Good evening, everybody, and welcome to a Thursday night members webinar. My name is Bruce Stevenson, and I have the privilege of chairing tonight's webinar. I don't think we've got any new members in tonight.
So usual rules apply. Questions into the Q&A box come through to me. We hold them in the end.
And, Sarah has very kindly agreed to answer those questions that come through for us. So we are in for a treat with tonight's presentation. Sarah Mason is a Liverpool graduate and a European and RCVS specialist in oncology.
She works at Southfields Veterinary Specialists in Essex, where she is the head of oncology. Sarah's area of interest includes the optimisation of chemotherapy protocols for small animal lymphoid neoplasia, radiation therapy, and combined medical and radiation therapy, including chemo radiation for multimodal treatment of neoplasia. So who better to talk to us about feline lymphoma?
Sarah, welcome back to the webinar vet, and it's over to you. Hi, thank you everyone for coming tonight. So I'm going to talk through feline lymphoma, treatment and management, and I'm going to use some cases to illustrate decision making in this relatively common disease in cats.
So, just very briefly, because my colleague gave a seminar on the presentation of feline lymphoma and staging a few weeks ago, which hopefully, many of you attended. I will just review that for anyone who missed it, just over a few minutes. And then I'll move on to talking a lot more in depth about chemotherapy, both commonly used protocols and also some of the more, recent developments in rescue protocols.
I will use some cases to talk through decision making and go through some of the common toxicities we see in our feline patients. And lastly, I will just give, a little bit of a taste of what we can use radiation for in feline lymphoma, and how we can combine that for, treatment with chemotherapy options as well. So, first of all, presentation.
So lymphoma can present in any organ system and obviously the clinical signs will depend where it is. With cats. They tend to present as sick.
So either they're not well in themselves or the owners have noticed something like diarrhoea or weight loss, for example, in the GI tract, or, dyspnea, tachypnea if it's a respiratory, lymphoma. And as usual with cats, they often manage to hide it fairly well and only come in when things are really overwhelming for them. So this table just illustrates some of the more common presentations.
Gastrointestinal is becoming more and more common nowadays. We see a lot more of these cases. We see less, probably mediasty than we used to.
We do see quite a lot of nasal lymphomas, particularly here in my job, partly because that is a radiation indication, so we tend to have advised case load. And then the less common ones, the other respiratory ones, renal lymphoma, relatively uncommon, and occasionally we see it in other places like skin and central nervous system. The interesting thing about feline lymphoma compared to dogs is that it rarely presents in the lymph nodes and certainly not in Europe.
Some of the US centres will describe that more commonly, but it's not something that we generally see commonly in, the UK aside from the, solitary cervical ones, which, Erin talked about a couple of weeks ago. So, moving on to treatment, the first thing to consider is obviously lymphoma is a systemic disease. It always has potential to be, even if it presents in a localised form.
So, for example, a lot of the respiratory ones, mediastinal, nasal, laryge do present just affecting that system. And when we stage these patients, we don't commonly find it elsewhere. But we know it can be, and we know that a lot of these patients, even if treated locally with radiation, for example, can relapse elsewhere.
So certainly chemotherapy would still be a good Option for treating them and potentially a better option in many cases. So that's the first decision to make for a localised lymphoma. Is it a chemotherapy candidate or a radiation candidate?
But in general, most patients will have disease elsewhere, for example, GI and chemotherapy as a first line treatments. So there is a lot of discussion amongst the oncology communities about whether to use a COP protocol or a COP protocol, so cyclophosphamide, incristine and prednisolone versus that type of protocol, but including doxorubicin. Another controversy we have is how long to continue treatment.
In dogs, we know that discontinuous protocols and standard of care. We tend to do the same in cats, but we don't have necessarily the same depth and strength of evidence for that. For feline patients also they don't tolerate hospital visits quite as well as dogs do.
