Many different treatments can help if your cancer has spread to bone, commonly called bone metastasis or bone "mets." Treatment can't cure bone metastasis, but it can relieve pain, help prevent complications, and improve your quality of life.
When breast cancer spreads to other parts of your body (metastatic breast cancer), it’s more likely to spread to your bones than any other organ. More than half of those with stage IV breast cancer will have bone metastasis, most often in the spine, pelvis, ribs, arms, and legs.
Doctors use two types of treatments for metastatic cancer in the bones. Systemic treatments can reach cancer cells throughout the body. Local treatments directly target the cancer in the bone.
The treatment you get will depend upon:
- Where your cancer started and the kind of primary tumor you have
- Which bones the cancer has invaded
- The extent of damage to the bones
- Which types of treatment you already have had
- Your overall health
Let your doctor know if your treatment isn't easing your pain and other symptoms. You may find that other approaches work better for you.
Chemotherapy
Chemotherapy is a common systemic treatment for bone metastasis. Your doctor will use a type of chemo that is effective against your primary tumor. So if you have metastatic lung cancer, for example, your doctor will use drugs that are effective against lung cancer.
How it works. Cancer medications target and curb cancer growth. In most cases, you take chemo by mouth or through a vein (by IV). This can often shrink the tumors, which will ease your pain and help you feel better.
Possible side effects. Chemo can kill normal cells in addition to cancer cells. The side effects you might have will depend on:
- The type and amount of drugs you take
- The length of your treatment
Common side effects of chemotherapy include:
- Loss of appetite, nausea, or vomiting
- Hair loss
- Mouth sores
- Infection
- Bleeding or bruising
- Weakness or fatigue
Your doctor can help you prevent or manage these. Most side effects go away once you stop treatment.
Hormone Therapy
Some types of breast and prostate cancers may be sensitive to hormones in the body. This still holds true when those cancers spread to the bones.
In some cases, your doctor may prescribe medications to block the interaction between certain hormones and cancer cells. In other cases, your doctor may suggest removal of hormone-making organs like the ovaries.
Bone-Modifying Agents
These drugs help prevent bone loss and fractures and treat damage to your bones from bone cancer tumors. They may also help with pain due to these tumors. There are two main types that doctors recommend for metastatic breast cancer: bisphosphonates and denosumab.
Bisphosphonates – ibandronate (Boniva), pamidronate (Aredia), and zoledronic acid (Zometa) – prevent bone loss or osteoporosis from endocrine treatments given for breast cancer. You take bisphosphonates by mouth or IV infusion, typically every 3 to 4 weeks. These drugs help by:
Side effects include:
- Fatigue
- Fever
- Nausea or vomiting
- Anemia
- Bone or joint pain
A rare and serious side effect is bone death (osteonecrosis) of the jaw. Ask your doctor about precautions to take before beginning this treatment. Osteonecrosis may cause:
- Jawbone pain, swelling, or numbness
- Loss of gum tissue
- Loose teeth
- Infection
Denosumab (Prolia, Xgeva) is a type of medicine called a monoclonal antibody. Scientists make monoclonal antibodies in a lab. They work like the natural antibodies your body makes to fight illness. Monoclonal antibodies go into your body to identify and attack germs or cancer cells. Denosumab in particular is a “RANKL inhibitor.” It blocks a protein called RANKL that breaks down bone.
Your doctor will inject the drug under the skin. It may take some months before any bone tumors start to shrink.
Denosumab may work as well as or better than bisphosphonates to prevent fractures. But it also can cause osteonecrosis, as well as low calcium levels in the blood.
Both denosumab and zoledronic acid also prevent spinal compression in women with cancerous growths (metastatic lesions) on the spine.
Radiopharmaceuticals
These drugs contain radioactive elements that target cancer cells. Doctors tend to use this systemic treatment when the metastasis is stimulating new bone growth. This is more common with prostate cancer.
If your cancer has spread to many bones, these drugs may be a better option than standard radiation, which uses a beam to aim radiation at each bone metastasis. However, sometimes doctors combine radiopharmaceuticals and standard radiation.
How it works. The doctor injects a single dose of the drug into a vein. It then travels to the areas of bone with cancer and gives off radiation to kill the cancer. This single dose may be effective against pain for several months. You can receive another treatment later.
Possible side effects. The most common ones include:
- Infections
- Bleeding
- Temporary increase in pain (flare reaction)
Immunotherapy
This systemic treatment helps your immune system spot and more effectively kill cancer cells. Some methods of immunotherapy have been used for a while, and some are still experimental.
How it works. Immunotherapy works in one of two main ways:
- It boosts your body's immune system to fight the cancer.
- It uses a lab-made version of proteins to kill cancer cells.
Examples of immunotherapy for cancer include:
- Cytokines -- substances secreted by the immune system that have an effect on other cells
- Monoclonal antibodies
- Tumor vaccines -- vaccines using a substance that prompts the immune system to respond to a tumor
Possible side effects. Side effects vary, depending upon the type of immunotherapy. They may include:
- Fever and chills
- Weakness
- Headache
- Nausea or diarrhea
- Rashes
Radiation Therapy
Radiation is a "local treatment" because it does not affect your entire body. It uses high-energy X-rays or particles to destroy or slow the growth of cancer cells in the bone. It helps most if you have only one or two bone metastases. You may get it alone or combined with other types of treatment.
How it works. A machine focuses a beam of radiation on the bone metastasis. This treatment, called external beam radiation, lasts only a few minutes. You may receive radiation in one large dose or in smaller amounts over several treatments.
Possible side effects. Early, temporary side effects depend on the location being treated, but may include:
Surgery
Surgery can often help relieve bone metastasis symptoms.
How it works. If a bone is broken, surgery may help relieve pain quickly. Surgery can also help stabilize a weak bone to keep it from breaking. The surgeon may insert:
- Screws
- Rods
- Pins
- Plates
- Cages
Possible side effects. These include the usual risks of any surgery, such as infection.
If surgery is not an option, your doctor may use a cast or splint, or inject bone cement to help you move better and relieve pain.
Ablation
With this local treatment, a needle or probe is put into the tumor to destroy it. Though used more often for other types of metastasis, ablation can help if you have a problem with one or two bone tumors.
How it works. Some methods of ablation use chemicals or alcohol to kill the tumor. Two common methods include:
- Radiofrequency ablation (RFA). A needle delivers an electric current to heat the tumor.
- Cryoablation. A probe is used to freeze the tumor.
Afterward, the doctor may fill the space created by ablation with bone cement to help stabilize the bone.
Possible side effects. This procedure is generally safe but may cause some temporary soreness, swelling, and bruising.
Nerve End Ablation
This noninvasive procedure uses ultrasound energy and imaging technology to provide pain relief by destroying nerve endings in the area of the tumor. Because there is no incision, and no probe is inserted, the procedure is typically done on an outpatient basis with a local anesthetic rather than general anesthesia. While complications are possible, they are rare.
How it works. A specialist uses imaging to target the specific area to be treated with ultrasound. Then, heat that's made when ultrasound penetrates the targeted tissue destroys nerve endings in the bone around the tumor. The destruction of nerve endings results in pain relief.
Possible side effects. Possible complications include skin burns and damage to heat-sensitive organs that are next to the treated area.
