East Asian Herbal Medicine to Reduce Primary Pain and Adverse Events in Cancer Patients : A Systematic Review and Meta-Analysis With Association Rule Mining to Identify Core Herb Combination

Systematic review and meta-analysis of 36 randomized controlled trials conducted in China in patients with primary cancer pain from various cancer types. The review compared ECCM versus conventional medicine and EAHM monotherapy versus conventional medicine, with no restriction by age or sex in the included trials.

Oral East Asian herbal medicine (EAHM) was evaluated either as monotherapy or added to conventional medicine (ECCM). The active regimens were given in capsule, powder, granule, or decoction form, typically once to four times daily for the trial-specific treatment period, and were compared with conventional medicine alone.

EAHM combined with conventional medicine was beneficial overall for cancer pain management. In ECCM versus conventional medicine, response rate improved (RR 1.06, 95% CI 1.04 to 1.09), continuous pain intensity decreased (SMD -1.74, 95% CI -2.17 to -1.30), duration of pain relief increased (SMD 0.96, 95% CI 0.69 to 1.22), Karnofsky performance status improved (WMD 10.71, 95% CI 4.89 to 16.53), and opioid use decreased (MD -20.66, 95% CI -30.22 to -11.10). Adverse events were also reduced across several symptom categories. EAHM monotherapy showed a smaller and less robust benefit, with continuous pain intensity improved (SMD -0.50, 95% CI -0.74 to -0.26) but response rate was not clearly significant (RR 1.03, 95% CI 0.99 to 1.07). The authors concluded that EAHM-combined therapy can be considered an option for cancer pain management, but better randomized trials are needed.

Overall evidence quality was low to moderate, and the methodological quality of the included trials was generally poor. Substantial heterogeneity was present for several outcomes, especially pain intensity, duration of pain relief, performance status, and opioid use. EAHM monotherapy evidence was limited and less consistent than combination therapy, and outcome reporting varied across studies.