Twelve-month estrogen levels in premenopausal women with hormone receptor-positive breast cancer receiving adjuvant triptorelin plus exemestane or tamoxifen in the suppression of ovarian function trial (SOFT): the SOFT-EST substudy

- Bellet, Meritxell; Gray, Kathryn; Gonzales-Martin, Antonio; Ferrer, Roser; Catalan, Roberto; Azaro, Analia; Rajasekaran, Agnita; Morales, Josefa; Vazquez, Josep; Fleming, Gini; Price, Karen; Regan, Meredith; Francis, Prudence; Lang, Istvan; Ciruelos, Eva; Lluch, Ana; Climent, Miguel Angel; Catalan, Gustavo; Avella, Antoni; Bohn, Uriel