Bone Cancer

Destroys normal bone tissue

Bone cancer is a malignant tumor that arises from the cells that make up the bones of the body. Doctors know bone cancer begins as an error in a cell’s DNA. The error tells the cell to grow and divide in an uncontrolled way.

When cancer is detected in bones, it either originated in the bones (as in primary bone cancer) or has spread to the bone after originating elsewhere (cancer that has metastasized to bone). In fact, when cancer is detected in bone, it most often has started in another organ or somewhere else and then spread to the bones. This cancer that has metastasized to the bone is named for the site where original cancer began.

Breast, prostate, and lung cancers are among the types of cancers that commonly spread to the bone in their advanced stages. Less commonly, cancer can begin within the bone as primary bone cancer, and this is true bone cancer. Primary and metastatic bone cancers are often treated differently and have a different prognosis. It is also important to note that benign (non-cancerous) tumors can also arise in the bones, and these benign tumors are more common than bone cancers.

It’s not clear what causes bone cancer, but doctors have found certain factors are associated with an increased risk, including inherited genetic syndromes, Paget’s disease of bone and radiation therapy for cancer since exposure to large doses of radiation, such as those given during radiation therapy for cancer, increases the risk of bone cancer in the future. Bone cancers are broken down into separate types based on the type of cell where 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, in the bones of the leg or arm.
• Chondrosarcoma: It begins in cartilage cells. It usually occurs in the pelvis, legs or arms in middle-aged and older adults.
• Ewing’s sarcoma: It’s not clear where in bone Ewing’s sarcoma begins, but the tumors most commonly arise in the pelvis, legs or arms of children and young adults.

Stages of bone cancer include:

• Stage I: At this stage, bone cancer is limited to the bone and hasn’t spread to other areas of the body. Stage I cancer is low grade, which means the cancer cells are less aggressive.
• Stage II: This stage of bone cancer is also limited to the bone and hasn’t spread to other areas of the body. But Stage II cancer is high grade, which means the cancer cells are more aggressive.
• Stage III: At this stage, bone cancer occurs in two or more places on the same bone. Stage III tumors can be either low or high grade.
• Stage IV: This stage of bone cancer indicates that cancer has spread beyond the bone to other areas of the body, such as other bones or internal organs.

Types of benign tumors include:

• Osteochondroma: It is the most common benign bone tumor affecting people under age 20.
• Giant cell tumor: It is a type of benign tumor that grows at the ends of the body’s long bones.
• Osteoid Osteoma: It is a benign bone tumor that usually develops in the long bones of the body such as the thighbone and shinbone and can occur more frequently in children and young adults.
• Osteoblastoma: It is a rare tumor that often develops in the bones of the spine, as well as the legs, hands, and feet. It mostly affects adolescents and young adults.
• Enchondroma: It is a type of benign bone tumor that originates from cartilage and most often affects the cartilage that lines the inside of the bones.

Surgery is the most successful treatment for benign bone tumors, except for some cases requiring radiotherapy.

Diagnosis

A patient’s symptoms, physical exam, and results of imaging tests and blood tests may suggest that bone cancer is present. But in most cases, doctors must confirm this suspicion by examining a tissue or cell sample under a microscope (a biopsy) in order to precisely determine what kind of cancer is present and confirm the diagnosis.

Other diseases, such as bone infections, can cause symptoms and imaging results that could be confused with bone cancer. Accurate diagnosis of a bone tumor often depends on combining information about its location (what bone is affected and even which part of the bone is involved), appearance on x-rays, and appearance under a microscope.

What imaging tests you undergo depends on your situation. Your doctor may recommend one or more imaging tests to evaluate the area of concern, including:

• Bone scan
• Computerized tomography (CT)
• Magnetic resonance imaging (MRI)
• Positron emission tomography (PET)
• X-ray
• Biopsy

Treatments

The treatment options for your bone cancer are based on the type of cancer you have, the stage of cancer, your overall health and your preferences. Different bone cancers respond to different treatments, and your doctors can help guide you in what is best for your cancer. For example, some bone cancers are treated with just surgery; some with surgery and chemotherapy; and some with surgery, chemotherapy and radiation therapy.

Chemotherapy is a drug treatment that uses chemicals to kill cancer cells. Chemotherapy may also be used in people with bone cancer that has spread beyond the bone to other areas of the body. The chemotherapy medications travel throughout your body. Radiation therapy, typically given along with chemotherapy, is often used before an operation. This may increase the possibility that amputation won’t be necessary.

Radiation therapy may also be used in people with bone cancer that can’t be removed with surgery. After surgery, radiation therapy may be used to kill any cancer cells that may be left behind. For people with advanced bone cancer, radiation therapy may help control signs and symptoms, such as pain.

Your doctor may surgically remove tumors or affected tissue. Surgery to remove and replace damaged bone is an option to stop cancers that spread quickly. For extensive bone damage in the arms or legs, amputation may be needed.

The goal of surgery is to remove the entire bone cancer. In most cases, this involves special techniques to remove the tumor in one single piece, along with a small portion of healthy tissue that surrounds it. Types of surgery used to treat bone cancer include surgery to remove cancer but spare the limb. If a bone cancer can be separated from nerves and other tissue, the surgeon may be able to remove the bone cancer and spare the limb. Since some of the bone is removed with cancer, the surgeon replaces the lost bone with some bone from another area of your body, with material from a bone bank or with a special metal prosthesis.

Surgery for cancer that doesn’t affect the limbs; if bone cancer occurs in bones other than those of the arms and legs, surgeons may remove the bone and some surrounding tissue. Bone removed during surgery can be replaced with a piece of bone from another area of the body, with material from a bone bank or with a special metal prosthesis. Surgery to remove a limb; bone cancers that are very large or located in a complicated point on the bone may require surgery to remove all or part of a limb (amputation). As other treatments have been developed, this procedure is becoming less common. You’ll likely be fitted with an artificial limb after surgery and go through training to learn to do everyday tasks using your new limb.