Michigan Gov. Rick Snyder has signed his state’s breast density notification law, bumping the number of states with such legislation to 21.
The new law, Public Act 517, requires breast density information to be included in the mammography results letter sent to women. It takes effect June 1.
Breast density is one of the strongest predictors of the failure of mammography screening to detect cancer, according to Breast Density Matters, a Michigan-based group that advocated for a breast density notification law. In addition to obscuring cancers on mammography, breast density is an independent risk factor for the development of breast cancer.