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Risk factors of breast cancer

Breast Cancer Risk Factors

Why do people get breast cancer?

Across all the people who get it, there’s no single reason why breast cancer occurs. Any one person’s risk of the disease is affected by various things—some of which can be changed, and some of which cannot.

Breast cancer risk factors you can’t change:

  • Being female: Breast cancer is about 100 times more common in women than in men
  • Age: Cancer risk goes up with time. About 2 out of 3 women with invasive breast cancer are age 55 or older
  • Genetics: Some 5% to 10% of breast cancers may be associated with genetic mutations
  • Family history: Having a close blood relative who’s experienced breast cancer increases a woman’s risk of getting the disease. However, as many as 8 out of 10 women with breast cancer don't have a family history
  • Race: Caucasian women are slightly more likely to get breast cancer than are African-American women. Asian, Hispanic, and American Indian women have a lower risk of getting breast cancer

Breast cancer risk factors you can change:

  • Alcohol use: Women who have 2 to 5 drinks a day have about 1.5 times the breast cancer risk of women who don't drink. Having 1 drink a day poses a very small increased risk
  • Excess weight: Being overweight or obese is linked to higher breast cancer risk, especially for women who have gone through menopause and for those who carry extra fat around the waist
  • Inactivity: Exercise has been shown to reduce the risk of getting breast cancer

How can a person’s genetic background affect her cancer risk?

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US.XON.10.04.010 Last Update: May 2010