Nearly 1 in 5 women who completed a detailed assessment of their personal risk for developing breast cancer rejected the results, according to a study published in the journal Patient Education and Counseling.
Most of the women who didn’t believe their result said they felt it didn’t take relevant family history of cancer into account, even though the assessment included questions about family history. They also believed their personal health habits should have led to either a higher or lower risk.
“If people don’t believe their risk numbers, it does not allow them to make informed medical decisions,” said senior study author Angela Fagerlin, PhD, research scientist at the VA Ann Arbor Center for Clinical Management Research.
“Women who believe their risk is not high might skip chemoprevention strategies that could significantly reduce their risk. And women who think their risk should be higher could potentially undergo treatments that might not be medically appropriate, which can have long-term ramifications.”
The study involved 690 women who had used a Breast Cancer Risk Assessment Tool (BRCAT) that indicated they were at above-average risk for developing breast cancer within five years. The women viewed a presentation about ways to help prevent breast cancer in women at high risk, including the use of chemopreventive medications like tamoxifen or raloxifene.
The women also answered a series of questions about known risk factors for breast cancer—including age, ethnic background, personal history of breast cancer, first-degree relatives who had breast cancer, age at first menstrual period, and how old they were when they first gave birth.
All the above, including the women’s BRCAT scores, led to two risk numbers: One reflected their risk for breast cancer in five years without chemoprevention; the other reflected their risk for disease in five years with chemoprevention.
Researchers then asked each woman what her risk numbers were. If her answers were incorrect, she was asked why: For example, did she forget? Did she make a mistake rounding off a number? Or did she think the numbers were wrong? If she thought the numbers were wrong, she was asked to explain why.
A total of 131 women misreported their risk. Of those, 27 percent said they forgot. But 22 percent said they disagreed with one or both of their numbers.
Many said they thought their risk should be higher because a relative such as an aunt had a history of breast cancer. In fact, a woman’s risk is increased by breast cancer in first-degree relatives—especially female relatives like a mother, sister or daughter, according to the American Cancer Society (ACS).
Other women believed their risk numbers should be lower because breast cancer did not run in their family. According to the ACS, more than 85 percent of women who get breast cancer do not have a family history of the disease.
On the other hand, some women believed their risk should be higher than reported because they didn’t live a healthy lifestyle.
The study’s findings are important because of the trend toward personalized medicine, said Laura D. Scherer, PhD, the study’s lead author. Risk calculators are used by doctors and consumers to assess an individual’s risk for many conditions, including diabetes and heart disease, according to background in the study.
But if people don’t believe their individual risks, they likely won’t get the most out of their medical care, Dr. Scherer noted.
The findings suggest that health providers shouldn’t assume their patients take the provider’s word about risk, the authors wrote. The study also suggests that people who have pre-existing beliefs about their health may benefit from more thorough explanations from their physicians about their risk factors.