Managing Cats with Cancer

Abstract

Ethical issues Caring for cancer patients presents many ethical issues for veterinarians and other veterinary health workers. The issues that most veterinarians think of relate to management of the patient when the owners’ preferences for treatment do not appear to be in the animal's best interest, as well as concerns about toxicities and about costs of veterinary services (advanced imaging, surgery, radiation therapy and chemotherapy). While not limited to the veterinary profession, we are more often faced with dilemmas about the appropriateness of palliative care and decisions about euthanasia than our medical colleagues. Equally important are the ethics of not treating patients, and the integration of unproven and alternative strategies into conventional care. A separate ethical issue arises from investigational therapies and research. Less often considered, but nonetheless relevant, are the ethics of suboptimal evaluation (staging) of patients prior to treatment, or of not informing owners about all the options available.

Client communication Ethical veterinary care is intertwined with good client communication. Without good communication, it is impossible, for example, to gain informed consent; and without informed consent, the ethics of cancer treatment are uncertain.

Goal This article, which draws in part on published research, where stated, and otherwise on the author's personal experiences/opinions and those of veterinary colleagues, is intended to provoke further thought and discussion on the ethics of caring for our cancer patients.

The treatment of cancer in pets has evolved to parallel treatment in humans, with certain differences. One of the most important differences is in the goal of therapy (see box). Cancer in veterinary patients is, in many respects, similar to other chronic illnesses such as kidney disease or heart disease — which, although they may not be cured, can often be controlled, providing a high quality of life.

Cure versus control.

In humans, many cancers are cured, and cancer survivors may enjoy many decades of comfortable life. For this reason, treatment of cancer in humans is aggressive and often associated with severe side effects. By contrast, for quality of life reasons, most pet owners (and presumably the pets themselves) prefer to avoid severe side effects and prolonged hospitalisation. In addition, the specialised supportive care units and strategies for human cancer patients are not available for pets. Veterinary cancer therapies are, therefore, primarily directed at maximising quality of life; and the aim is often tumour control, or remission, making the pet feel as normal as possible, rather than cure at any cost.

The ethics of treating cancer

There are a number of arguments made against treating animals with cancer; whether these are truly based on ethics, is less clear. All of us have preconceptions about cancer and its treatment that colour the way we react when we hear the term applied to pets. Often the ethical arguments against treating a pet for cancer centre on emotive statements such as:

• ‘It is cruel to subject animals to the awful side effects of cancer treatment.'

• ‘Cancer treatment is not worthwhile because such a short period of extra life is gained.'

• … and as an extension of the latter statement, from an internet source, ‘Cancer in dogs is one such disease where detection unfortunately happens in the later stages, rendering treatment almost immaterial and useless. In such cases, love, care and comfort are the three things that you can provide for your dying dog.' ¹ (This statement appears alongside links to a nutritional supplement in a way that is also ethically questionable.)

We all have preconceptions about cancer and its treatment that colour the way we react when we hear the term applied to pets.

The sentiments behind these various statements are no more ethical than the decision to treat a pet. The only truly ethical decision would be made by the patient themselves — and in veterinary medicine that is not possible. In the absence of such a decision, the best ethics a veterinarian can practise include prioritising their patient's comfort and making sure that the owners of a pet with cancer have the information available to make the best possible decision for the patient.

Informed consent — the purpose and the process

One of the key ethical factors in giving any medical news to clients, particularly if it involves cancer, is that you present a plan with the news, not just give the news. That means research and understanding before meeting with the owner. That plan should not be ‘This is what you are going to do', but rather ‘This is what you could do’ … then starts the process of informed consent.

For human patients who cannot give informed consent, the process of decision-making for their surrogate is very similar to the process used by owners of a pet with cancer. Such decisions must be made based on substituted judgement and best interests. In veterinary oncology, substituted judgement by necessity must involve some level of anthropomorphism and, as such, is very subjective based on the bond between the pet and owner, and the owner's experiences through real life and the media of cancer and cancer therapies. In humans, surrogate decisions have been shown to predict those of the patient with 68% accuracy. ² This is somewhat, but probably not statistically, better than chance. Less subjective for most pet owners is the process of balancing the benefits and risks of each option, and selecting those strategies for which the benefits maximally outweigh the potential negatives. For this reason, veterinarians should very clearly outline these options while seeking informed consent.

The purpose of informed consent in human medicine is to protect a patient's autonomy; and any procedure should only be undertaken after consent is obtained in an appropriate manner. In veterinary medicine, informed consent is by definition given by a surrogate, but this does nothing to remove the burden from either owners or veterinarians. While most veterinarians agree that giving information is an important part of informed consent, some may argue that persuasion is also acceptable and necessary. Particularly for owners who have limited medical knowledge, the argument goes, the veterinarian is clearly the person in the best position to evaluate and compare the different care options. In this situation, the veterinarian needs to be careful that the way information is presented does not constrain, but rather facilitates, owner choice.