So, you know, should we perhaps be using short term, more intense protocols for these guys or some protocols still describe continuing treatment for several years. So there really is no kind of standard across the community, but we, we do have options depending on different clinicians, and what others are willing to tolerate, and actually, often what the cast is willing to tolerate as well. So this, figure illustrates, it's not a paper, actually.
It's relatively old now, but still one of the biggest and probably most useful studies, looking at feline lymphoma outcomes. And this was published in 2009 in JSAP. So hopefully, that's accessible to a lot of people.
And it's a UK population of cats, which is particularly useful because a lot of the literature we work from is actually based in US populations, which may have different distributions of disease and different client expectations and, pursuable of treatment. So this looks at basically various subgroups of lymphomas. So if you look on the left-hand side, you can see that regardless of whether these were nasal, renal, central nervous system, laryngy or other.
A lot of these patients were dying fairly quickly. So the media, the 50% survival here, is in the region of about 200 days. But then we see this kind of tail of patients who do actually really well.
So there is in cats, always a subpopulation of cats that do much, much better with treatment than the, the average cat. On the right-hand side, the authors of this paper compared COP and COP protocols. And you can see from that cap from Mayer, there is no difference in outcome, depending on the chemotherapy protocol used.
We didn't see any better or worse outcomes with, COP or COP. This is a smaller study, from a colleague of mine at North Down's referrals, and she looked at, cats, young cats with mediastinal lymphoma. Again, compared, this was more of a referral population, but she compared cop and chop protocols, and again, didn't see any improvement or better outcomes in the cats that had COP versus cop.
And, showing a big US study. So, in Europe, most of the vets, oncologists, and general practitioners use COP protocols in cats, but in the US it is still very common to use CHOP. This is quite interesting, 119 cats from America, which is approximately the same number from the UK study I showed earlier.
And the outcome is pretty much the same if you have a look at these graphs. So from For me, I really don't see a huge benefit in using COP, and I will come on to have a look at some of those protocols with you in a bit more detail now, but my personal preference is the COP protocol for cats. So before we look at the protocols in a little bit more detail, it's worth mentioning that the first thing, the best prognostic indicator for our feline patients to have a good outcome is whether or not they respond to chemotherapy in the first place.
So it's a little bit cyclical. The others will often ask what the prognosis is. And I usually say, well, you know, there's probably a 30% chance that your cat will do really well.
If it's in that kind of tail of patients who do really well with chemo, there's probably about a 30% chance that the cat will do OK. So maybe live for around 6 months and have a good quality of life. And there's also the kind of 30% chance approximately that, the cat will not have a good response.
But the only way to tell is to actually give it chemo, because cats which do well, tend to be cats that have the best response to chemo in the first place. So I do always encourage owners to treat, even in quite sick patients, because we can see quite an amazing turnaround in some of the cats who are in that group who are going to have a complete response, just by having a single injection ofincristine, for example. So this, graph illustrates that effect.
So you can see the top is the, the patients that had a complete response to chemotherapy, and this comes from the same US paper, but it's a useful way of breaking it down. There's quite a vast and significant improvement in the patients that had a complete response. If you compare that to the patients that only had a partial response and those patients that had no response at all, and just died fairly quickly.
So this is an example of a 19-week CO protocol, which is the one we use, in my practise. So we, we have 4 colleges here, and, 2 of us prefer COP. One person prefers chop, and my other colleague kind of fluctuates between them.
So we have a standard 19-week protocol for the main reason being that it's a more dose intense protocol than the alternative, which is 25 weeks. And for me, it's less time for the cats to have to keep coming. So it gets the chemotherapy over and done with sooner, and also they get a higher dose in a shorter period of time.
So we tend to start off on week one, with in Christine, and most of the cats go on steroids unless there's a concern that they might be in, any degree of cardiac failure. It's not common, but sometimes these cats can be quite anaemic, and they may be fluids. So if they get a volume overloaded, the cardiologists are often a little bit worried about using steroids.
