Most women who get breast cancer don’t have it in their family

  • 5 to 10% of breast cancer is hereditary and caused by mutations (changes) in genes.
  • Having one or more close relatives (sister, mother, daughter, or grandmother/aunt on either side) who have been diagnosed with breast cancer increases a woman's risk of getting the disease, particularly if more than one relative is affected, and the affected relative(s) were diagnosed at a young age. If this is the situation in your family or if you are concerned about any cancers in your family, talk to your GP.


The National Medical Genetics Centre, Crumlin, has information on hereditary breast cancer to download at

Irish Cancer Society. Action Breast Cancer.  Helpline: 1800 200 700

Breakthrough Breast Cancer has a good publication on Risk at which lists risk under the headings Established, Possible and Doubtful.

Download & print this guide

Irish Breast Cancer Charter9 things you should know about breast cancer (PDF 478KB)