There are several options for women who have been found to be at an increased risk of developing breast cancer. These include:

Regular breast screening

This involves regular breast examinations, mammography (breast x-rays) and/or MRI scans (a scan that uses a magnetic field to build up a picture of the breasts). Such examinations help to find breast cancer early but they do not prevent it.

Breast cancers found at an early stage are often curable. The UK’s National Institute for Health and Clinical Excellence (NICE) is an independent body that gives guidance to doctors on the prevention and treatment of ill health. NICE’s Familial Breast Cancer Guideline recommends that women are offered yearly mammograms if they are aged 40 to 49 and have an increased risk of developing breast cancer. A recent study found that MRI screening was almost twice as effective as mammography in detecting breast cancer in women in this group. The NICE Guideline also recommends that MRI scans should be available to some women under the age of 50 who are at increased risk of developing breast cancer, depending on their family history and level of risk.

To find out more about early detection and screening, you may find it helpful to read our section on breast screening.

Taking part in research trials

There are trials that are looking into whether drugs (eg tamoxifen, anastrozole or raloxifene) can reduce the risk of developing breast cancer. However, some of these trials may not be suitable for all women.

Details of current research trials can be found on our trials section, by searching for cancer type 'breast' with 'prevention' in the text. So far, a drug that will reliably prevent breast cancer without causing too many side effects has not been found. However, research is continuing and it is certainly worth discussing with your doctors the benefits and disadvantages of taking part in such research.

Risk-reducing mastectomy

The subject of this section.

National UK guidance on familial breast cancer says that surgery to reduce the risk of breast cancer is only appropriate for a small proportion of women who are from high-risk families. Such surgery should be managed by a team of health professionals.

Women who may wish to consider this type of surgery include those:

• with a strong family history of breast cancer – especially if the breast cancer was diagnosed among several close blood relatives on the same side of the family (eg grandmother, mother, or sisters, and before the age of 50)
• who have a positive test for the BRCA1 and BRCA2 gene mutations/changes
• with a personal history of breast cancer and a high risk of recurrence (eg a woman may have already had breast cancer in one breast and there may be concern about risk of cancer in the other breast)
• who are at increased risk of breast cancer and also have breast microcalcifications (tiny calcium deposits) or have very dense breast tissue, which makes it difficult to detect breast cancer with mammography.

It is important to remember that not all women who are at increased risk of developing breast cancer will actually develop it. Some women who choose to have risk-reducing mastectomy may never have developed breast cancer. However, there is no way of knowing whether an individual woman will develop breast cancer or not. For some women, having mastectomy relieves their anxiety and their fear of developing breast cancer.

It is impossible for surgeons to remove every single breast cell during mastectomy and this depends to some extent on the type of mastectomy done. Usually about 90–95% of the breast tissue is removed.

A research study recently showed that bilateral risk-reducing mastectomy leads to a 90% reduction in the risk of breast cancer in women who have mutations in the BRCA1 and BRCA2 genes. Other earlier studies showed the same. So risk-reducing mastectomy significantly reduces but does not completely get rid of the risk of breast cancer.

Some experts believe that the chance of developing breast cancer after total mastectomy or skin-sparing mastectomy is actually less than 10%. This means that after having a risk-reducing mastectomy, a woman’s chance of developing breast cancer may actually be less than that of a woman in the general population.

Breast cancers in women who carry breast cancer gene changes/mutations usually occur at a younger age than usual. So, the younger you are when you have risk-reducing surgery, the more likely it is to prevent a breast cancer.

However, this is a very individual decision and the potential benefit of risk-reducing surgery must be balanced with other issues such as:

• How anxious you feel about the possibility of getting breast cancer and the impact it would have on your life.
• Plans for having children and being able to breast feed (breast-feeding can reduce your risk of breast cancer).
• Your age. Breast cancer is very rare in teenagers. Your genetic specialist can advise you about how the risk level changes with age.

It is also important to bear in mind that the fitter you are, the less likely it is that there will be complications following surgery. Also, some methods of reconstructive surgery would not be recommended if you have certain medical conditions (eg diabetes, high blood pressure), or if you are a smoker – so this may affect your options.

When to have surgery of this type is a very personal choice; discussing the above points with your breast surgeon and breast care nurse might help you to make the decision. Your genetic counsellor or breast surgeon may also be able to give you an estimate of your chance of developing breast cancer over the next 5–10 years versus your risk of developing it over your whole lifetime, which might help you reach a decision.