So, That can occasionally not be started till later, but the more standard process is to start the prednisolone and and Christine together. We give the cyclophosphamide, on week 2. Now, just to mention here, this is actually the same protocol we use for dogs and cats, but we do not give rosemide in cats, because cats do not get sterile hemorrhagic cystisis.
So toxicities for chemotherapy drugs, in cats and dogs are different. So while your canine patients, you worry about that, we, the feline, patients, we do not. So they just have the cyclophosphamide.
And usually I give that IV unless it's a very, standard sized cat because it allows us to dose more accurately. I think Christine on week 3, and then doxorubicin on week 4, which we give at 1 MB per kilogramme for cats, rather than using the 1 metre square dosage because of their small body surface area. And we then continue that, so they have a week off and then do the same again.
And that's repeated for 4 cycles before we then discontinue and hope that our patient has remission and stays in remission for a reasonable period of time. In comparison, this is an example of our high-dose COP protocol. You can find both of these protocols in the BSABA formula, for example.
We made a decision in my team that we would discontinue for our patients after about 6 months. So we have this 25 week protocol, as long as the patient is tolerating the treatment and the visits. So it's slightly different to the older it is in the formulary.
Again, the reason is we often we'll start with just in Christine to make sure that patients are well enough, they're tolerating treatment. And we give the vicreine sexhospect together on week 2 rather than week 1, and then vicreasing and double up again on week 4. It doesn't really matter.
And how you do this as long as they get 2 doses of cyclophosphide and the 4 doses of vincristine in the 1st 4 weeks. And also that there is at least a week break between the cyclophosphamide because that is the non-vielosuppressive drug. So both in pristine and cyclophosphide can be mallowsuppressive in cats.
But we usually see more of an issue with the cycles, so it's better. You, you don't want to give that kind of two weeks in a row, or you might end up with a quite a neutropenic patient. We then have 3 weeks off, and the cat comes back every 3 weeks and has vincristine and cyclophosphamide together, until it's completed this cycle, and then again, we stop, and they, go home, hopefully in remission.
We do check haematology before every chemo. And mainly we're looking at neutral and platelet counts. With these protocols, we, we don't expect to see, zombocytopenias because none of these drugs are particularly, suppressive off the, zropacytic line, but we are making sure that our neutrophil count is high.
Some of these patients are a bit anaemic. We generally see that improving during treatment, assuming that that is anaemia of chronic disease associated with the cancer. This is an option I quite like for those cats that are very stressed.
This is a 12-week CO protocol, which is published, by German Group. It's technically an LCHOP because they use Epirogenase on week one. I'll talk a little bit more about that later on when we talk about rescue therapies.
LSpirogenase is an enzyme which, acts specifically on neoplastic lymphocytes by inhibiting the uptake of the spirogene. And they use that in combination with fincristine, and then do a kind of mini chop protocol. And actually, the cats in this study, it wasn't a huge group of cats, but it was a relatively mixed population of, disease sites.
And the cats had similar outcomes to those with standard chop or protocols. So as well as response to treatment being a positive prognostic indicator, there are also some negative prognostic indicators for feline patients as well. So weight loss during chemotherapy is not a good indication of long survival.
That probably comes from the cats with GI lymphoma that are not in remission, or cats with chronic disease who are not in remission because they have a constant inflammatory state or are losing weight. Also, some of the studies show that anaemia at presentation is a negative prognostic indicator. I wouldn't not treat a cat because it's anaemic.
I have seen individual cats do really well despite being very anaemic presentation. So, despite, well, in some individuals, it may not be ideal, it's definitely still worth treating them because some of them will, will go on and do well. So, with regards to toxicity from the drugs that I've already talked about, I've mentioned cyclophosphamide.
