Prevention Trials in Women at Moderate Risk of Breast Cancer

The primary goal of most protocols of past and present mammary cancer clinical trials is the reduction of breast cancer incidence. The assumption that the selective estrogen receptor modulator (SERM) tamoxifen could prevent mammary cancer resulted from the experience obtained in palliative and adjuvant treatments. Several prevention clinical trials involve this SERM, e.g. P1, IBIS I, Royal Marsden Hospital Tamoxifen Prevention Trial, Italian Randomized Trial Among Hysterectomized Women. Second-generation trials tested other types of substances, such as aromatase inhibitors which were included in the IBIS II trial. Other trials investigate alternative SERMs, such as raloxifene, arzoxifene and lasofoxifene, as well as endocrine substances, such as gonadotropinreleasing hormone agonists and enzyme inhibitors (e.g. Cox-2 cyclooxigenases).