Sisters Unite

The Genetic Connection
Sisters of women who have had breast cancer have twice the risk of getting the disease than other women, according to Paula Juras, National Institute of Environmental Health Sciences project officer for the Sister Study.

Women who have breast cancer in their family’s history through mothers, grandmothers, or other female relatives also have a higher risk factor, she adds. Although studies have noted that there are some gene mutations that could account for higher incidence of cancer in some families, those mutations tend to affect only about 5 to 10 percent of the population, Juras says. 

While she doesn’t recommend automatic genetic testing, Juras does note that women with a family history of the disease should be checked more frequently, and perhaps even do more self-examinations than other women.

And for those who do have a strong chance of the mutations, genetic testing may be appropriate. This group includes women with an inherited BRCA1 or BRCA2 mutation, who have up to an 80 percent chance of developing breast cancer during their lifetime, and at a younger age than those without this genetic component. These women also have an increased risk for developing ovarian cancer.

While most women won’t need genetic testing, if there’s significant family history and concern about genetics, women should talk to their physician about the benefits and drawbacks of this kind of testing. And women who have a sister with breast cancer or a past experience with the disease and would like to be part of the Sister Study can find eligibility requirements, applications, and extensive information at sisterstudy.org.