Literature Search Strategy
MEDLINE was searched through to May 9, 2007 using a disease-specific medical subject heading (MeSH) descriptor ("breast neoplasms"), a treatment-specific descriptor ("chemotherapy, adjuvant"), and agent-specific descriptors ("aromatase/antagonists and inhibitors"). The Excerpta Medica database (EMBASE) was also searched through to May 9, 2007 using a disease-specific Excerpta Medica Tree (EMTREE) term ("breast cancer"), a treatment-specific keyword ("adjuvant chemotherapy"), and agent-specific terms ("anastrozole" or "letrozole" or "exemestane"). These terms and various synonyms were then combined with search terms for the following publication types: randomized controlled trial, systematic review, or meta-analysis.
The Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews were also searched through to May 9, 2007. Online conference proceedings from the American Society of Clinical Oncology (ASCO) Annual Meetings from 1999 to 2006 (http://www.asco.org) and the San Antonio Breast Cancer Symposia from 2001 to 2006 (http://www.sabcs.org) were also searched.
Relevant articles and abstracts were selected by one reviewer. The reference lists from all sources were searched for additional trials.
Study Selection Criteria
Articles were selected for inclusion in this systematic review, based on the following criteria:
- Third-generation aromatase inhibitors (anastrozole, letrozole, or exemestane) as adjuvant therapy were evaluated in a randomized controlled trial or meta-analysis.
- Trial primary outcomes included disease/event/relapse-free survival and/or overall survival.
- Clinical trial results were reported in full papers or abstracts.
Non-English trials were excluded, as transition capabilities were not available. Also, in order to concentrate on the most relevant data, trials designed solely to study toxicity or quality of life with no efficacy outcome were excluded from data abstraction, although their references are reported in the original guideline document.