title: Adjuvant endocrine therapy in hormone receptor-positive postmenopausal breast cancer: evolution of NCCN, ASCO, and St Gallen recommendations.
abstract: Endocrine therapy has a firm role in adjuvant treatment of women with hormone receptor-positive invasive breast cancer. Until recently, tamoxifen was the most commonly used adjuvant endocrine therapy in premenopausal and postmenopausal women. Several randomized clinical trials have studied the third-generation selective aromatase inhibitors (AIs) (anastrozole, letrozole, and exemestane) as adjuvant endocrine therapy in postmenopausal women. These studies compared therapy with an AI alone versus tamoxifen alone; 2 to 3 years of tamoxifen followed by switching to an AI versus continuation of tamoxifen; or extended therapy with an AI after approximately 5 years of tamoxifen therapy. No statistically significant differences in overall survival were observed. A single trial using extended treatment with an adjuvant AI suggests a small, statistically significant survival advantage in women with axillary lymph node-positive disease while showing no statistically significant decrease in survival with the use of an AI. The toxicities of the AIs are generally acceptable, with fewer endometrial cancers, gynecologic complaints, and thromboembolic events, but more bone fractures and arthralgias compared with tamoxifen alone. Three widely disseminated treatment guidelines, the National Comprehensive Cancer Network Breast Cancer Clinical Practice Guidelines in Oncology, the American Society of Clinical Oncology Technology Assessment on the Use of Aromatase Inhibitors, and the St Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer, now incorporate AIs in the adjuvant therapy of postmenopausal women with estrogen receptor-positive breast cancer.
authors.affiliation: Department of Medicine, Stanford University, 875 Blake Wilbur Drive, Stanford, CA 94305-5826, USA. rcarlson@stanford.edu
authors.forename: Robert W
authors.initials: RW
authors.lastname: Carlson
authors.forename: Clifford A
authors.initials: CA
authors.lastname: Hudis
authors.forename: Kathy I
authors.initials: KI
authors.lastname: Pritchard
mesh_terms: D005260:Female; D006801:Humans; D018931:Antineoplastic Agents, Hormonal / Q000592:standards / Q000627:therapeutic use; D047072:Aromatase Inhibitors / Q000592:standards / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy; D017024:Chemotherapy, Adjuvant; D006287:Health Planning Guidelines; D017698:Postmenopause; D017410:Practice Guidelines as Topic; D016032:Randomized Controlled Trials as Topic; D020845:Selective Estrogen Receptor Modulators / Q000592:standards / Q000627:therapeutic use; D012955:Societies, Medical; D013629:Tamoxifen / Q000592:standards / Q000627:therapeutic use; D014481:United States; D003245:Consensus Statements as Topic
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D020845:Selective Estrogen Receptor Modulators; D013629:Tamoxifen