Breast cancer in families

Breast cancer is the most common cancer in women in the UK. So even if you have a relative with the disease it doesn't necessarily mean that you are more likely to get breast cancer yourself. Most breast cancers are not due to inherited (genetic) factors and do not affect the lifetime risk for other relatives.

In relation to the level of risk, breast cancer in families can usually be classed in one of three groups, and you may hear these groups referred to in a number of different ways:

• average risk (also called sporadic or near population risk)
• moderate risk (also called familial/raised risk)
• high risk (also called hereditary/increased risk).

If you’re concerned about your risk of developing breast cancer it’s important that you get professional advice tailored to you and your family. By getting details of your family history, health professionals can assess whether or not your risk of breast cancer is higher because of your family history and whether any further action is needed.

What is a significant family history?

A family history looks at the past and present illnesses of your blood relatives (those related to you by birth not marriage) over several generations. When recording your family history your maternal and paternal families should be seperated.

A family history may be described as significant only where there are, on the same side of the family:

• two or more close relatives who have had breast cancer
• one or more close relatives who have had breast cancer before the age of 40
• close relatives who have had breast cancer and others who have had ovarian cancer
• one close relative who has had breast cancer in both breasts (bilateral) or who's had breast and ovarian cancer
• a male relative who's had breast cancer
• an ethnic background where faulty breast cancer genes are more common – for example, people with Ashkenazi Jewish ancestry.

OPERA - Online Personal Education and Risk Assessment

You might also want to have a look at Macmillan Cancer Support's online tool for assessing you risk of inherited breast cancer on their website.

How you might feel

If you are found to have an average risk of developing breast cancer you may feel reassured and relieved. However, it's important you go back to your GP if your family history changes or if you have concerns about your own breasts.

If you have a moderate or high risk of developing breast cancer, this can cause you to feel anxious or afraid as you approach the age at which a relative was diagnosed. You may also become concerned about the health of your children or have new anxieties about having children.

All cancer genetics clinics have genetic counsellors who you can talk to about how you're feeling.

Visit the Genetic Cancer Prediction through Population Screening (GCaPPS) website for information on a research study evaluating a genetic test for the general population to help identify those at high risk of inheriting breast cancer. Please note, this trial is for anyone over 18 whose grandparents are or were of Ashkenazi Jewish decent.