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

Purpose To 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. Methods ASCO convened an Update Panel and conducted a systematic review of randomized clinical trials investigating ovarian suppression. Results Two 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, sexual dysfunction, and diminished quality of life. Recommendations The Panel recommends that higher-risk patients should receive ovarian suppression in addition to adjuvant endocrine therapy, whereas lower-risk patients should not. Women with stage II or III breast cancers who would ordinarily be advised to receive adjuvant chemotherapy should receive ovarian suppression with endocrine therapy. The panel recommends that some women with stage I or II breast cancers at higher risk of recurrence who might consider chemotherapy may also be offered ovarian suppression with endocrine therapy. Women with stage I breast cancers not warranting chemotherapy should not receive ovarian suppression, nor should women with node-negative cancers 1 cm or less. Ovarian suppression may be administered with either tamoxifen or an aromatase inhibitor. Additional information is available at www.asco.org/guidelines/endocrinebreast and www.asco.org/guidelineswiki. (C) 2016 by American Society of Clinical Oncology