Summary of demographic information of the included studies
| Author/year | Country | Type | Age (years) | N | Indication | Intervention | Assessment tool | Treatment sessions | Provider | Efficacy | Adverse events | Evidence level* |
| Miller et al 201943 | USA | Retrospective chart review | 31–89 | 68 | Cancer-related pain | Traditional acupuncture/Seirin filiform needles | Edmonton Symptom Assessment Scale (ESAS) | 15–40 min/ treatment， median number of treatments was 2 (range 1–13) | Palliative medicine physician certified in medical acupuncture | Acupuncture improved cancer-related pain and other symptoms | Not reported | 4 |
| Lim et al 201142 | Canada | Pilot RCT | 31–81 | 20 | Advanced cancer pain | Electroacupuncture | (ESAS) | 20 min/ treatment weekly for 4 weeks | Principal investigator, a radiation oncologist and a certified medical acupuncturist | Acupuncture had an immediate effect on all symptoms including pain and it was well tolerated | Leg stiffness; falling asleep sensation | 2 |
| Dean-Clower et al 201045 | USA | Pilot prospective trial | >21 | 32 | Advanced cancer pain | Acupuncture | Brief Pain Inventory | 12 acupuncture sessions over 8 weeks | Licensed acupuncturists | Patients’ pain severity and pain interference scores were significantly improved | None | 3 |
| Johnstone et al 200241 | USA | Retrospective chart review | 19–80 | 41 | Cancer or cancer-related pain | Traditional Chinese acupuncture, auricular acupuncture, percutaneous electrical nerve stimulation, and Korean hand and Japanese scalp acupuncture+standard allopathic care | Visual Analogue Scale | Unknown number of acupuncture sessions over 4 months | Licensed physician; acupuncturist | 55% pain patients showed at least 30% improvement, and 33% showed at least 80% improvement | None | 4 |
| Dillon and Lucas 199944 | UK | Non-randomised cohort study | 22–78 | 28 | Malignant bone pain | Auricular stud acupuncture/Seirin semipermanent press needle | Subjective assessment of pain relief (0–4 scale) | 2-week intervals for 4 weeks | – | Auricular acupuncture significantly reduced pain levels | None | 3 |
*Levels of Evidence based on the Quality Rating Scheme for Studies and Other Evidence modified from the Oxford Centre for Evidence-Based Medicine for rating of individual studies; available online at https://www.cebm.net/2016/05/ocebm-levels-of-evidence/.
RCT, randomised controlled trial.