Comparative Effectiveness of Breast Cancer Screening and Diagnostic Evaluation by Extent of Breast Density
What is the best way to screen women with or without dense breasts? In the United States, 27.6 million women of screening age have dense breasts, and laws in almost half the states require notification so women may consider supplemental screening. Digital breast tomosynthesis, magnetic resonance imaging (MRI), and ultrasound are diffusing rapidly into community practice with insufficient evidence to guide screening decisions.
Should breast MRI be used before surgical decisions in women with newly diagnosed breast cancer? Preoperative MRI, used for evaluation of a new cancer diagnosis, is increasingly controversial due to conflicting evidence of benefit overall or for subgroups of women. While MRI detects additional disease, its impact on patient-centered clinical and patient-reported outcomes has not been adequately addressed, overall or by breast density.
The outcomes we hope to achieve are to (1) enable women to understand the effectiveness of different supplemental screening options (tomosynthesis, ultrasound, or MRI) by extent of breast density; and (2) allow patients with a breast cancer diagnosis to understand the risks and benefits of preoperative MRI by extent of breast density. Ultimately, we aim to inform screening guidelines and ensure that decisions about preoperative work-up are aligned with a woman’s individual characteristics and preferences.
Women we surveyed were concerned with how breast density should be factored into screening and clinical decisions to detect or treat breast cancer. We have incorporated questions and outcomes important to women throughout the study. For example, we will assess screening failures because 76 percent of women surveyed felt it was extremely important that the exam not miss the presence of breast cancer. We will also assess second cancer events, because it is important to women to have good estimates of subsequent disease risk when making diagnostic and surgical decisions.