In veterinary medicine, informed consent is by definition given by a surrogate, but this does nothing to remove the burden from either owners or veterinarians.

It is very difficult not to have your own biases about treatment for any patient, but this should not be allowed to interfere with appropriate communication of all the options available. If there is a clear superior option, then it should be presented as such: ‘The best treatment for this disease we can offer is this …'. However, my personal opinion is that such a statement should be followed by: ‘but that does not incorporate all of the non-medical factors that affect Fluffy as an individual and as part of your family; for that reason, it may not necessarily be the treatment option you choose.'

When pet owners enter a veterinary practice they are often feeling vulnerable; they are concerned for their pet, and often scared of the potential outcomes. The veterinarian is in a position of considerable power as they have both knowledge and experience, and probably a greater degree of emotional detachment. Therefore, their opinion is likely to be valuable to the client. However, it is possible for this power to be used to sway or influence people from the course they were planning to take. Persuasion is defined as an attempt to induce a person, through appeal to reason, to freely accept as his or her own, the beliefs, attitudes, values, intentions or actions advocated by the persuader.

It is possible that the pet owner will decide on a less effective treatment, a less costly treatment, or against any treatment, even when the veterinarian feels there are treatment options that have a high likelihood of success. It may be appropriate to meet an owner's decision with further information to reach an agreement. For example, it is clearly appropriate to investigate the reasons for a refusal of any treatment; persuasion by the process of discussion and providing information is also acceptable to most veterinarians. However, an ethical ‘line’ needs to be drawn as to what is acceptable as far as pressure to accept care is concerned. This is particularly true in veterinary practice where economic factors (both as a cost to the client, and as income to the veterinarian) may cloud the process of informed consent.

While persuasion does not contravene the spirit of informed consent, coercion, (‘the intimidation of a victim to compel the individual to do some act against his or her will') is clearly not acceptable. Coercion may include instilling guilt about their pet … ‘If you cared about Fluffy, you would see this is the best thing to do.’ Another form of coercion is indirect on the owner, and comes from the pet's cancer itself. The threat of a terminal illness may lead owners to accept risks and unknown therapies that they would not accept when allowed to calmly and rationally explore all options. It is important for the veterinarian to facilitate clear and logical evaluation of all choices for an owner of a pet with cancer.

An ethical ‘line’ needs to be drawn as to what is acceptable as far as pressure to accept care is concerned. This is particularly true in veterinary practice where economic factors may cloud the process of informed consent.

Staging and grading cancer

Clearly, the best treatment options will vary not only with the type of cancer, but also between individual patients. The more information that is made available to the owner about their pet's cancer, the easier a decision about treatment is to make. The owner of any patient with cancer should be counselled regarding the value of accurate diagnosis. A biopsy is technically simple in most patients, associated with minimal morbidity, and can provide not only a diagnosis, but also prognostic information that can be helpful to an owner struggling with the decision of whether to treat. Having made a diagnosis (with immunohistochemistry and grading of the cancer), accurate staging is essential to provide a prognosis for an animal with cancer and allow the owner to make a truly informed decision.

Thorough staging will include, for all patients, routine bloodwork and imaging as appropriate (radiographs, ultrasonography and/or computed tomography or magnetic resonance imaging), and is needed to fully assess the risks and potential benefit or otherwise of treatment. Such risks may not only relate to the cancer itself, but also to other, unrelated disease that can nonetheless affect options and outcomes. A cat with renal dysfunction, for example, may not be able to tolerate doxorubicin chemotherapy (as this can be nephrotoxic), and would require a dose reduction for carboplatin chemotherapy to avoid severe myelosuppression (as this drug is renally excreted). Failure to adequately stage a pet may, therefore, adversely affect their quality of life with treatment, and could potentially be life-threatening.

It is possible that some owners who do not want to treat their pet under any circumstances will not want to perform the recommended testing. This can be an ethical problem for the veterinarian; especially if the testing could identify a treatable problem (a biopsy may show a lesion to be inflammatory, and not neoplastic). Under such circumstances, continued dialogue is mandatory to explain the reasons for test recommendations and why they are crucial, to allow an owner to come to an informed decision on behalf of their pet.

Resources

A commonly stated concern relates to resources — along the lines of ‘all the efforts at cancer treatment ought to go into treating humans’ (Fig 1). For a cat that is, say, treated after-hours at a human radiation therapy facility, the argument might be that ‘My grandmother has been on a waiting list for radiotherapy for 2 months, and yet the staff are able to treat a cat after 5 pm; why can't they stay behind and treat Grandma.'

FIG 1.

