National Breast Cancer Coalition

Myth #13: Everyone who has a positive BRCA 1 or BRCA 2 test result will get breast cancer

FALSE. While women with a positive BRCA test have a much higher chance of breast cancer, it does not guarantee the development of the disease.

About 12 percent of women in the general population will develop breast cancer sometime during their lifetime. For women who have inherited a harmful mutation in BRCA1 or BRCA2, that number is much higher. There is a lot of controversy about the exact rate, but it appears to be up to 5 times higher than for women without the mutation.

A positive test result generally indicates that a person has inherited a known mutation in the BRCA1 or BRCA2 gene and has an increased risk of developing certain cancers. However, a positive test result provides information only about a person's risk of developing cancer. It cannot tell whether an individual will actually develop cancer or when. A couple different health management options are typically offered to those with a positive BRCA test. These options include more frequent screening tests, surgery (prophylactic mastectomy), or drugs ("chemoprevention") to reduce the risk of breast cancer. However, there is no strong eveidence that any of these options actually reduce the number of deaths from breast cancer. Women with a BRCA gene mutation must carefully weigh the benefits and risks of these health management options.

Conversely, testing negative for the gene does not mean one will never develop breast cancer—90-95% percent of women who develop breast cancer do not have a BRCA inherited gene mutation.

Learn more about BRCA 1 and BRCA 2 genetic testing and health management options for those testing positive. Become a member of NBCC today to join the mission to end breast cancer.