Complementary and Alternative Medicines and Cancer

If you are a cancer patient, you’re likely using complementary and alternative medicine (CAM), thinking about using it, or having CAM recommended to you by others. Surveys suggest that CAM use by cancer patients is fairly common. Whether you’re currently being treated for cancer or are a health professional who treats cancer patients, it’s important to understand the types of CAM, the impact of CAM on cancer, and how to make informed decisions about using CAM. Health professionals and cancer patients want the same thing: better cancer outcomes and better quality of life for cancer patients.

Last week I participated in the Canadian Association of Pharmacy in Oncology’s Fundamentals Day, where I had the opportunity to speak about CAM, pharmacy practice, and ethical, science-based patient care. What follows is a summary of that talk, which regular readers will see incorporates many familiar SBM topics. Rather than focusing on specific products (I only had 30 minutes), this talk looked at the phenomena of CAM, with the goal of equipping pharmacists to help patients make informed decisions about their cancer care.

What is CAM?

Depending on who you ask, you’ll get different definitions of what constitutes CAM. Some consider anything sufficiently “natural” is CAM. Others point to who sells it – CAM tends to be delivered by non-health-professionals, but some health professionals (and health organizations) offer CAM and conventional medicine side by side. David Gorski and others at this blog have written about the evolution of CAM, which started long ago as unconventional medicine, or quackery. These products came to be known as alternative medicine.

Alternative medicine sounds outside the mainstream (and it was), implying it’s an alternative to conventional medicine. Alternative medicine proponents didn’t like this, and so the term became “complementary and alternative medicine”, which retained the quackery, but added in utterly conventional treatments like dietary interventions and exercise.

But having “alternative” medicine in its name remained a problem for CAM proponents, so today the more common term you’ll see is “integrative”, reflecting the combined use of CAM and conventional medicine, where you can apparently have your chemotherapy, your acupuncture and your homeopathy, and they’re all “integrative”. But paraphrasing what Mark Crislip has said, when you integrate cow pie into apple pie, you do not make the apple pie better. You make it worse. And that’s the concern with CAM and cancer – does mixing in CAM with cancer treatment make patients better? Or worse?

The evolution of CAM

So if we don’t even have a common definition to work from, is it possible to objectively assess it? CAM is mostly defined by what it is not, rather than by what it is. This is the definition from the National Center for Complementary and Integrative Health (formerly called the National Center for Complementary and Alternative Medicine, and before that, the Office of Alternative Medicine). (See what they did there?):

Use of products like herbs, vitamins, minerals, and probiotics, and medical practices (e.g., acupuncture) which are outside of the mainstream Western medicine.

• ‘alternative’ when they are used in place of conventional medicine
• ‘complementary’ when they are used together with conventional medicine

As a science-based health professional, it’s easier to think of CAM today as a continuum, ranging from science-backed interventions, used alongside cancer treatments, that may help quality-of-life and symptoms (e.g., supportive care), to implausible, unproven or disproven treatments, some of which may be claimed to actually treat the underlying cancer:

The CAM continuum, ranging from science-backed treatments to those that are unproven or even pseudoscience

The easiest definition of CAM is attributed to Tim Minchin:

Do you know what they call alternative medicine that’s been proved to work? Medicine.

So how popular is CAM among cancer patients? It depends on what you consider CAM. Many people have spiritual beliefs, and based on some definitions, prayer could be considered CAM. Similarly for exercise – do you exercise when you have a cold? You could be using CAM, and not even know it.

Regardless of the definition, it’s fair to say that there is significant interest in CAM, and that prevalence is probably underestimated due to underreporting. A cancer diagnosis may motivate interest in CAM.

Why do cancer patients use CAM?

CAM is a cultural phenomenon, and not a product of science or evidence. As Steven Novella has noted previously, satisfaction with mainstream medicine is not an important factor in deciding to use CAM, and CAM users are generally satisfied with their mainstream care. CAM may be popular because its use aligns with a user’s personal philosophy, or simply to expand their options, perhaps because it is widely viewed as being natural and harmless. A 2013 systematic review in advanced cancer noted that use was felt to offer hope and even ambiguity about the future in these patients with a terminal cancer diagnosis. Patients who were younger, female, more educated, had a longer duration of disease, and had previously used CAM were more likely to use CAM. And a 2015 cross-sectional survey of patients at a academic cancer centre found that attitudes towards CAM predict CAM use. Patient age (<65 years), female gender and college education were associated with greater expected benefit from CAM.

The CAM lifecycle

Two or three decades ago, few randomized controlled trials of CAM therapies had been conducted, and the systematic review methodology was in its infancy. Since then there has been a significant increase in the evidence base for CAM, in terms of the number of trials and the quality of those trials. Parallel with this work has been improvements in the quality of systematic reviews across medicine, as well as the growth of the Cochrane Collaboration to support the development and dissemination of these systematic reviews. These evaluations have, on balance, demonstrated that most CAM therapies fail to provide objective benefits. But given CAM isn’t driven by evidence or even a rejection, necessarily, of conventional medicine, we shouldn’t expect the emergence of negative beliefs to cause a rejection of these therapies. Consequently, CAM has a predictable lifecycle:

• CAM may start out being promoted by anecdotes, often by those with vested interests.
• As interest builds, products undergo scientific scrutiny and possibly even clinical trials.
• When research show treatments to be effective, they may be endorsed or supported by “conventional” medicine (e.g., mindfulness, ginger for nausea, etc.)
• When trials show treatments are ineffective, a conspiracy is often blamed for suppressing and discrediting them (“Big Pharma!!!!”)
• Scientifically discredited therapies continue to exist in the CAM universe. Treatments are never discarded because they’re ineffective.

