In the EPT arm, both the baseline and change in mammographic density were significantly associated with breast cancer risk. Using these mammograms, researchers could "predict" those who would go on to develop breast cancer. Among the 20 percent of women with the greatest increase in mammographic density in the EPT arm of the study, breast cancer risk was more than tripled (3.6-fold) compared to the 20 percent increased risk in the group with the lowest increase or decrease in density.

"The overall result within this sub-study for the effect of EPT on breast cancer risk compared to placebo was similar to that of the WHI findings," says Byrne. The researchers reported an overall 24 percent increased breast cancer risk for those in the EPT arm.

"For women using hormone replacement therapy with estrogen and progestin, breast density is a factor that a physician should consider when tracking their breast health," concludes Byrne. "For general screening, breast density might one day be used to help determine mammograms that demonstrate uncertainty about a visual anomaly."

Source: Georgetown University Medical Center