Effects on the bones and joints

Treatments for breast cancer can increase the risk of bone thinning (called osteoporosis) or cause joint problems. This is because some treatments reduce the level of oestrogen, which helps keep bones strong. For example, chemotherapy can cause an early menopause, which reduces oestrogen. Some hormonal therapies cause a temporary or permanent menopause.

Joint stiffness and pain are common side effects of aromatase inhibitor drugs (AIs). These are a type of hormonal therapy. They reduce the risk of breast cancer coming back so it’s very important to keep taking them. Your doctor can prescribe drugs to control joint pain or change you to a different AI if you have difficult side effects.

You will have a scan to check your bones before and sometimes during treatment with an AI. Some women are prescribed bone-strengthening drugs to protect their bones.

You can help to look after your bones by:

  • taking regular physical activity, such as walking or gentle weight-lifting
  • eating a balanced diet with plenty of calcium and vitamin D
  • not smoking and sticking to sensible drinking guidelines.

Effects on the bones

Oestrogen helps to keep bones healthy and strong. All women have an increased risk of bone thinning (osteoporosis) after menopause. But after breast cancer, some women are at a greater risk because some cancer treatments increase the risk of bone thinning.

Rarely, radiotherapy weakens the bones in the treatment area, such as the ribs and collarbone.


Bone thinning

The following treatments for breast cancer can increase the risk of bone thinning:

  • chemotherapy, if it brings on an early menopause
  • stopping the ovaries from working by removing them or by giving radiotherapy, or using drugs called LHRH analogues, such as goserelin (Zoladex®)
  • hormonal therapy with aromatase inhibitors.

Before treatment with an aromatase inhibitor, national guidelines recommend that women have their bone health (density) checked by a DEXA scan using a very low dose x-ray. DEXA is short for dual energy x-ray absorptiometry.

These scans only take about 15 minutes. You lie on a couch while the scan is done. There are no injections involved and you don’t have to undress, as long as there aren’t any metal fastenings, such as zips, in the area to be scanned.

Your bone density can be monitored during and after treatment. Depending on the results, you may be prescribed calcium and vitamin D supplements and/or bone strengthening drugs (bisphosphonates) to minimise the risk of problems. If you have a history of osteoporosis in your family, ask your cancer specialist about using bisphosphonates to help prevent osteoporosis. There are also things you can do to protect your bones.


What you can do

Taking regular exercise, eating a healthy diet and stopping smoking can help to keep your bones healthy. Look at our section on effects on the heart for advice on stopping smoking and the benefits of exercise and healthy eating.

Exercise makes your bones stronger. Regular exercise that forces you to work against gravity (weight-bearing) is best. For example, walking, climbing stairs, dancing, hiking and gentle weight-lifting. Swimming isn't so helpful, as your bones aren't supporting your weight while you swim. If you already have osteoporosis, avoid exercises that put too much strain on your bones, such as jogging.

A physiotherapist or your breast care nurse can give you further advice about exercise after breast cancer.

It's important to make sure that you get enough calcium and vitamin D in your diet. Low-fat dairy products, eggs, green leafy vegetables, nuts, and whole fish (such as whitebait, sardines, and pilchards) are good sources of calcium. Vitamin D is essential to help the body absorb calcium. It's found in oily fish, eggs and food with added vitamins but we mainly get it from sunlight.

Most people get enough vitamin D by getting out and about in the summer months. If you have naturally dark skin, you need more sunlight to make vitamin D because of the pigment in your skin.

A well-balanced diet and exposure to enough sunshine will usually give you all the calcium and vitamin D you need. If you're not getting enough calcium or vitamin D, taking supplements may be helpful. Your specialist can advise you on this.

Drinking too much alcohol can interfere with the balance of calcium in your body so stick to sensible drinking guidelines.

The National Osteoporosis Society can give you more information about the prevention of osteoporosis and can inform you about helpful treatments.

Breast Cancer Care also has a helpful leaflet.


Radiotherapy damage to bones

Rarely, radiotherapy results in a reduced blood supply to bones in the treatment area (ribs and collarbone). This makes them thinner and increases the risk of a bone becoming infected or breaking, but this is very rare. If you have any symptoms, such as pain, always get them checked by your doctor, but there will usually be a simpler cause.

Treatment can involve taking painkillers or anti-inflammatory drugs. Sometimes calcium supplements, vitamin D, or bisphosphonates and antibiotics are given. Rarely, if the bone is damaged, treatment involving high pressure oxygen (hyperbaric oxygen therapy) may help the bones to repair or surgery may be done to remove damaged ribs.

We have more information about controlling cancer pain and about hyperbaric oxygen therapy.


Pain in the joints (arthralgia)

Women taking aromatase inhibitors (such as anastrozole, letrozole and exemestane) may have joint pain, which is probably caused by a fall in oestrogen levels. Joint pain is also a common symptom of the menopause.

Pain is most common in the hands and feet but may also affect the knees, hips, lower back and shoulders. It may be there all the time or come and go. Some women notice that their joints are stiffer in the morning when they first get up.

If you've recently started taking an aromatase inhibitor, the pain may settle over the next few months as your body adjusts to changes in hormone levels. Doctors can prescribe several different painkillers for joint and muscle pain. These range from simple painkillers such as paracetamol; to anti-inflammatory painkillers such as ibuprofen; to opiate-based medicines, such as codeine; or for severe pain, morphine.

If the pain is difficult to cope with, switching to a different type of aromatase inhibitor may be effective. If that doesn't work, switching to tamoxifen, which causes fewer problems with joint pain, usually helps most women. There is evidence that after taking an aromatase inhibitor, switching to tamoxifen doesn't increase the risk of breast cancer coming back.

Aromatase inhibitors are effective in reducing the risk of breast cancer coming back. It's important not to stop taking them without talking things over with your cancer specialist. There's usually something that can be done to improve the pain.

Small studies suggest that for women with lower levels of vitamin D, taking vitamin D3 supplements may improve symptoms. Talk it over with your doctor before taking a supplement.

Small studies have also found that acupuncture may help to reduce pain from joint symptoms. Some hospitals and primary care practices offer acupuncture on the NHS.

Research is going on to discover if a drug called glucosamine, often used to treat arthritis, may help some women. You can buy this over the counter in health shops and pharmacies, but it's not suitable for everyone. It may affect blood sugar levels, so may not be suited to people with diabetes. Talk to your GP or cancer specialist before taking it.


What you can do about joint problems

It's important to let your doctors know if joint or muscle pain is a problem for you. Don't stop taking your hormonal therapy without discussing it with your cancer specialist. Hormonal therapy is an effective treatment that reduces the risk of breast cancer coming back. Your doctor can prescribe drugs to help control the symptoms and look at other ways of improving them.

Regular exercise can help to strengthen the muscles around your joints, keep them flexible and reduce pain. Non-weight bearing exercises, such as swimming and cycling, may feel less uncomfortable and will help keep your joints healthy.

If you're having lots of problems, a referral to a physiotherapist for treatment and advice is sometimes helpful and your doctor can arrange this for you. If you're having difficulty carrying out daily tasks, you can ask to be referred to an occupational therapist. They'll be able to assess your needs and recommend aids and equipment to help you.

Some women find complementary therapies such as massage helpful. Some hospitals offer massage on the NHS.