Vincristine can cause some gastrointestinal signs, as can cyclophosphamide itself. In cats, again, we don't tend to see them like dogs, so we don't tend to see diarrhoea very commonly. It can often be like constipation signs, dehydration, just cats kind of not feeling well, hiding away, not eating.
So, some people will substitute for plastine. If the cat is not coping with Vincristine, it is actually a good alternative. So, in this prospective study, which was done in the US, the authors, randomised cats to have fincristine blastine and then crossed them over and found that outcomes, treatment outcomes were the same.
But the cats that had been Christine did actually suffer more GI toxicity than than blastine, so that's also a valid option for feline patients with lymphoma if they don't tolerate in pristine. So, moving on to a case. This is Bobby, who was a, pedigree cat, 4 years old, and he presented in respiratory distress.
He was quite hypnic and dyspneic and orhypneic, and had a pleural effusion, which you can see on his radiograph on The left, he had that drained and there was a mass, we found a mediastatal mass. So he had aspirs and cytology from his fluid, and that was diagnosed as mediasterile lymphoma. He was staged and there was no disease elsewhere.
We started Bobby on a cop, a standard high dose COP protocol, and he really did amazingly well. So he went through. Several cycles, I think he went through 3 cycles over about 18 months or 2 years, and he remained very, very well in between.
He had good quality of life. He tolerated the treatment without any significant toxicities. There were a couple of Neutropenic episodes.
And when we have that, we tend to just do a little do, delay. So if he was neutropedic on week 3, we just, you know, leave it for 3 days and then treat him 3 days later, assuming his neutral count was back up. And, eventually, he stopped responding to this.
He then One, the owners wanted to try some rescue chemotherapy. So he had some lamustine and cytarabine as rescue agents. And he enjoyed it a short period of time after that.
But certainly, he is an example of a patient that could do really well with his treatment. We did actually restage him each time. So every time he relapsed in his chest, we, restaged the abdomen, and he never had disease elsewhere.
It was always Media style which is very typical for this presentation, and he lived for around about 2 years, possibly a little bit longer, which obviously is really quite a good outcome for him. And then comparatively, this was a cat. She was an older cat called Izzy.
I think she was about 10 years old. And she actually presented with, cutaneous mass, on her flank. And she had had a couple of aspirants that were inconclusive and then gone to surgery to have, an excisional biopsy.
And she was, she was actually very well in herself, so she, she had just an excisional biopsy to find out what this mass was. And it came back, as lymphoma, which is quite uncommon. In the interim, the owner had called in to say that she was not doing well and had become tnick at home.
And you can see the radiograph on the left here. The clear reason for her tachypne is this very diffuse alveolar pattern, which was lymphoma. I've shown this.
It's actually quite rare. We don't see pulmonary lymphoma, or pulmonary involvement with lymphoma very commonly. And, it's quite a nice radiograph to show.
We, in the end did not treat this cat, because, partly because actually, she was unable to, she was so sick by the time she came in. She actually couldn't survive off a ventilator. And that's always a little bit ethically questionable to start giving chemo to a cat that Is that so, OK, she may have responded, but she also may not, and the order decided not to go through that.
And so she was unfortunately euthanized. But this is just to illustrate a kind of less common presentation and how that can manifest, in the skin. So just to talk a little bit about GI lymphoma, because this is quite common now, as I said, I'm sure everybody has seen cats with low grade lymphomas, which present with quite common GI sorry, quite chronic GI signs that are quite well in themselves, other than some weight loss, diarrhoea.
And that's compared with the high grade one, which is a very different disease. So with the low grade, usually small lymphocytes, good survivals do quite well with quite low grade chemos, whereas high grade ones could often the cats can be a little sicker. The lymphoblasts are usually large or intermediate in size, and the outcomes are generally not very good, even with chemo and surgery, although we do have this subpopulation of cats that do well.
And I will mention about large granular lymphocyte lymphoma briefly because that is something we do see a bit more of nowadays as well. So just a couple of examples of, patients. This was a study looking at, high grade lymphoma with surgery and COP, attempting to try and suggest that they do better with surgery and Chop them with just chemotherapy alone.
