Dr. Liptak: And one of the things that we all want as surgical oncologists is to not recommend a procedure that is not beneficial for an animal. We're not all about cutting big. Ideally, we cut as small as possible to achieve the same results as a bigger cut. It's not about the surgery or pull flap or this or that. It's really doing the best we can in the hope that we're improving the outcome for these patients and with as least complications and as least invasiveness as possible.
Dr. Venable: Welcome to the Veterinary Cancer Pioneers Podcast, the show where we delve into the groundbreaking work of veterinary professionals who are dedicated to advancing the field of veterinary oncology. I'm your host, Dr. Rachel Venable, and I'm thrilled to embark on this journey with you.
Well, welcome to the veterinary cancer pioneers podcast. I'm your host, Dr. Rachel Venable. And today I have the honor of interviewing our guest, Dr. Julius Liptak. And Dr. Liptak has quite the bio. He is a distinguished internationally recognized surgical oncologist. He is the co-editor of the Seminal Veterinary Oncology Textbook Withrow & MacEwen’s Small Animal Clinical Oncology. He has over a hundred publications in veterinary and human peer-reviewed journals. He's also involved with textbooks. Dr. Liptak is a surgeon and a fellow in surgical oncology. He was the founding president of the Veterinary Society of Surgical Oncology. And in 2010, he was awarded the Stephen Withrow Award for Advancing the Art of Science of surgical oncology. And in 2012, he was the ACVS founding fellow surgical oncology, which was only one of four in Canada. And also in 2020, he was accepted as the RCVS specialist in surgical oncology, which is actually only one of six in the world. So I feel very honored to have you on this podcast. I know you've done a lot. And I've read a lot of your papers and things and a lot of the advanced surgery and techniques that you do. And so I'm really interested to dive into a lot of that. And I know I just did a very brief overview of your bio. And I just thank you so much, Dr. Liptak, for being on the podcast today.
Dr. Liptak: Oh, happy to be involved.
Dr. Venable: Well, thank you. And kind of something I always like to ask people is just sort of what got you started, especially in veterinary surgical oncology because that's quite a niche. And I was reading through your bio, you're one of a very small category. So how did you get into this niche?
Dr. Liptak: That's a really good question. And I can really thank Rod Straw. So Dr. Rod Straw was the first fellow in surgical oncology that was ever trained by Dr. Withrow. And that was the first training program. And he's an Australian. He spent a number of years after his fellowship at Colorado state and then moved back home to Brisbane in Australia. He was giving a series of lectures at a conference and it just all clicked. It's like I once I attended those lectures is that's what I wanted to do and this is before I'd done an internship or a surgical residency it was like I knew I wanted to do that, so the very first thing I did was after the residency was to apply for the fellowship and actually a friend of mine Dr. Maureen Thompson who I was good, good friends within Brisbane got the fellowship a year or two before me because she knew about my interests and so she did the same route. So yeah, I knew before I was wanting to be a surgeon that I wanted to be a surgical oncologist.
Dr. Venable: And what is it about oncology that drew you there? I feel like we're kind of a different group, right? It's not something everybody goes into cancer. So what made you specifically, was it the challenge of that kind of surgery or was there something specific about cancer?
Dr. Liptak: I think it was more about cancer. I like numbers. So I like these statistics, the survival times, that aspect of things. But I also like that you could think out of the box and each patient was different and depending on the cancer type and where that was located and the owners and their wishes.
So I like that ability to use your head and think about what was possible. Particularly, following my fellowship training, it was really that every case was different and you weren't constrained by a box that you had to think within.
There were so many other different options if you had a curious and inventive mind and that owners were willing to go there if there weren't answers that were regularly proposed or available. I also really liked the ability to work with other people. So radiation oncologists, and medical oncologists work as this big team. There are so many aspects of surgical oncology that I really enjoyed, and it was an active area of research and obviously I liked the clinical research aspect of surgical oncology.
Dr. Venable: I like numbers too. I hadn't heard someone say that before but maybe that's also a connector for a lot of us in oncology is I like the fact that there's stats, and there's more science. I feel like sometimes in internal medicine it's getting that diagnosis, but when you really dive into the weeds, always like, wait, so how long, how do we know which drug, you know, maybe that's just because I didn't continue in internal medicine, maybe they have a lot more now. But that is, like that you said, the numbers. I hadn't thought of that, but that's really true. And working with people, certainly the surgical oncologist, you have to work with a lot of people because it can be quite complex.
How do you typically approach? Because I'm sure people probably send you sometimes the more complicated cases. So how do you try to approach those?
Dr. Liptak: Now a practice owner and we have a large specialty group which is lovely. Very much and always have been of the opinion that I'm a specialist in surgery and while I may know a certain level of medical oncology and radiation oncology, internal And if I'm working with a medical oncologist or internal medicine specialist, they know a hell of a lot more than I do in their specialty. So if I have those specialties available, there's an aspect of that case that needs attention, then I'm very happy to, you know, refer that patient in-house to maximize the outcome for that patient and their owner. If I have that expertise available in-house, then that's fantastic. So, to work with an anesthesiologist and a criticalist and internal medicine and you know all those different other specialties that just, you know, maximize the outcome for a patient then that's you know all I could ask for.
