Bone cancer is a rare type of cancer which starts in a bone. It can start in any of the many bones of the body; however, long bones of arms and the legs are more commonly affected. There are different types of bone cancer. Some occur mainly in children, while others commonly affect adults. Bone cancer doesn't mean cancers which start somewhere else in the body and metastasize to the bone; but cancer which originates in the bone itself. Treatment of bone cancer is done by radiation, chemotherapy, surgery or a combination of all.
Types of Bone Cancer
Bone cancers are differentiated into types depending on the cell type in which the cancer started. Given below are some of the common types of bone cancer:
- Osteosarcoma: This type starts in the bone cells and most commonly affects children and young adults.
- Chondrosarcoma: This type of bone cancer starts in the cartilage cells and commonly affects older adults.
- Ewing's Sarcoma: The cells, where this bone cancer type begins, are not clear. Ewing's sarcoma is thought to begin in nerve tissue inside the bone and it affects mostly children and young adults.
Stages of Bone Cancer
- Stage I: In this stage, the cancer is confined to the bone and hasn't metastasized to other parts of the body. This stage is considered not aggressive and low grade.
- Stage II: In this stage, the cancer is confined to the bone and hasn't metastasized to other parts of the body; however, biopsy testing reveals that the bone cancer is aggressive and high grade.
- Stage III: In this stage, the cancer is present in two or more different parts of the same bone. Biopsy testing reveals that the cancer can be either low grade or high grade.
- Stage IV: In this stage, the cancer has metastasized from the bone to other regions of the body, such as liver, lungs or brain.
Causes of Bone Cancer
The cause of many bone cancers is not clear. Doctors believe the cancer occurs due to an error in the DNA of a cell. This error causes the cell to grow and divide uncontrollably resulting in cancer. These abnormal cells continue to live instead of dying at a particular time. The buildup of these mutated cells result in a tumor/mass, which in turn infiltrates the nearby structures and/or metastasize to other parts of the body.
Risk Factors of Bone Cancer
- Inherited genetic syndromes, such as hereditary retinoblastoma and Li-Fraumeni syndrome may cause or increase the risk of having bone cancer.
- Precancerous conditions such as Paget's disease of bone affects the older adults and also increases the risk of developing bone cancer.
- Exposure to radiation from cancer treatment increases the risk of having a bone cancer in the future.
Signs and Symptoms of Bone Cancer
- Pain in the bone.
- Tenderness and swelling near the area which is affected.
- The affected bone may break.
- Weight loss which is unintentional.
Investigations for Bone Cancer
Depending on your condition, your doctor may order one or more of the following imaging tests:
- Bone scan.
- Computerized Tomography (CT) scan.
- Magnetic Resonance Imaging (MRI)
- Positron Emission Tomography (PET) scan.
Treatment of Bone Cancer
Treatment depends on the type of bone cancer, the stage of the cancer and patient's general health. Treatment options comprise of chemotherapy, radiation, surgery or a combination of all.
Surgery for Bone Cancer
The aim of surgery is removing the complete bone cancer. For this to happen, the doctors have to remove a small part of the healthy tissue surrounding the tumor along with the tumor. Different types of surgery done for treating bone cancer are:
- Surgery for Limb Amputation: Bone cancers which are large or are situated in a complicated region of the bone could require surgery for removing a part of the limb or the entire limb (amputation). Due to the development of more advanced treatments, surgery for amputation has become quite less common.
- Surgery to remove cancer and to save the limb can be done if the bone cancer can be removed from the nerves and other tissues. In such cases, the surgeon can remove the bone cancer and save the limb. As some part of the bone is removed along with the cancer, the lost bone is replaced with either some other bone from different part of your body or with some special prosthesis made of metal.
- Surgery for cancer where the limbs are not affected, such as if the bones of the arms and legs are spared and the cancer has occurred in other bones then the surgeon removes the bone and some healthy tissue surrounding the cancer, e.g. cancer in the ribs. The surgeon may remove the cancer and try to save as much bone as possible if the cancer involves the spine. The lost bone is replaced with either some other bone from different part of your body or with some special prosthesis made of metal.
Radiation Therapy for Bone Cancer
- This treatment utilizes high-powered energy beams like x-rays for destroying the cancer cells. During radiation therapy, you are told to lie down onto a table and a special machine moves about you and the energy beams are aimed at specific points on your body. Radiation therapy is usually given in conjunction with chemotherapy. Radiation therapy is commonly used before surgery. This helps in increasing the chances of saving the limb and preventing amputation.
- Radiation therapy can also be used after surgery. When the entire cancer cannot be removed with surgery, radiation therapy is done to kill any remaining cancer cells. In patients with advanced bone cancer, radiation therapy helps in managing the symptoms of cancer, e.g. pain.
Chemotherapy for Bone Cancer
- Chemotherapy is a treatment done using drugs/ chemicals to destroy cancer cells. Chemotherapy is commonly given intravenously to reach your whole body.
- Chemotherapy can be used alone or in conjunction with radiation therapy before surgery in order to shrink the bone cancer so that it becomes more manageable in size and so that the surgeon can save the limb during the surgery. Chemotherapy is also used in patients where the bone cancer has metastasized to other parts of the body.