Homeopathic medicines for adverse effects of cancer treatments.

Background: Homeopathic medicines are used by patients with cancer, often alongside conventional treatment. Cancer treatments can cause considerable morbidity and one of the reasons patients use homeopathic medicines is to help with adverse effects.

Objectives: Evaluate effectiveness and safety of homeopathic medicines used to prevent or treat adverse effects of cancer treatments.

Search Strategy: The following were searched up to November 2008: Cochrane PaPaS Trials Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CINAHL; BNI; CancerLIT; AMED; CISCOM; Hom-Inform; SIGLE; National Research Register; Zetoc; www.controlled-trials.com; http://clinicaltrials.gov; Liga Medicorum Homeopathica Internationalis (LMHI, Liga) conference proceedings; reference lists of relevant studies were checked; and homeopathic manufacturers, leading researchers and practitioners were contacted.

Selection Criteria: Randomised controlled trials (RCTs) of homeopathic medicines in participants with a clinical or histological diagnosis of cancer where the intervention was aimed at preventing or treating symptoms associated with cancer treatments. All age groups, and all stages of disease were included.

Data Collection And Analysis: Two review authors independently assessed studies for inclusion and two review authors extracted data. Three review authors independently assessed trial quality using the Delphi List and the Cochrane Collaboration's tool for assessing risk of bias. Disagreements were resolved by consensus. Where available, data were extracted for analysis.

Main Results: Eight controlled trials (seven placebo controlled and one trial against an active treatment) with a total of 664 participants met the inclusion criteria. Three studied adverse effects of radiotherapy, three studied adverse effects of chemotherapy and two studied menopausal symptoms associated with breast cancer treatment.Two studies with low risk of bias demonstrated benefit: one with 254 participants demonstrated superiority of topical calendula over trolamine (a topical agent not containing corticosteroids) for prevention of radiotherapy-induced dermatitis, and another with 32 participants demonstrated superiority of Traumeel S (a proprietary complex homeopathic medicine) over placebo as a mouthwash for chemotherapy-induced stomatitis. Two other studies reported positive results, although the risk of bias was unclear, and four further studies reported negative results.No serious adverse effects or interactions were reported attributable to the homeopathic medicines used.

Authors' Conclusions: This review found preliminary data in support of the efficacy of topical calendula for prophylaxis of acute dermatitis during radiotherapy and Traumeel S mouthwash in the treatment of chemotherapy-induced stomatitis. These trials need replicating. There is no convincing evidence for the efficacy of homeopathic medicines for other adverse effects of cancer treatments. Further research is required.