1. What is osteoporosis?
Osteoporosis is a condition where your bones lose their strength and thickness (density). This leads to bones becoming weaker and more likely to break (fracture).
Generally, osteoporosis causes no pain or symptoms, so often a person will not realise they have the condition until a fracture happens. The most common sites for a fracture are the wrist, hip and back (spine).
Although osteoporosis cannot be cured, treatments are available to try to keep the bones strong and less likely to fracture.
2. Breast cancer treatment and bone health
Some breast cancer treatments can increase your risk of osteoporosis.
Other things can also increase your risk of osteoporosis, including:
- Menopause
- Getting older
- Previous bone fractures
- Low body weight
- Having lower oestrogen levels due to breast cancer treatment
- Having a family history of osteoporosis
- Pre-existing medical conditions such as Crohn’s disease, coeliac disease, ulcerative colitis, overactive thyroid (hyperthyroidism) and diabetes
- Drinking too much alcohol
- Smoking
- Long-term medications used to treat arthritis or asthma (glucocorticoid steroids), or epilepsy (anticonvulsants)
Aromatase inhibitors
Aromatase inhibitors reduce the amount of the hormone oestrogen made in the body. This can reduce bone density and lead to osteoporosis. This can also increase the risk of fractures.
Aromatase inhibitors are usually used to treat breast cancer in postmenopausal women (when your periods stop).
Some women who still have periods (premenopausal) take aromatase inhibitors at the same time as having ovarian suppression. Having these 2 treatments together can reduce bone density.
See “Treatment to reduce your fracture risk” below for information on ways to reduce bone density loss.
Tamoxifen
Tamoxifen blocks the effect of oestrogen on breast cancer cells.
Tamoxifen may slightly increase the risk of osteoporosis for premenopausal women. This is unlikely to lead to osteoporosis, unless you’re given ovarian suppression (see below) as well.
However, your risk may be higher if you’re 45 or under and your periods have stopped for at least a year.
In postmenopausal women, taking tamoxifen slows down bone loss and can reduce the risk of osteoporosis.
Chemotherapy
can cause changes in the ovaries, which can lead to an early menopause. This means less oestrogen is produced, which can reduce bone density.
If you’re 45 or under and haven’t had a period for at least a year as a result of chemotherapy, you may also be at risk of osteoporosis, even if your periods restart.
Research has shown that postmenopausal women who have chemotherapy may lose more bone density than they would have without chemotherapy.
Ovarian suppression
Ovarian suppression describes treatments that stop the ovaries from making oestrogen, either temporarily or permanently. Having less oestrogen in the body can reduce bone density.
You can find more information and download a fact sheet about breast cancer treatments and osteoporosis on the Royal Osteoporosis Society website.
3. Assessing your risk of osteoporosis
Bone density scan (DEXA)
If your treatment team is concerned about your risk of developing osteoporosis and fractures, they may suggest a dual energy x-ray absorptiometry (DEXA) scan to check your bone strength before you start hormone treatment.
A DEXA scan measures bone mineral density (BMD). BMD is the amount of calcium and other minerals in an area of bone and is a measurement of bone strength. The lower your BMD, the more likely you are to be diagnosed with osteoporosis.
A DEXA scan uses a very small amount of radiation. While you are lying down, an open x-ray scanner will pass over your body taking pictures of your hips and sometimes lower spine. The scan takes around 20 minutes.
Your results will include a T score. The T score measures how your BMD compares to a range of young healthy adults with average BMD.
The BMD score ranges:
- T score above -1 is normal
- T score between -1 and -2.5 is classified as osteopenia (see below)
- T score at or below -2.5 is defined as osteoporosis
Find out more about DEXA scans on the Royal Osteoporosis Society website.
If you’re diagnosed with osteoporosis, your treatment team will advise you about any treatments you’ll need. They will also give you guidance on any changes to your diet or lifestyle that may be helpful.
Should I have a DEXA scan?
