Eur J Cancer. 2006 Feb;42(3):282-9. Epub 2006 Jan 11. Efficacy of homeopathic therapy in cancer treatment. Milazzo S, Russell N, Ernst E. Official summary: Department of Complementary Medicine, Peninsula Medical School, Universities of Exeter and Plymouth, Institute of Health and Social Care, 25 Victoria Park Road, Exeter EX2 4NT, United Kingdom. firstname.lastname@example.org Many cancer patients use homeopathic approaches to increase their body's ability to fight cancer, improve their physical and emotional well-being, and alleviate their pain resulting from the disease or conventional treatments. Homeopathy is highly controversial as there is no plausible mode of action for these highly diluted remedies. The aim of this systematic review is to summarize and critically evaluate the efficacy of homeopathic remedies used as a sole or additional therapy in cancer care. We have searched the literature using the databases: Amed (from 1985); CINHAL (from 1982); EMBASE (from 1974); Medline (from 1951); and CAMbase (from 1998). Randomised and non-randomised controlled clinical trials including patients with cancer or past experience of cancer receiving single or combined homeopathic interventions were included. The methodological quality of the trials was assessed by Jadad score. Six studies met our inclusion criteria (five were randomised clinical trials and one was a non-randomised study); but the methodological quality was variable including some high standard studies. Our analysis of published literature on homeopathy found insufficient evidence to support clinical efficacy of homeopathic therapy in cancer care. [b] Citation of the Discussion section from the full text article:[/b] Five out of six trials included in this systematic review yielded positive results, which suggest the effectiveness of homeopathic remedies for cancer care. Cancer patients appear to have benefited from homeopathic interventions specifically for chemotherapy-induced stomatitis, radiodermatitis and general adverse events from radiotherapy. Breast cancer survivors, suffering from menopausal symptoms, experienced a general improvement on their quality of life. Among the six studies we included, five were randomised and only one was not randomised. Statistical analysis for significance was performed in all the studies, but only four provided statistical features in their result sections. Oberbaum discussed highly significant differences between the groups regarding duration of symptoms, but no statistical features for those differences were given. This was a pilot study conducted in order to test the rationale for performing a more rigorously designed trial. The study by Kulkarni, investigating the effectiveness of some homeopathic remedies for radiation protection, concluded that the remedies reduced the degree of radiation reaction significantly, but results of their statistical analysis were not shown. This study also lacked complete information regarding patients and remedies, as well as essential methodological details, such as randomisation method. Even trials with a Jadad score of 5 were not devoid of flaws. The small sample size in Jacobs precluded definitive conclusions, and a major flaw in the study was the use of combination remedies in an ongoing daily regimen, without following over-the-counter instructions that suggested to discontinue use if adverse effects occurred. In the trial conducted by Thompson , the high placebo response can probably be related to a type II error in the study, since their sample size was only adequate for detecting large differences in response. Of the 6 trials included in this systematic review, only two reported statistically significant positive results of their primary outcomes. One of these was a RCT conducted by Oberbaum that showed encouraging results confirming the need to perform the trial on a larger scale. The other study was the RCT carried out by Balzarini , although this trial showed statistically significant differences in favour of the intervention group, these differences were not consistently observed at all time points. The rest of the studies indicated a positive trend towards homeopathic interventions for improvements in quality of life and symptom management, which seems to justify further investigations. Homeopathic remedies are thought to trigger the bodys own defence and self-regulatory response. However, their mode of action is unclear. As homeopathic remedies are often diluted beyond Avogadros number, no pharmacological action can be expected. Sceptics therefore insist that homeopathy s clinical success is solely due to a placebo response [ Homeopaths counter this criticism by postulating that homeopathic remedies work through mechanisms other than pharmacological ones . The evidence for homeopathic remedies in cancer care may not be fully conclusive but it does seem to warrant further study. Clinical trials of homeopathy should be rigorously designed to minimize bias. The existing trials have a number of limitations, e.g. sample size, which should be addressed in future research. Such research can be expensive and it is therefore a precondition that adequate research funds for homeopathy are made available. Considering that positive results have been obtained in some cases using the controversial remedy ‘‘Carcinosin’’ (a carcinogenic substance) and in some animals studies investigating the possible anticancer effect of homeopathic interventions, further studies testing homeopathy for tumour response should also be undertaken. The main limitation of our systematic review is the lack and sometimes poor quality of the primary data. The studies we evaluated were highly heterogeneous in virtually every respect. In some studies, individualized remedies were applied. Although individualization of therapy allows homeopathy to be practiced in its traditional fashion, this increases the complexity of comparing outcomes. In conclusion, the evidence emerging from this systematic review is encouraging but not convincing. Further research should attempt to answer the many open questions related to homeopathy.