New Insights into Endocrine Therapy for Young Women with Breast Cancer

Managing estrogen receptor-positive breast cancer in young women (<40 years) requires a multidisciplinary/personalized approach, covering both clinical and psychosocial aspects. Five years of tamoxifen has been the standard adjuvant endocrine therapy for many years. Recent data from the adjuvant randomized trials TEXT–SOFT show that the aromatase inhibitor exemestane plus ovarian suppression significantly reduces recurrences as compared with tamoxifen plus ovarian suppression. The ATLAS and aTToM trials represent the first evidence of a beneficial effect of extended endocrine therapy with tamoxifen in premenopausal women. Outside of a clinical trial, no data support neoadjuvant endocrine therapy in young women. In the metastatic setting, tamoxifen or aromatase inhibitors, both with ovarian suppression/ablation, should be the preferred choice, unless rapid tumor shrinkage is needed. No data are available with fulvestrant in young patients.