Bone Metastases in Breast Cancer: Symptoms, Diagnosis and Treatment

What are bone metastases?

Bone metastases, sometimes called secondary breast cancer in the bone, happen when breast cancer cells spread from the breast to one or more bones in the body. The bones are one of the most common places for breast cancer to spread to. The cancer in the bone is still breast cancer, made of breast cancer cells, not a new bone cancer, and it is treated as breast cancer.

Breast cancer can spread to any bone, but the ones most often affected are the spine (backbone), ribs, pelvis (hip area), skull and the long bones of the arms and legs. Some people have one area affected, while others have several. This is also called advanced, secondary or stage 4 breast cancer.

The NHS explains that secondary breast cancer cannot usually be cured. But for many people it can be controlled for months or years with treatment. The aim of treatment is to slow the cancer down, ease symptoms such as pain, protect the bones, and help you live as well as possible for as long as possible.

This page is general information, not personal medical advice. Everyone's situation is different. Your oncologist, breast care nurse and GP know your own circumstances, so please always check with your treatment team about what is right for you.

Symptoms to look out for

The most common symptom of breast cancer in the bone is pain in the affected area. Cancer Research UK describes this first symptom as a nagging ache in the bone, which may become painful when you move around and may make it difficult to sleep. The pain can be there both during the day and at night. Sometimes there is also swelling or tenderness over the bone.

Other symptoms can include feeling more tired than usual. Sometimes the cancer raises the level of calcium in the blood, a problem called hypercalcaemia. According to Cancer Research UK, this can cause tiredness, feeling sick (nausea), constipation, thirst, irritability and confusion. Hypercalcaemia can be treated, so it is important to report these symptoms early.

Bone weakened by cancer can sometimes break (a 'fracture') more easily, even without a fall or accident. This is called a pathological fracture. Tell your team straight away if you have sudden, severe bone pain or are unable to use a limb.

Many of these symptoms have other, far more common causes, such as everyday aches and pains. Having them does not mean the cancer has spread. But Cancer Research UK advises that if you have bone pain that lasts more than a week or two, you should let your doctor or treatment team know as soon as possible so it can be checked.

Spinal cord compression: an emergency to know about

If cancer affects the bones of the spine, it can press on the spinal cord. This is called metastatic spinal cord compression (MSCC). NICE describes it as a medical emergency: if it is not treated quickly, it can cause lasting damage, including problems with walking or permanent paralysis. Breast cancer is one of the cancers more often linked with MSCC, so it is important to know the warning signs.

Get urgent medical help, day or night, if you have any of these signs:

• New or worsening back or neck pain, especially a band-like pain that spreads around the body, or pain that is worse when lying down, coughing or straining.
• Weakness, numbness or pins and needles in your legs, arms or hands.
• Difficulty walking, or feeling unsteady on your feet.
• Problems controlling your bladder or bowel, such as difficulty passing urine, leaking or constipation that is new.

If you have these symptoms, contact your treatment team's emergency or acute oncology line straight away, or go to A&E, and explain that you have secondary breast cancer. NICE advises that scans and treatment for suspected spinal cord compression should be arranged urgently, because acting quickly gives the best chance of protecting movement and feeling.

How bone metastases are diagnosed

If your team thinks breast cancer may have spread to your bones, they will arrange tests to find out. According to Cancer Research UK, the tests used can include a number of different scans and blood tests, and you will not usually need all of them.

• Blood tests, including a check of your calcium level and how well your kidneys and liver are working.
• An isotope bone scan (also called a bone scintigraphy scan), which can show areas of bone that are affected.
• CT scans, which give detailed cross-section pictures of the body.
• MRI scans, which are very good at showing the spine and the spinal cord, and are often used if MSCC is suspected.
• X-rays of a painful or weakened bone.
• Sometimes a PET-CT scan, which can show active cancer cells in the body.

