Risk factors for breast cancer

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To date, we still do not know exactly what triggers breast cancer, but certain factors have been identified that are associated with an increased risk of developing the disease.

Woman growing older from childhood to old age

Age. This is the main risk factor linked to the onset of breast cancer. Risk increases with age.

Symbol of the woman and a clock representing the hormonal cycle

The hormonal cycles a woman experiences during her lifetime. Breast cancer development is affected by the action of hormones (oestrogens) on breast tissue. The early appearance of the first menstruation, a late menopause or the post-menopause use of hormone replacement therapy all increase the risk of breast cancer. Women who have never given birth (nulliparous) are also associated with a greater risk.

DNA molecule or helix

Family history. Individuals with a family history of breast cancer have a greater risk. This risk is greater when they are first-degree relatives (mother, sister or daughter).

Woman with a ribbon referring to breast cancer

Women who have previously had breast cancer or a benign proliferative breast disease have an increased risk of developing breast cancer in the future.


High breast density is associated with a greater risk of breast cancer.

Radiotherapy symbol

Exposure to ionising radiation, especially during puberty, and inherited mutations related to breast cancer both increase the risk.

Beer mug and wine glass

Alcohol consumption and obesity also escalate the risk of developing breast cancer.

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Substantiated information by:

Aleix Prat Aparicio
Ana Rodríguez García
Bárbara Ádamo
Montserrat Muñoz Mateu

Published: 20 February 2018
Updated: 20 February 2018

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