Bones are the most common place for metastatic breast cancer (MBC) to spread. Several treatment options can slow the spread of metastases. There are also treatment options to reduce the associated pain and fatigue and prevent bone breakage.
For over half of women with stage 4 breast cancer, the bones will be the first place it spreads to.
Cancer can spread to any bone in the body, but the most common places for this to occur are the long bones in the arms and legs, ribs, spine, and pelvis.
There is currently no cure for MBC, but people can continue to live full lives during treatment. There are a range of treatments for the MBC itself and for its symptoms.
Recent advances have substantially improved outcomes. There are more therapies currently undergoing trials.
This article looks at what happens when MBC spreads to the bones.
MBC that has spread to the bones may cause a variety of symptoms. These include:
The most common symptom is a new pain in the bones.
This pain is similar to arthritis or exercise strain in that it may come and go at first but become constant over time. The pain may also be worse when lying down or resting.
The pain may range from mild to severe and feel like a dull ache, stabbing, or burning.
When MBC appears in the bones, cancer cells can speed up or slow down the rate that bone cells, called osteoblasts and osteoclasts, build up and break down bone. This can increase the risk of fractures.
Fractures of this kind are called pathological fractures. This means that they are caused by disease rather than an accident.
Spinal cord compression
If the cancer spreads to the bones in the spine, a person can experience pressure on their spinal cord. This can cause a variety of symptoms, including:
- severe back pain, which may spread to the front of the body
- difficulty walking
- numb toes, fingers, or buttocks
- changes to back pain when lying down, standing, or lifting something
- difficulty controlling urine and bowel movements
MBC in the bones can cause the release of calcium into the bloodstream. Too much calcium in the blood is called hypercalcemia, and it can cause a variety of symptoms, including:
- nausea and vomiting
- loss of appetite
- confusion and loss of concentration
- passing significant amounts of urine
There are a number of therapeutic options for MBC in the bones. Treatment options may be tailored to the individual and may require a variety of medical interventions.
Therapies can be either local or systemic, meaning applied to the body as a whole.
Where a person has bone metastases, the goal is also to avoid complications, including fractures, spinal cord compression, radiation to the bones, and orthopedic surgery. Treatments may also improve symptoms and extend life.
Typically, systemic drug therapies are the main treatments for MBC. These include:
- targeted drugs
- hormone therapy
- a combination of the above
Stage 4 breast cancer is considered incurable, but treatments can either slow the growth of tumors or shrink them.
Along with systemic drugs, doctors may use local and regional treatment for MBS. Such therapies include surgery and radiation therapy.
Doctors often use
These treatments commonly include zoledronic acid, which is a bisphosphonate, and denosumab, which is a RANK ligand inhibitor. Both act by building healthy bone.
People with MBC of the bones may experience a variety of uncomfortable symptoms, but treatment options are available for specific symptoms.
Pain and fatigue
The treatment of pain from bone metastases will vary based on the location of the bone.
In some cases, treatments targeting the primary breast cancer may help shrink cancers of the bones. In other cases, a person may receive medications to counter the effect of the cancer on the bone.
Doctors may also use local treatments such as radiation therapy and surgery to help relieve pain from MBC of the bones.
Pain medications in the form of pills, patches, or pumps may also be helpful.
Fatigue is very common. Some treatments for this include:
- physical activity
- mindfulness practices
- cognitive behavioral therapy
- alternative therapies, such as Reiki and acupuncture
Doctors try to prevent fractures due to MBC of the bones. If X-rays show that a bone is at risk of breaking, they may suggest surgery to add metal rods to the weak part of the bone. This will prevent fractures.
If a bone is already broken, a surgeon may insert a steel support. In the case of broken bones in the spine, they may inject bone cement in a procedure called a vertebroplasty.
Doctors may also suggest radiation treatments to prevent further breakages.
Safety equipment such as walkers, shower chairs, and handrails may be helpful in preventing falls and fractures.
Spinal cord compression
If the cancer is causing pressure on the spinal cord, there are a few treatment options that may help relieve pain and prevent paralysis.
For example, a person may receive radiation therapy together with steroids or corticosteroids.
If there are any signs that the spinal cord is already damaged, a specialist will likely recommend surgery followed by radiation therapy. This may not be possible for those with advanced cancer or other serious medical issues, however.
High levels of calcium in the blood are treatable with intravenous fluids to protect the kidneys.
Medications such as bisphosphonate drugs can help lower blood calcium levels by blocking resorption of the bones.
Altered sexual function was the most common symptom.
Common treatments for people with MBC who are experiencing anxiety and depression include:
- one-on-one or group counseling
- cognitive behavioral therapy
- antianxiety medications
People should discuss their symptoms with a doctor. Treatment may depend on other medications they are taking.
MBC, or stage 4 breast cancer, is currently incurable. MBC may spread to the bones and cause pain and other symptoms.
Although MBC may not vanish completely, a range of treatments can help manage the condition for a number of years, and many people can live long lives with MBC. The cancer may be active or go into remission.
One study involving 18,322 people with stage 4 breast cancer with metastasis found that those with bone metastasis had the best survival of all metastasis sites.
According to the National Cancer Institute, the 5-year survival rate for regional MBC is
Receiving a diagnosis of MBC of the bones can be overwhelming.
For more than half of women with stage 4 breast cancer, the bones will be the first place it spreads to. This spread can cause a variety of symptoms, including pain, difficulty walking, fatigue, and nausea.
MBC that spreads to the bones is currently incurable, but treatment options are available to try to prevent further spreading and minimize the impact of the symptoms. Also, researchers are always trialing new therapies.