'No convincing evidence' for benefits of homeopathy in cancer treatment
Cancer Research UK has said that there is no convincing evidence that homeopathic medicines are effective in easing the side-effects of cancer treatment, despite a new review suggesting otherwise.
Some patients use homeopathic medicines - which consist of highly diluted substances derived from plants, minerals and animals - in an attempt to relieve the side-effects of conventional anti-cancer therapies, which can include nausea, vomiting, mouth sores, dermatitis and menopausal symptoms.
However, doctors advise that homeopathic medicine should not be taken to treat cancer itself and should only be used to complement cancer treatment if desired.
Researchers for the Cochrane Collaboration - an independent healthcare research organisation - reviewed eight randomised controlled trials involving 664 participants to investigate the safety and effectiveness of homeopathic medicines in people with cancer.
Three of the studies looked at how homeopathic medicines might be of benefit to patients undergoing radiotherapy; another three looked at their impact during chemotherapy; and two studies looked at the use of homeopathy to ease menopausal symptoms during treatment for breast cancer.
The reviewers noted that in one study - involving 256 participants - patients who used calendula ointment instead of a topical agent called trolamine tended to experience less skin irritation following radiotherapy.
Another study - involving just 32 participants - found that a combination of 14 homeopathic medicines called Traumeel S appeared to provide more relief from chemotherapy-induced mouth sores than a placebo (dummy pill).
Two small studies found positive benefits against the side-effects of radiotherapy, but the reviewers warned these may have been biased, while a further two studies did not find any benefits against the adverse effects of chemotherapy.
In the two studies which looked at how homeopathic medicines might help women experiencing menopausal symptoms as a result of breast cancer treatment, reviewers found no evidence of any benefit.
Lead author Dr Sosie Kassab, director of the Royal London Homeopathic Hospital's Complementary Cancer Service, commented: "We found preliminary data that suggest there may be benefit associated with two homeopathic medicines in specific circumstances, although these results need to be replicated in further studies.
"The effects of calendula may also depend on the formulation, as it can be prepared using a range of different methods."
She continued: "At present, there is no convincing evidence to support the use of homeopathic medicines for other adverse effects of cancer treatments. But very little research has been undertaken and more is required."
The review did not uncover any serious side-effects as a result of using homeopathic medicines, however, and Dr Kassab noted that there was "no indication that the homeopathic medicine interfered with conventional cancer care".
None of the studies looked at in the review focussed on the use of homeopathic medicine to treat emotional side-effects of cancer treatment.
Dr Lucille Marchand, clinical director of integrative oncology at the University of Wisconsin Paul P Carbone Comprehensive Cancer Centre, claimed: "If the patient believes strongly in the benefits of the homeopathic medicines, I believe that it has a higher potential of helping the patient."
Professor Edzard Ernst, professor of complementary medicine at the Peninsula Medical School, told the BBC that there were "several problems" with the studies examined by the Cochrane reviewers and that the report "simply confirms plenty of previous research demonstrating the unproven nature of homeopathy".
He explained: "First, independent replications are lacking completely but would be necessary before we can accept any of these treatments in routine healthcare.
"Second, nobody doubts that undiluted remedies can have effects; and interestingly, the positive studies here seem to be on such medicines rather than on the highly diluted treatments which are a hallmark of homeopathy. In fact, the calendula cream found to be effective in one study is not diluted at all and thus it cannot, to all intents and purposes, be considered to be a typical homeopathic remedy.
"Finally, this review found hardly any high quality studies in the first place."
Laura Bell, Cancer Research UK's science information officer, confirmed the review's limitations. She said: "Over the years, research in this area has produced mixed results. In keeping with this, most of the research reviewed in this study was of a low standard and provides no extra insight into the benefits of homeopathy. "One more rigorous study showed a cream might help with skin irritation caused by radiotherapy. Another showed a mouthwash may be able to give relief from mouth sores caused by chemotherapy. But the studies were small and have only been done once. "At the moment there is no convincing evidence that this type of treatment works and we need more scientifically robust evidence to show if homeopathy might help to relieve the side-effects of cancer treatment."