August 13, 2018 — Illinois Gov. Bruce Rauner approved the Illinois Breast Density Reporting Law (Public Act 100-0749) on Aug. 10, 2018 making Illinois the 36th state to report dense breast tissue to patients. It became the fifth state to enact a breast density law in 2018, joining Utah, Washington, Florida and Wisconsin.
Illinois’ law is the first to direct women to their breast imaging healthcare provider for information about the notification. Previous laws have directed women to their referring doctor for questions. According to Patti Beyer, patient advocate and founder of the Illinois Breast Density Initiative, “This means that women in Illinois are being encouraged to have a conversation with the expert, the radiologist, the doctor who determined their breast density, and dialog about the options for supplemental screening."
Beyer led the advocacy efforts in Illinois. She learned of the challenges of dense breast tissue from her sister who lives in California, one of the early adopters of a breast density law. Despite a normal mammogram, Beyer asked her healthcare providers about her breast tissue and found out that she has dense breast tissue. An adjunct ultrasound screening was prescribed and an invasive early-stage breast cancer was detected.
"The earlier cancer is detected and treated, the better the outcome,” said Rep. Michael McAuliffe. “Unfortunately, many women are left unaware that their mammogram results were inconclusive and that they have a right to additional testing.”
Approximately 40 percent of women aged 40 and over have dense breasts and may benefit from supplemental screening tests, in addition to mammography, to detect cancers. Women with extremely dense breasts are 4-6 times more likely to develop breast cancer than women with the least dense breasts.
Connecticut was the first state to enact a density reporting law in 2009, inspired by Nancy M. Cappello, Ph.D. Cappello’s advanced stage 3c breast cancer, metastasized to 13 lymph nodes, was discovered within weeks of her 11th normal mammogram. It was at this time that the impact of her dense breast tissue and its challenges to detect cancer by mammogram alone was revealed to her by her team of doctors.
For more information: www.areyoudense.org, www.densebreast-info.org
Related Dense Breast Tissue Content
High-Risk Clinic Arms Patients Against Breast Cancer
VIDEO: The Impact of Breast Density Technology and Legislation
October 24, 2025 