A review by Edzard Ernst in 2011 asked “How much of CAM is based on research evidence? The answer is very little. Ernst looked at 685 treatment/condition pairings in the The Desktop Guide to Complementary and Alternative Medicine and examined the quantity, quality, and level of evidence. He calculated that only 7.4% of these pairings could be considered to be based on sound evidence, and suggested this might be a “gross over-estimate”.

Case Study: Laetrile, the unsinkable cancer quackery: You’ll find obituaries written about laetrile as a quack cancer remedy back as far as 1981. This compound is chemically related to amygdalin, a substance found naturally in the pits of apricots and various other fruits. It was touted as a cancer treatment in the 1960’s, subject to trials, and found to be completely ineffective. Yet today it still persists, despite an abundance of evidence that demonstrates it does not work. (Quackwatch has an excellent summary of laetrile.) Earlier this month, BMJ Case Reports featured a prostate cancer patient who was taking apricot kernel extract and gave himself cyanide poisoning. Amazingly after being told that he was poisoning himself the man apparently has restarted the supplement.

When alternative medicine is chosen in place of conventional cancer therapy, outcomes are worse

As David Gorski summarized in an extensive past SBM post, alternative medicine kills cancer patients. Skylar Johnson’s study of the US National Cancer Database examined breast, lung, prostate and colorectal cancer outcomes by studying 280 patients who did not receive “conventional” treatment and were noted to receive alternative medicine. Overall the hazard ratio for death was 2.5 greater for patients using CAM as their treatment, instead of conventional medicine. The survival curves tell the story here – the differences were significant for three of the four cancers, with the exception of prostate cancer, likely because the long natural course of the disease:

Survival curves for (A) all patients, (B) breast, (C) prostate, (D) lung, and (E) colorectal cancers.

Johnson’s study is not the only paper that documents the relationship between alternative medicine use, and cancer. See, for example:

• Chang, 2006: “Alternative therapies used as primary treatment for breast cancer are associated with increased recurrence and death”.
• Han, 2011: “Alternative therapies used as primary treatment for breast cancer are associated with disease progression and increased risk of recurrence and death. Diminished outcomes are more profound in those delaying/omitting surgery.”
• Saquib, 2012: “The risk for an additional breast cancer event and/or death was higher for those who did not receive any systemic treatments; the use of dietary supplements or CAM therapies did not change this risk. This indicates that complementary and alternative therapies did not alter the outcome of breast cancer and should not be used in place of standard treatment.”
• Joseph, 2012: “Women who declined primary standard treatment had significantly worse survival than those who received standard treatments.” “The majority of the patients (57%) in our series initially chose CAM as the primary treatment instead of surgery. Those who had chosen CAM had disease progression with particularly poor disease-specific survival when compared to those who received standard treatment.”

As I noted in a past post, no specific CAM intervention has shown any meaningful benefit in cancer. Probably the most comprehensive single review is a systematic review by Gerber et al, published in Breast Cancer Research and Treatment in 2006, which looked at CAM effectiveness for early breast cancer. It concludes:

There is no compelling evidence that any of the numerous complementary treatments available is sufficiently effective in breast cancer patients to justify its use. It should be the responsibility of those who claim efficacy for CAM to support these claims with acceptable evidence, rather than the responsibility of those who criticize CAM to prove its non-efficacy.

Does concurrent use of CAM with conventional cancer care affect survival or quality of life?

It’s possible that CAM, when used concurrently with conventional medicine, might offer some subjective benefits, particularly for side effects. However, given the potential for CAM-drug interactions (in the case of supplements and herbal remedies), survival benefits shouldn’t be assumed. A study of a Korean population by Yun and colleagues suggested that CAM had no effect on survival and worsened, rather than improved, quality-of-life. Similarly, so did a Malaysian study by Chui. Armstrong found no difference in QOL due to CAM in a study of patients with brain tumours. Risberg, studying a Norweigan population, also observed that concurrent CAM use predicted a shorter survival. However, the U.S. Health, Eating, Activity, and Lifestyle Study found no relationship between CAM use and breast cancer (or overall) survival. It’s unfortunate that this is such a poorly studied area, given the widespread interest in CAM by cancer patients. Overall, based on this limited evidence, it’s reasonable to conclude CAM may offer patients subjective benefits. However, there is no convincing evidence CAM use actually improves quality of life or has any beneficial effect on survival.

Promoting dialogue and informed decision-making is essential

Understanding CAM approaches and perspectives are essential to have meaningful conversations with patients about CAM use. While patients may elect to use unproven therapies, it is essential for health professionals to provide a professional evaluation of these therapies, using their knowledge, skills and abilities to support informed patient decision-making. Recognizing that many cancer patients may not understand the scientific process that underlies and informs cancer treatment, describing the lack of benefits of CAM use (and the potential risks, even when used concurrent with conventional care) are important. The Clinical Oncology Society of Australia’s position statement on CAM summarizes a reasonable approach for health professionals when talking to patients about CAM, which includes this suggested approach by Schofield:

1. Ask what patients understand about their illness.
2. Respect culture, values and beliefs.
3. Ask about use of CAM.
4. Explore reasons for CAM use, and the evidence base.
5. Address issues they want to resolve with CAM use.
6. Discuss concern you may have about their use of CAM.
7. Advise patients about CAM use based on an assessment of the evidence.
8. Summarize the discussion and check that they understand.
9. Document the discussion and inform others involved in that patient’s care
10. Monitor and follow-up at the next consultation.

If CAM works, it does so according to scientific principles – not alternative ones. There is no evidence that most of CAM has much to offer cancer patients, even when used alongside conventional care. Importantly, no treatments, even some forms of CAM, are without any risk. Given cancer patients may be more willing to accept the risks of CAM, it is important for health professionals to underscore what is known (and not known) about these treatments and approaches, in order to support informed patient decisions.