Most Women Have an Inaccurate Perception of Their Breast Cancer Risk, Study Reveals
A large-scale survey of women undergoing mammography screening on Long Island, New York, indicates that the majority (90.6%) either underestimate or overestimate their lifetime risk for developing breast cancer. Furthermore, 4 in 10 women surveyed reported they had never discussed their personal breast cancer risk with a doctor. While some doctors have suspected that women have misconceptions about their own breast cancer risk, this is the first study to quantify the magnitude of this knowledge gap. The findings (Abstract 4) will be presented at the 2013 Breast Cancer Symposium on Saturday, September 7.
Breast Cancer Awareness Falls Short
“Women are surrounded by breast cancer awareness messages, through pink ribbons, walks, and other campaigns, yet our study shows that fewer than one in 10 women have an accurate understanding of their breast cancer risk—that means that our education messaging is far off and we should change the way breast cancer awareness is presented,” said lead study author Jonathan Herman, MD, an obstetrician and gynecologist at Hofstra North Shore-LIJ Medical School in New Hyde Park, New York. “If a patient doesn’t have a formal estimation, she will just be guessing her risk.”
Women need to have accurate knowledge about their own breast cancer risk to make appropriate decisions regarding screening and prevention. Women at greater than 1.66% 5-year risk and those at a greater than a 20% lifetime risk may benefit from chemoprevention with medications such as tamoxifen, raloxifene (Evista), or anastrozole and/or additional surveillance that might include annual MRI screening. Conversely, overestimation of risk can lead to unnecessary anxiety, testing, and interventions.
Survey Details
Researchers surveyed 9,873 women, 35 to 70 years of age, who were undergoing breast cancer screening at 21 mammography centers on Long Island. The survey also asked women to estimate their own risk of developing cancer over the next 5 years and over their lifetime. In addition, the survey included questions about patient demographics (race/ethnicity, religious affiliation, education, marital status, household income, health insurance), breast cancer risk factors (age at the time of first menstrual period, age at the time of giving birth for the first time, personal and family history of breast cancer, breast cancer biopsy findings), and any prior breast cancer risk assessments and discussions. Many of the questions were adapted from the National Cancer Institute’s Breast Cancer Risk Assessment Tool.
For each survey respondent, researchers compared the calculated actual lifetime risk to her subjective risk estimate. If a woman’s personal estimate differed from the calculated value by more than 10%, it was labeled as inaccurate. As an overall group, 707 women (9.4%) accurately estimated their risk, 3,359 (44.7%) underestimated risk, and 3,454 (45.9%) overestimated risk.
When parsed by ethnicity, Caucasian women were more likely to overestimate their risk, whereas African American, Asian, and Hispanic women were more likely to underestimate their risk. Although these differences between groups were statistically significant, the overall understanding of breast cancer risk among all subgroups in the study was low.
Importance of Knowing Breast Cancer Risk
According to Dr. Herman, increasing knowledge about breast cancer is everybody’s responsibility—primary care doctors, gynecologists, breast cancer foundations, and patients themselves all need to take initiative to improve women’s understanding of their risk. Breast cancer risk assessment tools are available to doctors online free of charge. “It takes a minute to go through the questions but that minute is not being spent often enough in doctors’ offices. Women should be aware of their breast cancer risk number, just as they know their blood pressure, cholesterol, and BMI [body mass index] numbers,” he said. Health insurance plans will cover the cost of additional screening only if women have a documented increased breast cancer risk.
Prior studies have suggested certain lifestyle factors that may reduce a woman’s risk of developing breast cancer. For young women who are at average risk, the most significant ways to reduce risk are to have children early in life, breastfeeding, and maintaining a healthy BMI.
A second phase of the research project, which will query primary care providers about their perceptions about women’s knowledge of breast cancer risk and how often they discuss breast cancer risk with their patients, is currently being developed.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
