The Breast Cancer Disease Site Group of Cancer Care Ontario identified the need for new guidelines for the adjuvant systemic therapy of early-stage breast cancer. The specific question to be addressed was "What is the optimal adjuvant systemic therapy for female patients with early-stage operable breast cancer, when patient and disease factors are considered?" A systematic review was prepared based on literature searches conducted using the medline and embase databases for the period January 2008 to March 5, 2012, and updated to May 12, 2014. Guidelines were located from that search, from the Standards and Guidelines Evidence directory of cancer guidelines, and from the Web sites of major guideline organizations. The literature located was subdivided into the broad categories of chemotherapy, hormonal therapy, and therapy targeted to her2 (human epidermal growth factor receptor 2). Although several of the systemic therapies discussed in this guideline can be considered in the neoadjuvant setting, the review focused on trials with rates of disease-free and overall survival as endpoints and thus excluded several trials that used pathologic complete response as a primary endpoint. Based on the systematic review, the working group drafted recommendations on the use of chemotherapy, hormonal therapy, and targeted therapy; based on their professional experience, they also drafted recommendations on patient and disease characteristics and recurrence risk. The literature review and draft recommendations were circulated to a consensus panel of medical oncologists who had expertise in breast cancer and who represented the regions of Ontario. Items without initial consensus were discussed at an in-person consensus meeting held in Toronto, November 23, 2012. The final recommendations are those for which consensus was reached before or at the meeting. Some of the key evidence was revised after the updated literature search. Evidence reviews for systemic chemotherapy, endocrine therapy, and targeted therapy for her2-positive disease are reported in separate articles in this supplement. The full three-part 1-21 evidence-based series, including complete details of the development and consensus processes, can be found on the Cancer Care Ontario Web site at https://www.cancercare.on.ca/toolbox/qualityguidelines/diseasesite/breast-ebs.
Keywords: Treatment guidelines; adjuvant systemic treatment; chemotherapy; consensus process; early breast cancer; endocrine therapy; her2-targeted therapy.