What is Bone Cancer?
Bone cancers are rare forms of cancer that can affect any bone in the body. Two types of bone cancer are multiple myeloma and bone sarcomas. About 2,000 primary bone cancers are diagnosed in the United States each year. Bone cancers can also happen when tumors that start in other organs, such as breasts, lung, and prostate, metastasize (spread) to the bone. Multiple myeloma is the most common type of bone cancer. The two most common bone sarcomas are osteosarcoma, which develops in new tissue in growing bones, and chondrosarcoma, which develops in cartilage. Osteosarcoma occurs more frequently in people ages 10 – 20, while chondrosarcoma occurs more often in adults.
Multiple myeloma, also known as plasma cell myeloma, myelomatosis, or Kahler’s disease is a cancer of plasma cells, a type of white blood cell normally responsible for producing antibodies. In multiple myeloma, collections of abnormal plasma cells accumulate in the bone marrow, where they interfere with the production of normal blood cells. Most cases of multiple myeloma also feature the production of a Para protein—an abnormal antibody which can cause kidney problems. Bone lesions and hypercalcemia (high blood calcium levels) are also often encountered.
Chondrosarcoma is a type of cancer that develops in cartilage cells. Cartilage is the specialized, gristly connective tissue that is present in adults and the tissue from which most bones develop. Cartilage plays an important role in the growth process.
There are many different types of cartilage that are present throughout the body. Chondrosarcoma is a malignant type of bone cancer that primarily affects the cartilage cells of the femur (thighbone), arm, pelvis, knee, and spine. Although less frequent, other areas (such as the ribs) may be affected.
Chondrosarcoma is the second most common type of primary bone cancer. A primary bone cancer is one that originates from bone, as opposed to starting in another organ and then spreading to the bone. This type of cancer rarely affects individuals under age 20 and continues to rise until age 75. The incidence between males and females is equal.
Bone Cancer Symptoms
Bone pain affects almost 70% of patients and is the most common symptom. Myeloma bone pain usually involves the spine and ribs, and worsens with activity. Persistent localized pain may indicate a pathological bone fracture. Involvement of the vertebrae may lead to spinal. Myeloma bone disease is due to the overexpression of Receptor Activator for Nuclear Factor κ B Ligand (RANKL) by bone marrow stroma. RANKL activates osteoclasts, which resorb bone. The resultant bone lesions are lytic (cause breakdown) in nature and are best seen in plain radiographs, which may show “punched-out” resorptive lesions (including the “pepper pot” appearance of the skull on radiography). The breakdown of bone also leads to release of calcium into the blood, leading to hypercalcemia and its associated symptoms..
Symptoms may include:
Bone cancer is accompanied by the following signs and symptoms:
- Dull, aching pain in the bone or joint
- Swelling or tenderness of the joints
- Fatigue, fever, weight loss, anemia
- Decreased appetite and nausea
Bone Cancer Risk Factors
People with the following conditions or characteristics may be at risk for developing multiple myeloma:
- Radiation exposure
- Exposure to petroleum products, benzene, herbicides, and insecticides
- Genetic factors
- Advanced age (over 65)
- African American descent (twice the risk of Caucasians)
People with the following conditions or characteristics may be at risk for developing osteosarcoma:
- Benign tumors and other bone diseases
- Radiation exposure
- Genetic factors
- Children, adolescents
- Males more than females
Your risk of developing chondrosarcoma is higher if you are age 40 – 60.
Diagnosing Bone Cancer
In addition to regular physical examinations that include blood, urine, and possibly other laboratory tests, many groups such as the American Cancer Society suggest talking with your doctor to learn more about the pros and cons of screening for Bone cancer to help you decide if it is right for you. The tests used for screening include:
A biopsy is a procedure in which tissue samples are removed from the body by a needle or during surgery, for examination under a microscope to determine if cancer or other abnormal cells are present.
By examining and performing tests on the biopsy sample, pathologists and other experts can determine what kind of cancer is present, whether it is likely to be fast or slow growing, and what genetic abnormalities it may have. This information is important in deciding the best type of treatment. Open surgery is sometimes performed to obtain a biopsy, but in most cases, tissue samples can be obtained without open surgery using interventional radiology techniques.
Some biopsies can be performed in a doctor’s office, while others need to be done in a hospital setting. In addition, some biopsies require use of an anesthetic to numb the area, while others do not require any sedation.
An X-ray is a diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
X-rays use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. Standard X-rays are performed for many reasons, including diagnosing tumors or bone injuries.
X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body structures onto specially-treated plates (similar to camera film) and a “negative” type picture is made (the more solid a structure is, the whiter it appears on the film).
