Breast cancer is the second cause of
cancer mortality worldwide and there is an unmet need for novel
anticancer agents.
Lapatinib is a novel
tyrosine kinase inhibitor for treatment of
breast cancer with
human epidermal growth factor receptor 2 (HER2) amplification. Given promising results in clinical studies, we investigated the survival benefits of
lapatinib use in patients with HER2-overexpressing advanced or metastatic
breast cancer. We searched MEDLINE, EMBASE, American Society of Clinical Oncology Meeting proceedings, San Antonio
Breast Cancer Symposia proceedings, and the Cochrane Library between 2000 and 2008 for randomized controlled trials where
lapatinib was used as single agent or in combination with or following other
therapies. Three trials (n=704) met the inclusion criteria. Study quality was assessed by two independent reviewers and meta-analyses were conducted. Significant differences were observed between
lapatinib-containing treatments to those without
lapatinib in terms of survival. Pooled estimates suggested the hazard ratios of 0.61 [95% confidence interval (CI): 0.50-0.74] for progression-free survival and 0.76 (95% CI: 0.60-0.97) for overall survival. Objective response rate and clinical benefit rate also showed significant differences in favoring the use of
lapatinib with odds ratios of 2.15 (95% CI: 1.48-3.11) and 2.23 (95% CI: 1.59-3.12), respectively. Heterogeneity between studies was not observed. In conclusion, addition of
lapatinib to conventional anticancer treatment might offer superior survival benefit to patients with advanced metastatic HER2-overexpressing
breast cancer. Further investigations on the use of
lapatinib in combination with
anticancer agents are warranted.