Cancer can spread from other parts of the body to the bones.
Metastatic cancer occurs when cancer cells spread from the original tumor to other parts of the body. Bones are a common place for these cancerous cells to start growing, and this causes metastatic bone cancer. Bone metastatic disease will occur in many patients with cancer at some point during the course of their disease, and it can affect the marrow or the outside of the bones.
Metastatic Cancer
When cancerous cells break off from the original tumor, they can travel through the bloodstream or the lymph system (this includes lymph nodes and vessels) to other parts of the body. Usually these cells die along the way, but occasionally they will settle in a new area, such as the bone marrow. This can occur in any bone in the body, but will most often happen in the shafts of the long bones of the body, such as the legs.
Signs and Symptoms
The most common symptom of bone marrow metastasis is bone pain. At first, this pain may come and go and be relieved with exercise; however, as the disease progresses, the pain may become constant and made worse with activity. Patients may also experience swelling, stiffness or tenderness in the bones. Anemia, or low red blood cell counts, may also indicate bone marrow cancer. These symptoms can have many causes, so it is important to check with a doctor to determine whether they are caused by cancer.
X-ray Diagnosis
It's important to discuss with a doctor any of the symptoms that are related to bone marrow metastasis. An X-ray scan is one way to detect some types of bone metastasis. It can detect both osteolytic metastasis, where the bones have been made less dense by the cancer, and osteoblastic metastasis, where the bones have been made more dense. Osteolytic metastasis shows up on an X-ray scan as dark spots, and osteoblastic metastasis shows up as white spots.
Other Bone Scans
A radionuclide bone scan is often used to determine whether a cancer has metastasized to the bone marrow. In this technique, the patient is injected with a radioactive substance called a "marker," which is attracted to diseased bone marrow throughout the body. Computed tomography (CT) scanning is similar to X-ray scanning, but instead of taking a single picture, it rotates around the patient, taking several from different angles to provide a detailed cross section of part of the body. Magnetic resonance imaging (MRI) uses strong radio waves and magnets to make a map of the body. MRI scans are useful for looking at the spinal cord. In a positron emission topography (PET) scan, radioactive sugars are injected into the bloodstream. Cancerous areas will absorb these sugars faster than regular cells, giving the doctor a picture of where the cancer is. Blood tests, such as tests to monitor the calcium level of the blood or detect anemia, may also be used to diagnose bone metastatic disease. Once a cancerous area is detected, a biopsy may be necessary.
Treatment
Bone marrow metastasis is typically treated by targeting the original cancer that caused it. This cancer can be treated with chemotherapy or hormone therapy. If the metastatic cancer has destroyed significant amounts of bone marrow, a bone marrow transplant may be necessary. If chemotherapy is successful in treating the cancer, the symptoms of bone marrow metastasis will often disappear.
Prevention
The only way to keep a cancer from spreading to the bone marrow or any other part of the body is to treat it before it has a chance to spread. Early detection is crucial, and screenings such as mammograms are necessary to detect cancer before it can start to spread. It is important to discuss with a physician what screenings are necessary and how frequently they should be administered to detect cancer as early as possible.
Tags: bone marrow, bone marrow, marrow metastasis, bone marrow metastasis, other parts