Figure 3.

Association of breast density by ER subtype. Cox proportional hazards model results for estrogen receptor–positive (solid circle) and –negative (open circle) invasive breast cancers comparing women with almost entirely fat, heterogeneously dens,e and extremely dense breasts compared with scattered fibroglandular density. The numbers in parentheses along the x-axis are P values calculated using a two-sided Wald test result to compare estrogen receptor–positive vs –negative cancer parameters within each age group. The error bars represent the 95% confidence intervals. CI = confidence interval; HR = hazard ratio.