Breast cancer remains the most frequent cancer in women and its incidence is increasing. However, the mortality rate has stabilized due to the progress made in the treatment of breast cancer over the last decade. In premenopausal women with hormone receptor-positive breast cancer, the goal of adjuvant treatment is to inhibit the impact of estrogen on the breast, either by blocking the estrogen receptors (with the use of tamoxifen) or by suppressing ovarian function (through surgical oophorectomy or treatment with luteinizing hormone-releasing hormone (LHRH) agonist).