And, that is certainly an option. Surgery can be very useful to palliate these cats, even if they don't respond well to the chemo afterwards. If they have a mass which is obstructing the intestine, then taking it out can make them feel a lot better.
If struggling to get a diagnosis. These are often not that easy to aspirate, particularly these lymph nodes are difficult to get a good quality samples from. Then actually, this also gives us a diagnosis because we have other differentials for feline intestinal masses, including mast cell tumour, and even some benign conditions.
So this is Choco, who was, I think he was a Maine Coon or a rag doll who presented to me last year. And he presented some vague signs of abdominal discomfort and weight loss, and we could palpate these two masses in his abdomen. Tried to get a diagnosis via FNA, but it came back as inconclusive.
And potentially mast cell, potential lymphoma, so in the end, he went to surgery. And these are pictures from a colleague doing the surgery, of the intestinal and mesenteric lymph node. So, Esteban resected as much of this as he could, that gave us the confirmation of the diagnosis, and we then started him with a cop protocol.
So, unfortunately, he did not respond well to the COP protocol. So then we had to go down the rescue chemotherapy line. He did not respond well to the Mustine, which I will come on to talk about in a minute.
He didn't respond well to Doubicin. And ultimately, he, he still lived for, I think it was about 6 months, with a good quality of life following the surgery, but he actually Never really had any kind of huge benefit in this field that was left in, which was monitored in terms of actually responding. So he was an example of a patient who did averagely, but not particularly well with his treatment.
Just to mention, because we, we actually get quite a few questions about chemotherapy in these, cats with low grade lymphoma. So these are the cats I talked about before, which have the diffuse infiltrates of, small lymphocytes. And there is a nice review now, which is free, open access online in BMC journal.
It's referenced there below. And you can actually go there and they have all of the different chemotherapy protocols described, because this is something that isn't commonly written in the formulary or anything. So this is a table taken from that paper, which illustrates what I said already, that these cats live, you know, between kind of 18 months and 3 years.
And the different protocols, are here, so 20 mg per squared every 2 weeks or 2 migs per cat given orally every 2 days, for example. That's the one I tend to use. But different people have different ways of delivering this.
The main, message to take home is that they seem to do well regardless. Recently, it has been reported that some cats with high grade, sorry, with low grade lymphoma will go on to develop high-grade disease, and I have seen it. So it's always worth keeping in mind when your low grade lymphoma cat starts to be unwell.
So on this graph, you can see it on the red line, that's the median survival time for the cats with low grade lymphoma, and the blue line is the median survival time after they transformed. So after they progressed from a low grade to high grade disease. And just to keep in mind, there is also this relatively uncommon subtype, but we are seeing more and more of it.
So this is large granular lymphocyte lymphoma, and you can see on the picture here, there's these little granules inside the lymphoid cells. These guys really do not do particularly well. Some colleagues have recently tried to report some case series, and there are odd patients that do well with chemo.
Potentially, lousine may be beneficial in these cats, but not, anything like the survival times we can see without other patients with high or low grade lymphomas. So talking a bit more about the chemotherapy options, so I've alluded already to different rescue agents. So, doxorubicin, for me, it's not particularly surprising that we do not see a benefit with COC protocols of a cop protocols and cats, because when we look at single agent doxorubicin, the response rate is actually quite low, around about 30%, maybe even a little bit less.
And doxorubicin, again, is something to consider in cats that are different toxicity than dogs. So with dogs, obviously, with doxA, we worry about GI signs and cardiac toxicity. It's not something we see in cats.
So, cats do not seem to get cardiac toxicity. And again, they, they don't get the same GI signs. They get kind of similar GI signs to the, the cristine, just a vague signs, but not very commonly.
