Comment on ‘Efficacy and Safety of Different Acupuncture Treatments for Cancer-Related Pain: A Systematic Review and Network Meta-Analysis’

To the Editor,

We read with great interest the recent article by Xie et al ¹ on the use of various acupuncture therapies for cancer-related pain. By synthesizing data from 111 randomized controlled trials (RCTs) involving a total of 9539 patients, the authors compared 29 different treatment modalities across 6 outcome indicators, highlighting the respective advantages of different acupuncture methods. We sincerely congratulate the authors on publishing an outstanding systematic review and network meta-analysis in Integrative Cancer Therapies. While this study provides valuable insights, we would like to highlight several methodological and clinical concerns that warrant further discussion.

First, the inclusion criteria of this study specified participants as patients with pathologically diagnosed cancer. However, the objective of the study was to compare the efficacy of various acupuncture interventions specifically for cancer-related pain. This broad inclusion may dilute the analysis, as not all cancer patients experience pain. Upon careful review of the included studies, we noted that several references (eg, references 57, 59, 96, and 104) included participants with cancer but not necessarily those suffering from cancer-related pain. These studies may therefore be irrelevant to the study’s objective and should be further validated.

Second, the duration of interventions among the included studies varied widely—from as short as 1 day to as long as 15 weeks. Dose is a critical factor influencing the efficacy of acupuncture interventions and clearly defining the time points for outcome evaluation could enhance the reliability of the findings. ² Moreover, some of the included studies had very small sample sizes, with the smallest comprising only seven participants (eg, reference 20). The effect estimates from such small-sample studies may be unstable and could potentially skew the combined results. ³

Third, the analysis did not consider the variation in pain severity or types of pain experienced by cancer patients. Cancer-related pain encompasses neuropathic, nociceptive, and mixed pain, each requiring tailored management. We recommend that the authors conduct subgroup analyses based on pain severity and type to further clarify their findings. ⁴

Finally, considering the noticeable asymmetry in the funnel plot, we suggest that more objective tests such as Begg’s and Egger’s should be used to identify potential publication bias in the network meta-analysis.

In conclusion, we sincerely appreciate the collective efforts of Xie et al in advancing the evidence on acupuncture therapies for cancer-related pain. Their work represents a meaningful contribution to this clinically relevant field. Nevertheless, we hope that the issues we have raised may help improve the accuracy and generalizability of the study’s findings.

Xiaoying Wang*, Qiongying Shen*, Xinyi HuThe Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China Yi Liang The Third Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China The Third Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China *These authors contributed equally to this work.