OBJECTIVE: As an antipsychotic agent that targets multiple neurotransmitter receptors, olanzapine has been added to antiemetic therapies. For better understanding the application of olanzapine in antiemetic strategies for breast cancer patients who suffered anthracycline plus cyclophosphamide-induced nausea and vomiting, we comprehensively reviewed the antiemetic researches related to olanzapine and pooled-analyzed the results to confirm the efficacy and safety of olanzapine in breast cancer.
METHODS: PubMed, Web of Science, EMBASE, and Cochrane CENTRAL databases were searched from inception through Sep 15, 2021. Both prospective and retrospective studies were eligible. The primary outcomes were complete response (defined as no vomiting and no use of rescue medications) and no nausea rate, and the secondary outcome was treatment-related adverse events.
RESULTS: Four studies with 466 breast cancer patients were identified in the pooled analysis. In the acute period (0-24 h), the olanzapine group had significantly higher rates of complete response (71.3% vs 48.1%, odds ratio [OR]: 2.66, 95% confidence interval [CI] 1.39-5.11, p = 0.003) and no nausea (70.0% vs 43.0%, OR: 3.55, 95% CI 1.76-7.18, p = 0.04) than the placebo group, while in the delayed period, the olanzapine group was also superior to the placebo group in terms of the complete response (82.5% vs 63.3%, OR: 3.81, 95% CI 1.58-9.15, p = 0.003) and no nausea (66.3% vs 51.9%, OR: 2.08, 95% CI 1.03-4.21, p = 0.04) rates. During the overall period in prospective studies, the proportions of complete response (50.0% vs 34.2%, OR: 1.93, p = 0.04) and no nausea (51.3% vs 25.3%, OR: 3.40, p = 0.0006) in the olanzapine group were higher than those in the placebo group.
CONCLUSIONS: Highly emetogenic chemotherapy breast patients could benefit from olanzapine-contained antiemetic therapy. Furthermore, since the cost is low, olanzapine is worth further clinical application and promotion.