When the body undergoes X-rays, different parts of the body allow varying amounts of the X-ray beams to pass through. The soft tissues in the body (such as blood, skin, fat, and muscle) allow most of the X-ray to pass through and appear dark gray on the film. A bone or a tumor, which is more dense than the soft tissues, allows few of the X-rays to pass through and appears white on the X-ray. At a break in a bone, the X-ray beam passes through the broken area and appears as a dark line in the white bone.
Radiation during pregnancy may lead to birth defects. Always tell your radiologist or doctor if you suspect you may be pregnant.
Computed tomography scan (CT or CAT scan) is a non-invasive diagnostic imaging procedure that uses a combination of special X-ray equipment and sophisticated computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. These cross-sectional images of the area being studied can then be examined on a computer monitor or printed.
CT scans are more detailed than general X-rays, showing detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans of internal organs, bone, soft tissue and blood vessels provide greater clarity and reveal more details than regular X-ray exams. CT scans also minimize exposure to radiation. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly.
In standard X-rays, a beam of energy is aimed at the body part being studied. A plate behind the body part captures the variations of the energy beam after it passes through skin, bone, muscle, and other tissue. While much information can be obtained from a standard X-ray, a lot of detail about internal organs and other structures is not available.
In computed tomography, the X-ray beam moves in a circle around the body. This allows many different views of the same organ or structure. The X-ray information is sent to a computer that interprets the X-ray data and displays it in a two-dimensional (2D) form on a monitor.
Using specialized equipment and expertise to create and interpret CT scans of the body, radiologists can more easily diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders.
CT scans of the chest can provide more detailed information about organs and structures inside the chest than standard X-rays of the chest, thus providing more information related to injuries and/or diseases of the chest (thoracic) organs.
Chest CT scans may also be used to visualize placement of needles during biopsies of thoracic organs or tumors, or during aspiration (withdrawal) of fluid from the chest. This is useful in monitoring tumors and other conditions of the chest before and after treatment.
While many images are taken during a CT scan, in some cases the patient receives the same or less radiation exposure than with a single standard X-ray.
CT scans may be done with or without “contrast.” Contrast refers to a substance taken by mouth or injected into an intravenous (IV) line that causes the particular organ or tissue under study to be seen more clearly. Contrast examinations may require you to fast for a certain period of time before the procedure. Your physician will notify you of this prior to the procedure.
Positron emission tomography, also called PET imaging or a PET scan, is a type of nuclear medicine imaging. A PET scan measures important body functions, such as blood flow, oxygen use, and sugar (glucose) metabolism, to help doctors evaluate how well organs and tissues are functioning.
PET is a powerful diagnostic test that is having a major impact on the diagnosis and treatment of disease. A PET scan (positron emission tomography scan) monitors the biochemical functioning of cells by detecting how they process certain compounds, such as glucose (sugar). PET can detect extremely small cancerous tumors, subtle changes of the brain and heart, and give doctors important early information about heart disease and many neurological disorders, like Alzheimer’s.
Most common medical tests, like CT and MRI scans, only show details about the structure of your body. PET scans give doctors images of function throughout the entire body, uncovering abnormalities that might otherwise go undetected. This allows doctors to treat these diseases earlier and more accurately. A PET scan puts time on your side. The earlier the diagnosis, the better the chance for treatment.
For example, a PET scan is the most accurate, non-invasive way to tell whether or not a tumor is benign or malignant, sparing patients expensive, often painful diagnostic surgeries and suggesting treatment options earlier in the course of the disease. Although cancer spreads silently in the body, PET can inspect all organs of the body for cancer in a single examination.
Today, most PET scans are performed on instruments that are combined PET and CT scanners. The combined PET/CT scans provide images that pinpoint the location of abnormal metabolic activity within the body. The combined scans have been shown to provide more accurate diagnoses than the two scans performed separately.
About nuclear medicine
Nuclear medicine is a branch of medical imaging that uses small amounts of radioactive material to diagnose or treat a variety of diseases, including many types of cancers, heart disease, and certain other abnormalities within the body. Depending on the type of nuclear medicine exam you are undergoing, the radiotracer is either injected into a vein, swallowed or inhaled as a gas and eventually accumulates in the organ or area of your body being examined, where it gives off energy in the form of gamma rays. This energy is detected by a device called a gamma camera, a PET scanner and/or probe.
Chondrosarcoma is described as either localized or metastatic.
Localized chondrosarcoma has not spread out of the bone where the cancer started. There may be one or more areas of cancer in the bone that can be removed during surgery.
Metastatic chondrosarcoma has spread from the bone in which the cancer began to other parts of the body. The cancer most often spreads to the lungs. It may also spread to other bones.