©iStockphoto.com/DrHeinzLinke

An ethical concern that is commonly voiced is that all available resources should be directed at treating human cancer patients rather than pets © iStockphoto.com/Dr Heinz Linke

I know of a radiation facility in Canada that had to stop treating pet animals for that reason — but it did not expand its hours for human patients, so there was no benefit to either party. Another example dates back to the mid—1980s when cisplatin was available in the USA at no cost for treatment trials in pets; at that time a colleague of mine visited Peru, where he found that cisplatin was not available at all, even for the treatment of human patients with cancer. These larger ethical dilemmas, while uncommon, are likely to be beyond the ability of a single veterinarian to solve.

Owners may have little support from family and friends when they decide to treat their pet. Often the argument is financial: ‘It cost $5,000 to treat your cat, and it died of cancer anyway'; sometimes this is considered ‘unethical'. It would seem, however, that this is not an ethical problem, but rather one of choices and priorities, and these will differ from person to person. Some people have such a strong bond with their pet, that they would access any resource to treat it. Other people may not want to forego things that they consider important, be it a holiday trip to the Bahamas or a new wide-screen television.

Ethical concerns of members of the cancer treatment team.

It is not only non-medical people who question the treatment of pets with cancer. Some veterinarians and veterinary nurses may also disapprove of cancer treatments for pets. For some nurses this comes from the far greater interaction they have on a personal level with a patient; for others, this arises because they may only be involved when there is a problem. For example, a colleague of mine once heard a veterinary critical care worker telling another: ‘We see nothing but problems with this new chemotherapy protocol they are using.’ Logic would dictate that to be true, as patients not experiencing problems rarely visit an emergency centre just to report the fact.

At other times, nurses may find themselves administering treatments they do not believe to be in the best interest of a patient. They should be aware that this is difficult for them to judge as they often have not been privy to communications between the veterinarian and the owners of the pet, and it is important for them to have a level of trust in the attending veterinarian's ethics. At the same time, this should not preclude nurses asking questions about care, and it is important for the veterinarian to take the time to explain the rationale, particularly when the care is questioned. Such concern is not limited to the veterinary profession. Thirty-eight per cent of critical care attending physicians and 25% of haematology/oncology attending physicians expressed the concern that ‘At times, I have acted against my conscience in providing treatment to children in my care,’ a worry shared by 48% of critical care nurses and 38% of haematology/oncology nurses in the same study. ³

In another study, nurses for human patients were invited to share a clinical situation in which they experienced moral distress related to a patient receiving care that they considered futile. ⁴ Nurses described clinical situations across care settings, with the most common conflict being that aggressive care denies palliative care. Conflicts regarding resuscitation code status, life support and nutrition also were common. Interventions provided to geriatric patients and patients with dementia were most commonly a cause of concern, but patients with cancer were next most frequently involved.

In the same study, when ICU nurses of human patients felt that the treatment they were providing was futile, they often described the treatment with terms such as ‘torture', ‘violence’ and ‘cruelty', ⁴ which are similar to terms used by some veterinary workers. Common sources of distress for staff include protection of patients, avoidance of care that clinicians would not choose for themselves, and conservation of financial or biological resources; such concerns may be further compounded when veterinary workers feel that families of patients distrust them when a recommendation to withdraw care is made.

The ethics of not treating cancer

Concerns that treatment is ‘futile’ or ‘not in the best interest of the patient’ are frequently raised about veterinary cancer therapies (see box above). The term ‘futile’ is ill-defined medically, with physiologic futility meaning that the intervention will have no physiological effect. Qualitative futility may be applied to an intervention that fails to end a patient's total dependence on medical care (ie, provide a cure). Quantitative futility has been suggested as applying to an intervention that in the last 100 cases has been useless (in itself a subjective term). The term ‘best interest’ (as applied to a patient) is also subjective, as what constitutes a benefit or encumbrance to a patient will depend on that patient's (and in our case, owner's) personal values; for many that imposition on quality of life is pain, but that is not true for all people.

I still hear of veterinarians that suggest to an owner that a cancer is untreatable, that treatment is associated with devastating side effects, and that the ‘kindest thing’ would be to perform euthanasia without a full discussion of other options available.

Is it any wonder then that, in veterinary oncology, assertions such as ‘futile treatment that is not in the best interest of the patient’ do little to help an individual owner in the decision of whether they should pursue treatment for their pet, let alone whether that treatment is reasonable. In the maze of subjectivity, the best ethical help a veterinarian can offer is to communicate clearly and openly, to guide the owner who is availing themselves of other resources, and to support whatever decision they make, regardless of whether it is a decision the veterinarian would make for himself or herself.

