A Comparison of Perceived Lifetime Breast Cancer Risk to Calculated Lifetime Risk Using the Gail Risk Assessment Tool

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. 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. 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. 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.