Canadian Society Breast Imaging Position Statement on Mammographic Breast Density and Supplemental Screening.

Screening aims to detect breast cancer before it becomes clinically apparent, enabling identification of tumors when they are smaller and have not yet spread and when treatment options are more effective, less invasive, and more affordable. However, screening mammography has known limitations, with breast density being a primary challenge. Denser breast tissue not only increases the likelihood of cancer but also makes tumors harder to detect due to overlapping tissue. Strong evidence now exists to support updating our previous guidelines to recommend supplemental screening beyond mammography for individuals with American College of Radiology category c or d breast density. Supplemental screening methods, such as MRI, contrast-enhanced mammography (CEM), or US (in that order of preference) can significantly improve cancer detection rates. We recognize that implementing these recommendations across Canada will present challenges. Nevertheless, a collaborative effort among radiologists, health care stakeholders, and policymakers is essential to drive gradual, meaningful improvements in breast cancer detection and outcomes.