Absolute improvements in freedom from distant recurrence with adjuvant endocrine therapies for premenopausal women with hormone receptor positive (HR+) HER2 negative breast …

503Background: The TEXT and SOFT trials randomly assigned premenopausal women with HR+ BC to exemestane plus ovarian function suppression (E+OFS), tamoxifen+OFS (T+OFS) and T alone. We previously examined absolute treatment effects on any BC recurrence across a continuum of recurrence risk to individualize endocrine therapy decision making. After 8.5 yrs median follow-up we now consider effects on freedom from distant recurrence. Methods: The TEXT and SOFT HR+/HER2- analysis population included 4891 pts and was stratified by chemotherapy use. The endpoint was distant recurrence-free interval (DRFI; time from randomization to first appearance of DR). For each pt, a previously defined continuous, composite recurrence risk index (CRI) was calculated from a Cox model incorporating age, nodal status, tumor size and grade, and ER, PgR and Ki-67 expression levels. Subpopulation …