Risk Factors and Prevention

At this time, scientists believe that breast cancer is caused by a combination of both known and unknown factors including genetics (such as family history of breast cancer), lifestyle choices (such as diet and alcohol use) and reproductive factors (such as age of menarche and menopause). The two most significant risk factors are being female and getting older. The majority of women diagnosed with breast cancer have no other known risk factors.

So far, researchers know of more than 20 factors that increase the risk of breast cancer. Some of these risk factors increase risk a great deal. Others increase risk by only a small amount. Yet while there have been great advances in research, it’s still not perfectly understood what causes breast cancer to develop. It’s likely a combination of risk factors that make cells in the breast turn cancerous. But exactly why a certain combination of risk factors might cause cancer in a particular woman and another combination would not is still unclear.

Factors that Increase Breast Cancer Risk

  • Being female
  • Getting Older
  • Inherited genetic mutations
  • Carcinoma in situ
  • Family history of breast, ovarian or prostate cancer
  • High breast density on a mammogram
  • Radiation exposure in youth
  • Benign breast disease (hyperplasia)
  • High levels of estrogen in the blood
  • Personal history of breast cancer
  • Menopause at age 55 or older
  • Not having children or having first child after age 30
  • High bone density
  • Overweight/weight gain
  • High socioeconomic status
  • Ashkenazi Jewish heritage
  • Drinking alcohol
  • Lack of exercise
  • Postmenopausal hormone use
  • First period before age 12
  • Current or recent use of birth control pills
  • Being tall
  • Not breastfeeding

There’s been great progress over the last 30 years in identifying risk factors for breast cancer. At this time, researchers agree on more than 20 factors that increase breast cancer risk and several factors that lower risk. Some of these risk factors affect risk a great deal and others by only a small amount. For more information on risk factors and prevention click here.