Bisphosphonates for primary breast cancer

Bisphosphonates are drugs that are used for a number of reasons.

For treating primary breast cancer

For primary breast cancer, bisphosphonates may be used to reduce the risk of breast cancer spreading to the bones and other parts of the body.

Zoledronic acid, which you may hear called by the brand name Zometa, is the bisphosphonate most commonly used in primary breast cancer.

Other uses of bisphosphonates

In addition to being used in primary breast cancer, zoledronic acid and other types of bisphosphonates may also be prescribed:

• For people who are at risk of, or who have, osteoporosis
• As treatment for secondary breast cancer in the bone

Bisphosphonates slow down or prevent loss of bone tissue. You may hear these drugs called bone-strengthening treatment.

In all our bodies, whether or not we have cancer, bone tissue breaks down over time and is replaced with new bone tissue. This is a natural process called bone remodelling.

Cancer cells seem to be drawn to areas where bone remodelling is taking place, so secondary breast cancer commonly affects the bones (as well as the lungs, liver and brain).

Bisphosphonates work by being absorbed in areas of the body where there is a lot of bone remodelling. This interferes with the remodelling process, so may reduce the risk of breast cancer spreading to the bones and elsewhere in the body.

Bisphosphonates are prescribed for women who have been through the menopause (post-menopausal women). They can be given regardless of whether the menopause has occurred naturally or because of breast cancer treatment.

The benefits of using these drugs before the menopause are less clear.

Bisphosphonates are usually prescribed for women who have had treatment for invasive breast cancer that has spread to the lymph nodes under the arm.

They may also be prescribed when women don’t have cancer in their lymph nodes but other factors increase the risk of cancer returning.

Bisphosphonates for primary breast cancer are usually started within 3 months of final surgery.

If you are having chemotherapy after surgery, you will usually start taking a bisphosphonate within 2 months of completing chemotherapy.

The bisphosphonate you’re given depends on what your treatment team suggest and what your preferences are.

The treatment will continue for around 2 to 3 years.

Zoledronic acid is given as a drip into a vein in your hand or arm (intravenously). It can be given every 6 months for 3 years or every 3 months for 2 years.

Like all drugs bisphosphonates have some side effects. Your treatment team will explain them to you.