Higher cancer risk in dense breasts

Women with dense breasts have five times the risk of developing breast cancer as those who don't, according to new research.

A review of breast cancer cases revealed that a substantial 16 percent were linked to density in at least half of the breast, say researchers at the Campbell Family Institute for Breast Cancer Research in Toronto. "That makes it a more potent risk factor than family history of the disease," says study author Dr. Norman Boyd.

Dense breasts have more tightly packed milk glands and ducts than other women's. You can't judge by size or feel, so take these steps:

Learn your "density grade." Your radiologist provides a rating on your mammogram report: "1" indicates no dense tissue; "2," at least one dense area; "3," dense tissue in 50 percent to 75 percent of your breast; and "4," dense tissue in more than 75 percent.

Consider more -- or better -- tests if you score a 3 or 4. A mammogram plus an ultrasound catches 97 percent of cancers in this tissue, and digital mammograms find 15 percent more positive cases than regular films. Also ask about an MRI scan.