Breast cancer sufferers using complementary therapies are at risk because the treatments could interact with conventional medicines with potentially dangerous results, doctors warned yesterday.

Breast cancer sufferers using complementary therapies are at risk because the treatments could interact with conventional medicines with potentially dangerous results, doctors warned yesterday.

More than half of women with breast cancer use complementary therapies such as vitamin pills and herbal formulas but few have been evaluated and some may be dangerous, specialists said.

Most women used the therapies to complement conventional treatment but some, such as shark cartilage and the Italian Di Bella therapy, were promoted as cures for cancer which were invariably bogus, they said.

Surveys show that between 50 and 70 per cent of breast cancer patients in England use complementary therapies. The findings are due to be presented to the European Breast Cancer conference in Hamburg today by Gillian Bendelow, reader in medical sociology at the University of Sussex.

Ms Bendelow said: "It is simply not realistic any more for doctors to think that they can ignore complementary and alternative medicines or that they can tell their patients not to use them. Patients appear to be turning to these therapies in increasing numbers and doctors need to take account of [them] when considering treatment options. Half of general practices in England now offer patients some access to complementary or alternative medicines."

Women who chose to use the therapies were in general younger, better educated and better off than those who did not. They used them to give them more control and a greater role in their care, to improve their quality of life and to ensure no stone was left unturned in the search for a cure.

Eric Winer, associate professor of medicine at Harvard University, told the conference that more studies of complementary therapies in cancer were needed. "Issues of safety are critical but in many cases extensive safety evaluation has not been undertaken. Relatively few therapies have been tested in conjunction with standard treatments and this is a serious problem," he said.

Dr Winer cited the example of St John's wort, a widely used herbal treatment for depression, which has been shown to interact with a range of conventional medicines.

Few studies had demonstrated unequivocal benefits for the therapies and some suggested women who used them were more likely to have physical and/or psychological symptoms, Dr Winer said.

Edzard Ernst, Britain's only professor of complementary medicine, at the Peninsula Medical School, Plymouth, told the conference that complementary therapies could ease symptoms but there was little evidence they could prevent or treat breast cancer.

"If an effective therapy such as a herbal medicine emerged it would immediately be taken up by mainstream oncology as happened with Taxol [for ovarian and advanced breast cancer] which came from the yew tree. It follows, almost automatically, that all existing alternative 'cancer cures' are bogus."

Professor Ernst said complementary therapies such as massage, aromatherapy, reflexology and relaxation could improve the quality of life of cancer patients and some, such as acupuncture for the nausea caused by chemotherapy, could combat its ill effects.

But others, marketed as cures, were dangerous. Examples included Essiac (a Canadian herbal mixture), Hoxley formula (also a herbal mixture), mistletoe, laetrile (derived from the seeds of bitter almonds and apricots) and shark cartilage.

"Several of these alleged cures are associated with significant risks, including the adverse effects of herbal remedies, contamination or adulteration, interaction with prescribed drugs and patients choosing an ineffective complementary therapy instead of life-saving conventional treatment," Professor Ernst said.


Di Bella therapy

Professor Luigi Di Bella claims his therapy raises the capacity of cells to defend themselves from cancer and limits the uncontrolled growth of tumour cells. It is based on a combination of somatostatin, vitamins, retinoids, melatonin, and bromocriptine.

Shark cartilage

Some studies have shown that shark cartilage cuts blood flow to tumours, limiting tumour growth.


A generic name for a herbal tea that is one of the most popular alternative remedies for cancer. Proponents believe it improves the body's ability to fight cancer and that it reduces the side-effects of chemotherapy and radiation treatments.

Mistletoe therapy

The European species of mistletoe (above) used in cancer treatment goes under the trade name of Iscador, which apparently stimulates the immune system. Two active ingredients are lectins and viscotoxins that can kill cancer cells and stop them replicating.


The trade name for laevo-mandelonitrile-beta-glucuronoside, this compound is related to amygdalin, a substance found in the pits of apricots.