What is “Integrative Veterinary Oncology” & can it be Evidence-Based?

An interesting article appeared recently in a widely-read veterinary journal that discusses so-called “integrative medicine” in veterinary cancer care in terms of evidence-based medicine (EBM). This article raises a number of interesting questions and concerns.

Raditic, DM. Bartges, JW. Evidence-based integrative medicine in clinical veterinary oncology. Vet Clin Small Animal 2014;44:831-853.

I’ve written about the notion of “integrative veterinary medicine” (IVM) before, and it is a highly problematic concept. These authors define it as “the use of complementary and alternative medicine (CAM) with conventional Western medicine systems.” This already contains some fallacies in that it labels science-based or “conventional” medicine as “Western,” which ignores the fact that the scientific approach to health and disease that underlies modern medicine has been developed and very successfully employed in all cultures around the world. While much of the development of modern science initially took place in Europe and North America, critical contributions to scientific medicine have come from many other places. And there is nothing intrinsically “Western” about scientific medicine. It has come to dominate medical practice around the world because of its demonstrable success, crossing cultural barriers rapidly and continuously.

This label also implies that the alternatives to conventional scientific medicine are fundamentally culturally distinct in origin and character. This may be true for some, such as Traditional Chinese Medicine (itself somewhat misleadingly named), but it is certainly not true for chiropractic, homeopathy, and many herbal and nutritional therapies which are include under the CAM umbrella and yet which were invented and practiced predominantly in Europe and North America.

In any case, defining IVM and the use of CAM along with conventional medicine begs the question of what CAM itself really is. As I’ve discussed before, it is largely an ideological category with little scientific meaning. It exists in part because of fundamental philosophical differences between CAM practitioners and proponents of science-based medicine, and partly to protect specific therapies in which proponents have personal faith from criticism and rejection regardless of the state of the scientific evidence concerning them. To call something CAM is not to define it, since many of the therapies included under the label are mutually incompatible in fundamental ways and have very different evidentiary profiles. The label signifies a particular kind of attitude and belief, not a real difference from the perspective of how or if one can demonstrate these therapies to be safe and effective using scientific means.

The authors further expand on their definition of IVM by defining CAM in terms of specific therapies they would include in the category and, tellingly, as anything “that are rational and supported by evidence to alleviate physical and emotional symptoms, improve quality of life (QOL), and possibly improve adherence to oncology treatment regimens.” This definition contains within it the assumption that these therapies are rational and supported by evidence. However, this often turns out not to be true for many of the practices included in the CAM fold, so this cannot be justly blithely assumed.

The authors then go on to justify the importance of knowledge about CAM therapies by pointing out some CAM therapies are widely employed. I agree, and I think it is vital that clinicians understand what the category itself is about and what the evidence says about specific therapies, though I suspect my conclusions would be quite different from those of the authors. They also acknowledge that the major drive for use of these therapies is psychological rather than based on any objective reason to expect they are safe and effective:

…human oncology patients use natural products to empower themselves, attempt to take control of their health… logically pet owners would apply these same emotions.

Once again, I agree, and I think it is important that veterinarians understand the roots of CAM use among our clients. This doesn’t mean, as the authors appear to imply, that we must support or encourage these practices, only that we must be knowledgeable about them and effective in understanding and communicating with our clients about their use. Often, if we are practicing truly evidence-based medicine, this communication is likely to involve discouraging the use of therapies for which there is no good reason to expect they are safe and effective.

The authors go on to acknowledge that the research evidence, particularly the most useful types of research, clinical trials, is scarce for most CAM practices. However, they imply that the reason for this is not the lack of a belief on the part of CAM practitioners that their therapies need scientific evaluation but simply a lack of funding for therapies that are not likely to be profitable:

Evidence-based research on CAM in an IM plan in veterinary clinical oncology is scarce, which is expected because large-scale research funding is typically provided for projects with potential for profits, such as with new, patented drugs.

