(RxWiki News) About one in eight American women will develop breast cancer at some point in her lifetime. That’s what the American Cancer Society estimates. A woman’s actual personal risk is based on many individual factors, though.
Researchers discovered that 20 percent of women in a recent study didn’t believe their individualized breast cancer risks when an assessment tool was used.
The women didn’t think the test considered their family history of breast cancer or their own personal health habits, even though the tool actually did ask about these factors.
Not believing, disagreeing with or not understanding cancer risks could lead to poor health decision making, the study's authors explained.
"Discuss your individual cancer risks with your doctor."
Angela Fagerlin, PhD, associate professor of internal medicine at the University of Michigan Medical School and a research scientist at the VA Ann Arbor Center for Clinical Management Research, led this study.
The researchers identified 690 women who were at above-average risk of developing breast cancer. They had elevated risks because of a family history of the disease. The women were recruited from the Henry Ford Health System in Detroit and Group Health in Seattle.
Participants took the BCRAT (Breast Cancer Risk Assessment Tool) — an interactive survey developed by scientists at the National Cancer Institute.
The tool calculates a woman’s risk of developing breast cancer within the next five years.
Study participants used the tool to answer questions about a number of risk factors, including age, ethnicity, personal history of breast cancer, age of first period, age when her first baby was born, number of first-degree relatives (parent, child, siblings) who have breast cancer and history of breast biopsies.
After learning their risk of developing breast cancer and being given information on ways to help prevent the disease, the women in this study were asked to recall their risk numbers.
Of the 48 percent of the women who did not report the correct number, one in five (22 percent) said they either didn’t believe or disagreed with the numbers.
When asked why they didn’t trust the numbers, 37.4 percent of the women said their family history made them more or less likely to get breast cancer.
The BCRAT does not factor in hereditary breast cancer risks, including being a carrier of a BRCA gene mutation and other family history risk factors. For this reason, some of the women may have had good reason to distrust their risk assessment.
Others may have been misinformed about the types of family cancer history that impact a woman's individual breast cancer risk.
And about one-third of the women said they had a gut instinct that the numbers seemed too high or low.
Adam Brufsky, MD, PhD, professor of medicine at the University of Pittsburgh School of Medicine, told dailyRx News, “This is somewhat surprising. As oncologists, we should try to do a more thorough job of explaining risk.”
Dr. Fagerlin described the relevance of this research: "Women who believe their risk is not high might skip chemoprevention [taking medications to reduce cancer risks] 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 findings from this research, which were published in August in Patient Education and Counseling, are part of a larger study looking at ways to assist patients understand cancer risk information.
No financial support information was reported.