Bone health and osteoporosis

What is osteoporosis?

Bone health is important throughout life. It becomes more important as we get older or if illness and medical treatment causes bone problems. After the age of 35, bone loss increases as part of the natural ageing process and this in itself can lead to a condition called osteoporosis.

Osteoporosis literally means porous bones. This condition leads to changes in the structure of the bones, leaving them more fragile and susceptible to breaking.

Osteoporosis is often not found until the time of the first fracture. The wrist, hip and spine are common sites where fractures occur. Although osteoporosis cannot be cured, treatments are available to try and help keep bones strong and less likely to break.

Who is at risk?

Osteoporosis affects one in two women and one in five men over the age of 50, but can affect people of all ages.

Some risk factors are:

• low levels of oestrogen due to natural early menopause, cancer treatment, early hysterectomy and removal of the ovaries or the eating disorder anorexia nervosa
• a parental history of osteoporosis
• long-term use of corticosteroid tablets used in the treatment of arthritis and asthma for more than six months
• medical conditions that affect the absorption of foods, such as Crohn's disease, coeliac disease or ulcerative colitis
• conditions that leave you immobile for long periods of time
• low body weight
• increased alcohol intake (three or more units a day) or smoking
• a diet that is low in calcium, for example a dairy-free diet.

Breast cancer treatment and bone density

Bone density refers to the amount of calcium and minerals in an area of bone and is a measurement of bone strength. Oestrogen is important for maintaining bone density and strength.

Pre-menopausal women who have been treated for breast cancer may be at an increased risk of developing osteoporosis due to chemotherapy and ovarian ablation and suppression which can cause early menopause and therefore a rapid reduction in oestrogen levels.

Aromatase inhibitor drugs - including anastrozole (Arimidex), letrozole (Femara) and exemestane (Aromasin) - are used for women who have been through the menopause (post-menopausal women). These drugs carry an increased risk of osteoporosis, but this depends on how healthy a woman’s bones were before they had breast cancer treatment. People who had good bone density levels before having breast cancer treatment are not thought to have such an increased risk of osteoporosis while taking this treatment.

Your specialist may want to check your bone density before you start taking aromatase inhibitors and you may also require additional bone density scans during your treatment. Depending on these scan results, you may be prescribed calcium and vitamin D supplements and /or bone-strengthening medication (bisphosphonates). These strengthen existing bone by slowing down the process of bone breakdown while allowing the production of new bone as normal. Lost bone cannot be replaced but bisphosphonates can strengthen existing bone and reduce the damage caused by osteoporosis.

Bisphosphonates are also used to treat breast cancer that has spread to the bones (secondary breast cancer in the bones). This is not the same as osteoporosis.

The drug tamoxifen works in a different way to aromatase inhibitors. Because of this, it may have a beneficial effect on the bones in post menopausal women. However in pre-menopausal women (women who haven’t been through the menopause), taking tamoxifen may slightly increase bone loss. This would not be expected to lead to osteoporosis unless you have been given additional treatments to stop your ovaries working.

What if you think you have osteoporosis?

If you are concerned about osteoporosis, talk to your specialist team or GP. They may refer you for a bone density scan to check the condition of your bones. Should you have osteoporosis there are ways to manage it.

Osteoporosis in people who have had breast cancer is commonly treated with bisphosphonates. These drugs may also be prescribed alongside an aromatase inhibitor to protect against the possible effects on the bones.

Bisphosphonates are also used to treat secondary breast cancer in the bone, however this is not the same as having osteoporosis.

If you are found to have osteoporosis, you will be advised about any drug treatment that is necessary, and will be given guidance on any changes to your diet or lifestyle that may be helpful.