This would seem to be contradicted by their own admission that, “In 2010, US herbal supplement sales exceeded $5.2 billion.” The reality is that CAM therapies are often very profitable. The reason herb and supplement manufacturers invest far less in scientifically evaluating the safety and efficacy of their products than to pharmaceutical companies is not because there is no profit to be made in these products but simply because the government does not require them to. Pharmaceutical products must demonstrate safety and efficacy to a certain, albeit imperfect, standard set by the FDA. Politics and ideology have led, however, to a different and far more lax standard for herbs and supplements, which are often assumed to be safe despite the abundant evidence that they can cause as much harm as conventional medicines.

In the absence of much clinical trial evidence, the authors place greater emphasis on less reliable kinds of evidence, such as in vitro and animal model studies and extrapolation across species. They hold out particular hope that metabolomics, the study of how the compounds and chemicals involved in metabolism are affected by particular diseases and interventions, such as herbs and supplements. While a great deal of useful knowledge can be gained by this kind of research, the study of such proxy markers for clinically relevant outcomes cannot substitute for clinical trials. The response of cancer cells in a petri dish or in a mouse to a purported cancer therapy have never proven to be very reliable indicators of the actual clinical response of cancer patients to the same therapy.

The rest of the article is largely a review of selected clinical and pre-clinical research on a few herbs, dietary supplements, and acupuncture. This is fine as far as it goes, but like any narrative review the only studies mentioned are the ones the authors, who are avowed proponents of such therapies, choose to discuss, so one has to bear in mind they may not be representative of the real state of the scientific evidence. In any case, what strikes me about this part of the paper is that the authors are describing the process of scientific evaluation of potential medical therapies from in vitro and animal model studies up through clinical trials. How, exactly, is there anything complementary or alternative about this?

What they describe is essentially the process of scientific, “Western” medicine, which routinely investigates the therapeutic and preventative value of such interventions. The only reason to call any of this alternative or distinguish it from conventional scientific medicine is to suggest that the use of these therapies should be somehow viewed differently from other medicines such as pharmaceuticals. The usual next step, which the authors never make explicit here, is to claim that these therapies should be open to use regardless of the state of the scientific evidence. They do, however, suggest that rather than evaluating the science for themselves as they would ordinarily do, veterinary oncologists should rely on the expertise and personal experience of veterinarians already using such therapies and already convinced of their value despite the lack of scientific evidence.

Collaboration between conventional oncologists and practitioners of IM, who have knowledge, experience, and training to use HDS and acupuncture, is needed to explore the possibilities of integrative veterinary…Although individual herbs are discussed here, integrative practitioners more often use herbal formulas and have identified safe, reliable sources of HDS products with known content; they also know possible interactions and understand dosing to prevent adverse effects. Veterinarians with this special training, education, and experience can be found through the organizations in Box 1.

The suggestion here is that these remedies can be viewed as “safe and reliable” and that adverse effects can be predicted and avoided despite the lack of scientific research simply because these veterinarians have personal experience in their use. This illustrates the underlying theme that occurs again and again in apologia for CAM. Proponents use language like “evidence-based” and promote supportive scientific research because these things have marketing value; they generate acceptance and the appearance of scientific validity. Yet in their hearts, the lack of scientific evidence for safety and efficacy does not diminish a confident belief in the safety and efficacy of these therapies. Science is a nice extra, something to convince the skeptics, but it isn’t seen as fundamentally necessary to the evaluation and safe use of these therapies. This attitude is incompatible with evidence-based medicine despite the appropriation of EBM terminology.

I appreciate the authors’ acknowledgement of the lack of convincing evidence to support the use of most CAM therapies in veterinary cancer care. And I agree that despite this, there is interest in such therapies on the part of clients. Veterinarians absolutely should be knowledgeable about these practices so they can guide and advise their clients. However, the appropriate response to the lack of good evidence for these practices is not to suggest that it cannot be obtained or that we can comfortably rely on individual experience and expertise instead.

Ultimately, for potential therapies with reasonable plausibility, the usual practice of science should be followed. Pre-clinical testing followed, if the evidence warrants, by clinical trials. Any use prior to the development of strong scientific evidence should be viewed as experimental, as likely to harm and to help the patient, and this should be clearly disclosed to clients. There is no reason to treat these therapies differently from any others or to give them special exemption from the usual standards of evidence.

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