Abstract: We included five RCTs (285 participants). Three studies were included in the original review and two more in the update. The authors of the included studies reported benefits of acupuncture in managing pancreatic cancer pain; no difference between real and sham electroacupuncture for pain associated with ovarian cancer; benefits of acupuncture over conventional medication for late stage unspecified cancer; benefits for auricular (ear) acupuncture over placebo for chronic neuropathic pain related to cancer; and no differences between conventional analgesia and acupuncture within the first 10 days of treatment for stomach carcinoma. All studies had a high risk of bias from inadequate sample size and a low risk of bias associated with random sequence generation. Only three studies had low risk of bias associated with incomplete outcome data, while two studies had low risk of bias associated with allocation concealment and one study had low risk of bias associated with inadequate blinding. The heterogeneity of methodologies, cancer populations and techniques used in the included studies precluded pooling of data and therefore meta-analysis was not carried out. A subgroup analysis on acupuncture for cancer-induced bone pain was not conducted because none of the studies made any reference to bone pain. Studies either reported that there were no adverse events as a result of treatment, or did not report adverse events at all. There is insufficient evidence to judge whether acupuncture is effective in treating cancer pain in adults.

Plain-language summary: We searched a wide range of electronic medical databases up to July 2015 for relevant studies. We included studies written in any language that included adults and compared treatment with acupuncture for cancer pain against no treatment, or usual treatment, or sham acupuncture, or other treatments. Since we were only interested in robust research, we restricted our search to randomised controlled trials (in which participants are randomly allocated to the methods being tested). We found five studies (with a total of 285 participants) that compared acupuncture against either sham acupuncture or pain-killing medicines. All five identified studies had small sample sizes, which reduces the quality of their evidence. One pilot study was well designed, but was too small to identify any differences in pain in women with ovarian cancer after electroacupuncture or a sham treatment. One study found that auricular (ear) acupuncture reduced cancer pain when compared with sham auricular acupuncture that was given at non-acupuncture points. However, the people in the sham acupuncture group could have been aware that they were not in the real acupuncture group and this could have affected the level of pain they reported. Another study found a difference between an electroacupuncture group and sham group in people with pancreatic cancer but again, there was no reported attempt to conceal which group people were in. One study found that acupuncture was as effective as pain-killing medication, and one study found that acupuncture was more effective than medication, but both studies were poorly designed and the study reports lacked detail. None of the studies described in this review were big enough to produce reliable results. None of the studies reported any harm to the participants. We conclude that there is insufficient evidence to judge whether acupuncture is effective in relieving cancer pain in adults. Larger, well-designed studies are needed to provide evidence in this area.