Research is now going on – through clinical trials – to find out whether taking the drug Tamoxifen may protect some women against breast cancer. Tamoxifen is already used to help treat the disease.

At the moment there is no firm evidence that you can prevent breast cancer, but it is easier to cure if it is found and treated early. You can help yourself by checking your breasts each month for lumps or other changes, and telling your GP if you notice anything unusual.

These days, early breast cancer is often found when a woman goes for a breast screening test, as part of the NHS breast screening programme.

If you are a woman aged 50 or over you can have a test every three years. The test is an X-ray called a mammogram. It can detect many cases of early breast cancer, but it is not a foolproof test. Even if you go for breast screening you should still check your breasts each month, and tell your GP of any changes.

If you have close relatives who have had breast or ovarian cancer your GP may refer you to a genetics service. The service can work out whether you have an increased risk of breast cancer, and what might be done to help you – for example, some women may be offered regular breast screening tests from a younger age than normal.

•  Click here for information on cancer prevention in general