Your risk is increased if you have had breast cancer before. This includes ductal carcinoma in situ. Having the following breast conditions can also increase your risk:
- Lobular carcinoma in situ (LCIS).
- Atypical ductal hyperplasia – there are slightly abnormal cells in the milk ducts in a small area of the breast.
- Dense breast tissue – when the breast is mostly made up of glandular and connective tissue and has very little fatty tissue.