Just how much high-density boosts breast cancer risk, though, is something that experts can only roughly estimate, Kerlikowske said. She said that women with very high-density breasts have about a fourfold increase in risk compared with women who have very low-density breasts.
And though density often decreases with age, especially after menopause, it remains a risk factor -- and one women can't do much about, Kerlikowske said.
Some experts have suggested that women with high-density breasts might consider a more frequent surveillance schedule. But she said there's not sufficient evidence to suggest, at least yet, that that would be a good idea. "We are trying to study that now," she said.
Women with dense breasts who are younger than 50 and premenopausal, though, might benefit from having digital rather than traditional mammograms, Kerlikowske said. "We are looking at different ways to measure breast density other than mammograms," she said, because "you can't keep having [frequent] mammograms," for safety reasons.
Buist said that older women who don't want to increase the density of their breasts could opt not to take combined hormone therapy, noting that "most women get an increase in density with that."
But beyond that, the two agreed, there's little additional advice doctors can offer women with dense breasts at this time.
To learn more about breast density, visit the U.S. National Cancer Institute.
SOURCES: Diana Buist, Ph.D., M.P.H., epidemiologist, and associate investiga
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