Background: A systematic review was undertaken to evaluate the evidence for the use of trastuzumab as (neo)adjuvant therapy for women with HER-2/neu-positive breast cancer and to develop and support recommendations pertaining to its use across five domains: as a single-agent therapy, in combination with chemotherapy, methods to identify women who will benefit from it, adverse events associated with it, and optimal dose, schedule, and duration.
Methods: MEDLINE, EMBASE, the American Society of Clinical Oncology, the San Antonio Breast Cancer Symposia proceedings, and the Cochrane Library were searched through May 2007 for reports of randomized controlled trials that met the inclusion criteria.
Results: Eight randomized trials, described across 23 citations, were identified. All six trials of adjuvant trastuzumab reported significantly improved disease-free survival (DFS) while 4 of 6 adjuvant trials showed significant improvement in overall survival (OS) for patients treated with trastuzumab over those that were not. Two trials of trastuzumab in the neoadjuvant setting reported significantly better pathological complete response (pCR) in patients treated with trastuzumab although both studies were limited by small sample size, and longer follow-up is needed.
Conclusion: Although the optimal duration, schedule, and timing of adjuvant trastuzumab remains undefined, the bulk of the available evidence supports that adjuvant trastuzumab be offered for 1 year to all patients with HER-2-positive and node-positive or high-risk node-negative (tumour >or= 1cm in size) primary breast cancer who are receiving or have received (neo)adjuvant chemotherapy.