Family History of Breast Cancer
Breast cancer is a malignancy of the breast, usually involving the ductal or lobular tissue (the tissue involved in milk production). A small percentage of breast cancers tend to cluster in families. These cancers can be caused by mutations in particular genes, such as BRCA1 and BRCA2. In some cases, genetic syndromes involving other cancers also include an increased risk of breast cancer, such as uterus, ovary, colon or prostate cancer.
Breast cancers caused by inherited gene mutations tend to occur earlier in life than non-inherited cases and are more likely to involve both breasts. A woman’s risk of breast cancer is higher if female relatives have had the disease, especially if they were a first degree relative and under 40 years of age at diagnosis. However, only about 5 -10% of all breast cancers are caused by family history and 1% by genetic mutations. 
If you are concerned about a family history of breast cancer (of one or more first degree relatives under the age of 50 diagnosed with breast cancer or other cancers such as uterus, ovary, colon or prostate cancer) you should discuss this with your GP. Your doctor may then if appropriate decide to refer you to the breast clinic for further assessment. Family History Guidelines for G.P.s
At the Breast Clinic, the doctor will take a detailed family history and discuss with you the future steps which may need to be taken with regards to further observation. This could include yearly clinical examinations, mammography, possible MRI and genetic testing of you or your relatives.
If you or your relatives undergo genetic testing, and it proves that there is a genetic risk for breast or other types of inherited cancer, you and your doctor can discuss the future options for you and your family members.
If your family history appears to significantly increase your risk of breast cancer you may be referred for genetic counselling to National Centre for Medical Genetics whose staff hold clinics in Galway at regular intervals throughout the year.