Risk Factors

While the causes of breast cancer are largely unknown, medical research has identified a number of risk factors that can increase a woman’s chance of developing the disease.

Some women may have many breast cancer risk factors and never get the disease, while others who have no risk factors get the disease. However, understanding your risks for breast cancer will help you actively monitor your breast health to detect potential problems at an early stage. It’s important to note that risk factors do not cause breast cancer, nor do they predict whether an individual will get the disease.

Lifestyle-Related Breast Cancer Risk Factors

  • Alcohol consumption – the American Cancer Society recommends that women who drink have no more than one drink per day.
  • Not being physically active – evidence is growing that regular physical activity reduces breast cancer risk.
  • Being overweight or obese – being overweight or obese after menopause increases breast cancer risk.
  • Not having children – women who have not had children or had their first after the age of 30 have a slightly higher breast cancer risk overall.
  • Not breastfeeding – most studies suggest that breastfeeding may slightly lower breast cancer risk, especially if it’s continued for a year or more.
  • Birth control – some birth control methods use hormones, which might increase breast cancer risk.
  • Using combined hormone therapy after menopause might slightly increase breast cancer risk.

Source: American Cancer Society, 2019

Uncontrollable Breast Cancer Risk Factors

  • Being a woman
  • Getting older
  • Family history of breast cancer
  • Having the mutated breast cancer genes BRCA1 or BRCA2 or other genes linked to breast cancer
  • Personal history of breast cancer
  • Starting your period before age 12
  • Starting menopause after age 55
  • Breast density
  • Having certain benign breast conditions
  • Prior radiation to your chest
  • Exposure to diethylstilbestrol (DES)

Source: American Cancer Society, 2019