoma: Low-grade means that the cancer cells are slow-growing and look quite similar to normal cells. They are less aggressive and less likely to spread to other organs or tissues. High-grade means the cancer cells are fast growing and look very abnormal. They are more aggressive and more likely to spread.
Stages of cancer:
Stage 1a) The cancer is low-grade and is still completely within the bone it started in. Stage 1b) The cancer is low-grade and has grown through the bone wall. Stage 2a) The cancer is high-grade and is still completely in the bone it started in. Stage 2b) The cancer is high-grade and has grown outside the bone wall. Stage 3) The cancer may be any grade and has spread to another part of the body, such as the lungs.
Treatment: The surgeon removes a tumour and will aim to take out an area of normal tissue around it to reduce the risk of the cancer cells growing again. To achieve this, some patients will receive limb-sparing surgery. The aim of this surgery is to preserve the limb where a tumour is rather than cutting it off.
Chemotherapy uses anti-cancer drugs to destroy cancer cells. It is also used before surgery to reduce the size of the tumour so it can be more easily removed. This can be useful to treat large tumours and can prevent the need to have the limb amputated.
Radiotherapy uses high-energy radiation beams to destroy cancer cells. Two or more low energy radiation beams are concentrated on the area of cancer, this allows the surrounding cells to be safe. However, this type of treatment may be used after surgery in some cases, if there is a chance that cancer has spread to the nearby soft tissues.