Veterinary oncology is currently practised with the highest regard for quality of life. Oncologists are usually truly holistic in their approach to a patient, evaluating concurrent diseases that could affect the toxicity of treatments, as well as assessing, and helping owners to continue to assess, the pet's quality of life. Surgery, chemotherapy and radiotherapy are all tailored to ensure these treatments are as effective as possible and yet provided with minimal side effects in the vast majority of patients. Although much less frequently than 20 years ago, I still hear of veterinarians that suggest to an owner that a cancer is untreatable, that treatment is associated with devastating side effects, and that the ‘kindest thing’ would be to perform euthanasia without a full discussion of other options available. Often that euthanasia is then performed without further testing, and often without even a biopsy. To me this is an ethical issue of much greater magnitude than offering or administering therapy.

A 14-year-old cat is presented for lethargy and depression ….

Scenario 1

On physical examination, a large mass is palpated in the anterior abdomen. You are fairly certain this is a neoplasm and suggest euthanasia.

Scenario 2

On physical examination, a large mass is palpated in the anterior abdomen. The rest of your physical examination is normal. You perform full haematology, a serum chemistry profile and urinalysis. Haematology shows mild normocytic, normochromic anaemia, and the profile shows mild elevations in serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP); the urine specific gravity is 1.050. Thoracic radiographs show no abnormalities and an abdominal ultrasonogram shows a solitary large hepatic tumour associated with the left lobe. A needle biopsy is performed and the diagnosis is a well-differentiated biliary cystadenoma. You discuss the prognosis with the cat's owner and she agrees to surgery. The cat recovers well from hepatic lobectomy, and lives a further 2 years.

Scenario 3

On physical examination, a large mass is palpated in the anterior abdomen. The rest of your physical examination is normal. You perform full haematology, a serum chemistry profile and urinalysis. Haematology shows mild normocytic, normochromic anaemia, and the profile shows mild elevations in serum ALT and ALP; the cat is mildly azotaemic and the urine specific gravity is 1.018. Thoracic radiographs show no abnormalities and an abdominal ultrasonogram shows a solitary large hepatic tumour associated with the left lobe and multiple smaller nodules in other lobes. A needle biopsy is performed of the large mass and two of the smaller masses and the diagnosis is a poorly differentiated biliary carcinoma at all sites. You discuss the poor prognosis with the owner, and the limitations of surgery and radiotherapy in treating this malignancy. You discuss the usual lack of efficacy of chemotherapy for treating this cancer and the difficulties created by inadequate renal clearance of some drugs, and provide information for the owner to read about the options. You also discuss palliative care (pain medications and nutritional support). The owner elects for chemotherapy and, despite supportive care and prophylactic antibiotics, the chemotherapy drug causes severe myelosuppression and the cat becomes septic. She is hospitalised for 3 days; supportive treatment allows full recovery. There is no response in the size of the tumours, some have grown substantially, and her owner decides to continue with only palliative care. Over the next 2 weeks, the patient continues to deteriorate, and euthanasia due to deteriorating health (azotaemia, dehydration, anorexia) is performed 4 weeks after initial presentation.

Consider, for example, the three scenarios described above. Whether the case management in each of these scenarios is ‘ethical’ or not, or which is the ‘more ethical', is obviously open to interpretation. Less subjectively, it seems clear that providing information is important in allowing the veterinarian to deliver appropriate ethical care for an individual patient and owner.

In the maze of subjectivity, the best ethical help a veterinarian can offer is to communicate clearly and openly, to guide the owner who is availing themselves of other resources, and to support whatever decision they make, regardless of whether it is a decision the veterinarian would make for himself or herself.

The ethics of euthanasia

Given that, for many pets with cancer, therapies are unlikely to be curative, patients will reach a point where the options for treatment have been exhausted or are limited due to availability, finances or coincident morbidities. In such patients, one option is euthanasia, and that is a path often taken by owners of such pets.

A common question from owners is: ‘How will I know it is time?’ Of course, there is no answer that will encompass all possibilities, patients and owners, but, in my opinion, saying ‘You will know’ is the least comforting response that a veterinarian can offer. The major contribution I feel we can make is to help the owner turn a subjective evaluation into a rather more objective evaluation, and that can be done by helping them to define what is good quality of life for their pet. Owners often have very clear ideas about what ‘side effects’ on quality of life they will tolerate from treatment of cancer, and it is often as simple as directing that same concern to what they will tolerate as a ‘side effect’ of the cancer itself.

One exercise that seems to help owners is to write a list of the things they feel make their pet's life enjoyable, the reasons that they make life fun, and how they (as an owner) can tell. Most owners will list food items and specific games or interactions, and in the process develop a quality of life ‘score’ for their pet. I suggest to them that they consult the list whenever they are worried whether their pet is ‘suffering'. If their pet is enjoying the majority of items on the list, then quality of life is probably acceptable; if there are only a couple of items checked, then the list should be consulted the next day and, if still limited, it may be time to get a veterinarian's advice (to make sure there are no simple interventions that could reverse the change), and then consider euthanasia, palliative care or hospice care (see box). In reality, it is probably the act of list-making that is the positive force when an owner is feeling discouraged, and many owners probably still use their general impression of their pet's life quality, rather than truly relying on a list; nonetheless, the exercise seems to serve a purpose in directing their concerns to a defined subject.

