Meta-analysis of phase III trials of docetaxel alone or in combination with chemotherapy in metastatic breast cancer

PURPOSE: Whether combination chemotherapy offers an advantage over sequential therapy in metastatic breast cancer (MBC) is still an unsettled issue. Polychemotherapy regimens containing taxanes has been shown to increase overall survival (OS), time to tumor progression (TTP), and overall response rate (ORR) when compared with regimens that did not contain a taxanes, while taxane-based doublets have a statistically significant benefit over single-agent taxane only for progression-free survival. However, the term "taxanes" generally includes both paclitaxel and docetaxel, drugs with different clinical activity. Aim of this work is to compare OS, TTP, and ORR in patients with MBC receiving docetaxel alone or in combination with chemotherapy using a formal meta-analysis. METHODS: We performed a systematic review of all published trials comparing docetaxel alone or in combination with other chemotherapeutic agents in MBC. RESULTS: Three randomized clinical trials including 1,313 patients were retrieved. A significant reduction of risk ratio was found in TTP (P ≤ 0.0001) but not in OS (P = 0.48) or ORR (P = 0.10) for patients treated with a chemotherapy agent plus docetaxel compared with docetaxel alone. Treatment with docetaxel alone is associated with a lower incidence of grade 3 diarrhea and stomatitis (diarrhea, P = 0.011; stomatitis, P = 0.0004). CONCLUSION: Combination chemotherapy regimens with docetaxel show a statistically significant advantage for TTP, but not for OS and ORR in MBC. This review confirms that it is unlikely that any single agent or combination chemotherapy regimen will emerge as superior in MBC, due to its heterogeneous nature.