Randomised controlled trials (RCTs) of trastuzumab (in combination with existing (neo)adjuvant chemotherapy or as a single agent) in women with HER-2/neu-positive breast cancer were eligible for inclusion. Trials had to report at least one of the following outcomes: overall response rate; disease-free survival; overall survival; toxicity; and quality of life. Trial results had to be published peer-reviewed articles or publicly available abstracts or presentations.
Six studies were of adjuvant (postoperative) trastuzumab and two of (neo)adjuvant (preoperative) trastuzumab. Most studies used trastuzumab for one year in doses of either 6mg/kg every 21 days or 2mg/kg weekly. Studies used a varied range of concomitant chemotherapy treatments that included drugs such as doxorubicin, cyclophosphamide, docetaxel and 5-fluorouracil. These were also the comparator treatments (either individually or in combination). Non-chemotherapy agents such as tamoxifen were also used. One trial used radiation therapy. Studies used different inclusion criteria, but all patients had either high risk or positive lymph nodes.
The authors stated that three reviewers were involved in the process of selecting studies, but no further details were provided.