Given the emotion arising out of end-of-life care for human patients, it is no wonder that some pet owners do not agree with euthanasia in principle, and that can be a concern to veterinary health care workers. I have often heard disparaging comments made about owners who ‘cannot see that Fluffy is suffering and should be put down', or owners that ‘are just being selfish and cruel’ by not euthanasing their pet with a terminal cancer.

Given the emotion arising out of end-of-life care for human patients, it is no wonder that some pet owners do not agree with euthanasia in principle, and that can be a concern to veterinary health care workers.

In human medicine, the concept of euthanasia is a strongly contested ethical one. In the USA, it was as recently as 1990 that a competent patient's decision to refuse medical treatment to prolong life was held to be a constitutional right under the Fifth Amendment (Cruzan vs Director of Missouri Department of Health, 110 Supreme Court 2841 [1990]). Just half a century earlier, in 1958, Pope Pius XII stated that physicians had no obligation to use ‘extraordinary’ means to forestall death; in this case meaning resuscitation and artificial respirators. ⁵ Obviously such terms as extraordinary are relative, meaning different things for ‘the same patient under different circumstances and for a different patient under the same circumstances'. ⁶

So where does that leave an individual owner grappling with whether they should pursue treatment or perform euthanasia? Euthanasia is a very important and very final act. I firmly believe that the role of veterinarians and nurses (beyond the obvious technical one of delivering euthanasia) is in explaining the benefits and limitations of euthanasia to an owner and answering questions about alternatives honestly and in a non-judgemental manner. If a pet is truly in pain, euthanasia is not the only method of relieving that pain. Discussion of the impact of pain medications on quality of life is important, but for a cat that cannot be euthanased, such pain relief should be administered quickly and effectively. Pet owners have a responsibility to re-evaluate their pet's pain status, and this may mean more regular veterinary evaluations to assess and readjust medications.

Hospice care should always be an alternative. ⁷

Hospice care.

Hospice care does not necessarily mean care in a separate facility, and is preferably carried out at home by the owner, with careful and frequent consultation with the veterinarian. Owners should be appraised as to the additional burden it will put on them, as far as time and nursing care are concerned, in addition to the emotional effects. If not able to provide that level of care, owners should be counselled as to alternatives (hospitalised hospice?). Hospice care does not preclude euthanasia, and owners should be encouraged to reassess their pet's quality of life and be reassured that euthanasia can be an alternative if they feel at any time their pet is suffering.

An aging stray urban cat is much more likely to experience a prolonged and horrible death than a patient that is well supported during hospice by a veterinarian and a dedicated owner.

While hospice care presents an ethical dilemma for many veterinary health care workers, the truth is that most pets with cancer are much loved and cared for; and for those reasons their end of life will be comfortable and free of major suffering even if they die ‘naturally'. Indeed, it is much more likely that an aging stray urban cat will experience a prolonged and horrible death than a patient that is well supported during hospice by a veterinarian and a dedicated owner.

The right thing?

The case of a patient with a progressive and visible tumour is one situation where veterinary staff may consider euthanasia to be the ‘right thing'; such pets are felt to be ‘suffering’ by virtue of their appearance. However, careful questioning of the owner about quality of life issues, and proactive pain and infection management, may allow such disfigured animals to live some comfortable time with an owner who is not prepared to euthanase. Veterinary oncologists make a point of developing the trust of their clients, and it is important that such trust should go both ways, and we should believe their reports about their pet.

The cat in Fig 2 had an advanced, squamous cell carcinoma that had become refractory to radiotherapy and chemotherapy. Despite her appearance, her owners reported that she felt good at home, was sleeping more and eating less, but could maintain hydration, and interacted with the family members in a normal way, still sleeping on their pillow at night and greeting them during the day. Although I was initially sceptical of their reports, when I spent more time with her, I could see that she was indeed interacting with them in a positive way.

FIG 2.

This cat's rapidly progressive squamous cell carcinoma had led to devitalised areas of skin and exposed bone, and had extended into her retrobulbar space. Yet with medical management of pain, and intermittent appetite stimulants, she was maintaining her hydration and body weight, had a good appetite, and was interacting with her owners. The overriding feeling among the veterinary personnel involved was how ‘cruel’ it was not to euthanase her — which her owners eventually did, when they felt her quality of life had reached a point where hospice care was no longer an option

It was important that I reassessed her pain and nutritional status regularly; and it was my responsibility to encourage the owners to consider the options for her at frequent intervals, and to offer euthanasia as an alternative, but it was not my place to recommend euthanasia as the only alternative.

