Breast Cancer Risk Factors

Most women who develop breast cancer do not have any risk factors, other than being a woman and getting older. Because of this, all women are at risk and need breast cancer screening at appropriate ages. The most important breast cancer risk factor is age, and the risk increase with age. Women in their 30s and 40s can get breast cancer – and should be checked regularly, especially if they have major risk factors. Most women who develop breast cancer, however, are in their 50s, 60s and older. [graph of breast cancer risk and age]

Major Risk Factors

Women with one or more of the following major risk factors should have a discussion with their physician about beginning routine cancer screening (with mammography and/or MRI) earlier than age 40:

  • Personal history of breast cancer. Women who have had breast cancer face increased risk for a second breast cancer.
  • Family history of breast and/or ovarian cancer, especially if the cancer is in your mother and sister, and if their cancer occurred at a young age (younger than age 50).
  • A known genetic mutation in your family.
  • Having radiation treatment to the chest area for a prior cancer.

Minor Risk Factors

Some of these minor risk factors, such as drinking alcohol, can be avoided, but most, such as a family history of breast cancer, cannot. These risk factors are considered to only slightly raise breast cancer risk.

  • Beginning menstruation at an early age
  • Older age at birth of first child, or never having given birth
  • Personal history of some types of non-cancerous (benign) breast disease
  • Breast tissue that appears dense on mammogram
  • Taking hormones such as estrogen and progesterone
  • Drinking alcohol
  • Being overweight; a sedentary lifestyle
  • Being Caucasian (all women still need screenings)
  • Family history in older (older than age 60), distant relatives (such as grandparents, cousins)

The National Cancer Institute’s online Breast Cancer Risk Assessment Tool can calculate your estimated risk for developing breast cancer.