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Breast Cancer Resource
Risk Factors

Risk Factors

Researchers have identified personal characteristics and behaviors that increase the chance of developing breast cancer. These are called risk factors. Risk factors do not cause breast cancer but can impact the likelihood that an individual will develop breast cancer. Risk factors are not guarantees that one will or will not have cancer in one’s lifetime. There are women who have several risk factors and never develop breast cancer and there are women who have few or no risk factors and develop breast cancer. Talk to your health care provider about your personal risk.

You can control some risk factors by altering your behavior; however other risk factors are part of who you are and are not controllable.

Factors that may increase your risk of developing breast cancer include:
• Being a woman
• Getting older (As women age, the likelihood of getting breast cancer increases, and one out of every eight women in the United States will develop breast cancer in her lifetime.)
• Family history of breast cancer—especially among first-degree relatives (parent, sibling or child)
• Having a genetic condition, such as a mutated copy of BRCA1 or BRCA 2 or other genes linked to breast cancer
• Having high breast density on a mammogram
• A personal history of breast or ovarian cancer, Hodgkin’s lymphoma (Hodgkin’s disease), uterine cancer, thyroid cancer, colon cancer or melanoma
• Previous occurrence of hyperplasia, DCIS (ductal carcinoma in situ) or LCIS (lobular carcinoma in situ)
• Having first pregnancy later in life or not having children
• Starting menstrual periods early (before age 12)
• Late menopause (after age 55)
• Being exposed to large amounts of radiation to the chest area
• Being overweight, especially after menopause
• Having more than one alcoholic drink a day
• Current or recent use of estrogen and progesterone or estrogen only hormone replacement therapy (HRT), or using HRT for a long time
• Current or recent use of birth control pills

Factors that may decrease your risk of developing breast cancer include:
• Maintaining a healthy weight or losing weight after menopause
• Being physically active
• Breastfeeding
• Limiting the amount of alcohol that you drink

Numerous studies have shown that the following are not risk factors:
• Using hair dye
• Miscarriages or abortion

Additional Resources:

Susan G. Komen for the Cure®: Risk Factors and Prevention(Under “Breast Health Information” choose the “Risk Factors and Prevention” sub-section.  We have found the “Breast Cancer Risk Factors Table” particularly helpful.)