What causes breast cancer?

The changes may build up during a person's lifetime or be inherited. A BRCA gene mutation is one inherited factor that can raise the chance of breast cancer, but many people with breast cancer do not have a known inherited mutation. Hormone exposure, age, family history, and previous chest radiation may also be part of an individual risk assessment.

Ductal carcinoma in situ is a non-invasive change in cells lining a breast duct. It can be found before cells move into surrounding breast tissue. Breast cancer is not caused by a single choice or event, and having a risk factor does not mean cancer will develop.

Discuss your personal and family history with a clinician, especially if close relatives had breast or ovarian cancer, a relative developed cancer at a young age, or a known BRCA mutation is present in the family. Depending on your history, you may be offered screening advice or genetic counselling.

Become familiar with how your breasts normally look and feel. Arrange an assessment for a new lump, skin or nipple change, nipple discharge, or a persistent change in one breast. These findings have several possible causes and need examination rather than self-diagnosis.

Book a timely appointment for a new breast or underarm lump, skin dimpling, an inward-turning nipple that is new for you, bloody nipple discharge, or a persistent change in breast shape or texture. Seek urgent help for severe illness, rapidly spreading redness with fever, or sudden breathing difficulty.

Ask how your family history affects screening, whether genetic counselling is appropriate, and which breast changes should be examined. If you have a diagnosis, ask whether testing the tumour or inherited genes would change treatment or advice for relatives.