Most Women Don't Understand Breast Cancer Risk
White women overestimated their odds while other groups underestimated, researcher found
In the general population, women have a 12 percent, or one in eight, lifetime risk of breast cancer. That increases to 20 percent, Herman said, if a woman's mother had breast cancer. If she tests positive for the BRCA mutations that boost breast cancer risk, the risk goes up to roughly 70 percent.
The survey findings come as no surprise to Dr. Mary Daly, chair of clinical genetics at Fox Chase Cancer Center, in Philadelphia, and director of its risk assessment program.
"When we ask women, what is the risk in the general population, and what is your risk compared to that, they can put themselves in a general category, of low, average and so on, but not [more] specific," said Daly, who reviewed the new findings but was not involved with the survey.
More women may have considered their own breast cancer risk after media attention about actress Angelina Jolie's recent decision to have a preventive double mastectomy after her mother died of ovarian cancer and Jolie tested positive for a BRCA gene mutation. BRCA1 and BRCA2 mutations increase the risk of breast and ovarian cancers.
The news about Jolie raised awareness in a good way, Herman said, with women seeking advice about what to do and whether they need the test.
At Fox Chase, there was a rise in requests for genetic testing, but many of the women asking about it were in the high-risk group, Daly said, so it was appropriate.
In the survey, black women underestimated their risk, which is lower than that for white women, Daly said. "Their incidence rates are lower, but their survival is also lower," she said, as a more aggressive cancer can strike them.
Most important, Daly said, is for women to learn their family history. "We like to go back at least two generations, parent and grandparents, on both sides."
Once a woman knows her risk, she needs to know if the screening schedule she follows is appropriate and what else she should be doing, Herman and Daly agreed.