Breast Cancer Risk: Perception vs. Reality
Study: Nearly 90% of Women Overestimate Breast Cancer Risk
June 8, 2005 -- There is no denying that
significant threat to women, but new research shows that the threat is not
nearly as great as most women perceive it to be.
The numbers are frightening. The American Cancer Society estimates that
about 211,000 women will be diagnosed with invasive breast cancer in 2005 and
just over 40,000 will die of the disease.
When asked to estimate the average lifetime chance of developing breast
cancer, nine out of 10 women overestimated the risk. In a new study, the
average woman guessed that the risk was three times higher than it actually
The study was conducted by researchers from the University of Michigan
Health System and was published in the June issue of the journal Patient
Education and Counseling.
"Breast cancer is so commonly in the news, and most of us can think of
friends or relatives who have been diagnosed with it. That leads us to
overestimate how common it really is," says study researcher Peter Ubel,
MD, who directs the University of Michigan Center for Behavioral and Decision
Sciences in Medicine.
"We forget that we know a lot of people with breast cancer because we
know a lot of people."
Roughly one in eight women will eventually develop breast cancer. In other
words, a woman has a 13% chance of developing breast cancer at some point
during her life.
When Ubel and colleagues asked 178 women to estimate the average woman's
lifetime breast cancer risk, 89% overestimated. On average they thought a
woman's chance of getting breast cancer was close to 50%.
The women were then counseled about their actual
Researchers asked the women how anxious or relieved the
medical counseling made them, and whether they thought a 13% lifetime risk was
high or low.
"After estimating that 46% of women will be diagnosed with breast
cancer, when they find out it's actually 13%, that seems relatively low and
women feel a sense of relief," says Angela Fagerlin, PhD, who led the
Numbers Don't Give Context
Ubel tells WebMD that the findings have implications both for researchers
and for doctors charged with educating patients about breast cancer risk. He
says that asking them to estimate their own risk can help put the actual risk
"We shouldn't just throw numbers at patients without giving them some
context for those numbers," he says. "If you tell a patient that her
breast cancer risk is [13%], that still may sound like a high risk to her. But
if they guess a much higher number, as most do, [13%] is reassuring."
The University of Michigan study is not the first to show that women tend to
overestimate their breast cancer risk. In a survey conducted by the American
Cancer Society in 2001, nearly half of the women questioned believed that their
risk was between 30% and 50%.