Doctors' groups and patient advocates are facing off over new state laws that require health professionals to warn women when mammograms reveal dense breast tissue. Density—the result of higher proportions of connective or glandular tissue—can make it more difficult to detect cancer, since both the tissue and tumors appear white on mammograms. In and of itself, density isn't a problem; as many as 40% of mammogram recipients have it, the New York Times notes.
While patient groups argue that women deserve to know about the potential risks, doctors worry that it could cause unnecessary stress, testing, and treatments. Density is a matter of opinion, they note. Studies have shown that women with dense breasts may face two to six times the risk of breast cancer. Research also shows that ultrasounds have been able to detect tumors unseen by mammograms, but those ultrasounds also prompted unnecessary biopsies. "I’m always worried when politicians start legislating the medical conversation, especially when it’s a medical conversation where the experts don’t know what needs to be said," says the American Cancer Society's chief medical officer.