Previous cancer and other breast conditions

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.

Radiotherapy to the chest at a young age

Women who have had radiotherapy to the chest at an early age (for example to treat Hodgkin lymphoma) have an increased risk of breast cancer.

Back to Potential causes of breast cancer

Hormonal factors

Your exposure to the hormones oestrogen and progesterone can affect your risk of developing breast cancer.

Genetic factors

There are sometimes genetic links between cancers in the same family.