Breast Cancer Risk Factors | Age, Genetics, Lifestyle, Family History

Breast Cancer Risk Factors

Breast Cancer Risk Factors

Breast cancer doesn’t have just one cause. It is a complex disease resulting from interactions between our genes, lifestyle and the environment.

Understanding breast cancer risk

Anything that increases a person’s chances of developing a disease is called a risk factor. Having many risk factors does not mean you will develop breast cancer, whilst having fewer risk factors will not definitely prevent the disease.

What can I do?

We can’t control some breast cancer risk factors e.g. gender and age. But there are risk factors you can influence such as lifestyle choices, as well as being breast aware, and attending routine screening appointments when invited to do so or requesting appointments from age 70.

Established risks

There is strong scientific evidence that these factors can increase your risk of developing breast cancer:

Being female

• Over 99 per cent of cases per year are in women.


• Over 80 per cent of breast cancer is diagnosed in women over the age of 50.

Family history

• A significant family history of breast cancer.

Breast density

• Having high breast density increases your risk of breast cancer. 

Lifestyle factors

• Alcohol
• Being overweight
• Not exercising.

Not having children

• Not having children or having them after 30
• Not breast feeding.

Additional female hormone exposure

• Taking the contraceptive pill
• Having hormone replacement therapy (HRT)
• Starting the menopause late and/or early periods.

Radiation exposure

• Hodgkin’s lymphoma treatment.

Other established risks

• A previous breast cancer diagnosis
Ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS)
• Some non-cancerous breast diseases
• Ethnic group
• Being taller.

Possible risks

Factors that might affect your breast cancer risk, but for which there is no conclusive scientific evidence:

  • Diet
  • Diabetes
  • Diethylstilboestrol (DES)
  • Night shift work
  • Smoking
  • Stress
  • Having uneven breasts

Read more about possible risk factors for breast cancer

Doubtful risks

Factors that are not thought to affect your breast cancer risk:

• Deodorants and anti-perspirants
• Having an abortion
• Breast implants
• Injury to the breast
• Pesticides or other pollutants

Read more about doubtful risk factors for breast cancer


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