Efficacy of auricular acupressure on chemotherapy-induced nausea and vomiting in breast cancer patients: a systematic review and meta-analysis of randomized controlled trials

Background Breast cancer (BC) constitutes a significant global health challenge. Chemotherapy-induced nausea and vomiting (CINV) severely impact patient quality of life. Current antiemetics, while providing some relief, prove inadequate. Auricular acupressure (AA) , originating from traditional Chinese medicine, demonstrates potential in managing CINV; yet, its efficacy and safety in the context of BC chemotherapy are still uncertain. Methods In compliance with PRISMA 2020 guidelines, we executed a systematic review and meta-analysis, searching PubMed, EMBASE, Cochrane CENTRAL,Web of Science, CNKI, and Wanfang until October 2023. We included randomized controlled trials (RCTs) that compared pure auricular acupressure (AA alone) or AA combined with consistent co-interventions across groups with standard care for BC patients and methodically performed data extraction, risk of bias evaluation, and meta-analysis. To ensure clear attribution of effect, subgroup analyses were performed between AA alone and AA plus other traditional Chinese medicine (TCM) interventions. Results Thirty-one RCTs involving 2,522 participants, predominantly from China, satisfied our inclusion criteria. Notable heterogeneity was detected. Although AA did not markedly decrease acute or delayed vomiting, it significantly enhanced strictly defined complete response (score 0, no symptoms) rates for nausea (RR 1.31; 95% CI 1.16 - 1.47; P < 0.0001) and overall CINV (RR 1.79; 95% CI 1.60 - 2.00; P < 0.0001). Subgroup analysis confirmed that effects were consistent in both AA alone and AA combined with TCM, supporting that AA contributed independently to the improvement. Enhancements were more pronounced with prolonged treatment, higher frequency, and targeted use of specific auricular points. Conclusion AA may improve the comprehensive management of CINV, specifically nausea, not acute or delayed vomiting - among BC chemotherapy patients. The effect can be primarily attributed to auricular acupressure, as subgroup analysis ruled out confounding from combined TCM interventions. Nonetheless, given the methodological constraints, the reliability of this evidence is provisional. Comprehensive, large-scale RCTs are essential to verify these results.