However, it can be renal toxic. So it is worth just checking your renal function in these guys, keeping an eye on creatinine if they are doing doxo. If it is a cat that has failed cop, you can try.
Some of them will respond, and obviously, in those cases, it's definitely worth using. Ellisparrogenase, I talked about before as well. So, historically, this was not very popular for cats.
Again, because the response rate was low. And some initial pharmacokinetic studies indicated it had a short duration of action in cats, which made people less keen to use it than in dogs. It used to be quite affordable, but now it's really expensive, which is not great, because for a cat, you only need a tiny bit of the vial they come in.
So what we sometimes do is we keep the leftovers from a dog. So if we have a medium-sized dog, there's usually a little bit of excess in those vials, and we freeze that. And then if we happen to be, well, fortunate enough that a cat requires rescue at the same, similar time as we've had to use as far as it is for a dog, then we can use that as a rescue agent.
And I've actually had reasonable success with this. I, I feel anecdotally that we see better responses than Historically pause it. So I quite like to use it.
It's unfortunate that asparagus has become so expensive now that we actually rarely use it for dogs either, so we often don't have the same, The excessive slash that we did before. Lamustine is another drug which is becoming a little bit more available and, and more widely used for feline lymphoma. So, It was originally looked at as a rescue therapy.
So, not particularly great in that cats with lymphoma which were rescued, was musty after failing a cup or hock protocol, only had a median response to that of about 39 days. But you can see from the range that some of them did really, really well. The cats with small or intermediate lymphomas did better than the cats with large cells, it's a more aggressive disease.
And somebody here noted that gastrointestinal ones seem to do particularly better than the non-gastrointestinal ones. So that kind of encouraged a further study looking at the most in specifically the GI lymphoma. And about 50% of cats in this study had a response.
So that's quite interesting, and we do use it. So the median response in this particular paper is 300 days, and I would agree that it's reasonable to do this. The mustine is an oral drug.
So it saves the having to have IVs, so for those patients that are, not very tolerant of treatment, it's a nice, Option And again, with themosine, the cats, you can see at the very bottom, those who did well were the ones that had a response to the treatment. And the ones that didn't respond, obviously had a less good outcome. And that's just it displayed there in a graph, which if you remember back to the previous cop and hop graphs, is very similar.
So actually, it's a first line treatment for GI lymphoma, the mustin certainly has a place. Just to mention, with chemotherapy, we've talked about IV and oral agents. This is definitely worth having a look at if you're giving chemotherapy in practise.
Again, it's open access free online in Journal of veterinary internal medicine. And this is what we work from in my practise to make sure that we, are working to the high standards of health and safety. Useful to make sure that you can do as much as you can from this, in your own practise as well.
And just a couple of pictures of the, the types of things that we consider. So, first of all, is disposing of chemo waste. I would certainly not expect a general practise to have the, practises in that referral practises have, but at least having a sealed unit, clearly labelled as chemotherapy.
For example, the cat in the middle, he is having his chemotherapy, you can see through a closed system, so we use these, lots of them available on the market now, but basically, that's safer for not having any incidents of chemotherapy spillage. You can see there that myself and my colleague are wearing thick gloves designed to chemotherapy, full sleeves, and you can't see our heads, but next to there is a picture of one of the nurses I used to work with wearing the face visors that we wear routinely for, injectable chemo and actually oral chemo as well, to be safe, we had a, a freak incident where one of the feline patients bit into a capsule of the Maine and sprayed the powder out. So that's a good, reason to be wearing face mask or eye protection.
So with toxicity, I've probably included quite a lot throughout the discussion, and Lemusin is one to be a little bit careful with. So all of the drugs in cats are a bit unpredictable in when they cause mal suppression. Some patients get very malsuppressed, and some just seem to not.
We don't have the same standards of time, so the deer, times in dogs are fairly predictable, but not so much in cats. And the musing is particularly bad for that. Then the deer can be anything between about 2 and 6 weeks.
