The human body is made up of 206 bones of various shapes and sizes to give it structure and shape. Bones provide protection to the internal organs against injury. Muscles attached to bones help us move around. Bones have another important function to perform through the spongy inner part the bone called bone marrow. The bone marrow manufactures the red blood cells, which circulate in the blood to supply oxygen to all parts of the body. Bones also regulate the body's store of vital micronutrients such as calcium and phosphorus. Bone cancer is the result of a bone tumor caused by an abnormal growth of cells within the bone. Cancers that start in the bone are referred to as primary bone cancer.
Cancers that start in another part of the body like the lungs, breast, or prostrate, and spread to bones are called secondary bone cancers. Primary bone cancers are formed in the cells of the bone and usually appear in the long bones of the body like the arms and legs. Osteosarcoma is the most common type of bone cancer appearing in the arms and legs of people between the ages of 10 and 25. Chondrosarcoma, found in the cartilage, the rubbery tissue around joints, usually affects adults. Ewing's sarcoma, another type of primary bone cancer is found among young children and in teenagers at the time of puberty when they undergo rapid growth. Chordoma, a tumor that affects the spinal cord and the base of the skull is relatively rare, and it affects people over the age of 30. Lymphoma and multiple myeloma are two common types of cancer associated with the bones. Lymphoma is a cancer of the lymph nodes that may also begin in the bones. Multiple myeloma is cancer of the bone marrow cells.
If there is excessive pain and swelling in the limbs, the doctor would conduct a complete physical examination and look for the presence of lumps as also tenderness in the area. The patient's medical history and details of any radiation or chemotherapy as also hereditary presence of cancers will also be recorded. Blood tests may be ordered to check the level of the enzyme alkaline phosphatase in the blood. There are certain cases when the cells forming bone tissue are highly active, therefore the levels of this enzyme in the blood are found to be high. However, this is not a conclusive test as several drugs affect the level of the enzyme in the blood. High levels of this enzyme are normal in growing children and pregnant women and people with healing fractures.
Imaging tests are the key to bone cancer diagnosis because they can accurately pin point the location and the size of the tumor. X-Rays taken from different angles reveal the shape and size of the tumor and also reveal bone degeneration, if any. A computed tomography (CT) scan gives more detailed information about the tumor with cross-sectional images of the bone. Magnetic Resonance Imaging (MRI) is an advanced medical test that provides information on the extent of damage caused by the tumor to the bone and its surrounding soft tissues, ligaments and nerves. A radionuclide bone scan is done by injecting a small amount of radioactive material into a vein and measuring the amount of this material collected in the bones. A PET scan or Positron Emission Tomography uses radio tracer glucose injected into the body to identify cancer cells because cancer cells tend to use more glucose than normal cells. Once a tumor is identified, doctors may do a biopsy to determine whether it is benign or malignant. A tissue sample of the bone tumor may be taken by the doctor who makes a hole in the bone with a needle-like instrument. This is called a needle biopsy. An orthopedic oncologist may do a surgical bone biopsy by making an incision to cut into the tumor to get a tissue sample. The tissue sample is sent to a pathologist to determine if the tumor is benign or malignant. Information regarding the source of the cancer, whether it is primary or secondary, will help determine the type of treatment required.
No specific bone cancer causes have been identified by scientists and researchers, although people with certain risk factors have been identified. People with Paget's disease or with a history of Paget's disease run the risk of bone cancer since Paget's disease is a chronic bone disorder. Those who undergo chemotherapy or radiation therapy for other medical conditions may be at risk for bone cancer. If the bone cancer has its roots in the family then the likelihood of a malignant bone tumor to the doctor when the patient presents other symptoms like joint pain and swelling, prompting the doctor to order further tests. Children with hereditary retinoblastoma, a rare form of cancer in the eye are at risk for developing osteosarcoma.
Persistent severe pain, swelling, and tenderness are common bone cancer symptoms noticed. In children with bone tumors, even minor injuries could result in fractures and therefore cause immense pain to thechild. Symptoms may be different depending on the type, location, and size of the tumor. Swelling or tenderness near the joints is often noticed when a tumor develops in or near a joint. Pain that is felt deep in the body, particularly in the bones of the limbs, may be intermittent in the early stages of cancer, but it becomes more persistent as the tumor grows. Anemia is a common symptom noticed in the case of cancer of the bone marrow. Other symptoms may include fatigue, weight loss, and fever. However, it should be noted that these are symptoms associated with several other diseases and not just with bone cancer. The presence of tumors in the bones may also affect the movements of patients and cause changes in gait or joint pain even in young people.
Bone cancer treatments vary depending on the type of cancer, whether it is primary bone cancer or secondary bone cancer that has spread from another location in the body. The size and location of the tumor and the stage of the cancer also have a bearing on the treatment options recommended by doctors. The general health of the patient and his/her age are also important factors to consider while choosing a treatment like surgery and chemo therapy. In cases of Ewing's sarcoma, a combination of radiation therapy and multidrug chemotherapy may be required since this type of cancer has a tendency to spread quickly to other parts of the body. Targeted therapy like radiation is used to kill recurrent cancer cells at the site of a tumor after a surgery to remove the tumor. Surgeons usually remove surrounding tissue along with the tumor to prevent the recurrence of cancer cells at the site and to ensure that the cancer does not spread farther.
Chemotherapy is recommended even in those cases where the tumor appears to be localized and is removed by surgery. This is done in order to ensure that minute tumor deposits do not remain and cause the cancer to spread to other parts of the body. Amputation of limbs with bone tumor has been greatly reduced in recent times thanks to new limb-sparing surgery. This surgery combines reconstructive surgery using bone grafts to replace the part of the bone take out with the tumor so that the patient can have near normal limb function. In the case of growing children with bone cancer, metal implants with the possibility of increasing length later are used to suit the needs of growth. Bone cement may be used to fill in small gaps when a bone tumor is removed surgically.
Chemotherapy, used before surgery, can help to reduce the size of the tumor and make the removal of the tumor easier and safer. New treatments and drugs are constantly being evaluated through clinical trials on cancer patients to study their efficacy. Participation in clinical trials is possible for those with bone cancer once they give their informed consent to a doctor after having understood the risks and requirements of the new treatment being studied. Complementary and alternative therapies for bone cancer patients include nutrition therapy to cope with side effects of chemotherapy and radiation. Physical therapy is often needed to improve mobility and help in the independent performance of day-to-day activities. Stretching and muscle strengthening exercises may be needed to prevent injuries and maintain body posture and balance. Pain management is an important part of bone cancer treatment. Several psychological factors which influence pain perception and patients need emotional and spiritual support during and after treatment.