The Efficacy of Olanzapine-Contained Antiemetic Therapy for Breast Cancer Patients: A Systematic Review and Pooled Analysis

Abstract

Purpose: As an antipsychotic agent that targets multiple neurotransmitter receptors, olanzapine has been added to antiemetic therapies. However, olanzapine is rarely used in the real-world antiemetic strategies for breast cancer patients who suffered chemotherapy-induced nausea and vomiting. Therefore, in this study, we comprehensively reviewed the antiemetic researches related to olanzapine and pooled analyzed the results from clinical studies to confirm the efficacy of olanzapine in preventing nausea and vomiting in breast cancer.Methods: PubMed, Web of Science, EMBASE, and Cochrane Central databases were searched from inception through April 19, 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.Results: Five studies were identified in the systematic review, four of which with 466 breast cancer patients were included in the pooled analysis. In the acute period (0-24 hours), 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. Conclusion: 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.