Unproven therapies

A further ethical issue for veterinarians treating cancer patients is how to advise owners about the various untested and unproven therapies.

• Internet therapies ‘Information’ is widely available about internet ‘therapies’ (usually nutritional or other supplements that are not listed as drugs and are marketed directly to pet owners). This information creates a perception of legitimacy without the testing and scrutiny for safety and efficacy that is required for acceptance in clinical veterinary practice. Those treatments that have no documentation and have outcomes that are unrecorded, or based on anecdote and hearsay, may not stand up to the scrutiny that validates a veterinarian's recommendation.

• Complementary and alternative medicine (CAM) While there may be some limited data as to the efficacy and toxicity of CAM, usually it is unpublished or anecdotal.

• Clinical trials Phase 1 studies are essentially studies to define a maximally tolerated dosage range in patients with cancer, rather than efficacy (which is only a secondary endpoint); phase 2 and 3 studies are designed to evaluate a specific treatment for efficacy in a group of patients. Drugs/treatments involved in such trials are usually going through the process of registration for commercial distribution, and have a body of toxicity and preclinical data behind them from which to infer some of the risks of treatment.

Owners of pets with limited options are more emotionally vulnerable, and so it is important that they understand all their potential choices.

Of obvious concern, when discussing new and investigational therapies with owners of pets with cancer, is how should consent be determined when the risks are unknown? Should consent be accepted for last resort therapies where the potential risks are appreciable, but the owner is prepared to go ahead nonetheless? It is critical in the process of gaining informed consent that disclosure should be as detailed and open as possible. Owners of pets with limited options are more emotionally vulnerable, and so it is important that they understand all their potential choices. Consent should not promise benefits, and should never mention cures. Discussion of risks should include serious risks, including the possibility of death. The alternative of pursuing only palliative or hospice care rather than treatment should be offered.

Peculiar to veterinary medicine, where most patients are not covered by insurance, is the economic pressure to undertake unproven treatments as an alternative to more expensive conventional treatments. If appropriate, it should be made very clear to owners that conventional therapies may provide control, palliation or even cure of their pet's cancer; the possibilities offered by an untested therapy are at best unknown, and at worst the opposite.

When asked about untested therapies for a patient under my care, my position is that until such time as evaluations of toxicity and risk of complications, preferably followed by controlled clinical trials, can be performed that ensure that pets are not likely to be harmed by a treatment, such treatments need to be compared critically to the established treatment options. It needs to be made clear that unlike established traditional therapies, internet therapies, CAM and pilot and phase 1 studies carry a higher risk of unanticipated side effects and with no knowledge of the chances for success; new and experimental is not necessarily better. If the owner understands all those facts, and still decides to go ahead, then you, as the veterinarian, have acted in an ‘ethically’ acceptable manner.

Internet therapies

Many internet-advertised therapies are touted as a ‘cure’ for cancer; a very emotive claim to owners of pets with cancer, a group of people who are emotionally vulnerable. Whenever a ‘cure for cancer’ arises it should raise suspicion. I feel that it is appropriate for veterinarians, as highly trained professionals whose first concern is the well-being of their patients and all animals with cancer, to be wary when a ‘site’ offers treatments that do not have a significant body of preclinical toxicity data; particularly when it is chosen to announce efficacy ‘results’ in the lay press rather than through the scientific literature.

Marketing directly through the lay media and internet is of concern, as I feel it takes advantage of worried pet owners’ fears and hopes, without the benefit of peer review. Such publicity may also state explicitly or imply tacitly that current ‘conventional’ cancer treatment is ineffective and associated with unacceptable side effects in pet animals. A helpful internet resource in trying to evaluate such therapies is www.quackwatch.org; this is a not-for-profit organisation that is taking a stand against undocumented treatments, including those for cancer. While mainly directed at human therapies, it also has relevance for veterinary patients.

Complementary and alternative medicine

Many consumers are attracted to CAM because they assume (and are told by friends, magazines and internet sites) that it is effective and almost free of risk. However, for the majority of CAM, finite risks do exist (by virtue of the supposition that the compounds are pharmacologically active); at the same time, our knowledge of CAM, particularly in pet animals, is insufficient to enable risk versus benefit analysis. In other words, in many areas of CAM there is not enough evidence to state with confidence that more good than harm is being done.

Due to the relatively less known actions and interactions of CAM, truly informed consent may be impossible to achieve. The way in which outcomes are defined also has a bearing on informed consent. CAM is considered holistic in its approach and, therefore, the therapeutic benefits may occur on levels that are not necessarily quantifiable (such as ‘feeling better'). In contrast, evidence-based medicine depends on reproducible, quantifiable outcomes, which can be difficult for CAM where outcomes are not so easily defined. In this situation should owners be protected from making potentially harmful choices for their pets?

