If one woman in your family—such as a mother, a sister, or a daughter—has had breast cancer, your risk of getting it is a little higher than for women who don’t have a family history of the disease. About 24 out of 100 women with one relative who has had breast cancer will get this cancer sometime during their lives.

[Chart based on American Cancer Society (2013). Breast cancer: Early detection. http://www.cancer.org/cancer/breastcancer/moreinformation/breastcancerearlydetection/index.]

If two relatives have had breast cancer, your risk for getting it goes up. About 36 out of 100 women with two relatives who have had breast cancer will get this cancer sometime during their lives.

[Chart based on American Cancer Society (2013). Breast cancer: Early detection. http://www.cancer.org/cancer/breastcancer/moreinformation/breastcancerearlydetection/index.]

Some women have BRCA1 gene changes. Their risk of getting breast cancer is much higher than average. For these women, about 55 to 65 out of 100 women will get breast cancer by age 70.

[Chart based on National Cancer Institute (2016). BRCA1 and BRCA2: Cancer risk and genetic testing. National Cancer Institute. http://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet. Accessed April 6, 2016.]

Some women have BRCA2 gene changes. Their risk of getting breast cancer is much higher than average. For these women, about 45 out of 100 women will get breast cancer by age 70.

[Chart based on National Cancer Institute (2016). BRCA1 and BRCA2: Cancer risk and genetic testing. National Cancer Institute. http://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet. Accessed April 6, 2016.]