Acupuncture and Derived Therapies for Pain in Palliative Cancer Management: Systematic Review and Meta-Analysis Based on Single-Arm and Controlled Trials.

Background: Acupuncture is a classical complementary therapy, but benefits in palliative cancer pain are still unclear due to lack of consistent evidence. Objectives: To comprehensively evaluate the effectiveness of acupuncture and derived therapies (such as electroacupuncture, laser acupuncture, and transcutaneous electrical nerve stimulation) for analgesia in palliative cancer care based on both single-arm and controlled trials. Design: Eight databases were searched from inception to August 31, 2020. Both single-arm trials and controlled trials were included. The primary outcome was the change in pain intensity, as evaluated by the numeric rating scale (NRS) and the visual analog scale. Subjects: Adults with cancer. Results: Forty-one controlled studies with 2685 participants and 18 single-arm studies with 1084 participants were included. For controlled trials, meta-analysis indicated that acupuncture and derived therapies in addition led to greater reductions in the NRS score than conventional analgesics alone (weighted mean difference [WMD]: 1.33 [0.85-1.82], p  < 0.001). For single-arm trials, meta-analysis showed that both the immediate effect (WMD: 1.57 [1.43-1.71], p  < 0.001) and long-term longitudinal effect (WMD: 1.81 [1.25-2.37], p  < 0.001) of acupuncture on analgesia were positive, as evaluated by the NRS, respectively. The benefits of acupuncture and derived therapies were also seen in quality of life and the global improvement rate. LI4 (Hegu) was the most frequently used acupoint. Conclusions: This systematic review supported the application of acupuncture and derived therapies for managing pain during palliative cancer care from two dimensions. Further studies could explore the effect of acupuncture on other predominant symptoms in palliative cancer patients.