TUESDAY, Oct. 15, 2002 (HealthDayNews) --
Many women who undergo prophylactic mastectomy of both breasts have an exaggerated perception of their breast cancer risk before surgery, says a study by University of Toronto researchers.
Nursing Professor Kelly Metcalfe, the lead author of a paper in tomorrow's issue of the Journal of the National Cancer Institute, said of the 75 women who participated in the study, 30 percent of them estimated their risk to be 100 percent.
"We don't even allot that level of risk to women who carry a mutation in one of the two breast cancer susceptibility genes. The highest risk we would give is 80 percent. So these women's risk estimates were very elevated, particularly for those who did not carry the genetic mutation," she said.
Prophylactic bilateral mastectomy is a preventive option for women who are at high risk of developing breast cancer. From 1991 to 2000, Metcalfe and Dr. Steven Narod of the Centre for Research in Women's Health at Sunnybrook and Women's College Health Science Centre and the University of Toronto identified 120 women who had prophylactic bilateral mastectomies. The 75 women who agreed to participate provided detailed family histories of the number and type of cancers within their family and the ages of onset.
"It's concerning that they thought their risk was that high," says Metcalfe. "In fact, we found that the women in the study with the lowest risk actually estimated their risk as the highest. We don't know what is driving these perceptions, whether it's from the media, their families or physicians. But it is troubling."
Metcalfe and Narod believe that any woman considering prophylactic mastectomy should undergo formal genetic counseling.
"Having a great-aunt who developed breast cancer in her 80s is probably not a high risk," Metcalfe says. "But numerous family members -- like your mother, sister, aunt and grandmother -- diagnosed with breast cancer at a very young age likely would constitute a significant family history."
More Information
The National Cancer Institute has more on preventive mastectomy.
