Abstract
BACKGROUND It is generally accepted that taxanes are among the most active chemotherapy agents in the management of metastatic breast cancer. OBJECTIVES To identify and review the randomised evidence comparing taxane containing chemotherapy regimens with regimens not containing a taxane in the management of women with metastatic breast cancer. SEARCH STRATEGY The specialised register maintained by the Editorial Base of the Cochrane Breast Cancer Group was searched on 2nd May 2003 using the codes for "advanced breast cancer", "chemotherapy". Details of the search strategy applied by the Group to create the register, and the procedure used to code references, are described in the Group's module on the Cochrane Library. SELECTION CRITERIA Randomised trials comparing taxane-containing chemotherapy regimens with regimens not containing taxanes in women with metastatic breast cancer. DATA COLLECTION AND ANALYSIS Data were collected from published trials. Studies were assessed for eligibility and quality, and data were extracted, by two independent reviewers. Hazard ratios were derived for time-to-event outcomes where possible, and a fixed effect model was used for meta-analysis. Response rates were analysed as dichotomous variables. Toxicity and quality of life data were extracted where present. MAIN RESULTS Twenty one eligible trials were identified of which 12 have published time-to-event data and 16 have reported response data. The quality of randomisation was generally not described. An estimated 2621 deaths in 3643 randomised women demonstrate a statistically significant difference in favour of taxane-containing regimens with a HR for overall survival of 0.93 (95% CI=0.86-1.00, p=0.05) and no statistically significant heterogeneity. If the analysis is restricted to trials of firstline chemotherapy the HR changes to 0.92 and is no longer statistically significant (95% CI 0.84-1.02, p=0.11). There was also a significant difference in favour of taxanes in relation to time to progression (overall HR 0.92, 95%CI 0.85-0.99, p=0.02) and overall response in assessable women (overall OR 1.34, 95%CI 1.18-1.52, p<0.00001) however there was strong statistical evidence of heterogeneity (P<0.00001), probably reflecting the varying efficacy of the comparator regimens used in the trials. AUTHORS' CONCLUSIONS When all trials are considered, taxane-containing regimens appear to improve overall survival, time to progression and overall response in women with metastatic breast cancer. The degree of heterogeneity encountered indicates that taxane-containing regimens are more effective than some, but not all non-taxane-containing regimens.