And I have seen it even longer than 6. That can be very frustrating because you can't give them anything else masuppressive if they're, already neutropenic. It can also cause rarely in cats, it can cause renal or pulmonary toxicity.
But interestingly, like with dogs, they do not get the hepatotoxicity that we see with dogs. This one must do. So again, just an interesting feature of how our feline patients metabolise these drugs differently and have different organ sensitivities in terms of toxicity.
Just to cover a couple of rescue protocols which have been published, just for completeness, DMAC is a protocol which was quite popular with dogs for a while, but has kind of got out of fashion a bit because it's very expensive and actually not as beneficial as an initial data would suggest. Response rates tend to be quite short. So this is dexamethasone, malalan, actinamycin D, and cytarabine.
In combination, given over a two-week cycle, it's really intense for cats. It's intense for dogs, but for cats particularly, I think it's, a lot of visits. And the response rates were only 26% with really poor survival times.
Bearing in mind, these patients have already failed treatment and probably have quite, sorry, chemo sensitive. Resistant lymphomas. Another one from the US, Mom, we can't actually get meromethamine, but this is using a combination of reassing mealan.
Again, very poor, responses, just occasional patients that did well with that one. Lastly, just to talk a bit about radiation, so on the left, there is a picture of a linear accelerator, one of the older style ones, which it's used to treat localised lymphomas in our feline patients and it's only available at specific specialist centres, but definitely worth mentioning because it has a role in this disease. So what kind of patients, candidates, certainly nasal lymphoma.
I'll show some of the studies in a minute. They should definitely be staged and definitely the fear of disease elsewhere before they're treated. It can be used for abdominal lymphoma, so GI lymphoma, but only in we, we only offer it in combination with chemo in patients that have remission.
So the idea is they need to be responding to the chemo and then we consolidate with, radiation treatment. It's not great to use as a single agent, and not all centres will offer it. We can do it from mediastyal.
It's not great in my experience. It's more of a rescue treatment. The lungs and heart are very sensitive to radiation, so we can only give relatively low doses.
It's in humans, it's used quite commonly for mental lymphomas. So those lymphomas that affect the neck. And down into the mediastinum.
And they tend to combine it with chemotherapy. So it certainly has some potential, particularly when the new machines are more available and we can be more targeted. And if you have a localised lymphoma anywhere really, particularly if it's not responding to chemo, it's worth a try, or using with chemo in certain patients, which I have an example of just coming up now.
So, just because nasal lymphoma is one of the more commonly reported in the literature, and because patients can have a really good outcome, I think it's worth mentioning. So, these are the five main papers looking at, radiation and chemo. So you can see there that in 3 of the studies, the cats had a mixture of both.
And then there's one study each where they had radiation or chemo alone. So they actually all do. Fairly similarly.
Obviously, these are different populations, but certainly 18 months, 2 or 3 years is the average. But this is kind of headline. So we see this a lot in textbooks, but actually, there's still quite a number of patients who don't do so well.
So if you think back to that first slide, you know, it's still a significant number of those nasal patients were dying within the 1st 6 months. And in the more recent paper, this one here, about 30% of patients that had radiation actually relapsed elsewhere. So we should still remember that this is a systemic disease and Well, these options are available.
Clients should be very well informed and really consider what the best option is. You know, radiation is shorter, less toxicities than chemo, potentially a good outcome if you're in 70% of patients who are doing well with that. That's just a picture of a cat, patient we had who did very well despite the massive disease burden and treated with just radiation.
This is my last case, which is Gizmo. Really interesting case. So he presented to one of my colleagues, at North Downs as well, actually, with this lesion, which is, this is a cutaneous lymphoma, and it's on his tarsus.
And this has been described in cats a few years ago as a kind of specific entity that they, there is a population of cats which get this cutaneous tarsus lymphoma, which we don't really understand why it's there. Those cats, they present with localised disease. They're well, otherwise, they treat with chemo and they live for on average about 200 days, but most of them relapse systemically.
