To the Editor: The data from the Nurses' Health Study, reported by Colditz et al. (June 15 issue),1 show a significant increase in the risk of breast cancer with hormone-replacement therapy. I am at a loss, however, about how to counsel my patients on the basis of these data. The relative risks are presented, but there is no mention of the absolute risk, which would be of much value to patients facing a decision about taking hormones. The use of patient-years is confusing and counterintuitive for clinical purposes. In an attempt to obtain an overview of the data, I have.