The U.S. will soon require that all women getting mammograms receive information about their breast density, about half of women over 40 have dense breasts, which can sometimes make it harder to spot cancer on x-rays. Dense breast tissue is one factor that can boost a woman's chances of developing cancer. The FDA will now require that women get information about the density after receiving a mammogram. Those who do have dense breasts will be told to talk with their doctor, while professional guidelines do not specify the next steps, some doctors may recommend more scanning, including ultrasound or MRI. Sagar Meghani, Washington