So Gizmo presented, I think it was last October, or last September, and he had actually combinations. So he had chemotherapy and North Down's. And that was, I think, a 12 or 16 week CO protocol.
He came to me and I just had a very short radiation protocol, 20 degree. And He responded really, really well. So that lesion went away with the radiation before he had the chemo.
So we know that it was a radio sensitive lesion. And he then had the chemo to try and avoid any systemic progression or systemic failure. And he has been really well for the last year, until about 2 weeks ago, my colleague.
Emailed me again and said he's represented, and now he has the over on his other tus. So the owners now want to do the same again. They're gonna come and have another course of radiation to his other leg, and he's gonna then have another cycle of chemo with my colleague as well, and hopefully, hopefully have a similar outcome.
So that is everything really, just to summarise. Lymphoma obviously presents many locations. We can treat with various chemotherapy protocols, most of which are well tolerated, most of which result in good medium-term responses, and some in long-term survivals.
And that radiation is also an option, can be combined. I, if I do radiation, I tend To shorten the chemo protocol as well, and try to really choose the patients which are good candidates for one or the other or both. And just, thank you to my team who are all amazing.
My, veterinary team on the left, and the chemotherapy nurses all dressed up in their gear, and the radiation team at the top. So I am happy now to take any questions if anybody has any. And, thank you very, very much for logging in and listening this evening.
Sarah, that was absolutely fascinating. And it's so nice to hear that there is all this advance going on. I can remember, not that long ago in my real life, that, you know, lymphoma, when you diagnosed it, that was the end of it.
But it's nice now that there's, there's so much work being done. And, and, although it's not forever, giving them good quality of life for 18 months or 2 years is brilliant. Yeah, and that's, it's really rewarding to treat them, you know, the patients that do well are great, and it, it is all about quality of life.
You know, we do, we do consider that as our primary objective when we treat patients. So, that's what it's all about. Yeah, yeah.
And it, I mean, that goes with any disease, but especially with these neoplasia cases. And it's, it's sometimes hard for the owners to To grasp the concept of, of doing chemo or radiation on their pets. I, I mean, I remember sometimes talking to clients and they look at you as if you've crawled out of a piece of cheese and they go, really, you could do that on the animal?
You know, so it's, it's great. Yeah. So, Greg has asked a question.
Has anyone tried electrochemotherapy in nodal cutaneous lymphomas in cats? Oh, that is a very good question. And the answer is, I do not know.
So, I, I've never seen it reported. It, it isn't reported to my knowledge. And my colleagues who do it, so I have a couple of colleagues around the UK who do electro chemotherapy.
I've never heard them talk about it. It's not really the most common indication for electro chemotherapy, because, obviously, we tend to treat it systemically. And the people who use electro chemotherapy are using it more for solid tumours, because they're less, sensitive to it, if it's given intravenously.
So, I would say probably not. Because we have, because they're very sensitive with intravenous, they're not likely to be any more sensitive by injecting it directly in. And because we also have the radiation option, I think it's quite unlikely.
OK. An interesting concept to think about though. Yes, yeah, yeah, to inject chemo directly into a lymphoma.
Definitely. Yeah. Well, Sarah, there doesn't seem to be any other questions coming through.
I think your presentation was so definitive and expansive that you covered certainly all the questions that I had before we started. So that's absolutely fabulous. Good, thank you.
Thank you for your time tonight and thank you for sharing your expertise with us. I, I, I'm sure that there's loads and loads of, of, parents, pet parents out there that are incredibly grateful for the work you do and, and we do appreciate you sharing it with us. So thank you for your time.
Thank you. Thank you for inviting me and thank you for listening. Folks, that's it for us tonight.
To Luke, my controller in the background. Thank you for your help and for all of you for attending. Thank you so much and good night until the next one.