Breast cancer cells sometimes metastasize — travel from the breast to a new place and start growing in a different part of the body. Metastatic breast cancer is also known as stage 4 breast cancer. Breast cancer usually spreads to the bones. More than 50 percent of people with stage 4 breast cancer experience cancer spreading to the bones.

It’s important to be aware of the symptoms of bone metastasis if you have received a breast cancer diagnosis. Knowing what to watch out for could help you find signs of new cancer early. Several therapies can help reduce the risk of cancer spreading or help treat metastases.

The idea of breast cancer spreading to other parts of the body is stressful, especially because some bone metastases don’t always cause symptoms. Make sure to tell your oncologist if you notice any health changes, including the following potential signs and symptoms that may point to breast cancer bone metastasis.

1. Bone Pain

Cancer cells are more likely to spread to some bones than others. One of the most common sites of bone metastasis is the spine, which can lead to back pain. Hip pain caused by cancer cells growing in the pelvic bones or femur (thigh bone) is also common. Bone pain may affect any other bones, such as your ribs, causing pain.

At first, bone pain caused by metastasis often comes in waves. You may have to live with pain for a short period and then feel better. Eventually, the pain will occur more often until it stops going away. This pain also tends to get worse at night or when you sit or lie down.

Pain in breast cancer can have other causes. Your health care team can help identify and manage any pain.

2. Broken Bones

If you suddenly feel intense pain and can’t move a particular part of your body, you may have a broken bone or a fracture (pathologic fracture). A pathologic fracture is a broken bone that occurs due to another disease or condition that has weakened the bone’s structure. Breaks happen not because of a significant trauma but because metastases weaken the nearby bone. Other symptoms of a broken bone include swelling, bruising, a bump, or tenderness when you touch the area.

3. Leaking Urine

Urinary incontinence occurs when you unintentionally leak some urine. For people with breast cancer, this may be a sign of spinal cord compression. Your spinal cord is a bundle of nerves that runs from your brain down your spine. If breast cancer spreads to your vertebrae (the bones of the spine), one vertebra may break and press against your spinal cord, leading to compression and various symptoms.

Urinary incontinence isn’t always a symptom of breast cancer metastasis. It can also occur due to urinary tract and vaginal infections, diabetes, arthritis, Parkinson’s disease, or medications. In general, urinary incontinence is more common in older adults. However, tell your oncologist if you experience this as a new symptom while living with breast cancer.

4. Inability To Control Bowel Movements

Another sign of breast cancer spreading to bones is bowel incontinence — loss of bowel control. Bowel incontinence can also occur because of spinal cord compression. This symptom may cause stool to come out when you don’t want it to. It can also indicate spinal cord compression caused by bone metastasis. On the other hand, spinal cord compression may also make it more difficult to go to the bathroom.

5. Other Symptoms of Spinal Cord Compression

About 95 percent of people with spinal cord compression report having pain in their neck or back. Spinal cord compression can also lead to other issues, including nerve pain in your buttocks or legs, limping, an inability to have sex, or numbness and weakness in a certain part of your body, such as your hand, leg, or abdomen.

Spinal cord compression needs to be treated right away. It can worsen quickly and may lead to paralysis. Contact your doctor or go to the emergency department if you have breast cancer and think you may be having signs of spinal cord compression.

6. High Calcium Levels

Tumors in your bones can cause your bone tissue to break down. More than 99 percent of calcium is stored in bones. When bones get damaged or weak, they release some of this calcium into the blood.

High levels of calcium in the blood, known as hypercalcemia, can lead to additional symptoms, such as:

• An upset stomach, nausea, or vomiting
• Loss of appetite
• Constipation
• Extreme thirst or increased urination
• Heart palpitations (irregular heartbeat)
• Tiredness or weakness
• Confusion
• Depression

Hypercalcemia can be detected with a simple blood test.

Treatments for Bone Metastasis

If there is a chance you have bone metastases, your doctor may recommend additional tests for diagnosis, including an X-ray, a bone scan, a CT scan, or an MRI. They may also take a sample of the bone (biopsy) for laboratory testing.

Several treatment options can kill cancer cells in your bones, strengthen your bones, and reduce symptoms to help you feel your best when living with metastatic breast cancer.

Cancer-Killing Treatments

Targeted therapy drugs can help treat bone metastases if your cancer cells contain certain gene or protein changes. HER2-positive cancer (breast cancer that contains high levels of a protein called HER2) can often be treated with medications like trastuzumab (Herceptin) or pertuzumab (Perjeta). Additionally, breast cancer cells that contain estrogen receptor (ER) or progesterone receptor (PR) can be treated with other targeted therapies like palbociclib (Ibrance) or everolimus (Afinitor).

Targeted therapy drugs are often given along with chemotherapy. Additionally, hormone therapy may help treat bone metastases if your breast cancer is ER- or PR-positive. When hormone therapy is paired with a drug called ribociclib (Kisqali), the combination treatment does better than chemotherapy at slowing down the spread of aggressive tumors.

Other cancer treatments like radiation therapy or surgery may also help if you have only a small number of metastases.

Bone-Strengthening Treatments

Two types of medications can make your bones stronger, reducing your risk of serious problems if you have bone metastases. They can also reduce the risk of cancer cells spreading to your bones.

Bisphosphonates such as pamidronate (Aredia) and zoledronic acid (Zometa) slow down and prevent bone loss. They are given intravenously every three to four weeks or every three months. Another option is the RANK ligand inhibitor denosumab (sold as Prolia and Xgeva). This medication attaches to osteoclasts (cells that break down bone) and stops them from dissolving too much bone tissue. Denosumab is given as an injection about once every 6 months.

These treatments can lower the chances that you’ll break a bone or be diagnosed with hypercalcemia. They can also ease pain and stop bone metastases from growing bigger. However, in some cases, they cause a rare side effect called osteonecrosis of the jaw, in which part of the jawbone dies. If you need bone-strengthening drugs, your doctor may recommend getting any necessary dental work done before starting them.

Treatments To Relieve Symptoms

Bone pain can be treated with different types of painkillers. Over-the-counter options such as ibuprofen and acetaminophen may be enough to ease mild aches and pains. However, ask your doctor before taking these, as you might need to stay away from certain medications if you have heart failure or kidney disease.

You may be able to take stronger painkillers if you have severe pain. Your doctor may prescribe opioids like morphine or oxycodone, which may lead to nausea, fatigue, or constipation. Steroid medications can also ease pain and swelling.

Treatments often used to kill cancer cells, such as radiation, chemotherapy, and hormone therapy, may also be used to relieve symptoms. This may include intravenous radiation, in which a radioactive substance is delivered through a vein and travels to your bones to kill cancer cells. These therapies can shrink bone metastases, which can lessen pain and help prevent bone fractures.

Ablation is a technique that uses extreme heat, freezing temperatures, or electrical currents to destroy or shrink tumors in the bone. This approach can help relieve pain caused by metastasis.

Your doctor may also recommend surgery to fix a broken bone or strengthen a bone that is at risk of breaking. Doctors can use metal plates, screws, or bone cement to stabilize your bones.

Physical therapy can also help you build strength and flexibility and allow you to move around more easily. This treatment may help you better manage or prevent pain and improve your quality of life.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 67,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Have you had bone metastases with breast cancer? Share your experience in the comments below, or start a conversation by posting on your Activities page.