External application of traditional Chinese medicine in the treatment of bone cancer pain: a meta-analysis

BACKGROUND: Bone cancer pain presents a clinical challenge with limitations of current treatments. Many patients seek additional therapies that may relieve pain. Many external applications of traditional Chinese medicines (EAs-TCMs) have been evaluated in clinical trials, but fewer are known about them outside of China. The objective of this study is to assess the efficacy for bone cancer pain. METHODS: A systematic literature search was conducted in seven databases until December 2014 to identify randomized controlled trials (RCTs) about EAs-TCMs in the treatment of bone cancer pain. The primary outcome was total pain relief rate. The secondary outcomes were adverse events at the end of treatment course. The methodological quality of RCTs was assessed independently using six-item criteria according to the Cochrane Collaboration. All data were analyzed using Review Manager 5.2.0. We included any RCTs evaluating an EA-TCM for the treatment of bone cancer pain. We conducted a meta-analysis. RESULTS: We included six RCTs with 534 patients. In general, the reporting of methodological issues was poor. Compared with morphine sulfate sustained release tablets (MSSRTs) or radiotherapy or bisphosphonates, we analyzed data from five trials reporting on complete response effect score (relative risk (RR) = 5.38, 95 % confidence interval (CI) = 2.80–10.31, P < 0.00001) and partial response (RR = 1.18, 95 % CI = 1.02–1.37, P = 0.02) and six trials reporting on total pain relief rate (RR = 1.49, 95 % CI = 1.43–1.67, P < 0.00001). Six RCTs showed significant effects of EA-TCM for improving pain relief in patients with bone cancer pain. In addition, no severe adverse events were found. CONCLUSION: This systematic review showed positive but weak evidence of EA-TCM for bone cancer pain because of the poor methodological quality and the small quantity of the included trials. Future rigorously designed RCTs are required.