What is Bone Cancer ?
Bone cancer is an uncommon cancer that begins in a bone. Bone cancer can begin in any bone in the body, but it most commonly affects the long bones of the arms and legs.
Several types of bone cancer exist. Some types of bone cancer occur primarily in children, while others affect mostly adults.
The term “bone cancer” doesn’t include cancers that begin elsewhere in the body and spread (metastasize) to the bone. Instead, those cancers are named for where they began, such as breast cancer that has metastasized to the bone.
Bone cancer also doesn’t include blood cell cancers, such as multiple myeloma and leukemia, that begin in the bone marrow the jelly-like material inside the bone where blood cells are made.
Bone pain is the most common symptom of Bone Cancer.
It usually begins with a feeling of tenderness in the affected bone, which gradually progresses to a persistent ache that often feels worse during the night and when the bone is in use.
In cases of Ewing’s sarcoma, bone pain usually gets worse quite quickly.
Bone pain that is caused by bone cancer is sometimes wrongly mistaken for arthritis in adults and “growing pains” in children and teenagers.
If you have bone cancer, you may also experience swelling and redness (inflammation) or detect a noticeable lump on or around the affected bone. If the bone is near a joint, the swelling may make using the joint difficult.
In some cases the cancer can weaken a bone so it can become fractured or broken after a minor injury or fall.
Less common symptoms of bone cancer include:
- a high temperature (fever) of 38C (100.4F) or above
- unexplained weight loss
- sweating; usually at night
Who is at risk for Bone Cancer?
Each year, around 3,000 cases of cancer of the bones and joints are diagnosed in the U.S. Primary bone cancers are not common and make up less than 0.2% of all cancers. Bone cancers are more common in young adults and children than in older people. Cancer found in the bones of an older adult most likely is metastatic from another location in the body.
Risk factors have been identified for the development of certain bone cancers. Risk factors include the following:
- Previous treatment with radiation therapy
- Previous chemotherapy with drugs known as alkylating agents
- Mutation in a gene known as the retinoblastoma (Rb) gene
- Associated conditions, such as hereditary retinoblastoma, Paget’s disease of bone, Li-Fraumeni syndrome, and Diamond-Blackfan anemia
Are there different types of primary Bone Cancer?
Yes. Cancer can begin in any type of bone tissue. Bones are made up of osteoid (hard or compact), cartilaginous (tough, flexible), and fibrous (threadlike) tissue, as well as elements of bone marrow (soft, spongy tissue in the center of most bones).
Common types of primary bone cancer include the following:
- Osteosarcoma, which arises from osteoid tissue in the bone. This tumor occurs most often in the knee and upper arm.
- Chondrosarcoma, which begins in cartilaginous tissue. Cartilage pads the ends of bones and lines the joints. Chondrosarcoma occurs most often in the pelvis (located between the hip bones), upper leg, and shoulder. Sometimes a chondrosarcoma contains cancerous bone cells. In that case, doctors classify the tumor as an osteosarcoma.
- The Ewing Sarcoma Family of Tumors (ESFTs), which usually occur in bone but may also arise in soft tissue (muscle, fat, fibrous tissue, blood vessels, or other supporting tissue). Scientists think that ESFTs arise from elements of primitive nerve tissue in the bone or soft tissue. ESFTs occur most commonly along the backbone and pelvis and in the legs and arms.
Other types of cancer that arise in soft tissue are called soft tissue sarcomas. They are not bone cancer and are not described in this resource.
Do we know what causes Bone Cancer?
The exact cause of most bone cancers is not known. However, scientists have found that bone cancers are associated with a number of other conditions, which are described in the section on risk factors. Still, most people with bone cancers do not have any known risk factors. Research is underway to learn more about the causes of these cancers.
Scientists have made great progress in understanding how certain changes in a person’s DNA can cause normal cells to become cancerous. DNA carries the instructions for nearly everything our cells do. We usually look like our parents because they are the source of our DNA. However, DNA affects more than our outward appearance. It may influence our risks for developing certain diseases, including some kinds of cancer.
DNA is divided into units called genes. Genes carry the recipes for making proteins, the molecules that determine all cell functions. Some genes contain instructions to control when our cells grow and divide. Genes that promote cell division are called oncogenes. Others that slow down cell division or make cells die at the right time are called tumor suppressor genes. Cancers can be caused by DNA mutations (defects) that activate oncogenes or inactivate tumor suppressor genes. Some people with cancer have DNA mutations that they inherited from a parent. These mutations increase their risk for the disease.
The DNA mutations that cause some inherited forms of bone cancers are known (see the section, “What are the risk factors for bone cancer?”). In many cases, genetic testing can be used to see if someone has one of these mutations.
