Result card

  • CUR3: Which are the known risk factors for acquiring the condition?
English

Which are the known risk factors for acquiring the condition?

Authors: Sarah Baggaley, Massimo Gion

Internal reviewers: Luciana Ballini, Aurora Llanos, Antonio Migliore, Claudia Wild

The information used for this section was from cancer research charity websites.

The known risk factors that affect the incidence of breast cancer include:

  • Age

Age is the strongest risk factor for breast cancer (after gender): the older the woman, the higher the risk.

  • Reproductive history
    • Age at menarche: Early age at menarche has been consistently associated with an increased risk of breast cancer.
    • Age at first birth: The younger the woman, the lower the risk of breast cancer.
    • Parity: Childbearing reduces the risk of breast cancer. The higher the number of full-term pregnancies, the lower the risk.
    • Breastfeeding: Women who breastfeed have a lower risk of breast cancer compared with women who do not breastfeed.
    • Age at menopause: Late menopause increases the risk of breast cancer.
    • Oral contraceptives: The use of oral contraceptives increases the risk of breast cancer. There is no increased risk 10 years after stopping the use of oral contraceptives.
    • Hormone replacement therapy (HRT): Women who take HRT have an increased risk of breast cancer compared with those who do not. The risk increase is temporary and diminishes within 5 years of stopping the use of oral contraceptives.
  • Previous breast disease

Women with a history of benign breast disease and women who have received treatment with radiation therapy to the breast or chest can have an increased risk of breast cancer. Women with a previous diagnosis of breast cancer have an increased risk of developing a second primary breast tumour.

  • Family history

Breast cancer is higher among women whose close relatives have, or have previously had, breast cancer. Having a first-degree relative (mother or sister) with breast cancer approximately doubles a woman’s risk.

It is estimated that 5–10% of breast cancers are hereditary, resulting from gene mutations inherited from a parent. Inherited mutations in the BRCA1 and BRCA2 genes are the most common cause of hereditary breast cancer. Women with a mutation in either gene are at high risk of developing breast cancer in their lifetime, often at a younger age and in both breasts compared with women without a BRCA mutation.  

  • Lifestyle factors                                                      
    • Being overweight or obese: Women with a high body mass index (BMI) have an increased risk of breast cancer, particularly post-menopausal women.
    • Physical activity: Evidence is developing that exercise reduces the risk of breast cancer, with the strongest association shown for post-menopausal women.
    • Alcohol consumption: The consumption of alcohol is linked to an increased risk of developing breast cancer and the risk increases with the amount consumed.
    • Diet: There is some evidence that a high intake of saturated fat is linked to an increased risk of developing breast cancer.

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Important
Completely
Baggaley S, Gion M Result Card CUR3 In: Baggaley S, Gion M Health Problem and Current Use of the Technology In: Jefferson T, Vicari N, Raatz H [eds.]. Prognostic tests for breast cancer recurrence (uPA/PAI-1 [FEMTELLE], MammaPrint, Oncotype DX ) [Core HTA], Agenzia nationale per i servizi sanitari regionali (age.na.s), Italy ; 2013. [cited 2 December 2022]. Available from: http://corehta.info/ViewCover.aspx?id=113

References