Most people starting on an aromatase inhibitor will have a DEXA scan to check their bone density. Your treatment team will tell you whether you need to have a DEXA scan and when this will be.
If you have bisphosphonates as part of your treatment plan, you will not need to have a DEXA scan. This is because bisphosphonates are a treatment for osteoporosis.
If you have tamoxifen, you will not need to have a DEXA scan unless you have other risk factors. This is because tamoxifen does not cause significant changes to bone density.
Follow-up DEXA scans may be repeated after 2 to 5 years for some people.
However, if you're taking bisphosphonates, don't have side effects and have not had any fractures while taking it, then it is likely the drug is working. If this is the case, you will not need regular DEXA scans.
How often you need a DEXA scan will depend on your individual situation. Your treatment team will discuss this with you.
Diet and breast cancer: Why is a balanced diet important?
Learn about what makes up a healthy, balanced diet and how you can eat healthily during and after breast cancer treatment.
Osteopenia
A DEXA scan may show you have decreased bone density, but not enough to be classed as osteoporosis. This is called osteopenia.
If you have osteopenia, you may have a higher risk of fractures. Some people with osteopenia will go on to develop osteoporosis, but osteopenia does not always lead to osteoporosis.
If you have osteopenia with no other risk factors, you will be given advice about changes you can make to your lifestyle such as diet and exercise. You may also be advised to stop or cut down smoking and limit your alcohol intake. You won’t usually need treatment.
Find out more about looking after your bones and eating a healthy diet.
If you have osteopenia and you are taking an aromatase inhibitor, you may be given treatment to reduce your risk of fracture. Your treatment team will discuss this with you.
Fracture risk assessment
Research has shown that your risk of breaking a bone (fracture risk) can be assessed by including other risk factors, such as:
- Your age
- Family history of hip fractures
- Whether you have had a fracture in the past
Some people are more at risk of fracture than others. Lifestyle changes and treatments to strengthen your bones can reduce your risk.
4. Treatment to reduce your fracture risk
Osteoporosis cannot be cured, but treatments are available to try to stop bones losing more density and to make them less likely to fracture.
You will be advised about any appropriate drug treatment and its possible side effects.
The Royal Osteoporosis Society website has more information on drugs to prevent and treat osteoporosis.
Supplements
Your treatment team may recommend a calcium and vitamin D supplement.
You may be prescribed a tablet that contains both, such as Adcal D3.
Bisphosphonates
Bisphosphonates are usually given to treat osteoporosis in people who have had breast cancer.
Common bisphosphonates include:
- Alendronate
- Zoledronic acid
- Risedronate
- Ibandronate
Bisphosphonates help strengthen your bones and reduce your risk of fractures. They can be given as a tablet or as an injection into the vein.
You may also be prescribed bisphosphonates to protect your bones if you’re taking an aromatase inhibitor, such as exemestane, letrozole or anastrozole.
Bisphosphonates may be used as a treatment to reduce the risk of primary breast cancer spreading. They are also sometimes given as a treatment for metastatic (secondary) breast cancer in the bone. This is not the same as having osteoporosis.
Denosumab
Denosumab slows down bone loss in osteoporosis and may be recommended to reduce your risk of fractures.
It's given as an injection twice a year.
It’s a treatment for postmenopausal women who are unable to take certain bisphosphonates. Denosumab is also sometimes given as a treatment for metastatic (secondary) breast cancer in the bone.
Raloxifene
Raloxifene is given to prevent and treat osteoporosis in postmenopausal women. Raloxifene is only prescribed for women after they have completed their breast cancer treatment.
Teriparatide
Teriparatide is usually only recommended if you are unable to have bisphosphonates or denosumab. It may be suggested if you have a very high risk of fracture, particularly of the spine.
5. Further support
For more information and support on looking after your bones during treatment, you can call our free helpline – see below for ways to get in touch.
You can also find more information about osteoporosis and bone health on the Royal Osteoporosis Society website.
