
Thursday, 5 March 2009
The Bones

Questions for the Doctor
- Is it primary or secondary cancer of the bone?
- Where has it spread from?
- Do you recommend chemotherapy?
- What is the prognosis?
Side Effects of the Treatment
Chemotherapy uses very powerful medication to try to kill cancer cells. Unfortunately, some normal cells are also killed in the process. The medications are designed to kill rapidly dividing or growing cells. The normal cells that are affected often include hair, blood-forming cells, and cells lining the digestive system. Side effects include nausea and vomiting, loss of hair, infection, and fatigue. Fortunately, these side effects usually resolve after the chemotherapy is over. Good nutrition is important for your body to fight the cancer. You may be referred to nutrition specialist to help with this, especially if you experience nausea and loss of appetite.
The main side effects from radiation therapy include fatigue, loss of appetite, and damage to the surrounding skin and soft tissues. Prior radiation therapy can also increase the risk of wound problems from surgery in the same area.
Treatment of Bone Cancer
Surgery is often used to treat bone cancer. The goal of surgery is usually to remove the entire tumor and a surrounding area of normal bone. After the tumor has been removed, a pathologist examines it to determine if there is normal bone completely surrounding the tumor. If a portion of the cancer is left behind, it can continue to grow and spread, requiring further treatment. Historically, amputations were frequently used to remove bone cancer. Newer techniques have decreased the need for amputation. In many cases, the tumor can be removed with a rim of normal bone without the need for an amputation. Depending on the amount of bone removed, the surgeon will replace something in its location. For smaller areas, this may be either bone cement or a bone graft from another place in your body or from the bone bank. For larger areas, the surgeon may place larger grafts from the bone bank or metal implants. Some of these metal implants have the ability to lengthen when used in growing children.
You may be referred to a medical oncologist for chemotherapy. This is the use of various medications used to try to stop the growth of the cancer cells. Chemotherapy can be used prior to surgery to try to shrink the bone tumor to make surgery easier. It can also be used after surgery to try to kill any remaining cancer cells left following surgery.
You could also be referred to a radiation oncologist for radiation therapy. The radiation therapy uses high-energy x-ray aimed at the site of the cancer to try to kill the cancer cells. This treatment is given in small doses daily over a period of days to months.
Diagnose of Bone Cancer
Next, your doctor will likely order some imaging studies. Plain x-rays are often ordered first. In some cases, if the cancer is identified very early it may not show up on plain x-rays. The appearance of a tumor on the x-ray can help determine the type of cancer and whether or not it is benign or malignant. Benign tumors are more likely to have a smooth border while malignant tumors are more likely to have a ragged border. This is because the benign tumors typically grow more slowly and the bone has time to try to surround the tumor with normal bone. Malignant tumors are more likely to grow more quickly, not giving the normal bone a chance to surround the tumor.
A CT scan (CAT scan or computed tomography) is a more advanced test that can give a cross sectional picture of your bones. This test gives very good detail of your bones and is better able to identify a possible tumor. It also gives additional information on the size and location of the tumor.
An MRI (magnetic resonance imaging) is another advanced test that can also provide cross sectional imaging of your body. The MRI provides better detail of the soft tissues including muscles, tendons, ligaments, nerves, and blood vessels than a CT scan. This test can give better detail on whether or not the bone tumor has broken through the bone and involved the surrounding soft tissues.
A bone scan is a test that identifies areas of rapidly growing or remodeling bone. The bone scan is often taken of the entire body. This test may be ordered to see if there are any other areas of bone involvement throughout the body.
If a tumor is identified, your doctor will use all of the information from the history and physical examination along with the laboratory and imaging studies to put together a list of possible causes (differential diagnosis).
Your doctor may then obtain a biopsy sample of the tumor. This involves taking a small sample of the tumor that can be examined in the laboratory to determine what kind of tumor it is. The biopsy can be obtained either through a small needle (needle biopsy) or through a small incision (incisional biopsy).
Symptoms of Bone Cancer
Types of Bone Cancer
- Osteosarcoma
- Ewing's sarcoma
- Chondrosarcoma
- Malignant fibrous histiocytoma
- Fibrosarcoma
- Chordoma
Osteosarcoma is the most common primary malignant bone cancer. It most commonly affects males between 10 and 25 years old, but can less commonly affect older adults. It often occurs in the long bones of the arms and legs at areas of rapid growth around the knees and shoulders of children. This type of cancer is often very aggressive with risk of spread to the lungs. The five-year survival rate is about 65%.
Ewing's sarcoma is the most aggressive bone tumor and affects younger people between 4-15 years of age. It is more common in males and is very rare in people over 30 years old. It most commonly occurs in the middle of the long bones of the arms and legs. The three-year survival rate is about 65%, but this rate is much lower if there has been spread to the lungs or other tissues of the body.
Chondrosarcoma is the second most common bone tumor and accounts for about 25% of all malignant bone tumors. These tumors arise from the cartilage cells and can either be very aggressive or relatively slow-growing. Unlike many other bone tumors, chondrosarcoma is most common in people over 40 years old. It is slightly more common in males and can potentially spread to the lungs and lymph nodes. Chondrosracoma most commonly affects the bones of the pelvis and hips. The five-year survival for the aggressive form is about 30%, but the survival rate for slow-growing tumors is 90%.
Malignant fibrous histiocytoma (MFH) affects the soft tissues including muscle, ligaments, tendons, and fat. It is the most common soft-tissue malignancy in later adult life, usually occurring in people 50-60 years of age. It most commonly affects the extremities and is about twice as common in males as females. MFH also has a wide range of severity. The overall five-year survival rate is about 35%-60%.
Fibrosarcoma is much more rare than the other bone tumors. It is most common in people 35-55 years of age. It most commonly affects the soft tissues of the leg behind the knee. It is slightly more common in males than females.
Chordoma is a very rare tumor with an average survival of about six years after diagnosis. It occurs in adults over 30 years of age and is about twice as common in males as females. It most commonly affects either the lower or upper end of the spinal column.