Chemotherapy-induced nausea and vomiting (CINV) are the side effects most feared by cancer patients — and one of the principal reasons for treatment abandonment. Even with the advance of modern antiemetics (5-HT3 antagonists, NK1 antagonists, dexamethasone), a significant share of patients still experience uncontrolled CINV, especially in the delayed phase (24–120 hours after chemotherapy) and in subsequent cycles. A meta-analysis published in Cancer Medicine in 2023, pooling 38 randomized clinical trials with 2,503 patients, offers a comprehensive overview of acupuncture efficacy as adjuvant therapy in CINV control.
The study was conducted by Yan and colleagues and systematically searched for evidence in multiple databases, including PubMed, Cochrane Library, EMBASE, CNKI, and Wanfang. Only RCTs that evaluated acupuncture — alone or in combination with usual care — versus usual care alone, for prevention or treatment of nausea and vomiting associated with chemotherapy in adults with cancer, were included. Methodologic quality was assessed by validated risk-of-bias tools. The total of 38 RCTs represents one of the largest bodies of evidence available on the topic, covering different cancer types, chemotherapy regimens, and acupuncture protocols.
RESULTS OF THE ACUPUNCTURE META-ANALYSIS FOR CINV (CANCER MEDICINE, 2023)
Methodology: Which Studies Were Included?
The authors applied rigorous inclusion criteria: only RCTs with usual-care control group (no acupuncture), primary outcome of complete control of vomiting (total absence of emetic episodes) or secondary outcomes such as number of vomiting episodes, intensity of nausea, and quality of life. Studies that compared acupuncture with sham acupuncture were analyzed separately to control for placebo effect. Heterogeneity across studies was substantial, reflecting variability in acupuncture protocols (number of sessions, selected acupoints, stimulation techniques) and in chemotherapy regimens (highly emetogenic vs. moderately emetogenic).
Outcomes were stratified into acute phase (0–24 hours after chemotherapy) and delayed phase (24–120 hours). This distinction is clinically important: in the acute phase, modern antiemetics already have reasonable efficacy; it is in the delayed phase that acupuncture demonstrated the most striking benefit (RR 1.47), precisely the period in which NK1 antagonists have greatest impact. The temporal overlap between acupuncture mechanisms (vagal modulation, beta-endorphin release, action on the nucleus of the solitary tract) and the mechanisms of delayed CINV (mediated by substance P and NK1) suggests possible physiologic complementarity.
Acupoints and Protocols: what the Literature Shows
The 38 RCTs used 24 different acupoints, but three emerged as the most frequent: ST-36 (Zusanli, in the tibialis anterior muscle), PC-6 (Neiguan, in the anterior forearm), and CV-12 (Zhongwan, in the upper-middle abdomen). This concentration around acupoints established by traditional Chinese medicine for gastric regulation is relevant: PC-6 has specific evidence for nausea of multiple etiologies (pregnancy, postoperative, motion sickness), and ST-36 has documented effects on gastrointestinal motility and the neuroendocrine axis. The diversity of 24 acupoints across the 38 studies, however, is also a limitation: it makes synthesis of an optimized protocol difficult and suggests that real clinical practice uses individualized combinations that standardized RCTs do not fully capture.
Session frequency and duration varied widely: from one application per chemotherapy cycle to daily sessions throughout the duration of treatment. The authors were unable to identify a clear dose-response, which limits the definition of an optimal protocol. In clinical practice, the medical acupuncturist tends to adjust frequency according to the chemotherapy cycle — applying acupuncture in the 24–48 hours preceding and the 48–72 hours following infusion to cover both the acute and delayed phases.
Frequently Asked Questions
No. Current evidence positions acupuncture as adjuvant therapy — added to the standard antiemetic protocol (5-HT3 antagonists, dexamethasone, and, when indicated, NK1 antagonists), not substitutive. None of the 38 RCTs evaluated in this meta-analysis was designed to assess acupuncture in substitution for antiemetics. The benefit demonstrated is additional: patients already receiving optimal antiemetic care have even better control when acupuncture is integrated.
The risk exists but is manageable with adequate protocol. In the context of neutropenia (neutrophils <500/mm³), case-by-case evaluation is recommended. Technical adaptations include: fine-gauge needles (0.16–0.20 mm), reduced depth, immediate single-use disposal, rigorous hygiene of the insertion site with antiseptic. The medical acupuncturist must have access to the patient’s recent complete blood count and coordinate with the oncologist on safe windows for sessions, ideally outside leukocyte nadir periods.
The 38 RCTs included in this meta-analysis covered different chemotherapy regimens, from highly emetogenic (cisplatin, high-dose cyclophosphamide) to moderately emetogenic. The results were consistent across the analyzed subgroups, but the effect was numerically more striking in highly emetogenic regimens — exactly where additional benefit is most needed. For low-emetogenicity chemotherapies with good conventional antiemetic response, the role of acupuncture may be less pronounced, although the favorable safety profile justifies offering it.
Founded in 1989 by physicians trained at the University of São Paulo (USP) and specialized in China, CEIMEC is a Brazilian national reference in the teaching and practice of medical acupuncture. With more than 3,000 physicians trained over 35 years, it collaborates with HC-FMUSP and is recognized by the Brazilian Medical College of Acupuncture (CMBA/AMB).