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.

Bone thinning

After the menopause, all women have an increased risk of bone thinning (osteoporosis). But after breast cancer, some women are at a greater risk. This is because breast cancer treatments can reduce the amount of oestrogen in the body and oestrogen helps to keep bones healthy and strong.

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 
  • hormonal therapy with aromatase inhibitors (anastrozole, exemestane or letrozole).

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. 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). These help 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 is some research evidence that bisphosphonates may help to prevent the risk of the cancer coming back in the bones (secondary bone cancer). Your doctor or specialist nurse can give you more information and may ask you to take part in a research trial.

What you can do to keep your bones healthy

Regular exercise, a healthy diet and stopping smoking can help to keep your bones healthy.


Exercise makes your bones stronger. Regular exercise that forces you to work against gravity (weight-bearing) is best. Good exercises to try include:

  • walking or hiking
  • climbing stairs
  • dancing
  • 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 and sardines) 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 about 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 treatments. Breast Cancer Care also has a helpful leaflet.

Radiotherapy damage to bones

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

Radiotherapy can reduce the blood supply to bones. This makes them thinner and increases the risk of a bone breaking, but this is very rare. If you have any symptoms, such as bone pain, always get them checked by your doctor. Usually the symptoms will be caused by something else.

Treatment can involve taking painkillers or anti-inflammatory drugs. Sometimes calcium supplements, vitamin D or bisphosphonates and antibiotics are given.

We have more information about managing cancer pain.

Pain in the joints (arthralgia)

Women taking aromatase inhibitors (such as anastrozole, letrozole and exemestane) may have joint pain and sometimes muscle pain. This 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 can also occur in 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.

Treatment for joint pain

Doctors can prescribe several different painkillers for joint and muscle pain. These include:

  • simple painkillers, such as paracetamol
  • anti-inflammatory painkillers, such as ibuprofen
  • opiate-based medicines, such as codeine or morphine for severe pain.

If the pain is difficult to cope with your doctor may suggest changing the type of aromatase inhibitor you take. If that doesn’t work, they may suggest switching to tamoxifen. Tamoxifen causes fewer problems with joint pain. 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 very good at reducing the risk of breast cancer coming back. You should not stop taking your treatment without first talking things over with your cancer specialist. There is 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.

Research has shown that regular exercise can help to strengthen the muscles around your joints. This can help to 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.

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. Remember, the needles should not be used on the arm of the affected side.

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 alter blood sugar levels, so may not be suitable for 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. Your doctor can prescribe drugs to help control the symptoms and look at other ways of improving them.

Try to keep active and do some regular gentle exercise.

If you’re having lots of problems with pain, a referral to a physiotherapist for advice and treatment is sometimes helpful. 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 (OT). 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.