Supplemental Breast Cancer Screening in Women With Dense Breasts Should Be Offered With Simultaneous Collection of Outcomes Data

While mammographic screening reduces deaths from breast cancer, all women do not share this benefit equally. Much as inadequate patient preparation for colonoscopy can hide colon cancer, dense breast tissue on mammography can hide breast cancer, especially if the cancer lacks calcifications. Women with heterogeneously or extremely dense breasts who have cancer detected soon after a normal mammogram because of clinical symptoms are said to have “interval cancers.” Interval cancers tend to be more aggressive and larger, and have worse prognosis than screen-detected cancers. Because a “negative” screening mammography result does not reliably rule out cancer in women with dense breasts, experts and advocates have promoted breast density notification laws in hopes that knowledge of having dense breasts will empower an individual woman to push for adequate screening to include supplemental tests.