Mix but don't mismatch: cancer treatments
* Helen Francombe
* From: The Australian
* December 11, 2009 12:00AM
STEPHEN Clarke confesses to being sceptical at the outset of a scientific trial of qigong, a Chinese mind-body practice involving gentle movements, meditation and breathing exercises.
But by the trial's end he couldn't deny there was something real, and good, happening to the cancer patients in the qigong classes led by Byeongsong Oh.
Oh, a traditional Chinese medicine practitioner, is lead author of the study, published in the journal Annals of Oncology.
"Patients kept telling us `I really feel better' and they had less fatigue and better mood," says professor Clarke, paper co-author and oncologist at the Sydney Cancer Centre and head of the Concord Hospital clinical school.
But even more surprising were the reductions in patients' blood levels of CRP, or C-reactive protein, compared with the patients who did not do qigong. The protein is a measure of inflammation in the body, which can be related to cancer activity.
The patients doing qigong also had better cognitive function, less pain and less nausea and vomiting after chemotherapy, Oh says.
"They were really quite exciting results," says Clarke, who was so impressed that qigong classes are now offered to patients at the Sydney Cancer Centre. Oh will also run classes at Sydney Adventist Hospital, Concord Hospital and Royal North Shore Hospital in the new year.
In the traditional Chinese medicine model, qigong is described as increasing the flow of energy throughout the body. But in Western medicine the effect could be explained in terms of the "relaxation response", where reducing emotional and physical tension leads to better immune function, Clarke says.
While this trial is a story of harmonious Western medicine and complementary therapy, that's not always the case. As Clarke notes, almost every second patient coming in for chemotherapy is taking some kind of complementary medicine or supplement that could interfere with treatment by making it less effective or more toxic. The problem is that often their doctors don't know.
"Complementary medicine is a $2 billion industry in Australia, so there are a lot of people using it, but a fair percentage of those are not telling their doctors," says Clarke, who spoke about complementary medicines at the Clinical Oncological Society of Australia's recent conference on the Queensland Gold Coast.
Many patients feel uncomfortable talking about their complementary medicines with their doctors because they sense a dismissive attitude and this can lead to a dangerous breakdown in communication, he says. "Cancer clinicians need to take their patients' interest in alternative therapies seriously, while patients need to understand that mixing conventional and unconventional therapies can reduce the efficacy of prescription medicines and increase overall drug toxicity."
For example, some herbal supplements can change the way patients' bodies absorb or excrete their chemotherapy drugs. If excretion is slowed down, they could get much more toxicity from the drug, and if excretion is sped up, the drug could be out of their system too fast to do its job properly.
Geeta Sandhu is a cancer pharmacist and safe medicines specialist at Brisbane's Princess Alexandra Hospital, where all patients attend an information session before they have chemotherapy. Patients are asked to bring in absolutely everything they are taking, including vitamins, supplements and herbs, to head off any potential interactions.
This has proved worthwhile. A one-month survey of cancer patients by Sandhu and her colleagues Trang Le and Janet Weir showed more than half take some kind of complementary medicine, and 84 per cent of these have the potential to cause problems with their cancer treatment. Sandhu says: "When we find patients are taking something with the potential for interaction, we talk it over with them and they usually decide to stop taking the supplement once they have the information."
Antioxidants are a prime example of a popular but problematic supplement, as they can cancel some of the effect of chemotherapy,Sandhu explains. "Chemotherapy drugs work by free radical oxygenation to kill cancer cells and antioxidant supplements mop up these free radicals that chemotherapy tries to create, so they are potentially reducing the efficacy of treatment."
In some cases patients unwittingly take supplements that could stimulate their cancer. For instance, some women with breast cancer take herbal supplements with oestrogen-like effects to help with symptoms of early menopause. Sandhu warns that's dangerous for those who have the kind of breast cancer that's sensitive to oestrogen as the supplement could stimulate their cancer to grow.
Black cohosh, a component of some herbal remedies for menopause symptoms, is one such oestrogenic supplement Sandhu watches out for with women who have breast cancer. She says black cohosh can also cause serious liver problems in some people. "But black cohosh may not be as problematic for women who don't have an oestrogen-sensitive tumour and don't have any risk factors for liver problems, so we have to look at it on a case-by-case basis."
Other supplements that can cause toxicity include apricot kernel extracts (laetrile/amygdalin), which contain small amounts of cyanide and in significant doses could lead to cyanide poisoning.
While there's reasonable evidence about the safety and efficacy of complementary medicines, more is definitely needed, Sandhu says. "The level of evidence is not as solid as we would like; there aren't the big trials we get with drug companies."
"We need more information" is the message COSA gets from its members, says Kathy Ansell, a COSA project co-ordinator who helps facilitate the complementary therapies interest group. "They want their patients to get the best treatment and are keen to see the evidence about what works and what doesn't. It also upsets them to see patients wasting money on things that don't work and, in some cases, using therapies that can be harmful," she says.
Ansell, a former oncology nurse, is working on a website with reliable information about complementary medicines for COSA members, who include oncologists, pharmacists and nurses.
And as reported in Weekend Health last week, University of Sydney pharmacology professors Basil Roufogalis and Andrew McLachlan have teamed up with medical information provider Unity Health to launch an internet database that allows subscribers to search for drug and herb interactions.
Still, for many complementary therapies, the trials simply have not been done, Clarke says.
He argues rigorous trials of complementary therapies offer two benefits: reliable information on efficacy and safety, and more willingness from patients to tell doctors about their complementary therapies. "When patients see that doctors are taking complementary therapies seriously by studying them, they feel they are less likely to get a negative reaction about their own complementary therapies," he says, adding that it's likely that trials of complementary therapies would identify some that are truly effective.
"Many of our conventional cancer drugs are derived from herbs or are based on old remedies, so it is only logical that some other herbal supplements may be of real value," he says.
Cancer Council Australia chief executive Ian Olver would also like to see many more complementary therapies subjected to scientific trials. "We want patients to know about interactions between complementary therapies and medical treatment, and also what they can realistically expect from a therapy because there are some pretty extravagant claims made for some of them."
Apart from potential physical harm, patients can also be hurt in the hip pocket, Olver says, as many complementary therapies aren't cheap.
Self-empowerment is one of the reasons many people with cancer use complementary therapies, but it also has to do with pursuing every last possibility. "We are absolutely not critical of patients exploring these, but we want to make sure they have information about what is useful and what is potentially harmful. Just because it is natural doesn't mean it is safe."
Cancer Council NSW's booklet can be obtained at
www.cancercouncil.com.au or by calling 13 11 20.