Background: Understanding the accuracy of a woman's perceived breast cancer risk can enhance shared decision-making about breast cancer screening through provider and patient discussion. We aim to report and compare women's perceived lifetime breast cancer risk to calculated lifetime breast cancer risk. Methods: Women presenting to Mayo Clinic in Arizona and Minnesota in July 2016 completed a survey assessing their perceived breast cancer risk. Lifetime Gail risk scores were calculated from questions pertaining to health history and were then compared with perceived breast cancer risk. Results: A total of 550 predominantly white, married, and well-educated (≥college) women completed surveys. Using lifetime Gail risk scores, 5.6% were classified as high risk (>20% lifetime risk), 7.7% were classified as intermediate risk (15%-20%), and 86.6% were classified as average risk (<15%). Of the 27 women who were classified as high risk, 18 (66.7%) underestimated their risk and of the 37 women who were intermediate risk, 12 (32.4%) underestimated risk. Women more likely to underestimate their risk had a reported history of an abnormal mammogram and at least one or more relative with a history of breast cancer. Surveyed women tended to overestimate risk 4.3 (130/30) times as often as they underestimated risk. Conclusion: In a group of predominantly white, educated, and married cohort of women, there was a large portion of women in the elevated risk groups who underestimated risk. Specific aspects of medical history were associated with underestimation including a history of abnormal mammogram and family history of breast cancer. Overall, in our sample, more women overestimated than underestimated risk.
Keywords: breast cancer risk; breast cancer screening; perceived breast cancer risk.