Breast cancer Breast cancer is the most common female cancer in the UK. It is very rare in women under 30, but for older women it becomes more common. Men can also develop breast cancer, but this is happens very rarely. Around one in nine women in the UK (11%) will develop breast cancer during their lifetime. About 39,000 women are diagnosed in the UK each year, and over 200 men. Most cases of breast cancer are not inherited (not caused by a faulty gene which has been passed down from generation to generation), but where a breast cancer gene is present it greatly increases the risk that that person will develop the disease. Men can carry the known breast cancer genes, but they are very unlikely to get ill. However, men can pass the gene on to their children. So far, scientists have identified two genes that are responsible for about 5 to 10% of breast cancer cases. They can also increase a person's risk of developing ovarian cancer. They are called BRCA1 and BRCA2. It is quite likely that more genes will be found in the future, but even then the vast majority of breast cancer cases will occur without a strong family history (without a genetic mutation having been passed down the generations)

Further information can be found on this page about: London IDEAS and breast cancer Information about breast cancer I have breast changes, what next? Diet and breast cancer Genetics and breast cancer Genetics, patients and their families Further information Common questions

London IDEAS and breast cancer

About 1 in 20 cases (5 %) of breast cancer has a genetic link. London IDEAS is carrying out several projects to improve access to breast cancer services and to enhance awareness of genetics in breast cancer among health professionals (particularly GPs, general practice nurses and midwives). You can find out more about our work here.

Information about breast cancer

There are several good websites and publications for information about breast cancer, its diagnosis and treatment.

Following these links will take you specifically to background information

Cancerbackup background information	Cancer Research UK background information	NHSDirect Online background information	Breakthough background information

I have breast changes – what next?

The first step is to see your GP, who will examine you. You will be referred to a breast cancer clinic if your GP thinks there is a possibility of cancer. If you have attended an NHS Breast Screening Programme, you will be referred in a similar manner if there is a suspicion of cancer.

Further information about what happens next can be read about in this website:

Breakthrough "I have breast changes"

To find out what is known about diet and prevention of breast cancer, follow these links:

Cancer Research UK diet and prevention	NHSDirect Online diet and prevention

Genetics and breast cancer

Most breast cancer cases are not inherited (not caused by a faulty gene that has been passed down from generation to generation). Only about 1 in 20 cases (5 %) involve an inherited genetic factor. Many other aspects of a woman's life can influence the development of breast cancer, such the age at which she has children. It is also thought that there are many other as yet unknown factors involved.

Two genes have been identified so far that increase the risk of developing breast, and to a lesser extent ovarian, cancer: BRCA1 and BRCA2. The child of a person with one of these genes has a 50:50 (1 in 2) chance of inheriting the same gene. Having one of these genes does not mean breast cancer will definitely develop, but it does mean the risk is much greater than for women who don't carry this particular genetic mutation.

Testing for cancer susceptibility genes is a two-step process: the specific gene variation ("mutation") in the family member with cancer must be found, then a predictive gene test can be offered to unaffected family members.

Genetics, patients and their families

The usefulness of genetic testing in cancer susceptibility genes is probably over-rated by both the general public and the medical profession and this has led to very high demand in UK genetics centres from patients wanting a genetic test.

Not everyone with a family history of breast cancer is in a "high risk" category, and therefore genetic testing is not suitable for the majority of people even with some family history.

If you only have one, or even two, elderly relatives who have had breast cancer, you are still not at significantly increased risk of getting breast cancer yourself. On the other hand, if your relatives were relatively young when they got cancer, or if there are cases of bilateral cancer (in both breasts), or of male breast cancer or breast and ovarian cancer in your family, you are likely to be at significantly increased risk.

Doctors seeing someone with a family history will decide whether they are at low, moderate or high risk:

• High risk families: two or more relatives with breast and/or ovarian cancer, at least one of which was relatively young when she got ill.

Members of these families are cared for by health professionals working in cancer genetics, breast care and primary care. They are offered genetic testing. However, in the majority of cases no mutation is picked up.

• Moderate risk families: might have a number of elderly relatives with breast cancer, or only one member with breast cancer who got ill when she was very young (under 45).

  Members of these families are cared for by the breast and primary care teams in the NHS. Patients are offered regular mammographs. Genetic testing is not normally necessary.

• Low risk families: might have one elderly member with breast cancer.

  Members of these families do not need further medical intervention, but it is important that any anxieties are discussed, and that individuals are reassured.

For further information about breast cancer genetics:

CancerBACUP is developing new information leaflets about genetics and cancer, and provides an overview about breast cancer genetics on its website:

Cancerbackup breast cancer genetics

Breakthrough breast cancer explains the issues that arise for people who are offered, or are considering, taking a genetic test:

Breakthrough genetic tests

Further information:

Cancerbackup cancer information service	Cancer Research UK reading list