Occasionally the team may take a small sample of tissue (a biopsy) from a bone to confirm the diagnosis and to check the features of the cancer cells, such as whether they are oestrogen receptor positive or HER2 positive. This helps your team choose the treatments most likely to work for you. Waiting for tests and results can be a worrying time, and your breast care nurse is there to support you through it.

Treatments to control the cancer

Treatment for secondary breast cancer in the bone aims to control the cancer, relieve symptoms and keep you well. The exact plan depends on the features of your cancer, your previous treatments, your general health and your wishes. The NHS explains that the main treatments that act on the cancer throughout the body include the following:

• Hormone (endocrine) therapy, for cancers that are hormone receptor positive. This is often one of the first treatments used because it can work well with relatively mild side effects.
• Targeted therapies, such as CDK4/6 inhibitors used alongside hormone therapy, or HER2-targeted drugs for HER2 positive cancers.
• Chemotherapy, which may be used if hormone therapy is no longer working or if the cancer needs to be controlled quickly.
• Newer treatments such as immunotherapy or antibody-drug conjugates may be options for some people, depending on the type of breast cancer.

These treatments can keep the cancer under control for a long time, and your team will review how well they are working with regular scans and check-ups. If one treatment stops working, there are often others to try. Your oncologist can talk you through which options are suitable for your particular cancer.

Radiotherapy for bone pain

Radiotherapy uses carefully targeted high-energy rays to treat a specific area of bone. It is one of the most effective ways to relieve pain from bone metastases. Cancer Research UK explains that radiotherapy to a painful bone can ease pain, help strengthen the bone, and lower the risk of a fracture or of new painful areas developing.

Radiotherapy for bone pain is often given as a single treatment or a short course of a few sessions, so it is usually quick and convenient. The treatment itself is painless. It can take some days or weeks for the full benefit to be felt, and sometimes the pain briefly flares before it improves, so your team will make sure you have pain relief to use in the meantime. Side effects are usually mild and depend on the area treated, for example some tiredness or temporary soreness near the treated bone.

Bone-strengthening drugs

Two main types of bone-strengthening drug are used when breast cancer has spread to the bones. According to the NHS and Cancer Research UK, these drugs can reduce pain, strengthen the bones, lower the risk of fractures and help control a raised calcium level.

• Bisphosphonates (such as zoledronic acid, given as a drip, or ibandronic acid). These slow down the cells that break down bone, which helps protect and strengthen it.
• Denosumab, a targeted drug given as an injection under the skin. Cancer Research UK explains it may be offered to people who cannot have bisphosphonates, and it also helps strengthen the bones and reduce the risk of them breaking.

These drugs are usually given at intervals over a long period, alongside your other cancer treatment. A possible but uncommon side effect is a problem with the jaw bone called osteonecrosis of the jaw. Because of this, your team will usually advise a dental check-up before you start, and good dental care while you are on treatment. Calcium and vitamin D supplements are often recommended too. Tell your dentist that you are taking these drugs before having any dental work, and report any jaw pain, swelling or loose teeth to your team.

Managing pain, fractures and everyday life

Good pain control is a key part of care, and there is a lot that can help. Pain relief ranges from everyday painkillers to stronger medicines, and your team will adjust these to keep you comfortable. The NHS advises taking pain relief regularly, as prescribed, rather than waiting for pain to build up. Tell your team if your pain is not well controlled, as the plan can always be changed.

If a bone is weak or has broken, an orthopaedic surgeon may sometimes recommend an operation to fix or support it, for example by putting in a metal pin or rod. This can relieve pain and help you stay active and mobile. Physiotherapists and occupational therapists can also suggest aids and exercises to help you move safely and protect your bones.

Palliative care teams are experts in controlling symptoms such as pain and tiredness, and in supporting your wellbeing. Being referred to a palliative care team does not mean treatment is stopping; it simply adds extra support to help you live as well as possible. Many UK charities, along with your breast care nurse, can offer emotional support, practical advice and information for you and your family.

Charities like ours work to improve awareness, early detection and access to diagnosis and treatment, so that more people are diagnosed earlier and can get the support they need.