Most bone cancers are not caused by inherited DNA mutations. They are the result of mutations acquired during the person’s lifetime. These mutations may result from exposure to radiation or cancer-causing chemicals, but most often they occur for no apparent reason. These mutations are present only in the cancer cells and so cannot be passed on to the patient’s children.
Scientists are making progress in understanding this process, but there are still some points that are not completely understood. As their knowledge increases, they hope to develop ways to better prevent and treat bone cancers.
How Cancer Spreads to Bone
“Bone metastases can be a difficult concept to grasp,” says Julie Fasano, MD, a medical oncologist with Memorial Sloan-Kettering Cancer Center’s Commack Facility in Long Island, N.Y. Although it usually shows up within two to three years of diagnosis, it can appear many years later, she says. Sometimes, it doesn’t cause any symptoms.
How does it happen? Metastasis can occur when cancer cells break away from the primary tumor, where the cancer began. The cells may then enter the bloodstream or lymph system and travel to the bone marrow. “The matrix of the bone marrow secretes cytokines,” Fasano says. These proteins may attract cancer cells.
Cancer cells can remain hidden and inactive in bone for a long time. This means they can evade treatment. At some point, however, the cells may begin to multiply and grow new blood vessels to obtain oxygen and food. This allows a tumor or tumors to form.
Scientists are just beginning to understand what happens in the bone to prompt this process, Fasano says. Once metastasis begins, there may be a “vicious, self-perpetuating cycle.” The release of cytokines may attract yet more cancer cells to the bone marrow, and this may help cancer cells survive.
Types of Bone Cancer
Bone cancers are broken down into separate types based on the type of cell where the cancer began. The most common types of bone cancer include:
- Osteosarcoma. Osteosarcoma begins in the bone cells. Osteosarcoma occurs most often in children and young adults.
- Chondrosarcoma. Chondrosarcoma begins in cartilage cells that are commonly found on the ends of bones. Chondrosarcoma most commonly affects older adults.
- Ewing sarcoma.It’s not clear where in bone Ewing’s sarcoma begins. It’s believed that Ewing’s sarcoma may begin in nerve tissue within the bone. Ewing’s sarcoma occurs most often in children and young adults.
How often does Bone Cancer occur?
Primary bone cancer is rare. It accounts for much less than 1 percent of all cancers. About 2,300 new cases of primary bone cancer are diagnosed in the United States each year. Different types of bone cancer are more likely to occur in certain populations:
- Osteosarcoma occurs most commonly between ages 10 and 19. However, people over age 40 who have other conditions, such as Paget disease (a benign condition characterized by abnormal development of new bone cells), are at increased risk of developing this cancer.
- Chondrosarcoma occurs mainly in older adults (over age 40). The risk increases with advancing age. This disease rarely occurs in children and adolescents.
- ESFTs occur most often in children and adolescents under 19 years of age. Boys are affected more often than girls. These tumors are extremely rare in African American children.
Risk factors of Bone Cancer
It’s not clear what causes bone cancer, but doctors have found certain factors are associated with an increased risk, including:
- Inherited genetic syndromes. Certain rare genetic syndromes passed through families increase the risk of bone cancer, including Li-Fraumeni syndrome and hereditary retinoblastoma.
- Paget’s disease of bone. This precancerous condition that affects older adults increases the risk of bone cancer.
- Radiation therapy for cancer. Exposure to large doses of radiation, such as those given during radiation therapy for cancer, increases the risk of bone cancer in the future.
What are the treatment options for Bone Cancer?
Treatment options depend on the type, size, location, and stage of the cancer, as well as the person’s age and general health. Treatment options for bone cancer include surgery, chemotherapy, radiation therapy, and cryosurgery.
- Surgery is the usual treatment for bone cancer. The surgeon removes the entire tumor with negative margins (no cancer cells are found at the edge or border of the tissue removed during surgery). The surgeon may also use special surgical techniques to minimize the amount of healthy tissue removed with the tumor.
Dramatic improvements in surgical techniques and preoperative tumor treatment have made it possible for most patients with bone cancer in an arm or leg to avoid radical surgical procedures (removal of the entire limb). However, most patients who undergo limb-sparing surgery need reconstructive surgery to maximize limb function.
- Chemotherapy is the use of anticancer drugs to kill cancer cells. Patients who have bone cancer usually receive a combination of anticancer drugs. However, chemotherapy is not currently used to treat chondrosarcoma.
- Radiation therapy, also called radiotherapy, involves the use of high-energy x-rays to kill cancer cells. This treatment may be used in combination with surgery. It is often used to treat chondrosarcoma, which cannot be treated with chemotherapy, as well as ESFTs. It may also be used for patients who refuse surgery.
- Cryosurgery is the use of liquid nitrogen to freeze and kill cancer cells. This technique can sometimes be used instead of conventional surgery to destroy the tumor.
