What is bone metastasis?
When cancer in one part of the body grows and spreads to another part, it is said the cancer has metastasized. When the cancer spreads to a bone it is called bone metastasis.
Bone has a hard outer layer and a spongy inner layer. Inside that inner layer is bone marrow. All parts of the bone have blood vessels running through it, and through this network of blood vessels, cancer can spread.
Using laboratory and imaging tests doctors can tell when a cancer began in the bone (primary cancer) or has spread to the bone (secondary cancer). Tests can show what types of cells are within the cancer that was found in the bone.
For example, if the person originally had breast cancer and is now showing symptoms of bone cancer, tests can show the bone cancer has breast cells in it and is therefore a secondary breast cancer in the bone, not a different kind of cancer. This information is important because it can have a significant impact on how the cancer is treated.
When cancer cells break away from a tumor, they move through the body by blood vessels or the lymphatic system (part of the circulatory system). These cells may land in a different part of the body and that is how cancer metastasizes or spreads.
Signs and symptoms
Symptoms of bone metastasis are often vague and depend on a variety of factors including the type and location of the tumor, as well as your child’s age and general health. Patients with bone metastases already have a known cancer somewhere else in their body.
Symptoms of bone metastasis in a patient with a known tumor include:
- Bone pain, especially at night or at rest
- Bone fractures
- Compression of the spinal cord, which can cause pain and numbness in certain areas of the body due to pressure on the spinal cord
- Specific complaints such as loss of bowel and bladder control
Testing and diagnosis
Diagnosing bone metastasis requires a thorough imaging evaluation, a physical examination and a detailed medical history of your child, including any personal history of cancer.
At Children’s Hospital of Philadelphia (CHOP), clinicians use a variety of diagnostic tests to diagnose bone metastasis and malignant tumors, including:
- X-rays, which produce images of bones.
- Magnetic resonance imaging (MRI), which uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs, soft tissues, muscles, ligaments and other structures within the body. Your child is exposed to no radiation during an MRI.
- Computed tomography (CT) scan, which uses a combination of X-rays and computer technology to produce cross-sectional images ("slices") of the body.
- Radioisotope bone scan, which can help locate areas of abnormal growth.
- Needle biopsy, which is a procedure where a doctor places a small needle through the skin and into the lesion to withdraw a small sample of the abnormal tissue. The tissue is analyzed to confirm any findings.
- Blood tests, which can help determine drug usage and effectiveness, biochemical diseases and organ function.
At CHOP, experts at the Bone and Soft Tissue Tumor Program at CHOP take a team approach to treatment. Orthopaedic, cancer and other specialists collaborate to provide your child with individualized care and the best possible outcomes.
Our program is led by Kristy L. Weber, MD, and Alexandre Arkader, MD, nationally renowned surgeons who specialize in treating bone and soft tissues tumors, limb-sparing surgery and reconstructive surgery.
Bone metastasis can be fast-growing, so treatment must be similarly aggressive. The best way to treat bone metastasis is to treat the primary or original cancer so that is stops spreading to new bones.
There are some treatments that can protect the bone from being destroyed by cancer. One such treatment is a class of drugs called bisphosphonates, which decrease the risk of complications such as bone fractures, and lower blood-calcium levels that are too high.
There are numerous options for treating existing bone metastasis including surgery, chemotherapy, proton radiation, or a combination of therapies. Your child’s doctor will discuss the best option for your child.
In most cases, the goal of surgery is to stabilize the affected bone to prevent or treat a fracture. This could include reinforcing the bone with metal plates, screws or inserting hollow metal rods inside the bone.
In some cases, another surgery — a surgical resection and reconstruction — may be recommended to remove a tumor and restore function at the site of the tumor.
Though surgery for bone metastasis is highly effective, we understand that any surgery can be a stressful experience for your child and family. At CHOP, we offer a wealth of resources about how to prepare your child for surgery and what to expect during surgery.
Additionally, we employ numerous best practices before, during and after surgery to decrease the risk of infection and increase positive outcomes. For more details about safety protocols at Children's Hospital of Philadelphia, see safety in surgery.
Chemotherapy refers to medicines that help fight cancer. They are given by mouth, in the vein, in the muscle or under the skin.
Radiation therapy uses high-energy waves such as X-rays to kill or shrink cancer cells. It can be targeted to almost anywhere in the body.
Proton therapy is an innovative form of radiation treatment that allows for more precise radiation doses delivered to cancerous tumors. Proton therapy’s greatest benefit is that it is less damaging to the surrounding healthy tissue because it delivers most of its energy to a very narrow field at the location of the tumor. Learn more about proton therapy.
After surgery, your child may spend one or two nights in the hospital and require pain medications until the surgical site heals. Most children are encouraged to resume as active a life as possible.
Your child will see the orthopaedic surgeon about one to two weeks after surgery, then again at three and six months post-surgery. Regular monitoring by trained clinicians is strongly encouraged to monitor for possible progression of disease.
Bone metastasis can continue to cause symptoms and show up in other bones so it is important for your child to see a physician regularly, especially if any symptoms recur.
During follow-up visits, X-rays and other diagnostic testing of the tumor site are recommended to closely monitor your child’s health.
Follow-up care and ongoing support and services are available at our Main Campus and throughout our CHOP Care Network. Our team is committed to partnering with parents and referring physicians to provide the most current, comprehensive and specialized care possible for your child.
If your child needs continued monitoring into adulthood, he can continue to see some of the same doctors who treated him. CHOP’s Bone and Soft Tissue Tumor Program works closely with Penn Medicine. For families who live farther away and need continued monitoring, our clinical professionals will help your child transition to adult care near home.
Long-term outcomes for children with bone metastasis are varied and depend on the type of primary or original cancer, how well your child responds to treatment, and if the cancer has spread to more than one location.