Older Women With Strong Bones May Benefit From Mammograms
Dec. 7, 1999 (Washington) -- Tests that determine the health of bones in older women could be used to pinpoint which women should have regular mammograms once they reach age 65, and many who have a lower density do not need screenings because they are at lower risk of breast cancer.
That's according to a study in the Dec. 8 issue of the Journal of the American Medical Association by researchers at the University of California, San Francisco (UCSF and the Veterans Affairs Hospital there. They say four studies have shown that people with low bone mineral density, which can produce osteoporosis and bone fractures, also have a lower risk of breast cancer. This may be the case because, while the lack of the female hormone estrogen can lead to brittle bones, high estrogen levels may have a role in causing breast cancer.
The lead author of the study, Karla Kerlikowske, MD, tells WebMD that this newest report is the first to suggest a revision of mammography guidelines for screening schedules based on knowledge of bone density measurements. Kerlikowske is an assistant professor of biostatistics and epidemiology at UCSF. "I think the focus ought to be on women aged 50-69, where the benefit is only moderate but at least there is a benefit. The benefit [of mammography] is small for all people after age 70, and it is really small after that," she says.
Today's guidelines call for all women aged 40 and above to have annual mammograms. What many physicians say is puzzling is that there is no clear guidance on what age to stop performing them.
This study compared the life expectancy of women who continue mammography screening after age 69 with those who do not, based on bone mineral density measurements taken when they were 65. It also addressed the costs to society of mammograms and treatment of breast cancer, as well as women's preferences. "We found that continued screening mammography to age 79 is moderately cost-effective only if those with higher bone mineral density are screened," the authors write.