In many areas of complementary and alternative medicine there is insufficient evidence to state with confidence that more good than harm is being done.

The ethics of CAM, therefore, encompass not just medical efficacy, but the question of informed consent. Denial of CAM can only be ethical if clear risks are presented, but at the same time provision of CAM can only be ethical if evidence for the true benefits of treatment is available. Yet ethical considerations for CAM mainly centre on the principle of non-maleficence (‘do no harm').

CAM is frequently offered outside the laws that govern conventional medications, including quality control and safety testing. As research demonstrates efficacy and safety of CAM therapies, they become incorporated into conventional practice and cease to be regarded as CAM.

Clinical trials

As touched on earlier, a critical part of the necessary evaluation of a new drug is a carefully designed and rigorous clinical trial. This is the only way to provide the evidence of safety and efficacy that is required by regulatory authorities for the approval of drugs; and should withstand the process of peer-review for publication in veterinary and medical journals. Treating individual patients without the framework of an appropriate study design can contribute useful early information, but it constitutes a pilot study and not a clinical trial.

The American Cancer Society, for example, evaluates cancer treatment methods by asking three fundamental questions:

• Has the treatment been objectively demonstrated in the peer-reviewed scientific literature to be effective?

• Has the treatment shown potential for benefit that clearly exceeds the potential for harm?

• Have objective studies been correctly conducted under appropriate peer review to answer these questions?

Considerate communication.

Suggestions for improving communication with the owner of a pet with cancer ^10–12

• Be mindful of language and cultural barriers, as well as physical barriers such as auditory or visual problems.

• Encourage support persons to be present.

• Empathise. Try to put yourself in the owner's shoes. Reflect on your attitudes and responses. Do you have a tendency to be dismissive, defensive or overly familiar?

• Have clear objectives, assume nothing and be flexible.

• Introduce yourself and establish rapport.

• Listen and ask open but directive questions. ‘You'd like to go ahead with the chemotherapy, wouldn't you?’ only requires a yes or no response. If the question were reframed as: ‘What are your feelings about treatment options?’ you can obtain the answer to the original question but also allow the opportunity to talk through concerns about the treatment, and for the owner to ask further questions. ¹²

• Question and summarise until you have the whole picture; encourage questions from the owner.

• Acknowledge and address issues.

• Summarise and screen for other issues. Check understanding regularly.

• Be simple and clear. Tailor the information to the owner. Write down complex information, using diagrams if necessary. Repeat and summarise. People may require information to be repeated a number of times, and on different visits.

• Reinforce realistic hopefulness.

Breaking bad news ¹⁰

• Schedule adequate time.

• Choose a private, quiet and comfortable location.

• Sit face-to-face with the owner.

• Maintain eye contact and, if appropriate, make physical contact (such as touching the owner on the hand, or patting the patient).

• Be prepared. What do they know and want to know? ‘What is your understanding of your pet's illness?'

• Warn that you have serious news. ‘I am afraid I have some difficult news.'

• Be simple and clear. Tailor the information to the owner.

• Has the message been understood? If not, check how much more information they wish to know. Paraphrasing may help, reformulating key words or phrases the owner has said.

• Pause to let the information sink in, then respond to their reaction and to difficult questions.

• Summarise and establish a plan to move forwards. Providing written information may be very helpful.

Clinical trials are not limited to specific drugs or therapies and the potential for performing clinical trials with CAM exists, and indeed some have been performed. As mentioned, such trials may demonstrate efficacy, at which point the treatment ceases to be complementary and alternative and is incorporated into ‘conventional’ medicine.

The gold standard of phase 3 clinical trials (where the efficacy of a new treatment is compared with an established treatment) involves randomisation of treatment strategies; this has both positive and negative ethical potential. From a negative perspective, randomisation removes the notion of individual medicine, as a treatment is assigned on the basis of chance. A positive perspective relates to the fact that the preferences of an individual vet are almost never held by 100% of the veterinary profession. Where there is honest professional disagreement about a preferred treatment (so-called clinical equipoise) randomisation of treatment is a way to resolve such disagreement. As such, overruling the hunch or intuition of an individual veterinarian would not be considered unethical.

