Adjuvant Endocrine Therapy for Women With Hormone Receptor-Positive Breast Cancer: ASCO Clinical Practice Guideline Focused Update.

PURPOSE: To update the ASCO clinical practice guideline on adjuvant endocrine therapy based on emerging data about the optimal duration of aromatase inhibitor (AI) treatment. METHODS: ASCO conducted a systematic review of randomized clinical trials from 2012 to 2018. Guideline recommendations were based on the Panel's review of the evidence from six trials. RESULTS: The six included studies of AI treatment beyond 5 years of therapy demonstrated that extension of AI treatment was not associated with an overall survival advantage but was significantly associated with lower risks of breast cancer recurrence and contralateral breast cancer compared with placebo. Bone-related toxic effects were more common with extended AI treatment. RECOMMENDATIONS: The Panel recommends that women with node-positive breast cancer receive extended therapy, including an AI, for up to a total of 10 years of adjuvant endocrine treatment. Many women with node-negative breast cancer should consider extended therapy for up to a total of 10 years of adjuvant endocrine treatment based on considerations of recurrence risk using established prognostic factors. The Panel noted that the benefits in absolute risk of reduction were modest and that, for lower-risk node-negative or limited node-positive cancers, an individualized approach to treatment duration that is based on considerations of risk reduction and tolerability was appropriate. A substantial portion of the benefit for extended adjuvant AI therapy was derived from prevention of second breast cancers. Shared decision making between clinicians and patients is appropriate for decisions about extended adjuvant endocrine treatment, including discussions about the absolute benefits in the reduction of breast cancer recurrence, the prevention of second breast cancers, and the impact of adverse effects of treatment. Additional information can be found at www.asco.org/breast-cancer-guidelines .

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.

Adjuvant endocrine therapy for women with hormone receptor-positive breast cancer: american society of clinical oncology clinical practice guideline focused update.

PURPOSE: To update the ASCO clinical practice guideline on adjuvant endocrine therapy on the basis of emerging data on the optimal duration of treatment, particularly adjuvant tamoxifen. METHODS: ASCO convened the Update Committee and conducted a systematic review of randomized clinical trials from January 2009 to June 2013 and analyzed three historical trials. Guideline recommendations were based on the Update Committee's review of the evidence. Outcomes of interest included survival, disease recurrence, and adverse events. RESULTS: This guideline update reflects emerging data on duration of tamoxifen treatment. There have been five studies of tamoxifen treatment beyond 5 years of therapy. The two largest studies with longest reported follow-up show a breast cancer survival advantage with 10-year durations of tamoxifen use. In addition to modest gains in survival, extended therapy with tamoxifen for 10 years compared with 5 years was associated with lower risks of breast cancer recurrence and contralateral breast cancer. RECOMMENDATIONS: Previous ASCO guidelines recommended treatment of women who have hormone receptor-positive breast cancer and are premenopausal with 5 years of tamoxifen, and those who are postmenopausal a minimum of 5 years of adjuvant therapy with an aromatase inhibitor or tamoxifen followed by an aromatase inhibitor (in sequence). If women are pre- or perimenopausal and have received 5 years of adjuvant tamoxifen, they should be offered 10 years total duration of tamoxifen. If women are postmenopausal and have received 5 years of adjuvant tamoxifen, they should be offered the choice of continuing tamoxifen or switching to an aromatase inhibitor for 10 years total adjuvant endocrine therapy.

American Society of Clinical Oncology clinical practice guideline: update on adjuvant endocrine therapy for women with hormone receptor-positive breast cancer.

PURPOSE: To develop evidence-based guidelines, based on a systematic review, for endocrine therapy for postmenopausal women with hormone receptor-positive breast cancer. METHODS: A literature search identified relevant randomized trials. Databases searched included MEDLINE, PREMEDLINE, the Cochrane Collaboration Library, and those for the Annual Meetings of the American Society of Clinical Oncology (ASCO) and the San Antonio Breast Cancer Symposium (SABCS). The primary outcomes of interest were disease-free survival, overall survival, and time to contralateral breast cancer. Secondary outcomes included adverse events and quality of life. An expert panel reviewed the literature, especially 12 major trials, and developed updated recommendations. RESULTS: An adjuvant treatment strategy incorporating an aromatase inhibitor (AI) as primary (initial endocrine therapy), sequential (using both tamoxifen and an AI in either order), or extended (AI after 5 years of tamoxifen) therapy reduces the risk of breast cancer recurrence compared with 5 years of tamoxifen alone. Data suggest that including an AI as primary monotherapy or as sequential treatment after 2 to 3 years of tamoxifen yields similar outcomes. Tamoxifen and AIs differ in their adverse effect profiles, and these differences may inform treatment preferences. CONCLUSION: The Update Committee recommends that postmenopausal women with hormone receptor-positive breast cancer consider incorporating AI therapy at some point during adjuvant treatment, either as up-front therapy or as sequential treatment after tamoxifen. The optimal timing and duration of endocrine treatment remain unresolved. The Update Committee supports careful consideration of adverse effect profiles and patient preferences in deciding whether and when to incorporate AI therapy.