Adjuvant Endocrine Therapy for Women With Hormone Receptor–Positive Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update on Ovarian Suppression

PurposeTo update the ASCO adjuvant endocrine therapy guideline based on emerging data concerning the benefits and risks of ovarian suppression in addition to standard adjuvant therapy in premenopausal women with estrogen receptor–positive breast cancer.MethodsASCO convened an Update Panel and conducted a systematic review of randomized clinical trials investigating ovarian suppression.ResultsTwo trials investigating the addition of ovarian suppression to tamoxifen did not show an overall clinical benefit for ovarian suppression. Nonetheless, the addition of ovarian suppression to standard adjuvant therapy with tamoxifen or with an aromatase inhibitor improved disease-free survival and improved freedom from breast cancer and distant recurrence compared with tamoxifen alone among the subset of patients who were at sufficient risk for recurrence such that adjuvant chemotherapy was warranted. Compared with tamoxifen alone, ovarian suppression was associated with a substantial increase in menopausal symptoms, ...