摘要Background:Pain associated with cancer is one of the greatest causes of reduced quality of life in patients.Acupuncture is one of the treatments used to address this issue,with the great advantage of having little or no side effects,especially when compared with pharmacological pain-killers.Objective:The aim of this systematic review and meta-analysis was to evaluate the current evidence regarding the efficacy of acupuncture for cancer pain.Search strategy:Six electronic databases(PubMed,EBSCO,Cochrane Library,Scielo,b-On and Scopus)were searched for relevant articles about pain relief in cancer patients from their beginning until 2022 using MeSH terms such as"acupuncture,""electroacupuncture,""ear acupuncture,""acupuncture anal-gesia,""oncological pain,"and"cancer pain."Inclusion criteria:Studies included were randomized controlled trials(RCTs)where acupuncture was compared with no treatment,placebo acupuncture or usual care.Data extraction and analysis:Three independent reviewers participated in data extraction and evaluation of risk of bias,and a meta-analysis was conducted.The primary outcome was pain intensity,measured with the visual analog scale,numeric rating scale,or brief pain inventory.Secondary outcomes also assessed were quality of life,functionality,xerostomia,pain interference,and analgesic consumption.Results were expressed as standardized mean difference(SMD)with 95% confidence interval(CI).Results:Sixteen RCTs with a total of 1124 participants were included in the meta-analysis,with the majority of the studies presenting a low or unclear risk of bias.Acupuncture was more effective in reduc-ing pain than no treatment(SMD=-0.90,95% CI[-1.68,-0.12]),sham acupuncture(SMD=-1.10,95% CI[-1.59,-0.61])or usual care(SMD=-1.16,95% CI[-1.38,-0.93]).Conclusion:The results of this study suggest that acupuncture may be an effective intervention to reduce pain associated with cancer.Despite some limitations due to the low quality and small sample size of some included studies,as well as the different types and stages of cancer,acupuncture might provide an effective and safe treatment to reduce cancer pain.