Communicating about cancer

Communication and ethics are intertwined. Without good communication, it is impossible to gain informed consent, and without informed consent, the ethics of cancer treatment are uncertain. Particularly when being seen by general practitioners, many clients are not told of the incurable nature of their pet's cancer (for human cancer patients this figure is more than 25%) and many owners of pets with metastatic cancer believe that treatment regimens are meant to be curative rather than palliative (>33% in human oncology). ⁸ Many owners are not told of treatment side effects, and veterinarians often may not ask a client if they understand the information that has just been presented. In human medicine, 40% of oncologists do not offer a prognosis unless specifically asked. ⁹

Time and information resources

In human as well as veterinary oncology, a lack of time is often (and rightly) blamed for this lack of communication. For that reason, when discussing the diagnosis and treatment alternatives with an owner of a pet with cancer, a longer than routine consultation should be scheduled. In addition to time, human cancer patients have identified other factors that contribute to poor delivery of bad news; they cite excessive physician bluntness, location or timing not being conducive to serious discussions and lack of maintenance of hope. ⁸

Veterinarians and owners often ‘collude’ in misinformation; it is important that we recognise when a pet owner is avoiding asking the ‘bigger questions’ about their pet's prognosis and treatment.

It is important for veterinarians to provide the information in an easily understood conversation, with repeated statements that allow the owner to restate the information themselves. To enable owners to really gain as much detail as required during a consultation, I allow a full hour for each new visit and 45 minutes for any rechecks. Often some of this time is spent with ‘filler chat', which might appear to be wasted time to a financial director. My opinion is that such time allows the owner to focus, builds trust, and reduces the need for follow-up conversations over the phone, where misunderstanding is more likely to happen, and comments are much easier to misread (by both client and veterinarian).

Veterinarians and owners often ‘collude’ in misinformation; and it is important that we recognise when a pet owner is avoiding asking the ‘bigger questions’ about their pet's prognosis and treatment. If an owner is to make an informed decision, they must have the most up-to-date material presented in the most unbiased way possible. Written information is critical in this regard, as the focus for many owners is suboptimal when they are thinking about the amount of time they have left with their pet. Unless the pet is in a critical state (and they can be), I encourage owners to take time to consider all options carefully. For some owners, this may mean taking one or more days to fully evaluate their options; many conversations may be necessary during this time. I also encourage owners to use email for specific questions — my written reply cannot be easily misunderstood and further written material can easily be sent as attachments.

‘Whatif he were your cat?'.

A pet owner's decision about whether to opt for treatment is an individual one, and not a decision to be made lightly, but it should be made with all available information presented in a concise and non-directional way. The often-asked question, ‘What would you do if he were your cat?’ is difficult to answer purely objectively. I usually preface my response with the admission that I am biased as an oncologist, as I believe in what I do; and that I have treated my own animals with chemotherapy, not always successfully. Usually, I say I would treat if he/she were my pet — but not always.

My impression over the years is that my stated decision does not influence owners at all (they often do the exact opposite of what I say); rather, their level of trust in me increases because I offer an honest response, and they feel I will support whatever decision they make. To me that is more ‘ethical’ than refusing to give a personal opinion.

Survival data

What is often misunderstood by owners is the use of median values. Remissions for any individual patient may be of short duration, or they may be longer than expected and this should be explained to owners. If the median survival is presented as being 12 months, many owners consider this guaranteed time that they will have with their pet; other owners will become discouraged because they will lose their animal when a year is up. Interestingly, in human oncology, it has been suggested that fixed life expectancies may taint remaining time, and that uncertainty as to when life ends is a prerequisite for life to have meaning and value. ⁹ This should be considered when discussing prognosis with the owner of a pet with cancer.

One option is to present the data in different ways. If using medians, it is important to emphasise that this means 50% of pets live longer than that time, and that 50% live a shorter period of time. Another way to present survival data is in terms of the percentage of patients alive 1, 2 and 3 years after treatment (if these data are known). Finally, mention of individual patients known to live a long time may inspire hopefulness (even if a very small number), and can be balanced against the proportion of patients known not to respond to therapy at all.

Symptom management

A pet owner should never be told ‘there is nothing more to offer’ as this ignores the importance of symptom management (such as pain medications and nutritional support) and creates a sense of abandonment. It is important for the veterinarian, faced with such circumstances, to emphasise goals such as comfort management and maintaining quality of life.

Communication skills and challenges

Interestingly, clinical experience has not been shown to improve communication difficulties, but didactic and training courses do appear to improve such skills.

Communicating bad news brings the greatest challenges. Physicians frequently report difficulty in explaining a lack of curative options, and negotiating the transition to hospice care. Nearly two-thirds of human oncologists find it stressful to deal with a patient's emotional responses. Many practitioners feel guilty or to blame for the bad news. Likewise, in veterinary medicine, such stress is anecdotally described under similar circumstances and most of us have felt it. Interestingly, physicians who have problems delivering bad news have been suggested to be more likely to offer aggressive treatments that may not be likely to help. ⁸

Conclusions

The ethics of cancer care are complex and depend on careful and considerate communication, leading to informed consent. As long as the veterinarian is providing all the options and keeping the client appraised of all the options, they should have little concern about meeting the criteria for ethical veterinary care.