Medicines to Treat Bone Metastases
- Bone is the third most common place for cancer to spread, after the lung and liver.
- Prostate, lung, breast, and kidney cancers are some of the most common types that spread to the bone.
- Drugs called RANK-L inhibitors and bisphosphonates block the action of cells that lead to bone destruction.
- Chemotherapy and hormone therapy treat cancer all over the body, including in the bones.
Bone is the third most common place that cancer spreads, or metastasizes, after the lung and liver, says Dr. Alan Alper Sag, interventional radiologist at Duke University Medical Center. “Some patients have bone metastases at the time of diagnosis, while others develop it at a later time,” he says.
Read More“As medicine advances our ability to manage patients with metastatic cancer, and with the success of new targeted therapies and immune therapies, we are seeing patients live longer with their disease, and the need to recognize and treat metastatic bone disease has become more important than ever,” says Dr. Julia Visgauss, orthpedic surgical oncologist at Duke Cancer Center.
Symptoms of Bone Metastases
Cancer that has spread to the bone can cause a few different symptoms, and one in particular. “Pain is the most common symptom,” says Dr. Carla Falkson, breast oncologist and director of the Breast Oncology Clinical Research Program at the University of Rochester Wilmot Cancer Institute.
Cancer can also weaken the bones and cause them to break, which “can result in major functional effects impacting quality of life,” Dr. Sag says. Cancer that spreads to the bones can also lead to “painful fractures, spinal cord compression, and bone marrow effects that can affect survival.”
Related: Surgery to Treat Bone Pain: What You Need to Know
Sometimes pain is the first sign that the cancer has spread to the bone. In other cases, there is no pain, and the metastasis is picked up on a computed tomography (CT) or magnetic resonance imaging (MRI) scan done for another reason.
The goals in treating patients with metastatic bone disease are to "minimize pain and maximize function,” Dr. Visgauss says. One way to achieve those goals is with drugs such as RANK-L inhibitors, bisphosphonates, chemotherapy, or hormone therapy.
What are RANK-L Inhibitors?
Your bones aren't static. They're constantly remodeling themselves. Cells called osteoclasts break down old bone, while cells called osteoblasts make new bones. "In metastatic bone disease, this balance is disrupted," Dr. Visgauss tells SurvivorNet. "The tumor overactivates the osteoclasts, leading to bone destruction."
Rank ligand (RANK-L) is a substance in the body that activates osteoclasts. RANK-L inhibitors are a class of drugs that block RANK-L, which stops osteoclasts from destroying bones.
Doctors prescribe the RANK-L inhibitor denosumab (Xgeva) to treat cancer that has spread to the bones. [Another RANK-L inhibitor, Prolia, treats the bone-weakening disease, osteoporosis.]
Xgeva comes as an injection that you get under the skin. It can reduce the risk of fractures in patients with bone metastases from a variety of different tumors, says Dr. Chien-Shing Chen, an oncologist at Loma Linda University Health.
When Do Doctors Prescribe Bisphosphonates?
Bisphosphonates are another type of medication that blocks the action of osteoclasts to help strengthen bones. These drugs are also used in the treatment of osteoporosis. The bisphosphonates that doctors prescribe to treat bone metastases include pamidronate (Aredia) and zoledronic acid (Zometa).
Bisphosphonates help to relieve pain, weakness, and other side effects from cancer that has spread to the bone. By doing so, they can improve a person’s quality of life.
Related: When Cancer Spreads to Bones There are Treatment Options Can Radiation Help?
"Both bisphosphonates and RANK-L inhibitors are used to help minimize the risk of fractures, and are recommended for most patients with metastatic bone disease," Dr. Visgauss says. One exception is people with kidney damage, who may need to avoid these drugs. "Your medical oncologist will decide which of these medications may be most appropriate for you."
Chemotherapy and Hormone Therapy
These treatments are considered systemic, meaning they treat cancer throughout your body. Chemotherapy uses strong drugs to destroy rapidly-dividing cells, including cancer cells. Hormone therapy blocks the actions of hormones such as testosterone and estrogen that fuel the growth of certain cancers.
Both treatments are part of the overall therapy for cancer. In the process of targeting cancer cells throughout your body, they treat bone metastases, as well. "Bone metastasis are part of the whole cancer picture, so chemotherapy will be used for this in the same way as chemo is used for any other kind of stage IV cancer," Dr. Falkson says.
Hormone therapy is most often used to treat breast and prostate cancers, adds Dr. Chen.
If you’re diagnosed with a bone metastasis, or you have symptoms like bone pain, discuss them with your oncologist. There are many treatments, in addition to these, that can help control your symptoms and possibly lengthen your life.
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