Lobular involution, mammographic density, and breast cancer risk: visualizing the future?

In this issue of the Journal, Ghosh et al. (1) describe the application of two visual assessments to predict breast cancer risk—lobular involution, a histological observation, and mammographic breast density (MBD), a radiological assessment. Previously, this group has demonstrated that more extensive lobular involution was inversely related to both MBD (2) and breast cancer risk (3) in a cohort of women diagnosed with benign breast disease at the Mayo Clinic. Herein, the authors extend this work by showing that a benign biopsy demonstrating histologic changes consistent with incomplete or no involution or a mammogram classified as high density is independently associated with breast cancer risk, and in combination, they are associated with an even greater risk. These findings suggest that visual representations of the architecture of the breast on both microscopic (ie, involution) and macroscopic (ie, MBD) levels potentially represent clinically useful intermediate endpoints. The assessment of these “phenotypes” holds Lobular Involution, Mammographic Density, and Breast Cancer Risk: Visualizing the Future?