Dr. Venable: I think that's good because it's true if you're just sort of a lone man on your own island, it's hard to do, I'm sure a lot of the complicated surgeries that you do, and it would be hard to get all that done. What would you say is one of the more challenging surgical procedures that you've done or that you routinely do?
Dr. Liptak: There's ones that I like that, actually not that challenging on paper they are, like chest wall resections. I find some of the more interesting ones and the ones I really enjoy, but actually sometimes take a lot out of me is the oral and maxillofacial surgery. So the planning that goes into those and the risk of complications afterwards.
I think some owners in particular, and maybe referring vets don't really realize, is that when you practice at this kind of level where you're doing complex cases, the complication rates also go up. And they're just inherent complications. They're not the ones that mistakes or anything else like that. You know, for instance, a cordal maxillectomy, they have a 30% plus rate of dehiscence. And so that means that You have to counsel the owner through that and prepare them for that possibility before surgery. But when it happens, it takes a lot out of you. It's a bit of a stress. It's another case to add to your caseload. And emotionally, it's just draining sometimes. That's where some cases become challenging. Flaps, they have, it's always cool to do flaps, but flaps have a 90% complication rate. It's a bumpy road for that recovery and you see a lot of that client, and they can get frustrated, and you get frustrated with these inherent complications happen.
So I like doing surgeries that are challenging and I particularly like things like chest wall resections because they don't have that complication rate and for some tumour types you have a great outcome like chondrosarcomas. So that's what I really like. If you've got a challenging surgery that makes you think that incorporates a number of different specialties in the workup and the care of it, like chest wall with anesthelogists and critical care specialists. But the recovery is quick, it's not complicated, and the outcome is great, then that's kind of the ideal case.
Dr. Venable: That does sound the most rewarding. I agree. I think complications, even with chemotherapy, I hate when we have just those bad complications. So I can only imagine in surgery, just internship residency seeing some, you know, but never quite being a surgeon. So I could totally understand from there. And you've certainly done a lot of different complicated surgeries or just, you know, some of the publications and things I've seen. I feel like you like to try to push the envelope a little bit to get people to know they can do these things. And what would you say is maybe one of the frustrating things that you run into? Like I know for me as an oncologist, I like to recommend surgery. And there's certain surgeries I find that I get more pushback on than others from people.
I feel like sometimes when you do your publications and your textbooks and things, you're trying to encourage people like, hey, this can be done. Or maybe this dogma that we thought, you know, there isn't actually a lot of research on it. So what would you say is kind of maybe your pet peeve or one of those things you really hoping people get when they read your textbooks or your articles?
Dr. Liptak: Yeah, I think there are certain procedures that frustrate me, and mandibular to me and cats is a classic example. So we had this 2006 paper, a good paper, you know, a number of cases, but it was a transition paper in that a lot of those cases didn't have feeding tubes at the start, and hence has a high complication rate as a result of cats not eating because they weren't getting the supplementary feeding. And it's that complication rate that was published in that paper that has turned many vets off that procedure.
But you dig into that paper, and it had 85% owner satisfaction, and that was before better pain control, better post-operative management, and better nutritional management. And then when you look at the actual statistics in that paper, you have far superior survival rates. And if you get those cats out beyond a year, then hardly any of them succumb to their disease with better case selection as in we see these cases earlier so we can get better margins and get better local treatment control then these cats can survive a long time and the vast majority are able to eat voluntarily so in the kind of the surgical oncology circles, we have this kind of feeling that if they're eating before surgery, they'll eat after surgery, and in most of the cases that's true. Yet I get so many people say to me that, no, don't like things in cats. That's just not the way to go. It's cruel. Everything else. And it's purely based on this complication rate. Then they apply the same thing to maxillectomy, which we showed in that paper that we published a couple of years ago, totally different to mandibles. And they eat quickly, they very rarely require feeding tubes, and the prognoses were amazing. I didn't expect the prognoses that we got in those 60 cats.
Things like that, that's the pet peeve as in there's this kind of inbuilt bias against it when there's no good evidence for that. So they're the kind of things I like to be able to turn around. You know, some of these surgeries are big, but dogs and cats are amazing creatures, and they recover very quickly. And one of the things that we all want as surgical oncologists is to not recommend a procedure that is not beneficial for an animal. We're not all about cutting big, Ideally, we cut as small as possible to achieve the same results as a bigger cut. So we want the best for the animal and their owner. It's not about the surgery or pool flap or this or that. It's really doing the best we can in the hope that we're improving the outcome for these patients and with as least complications and as least invasiveness as possible.
So that kind of occasional misconception that, you know, we just want to cut big and that's all we want to do is something that we're not about as surgical oncologists as a group.
Dr. Venable: Yeah, I like that because it there is that balance of trying to find you have to be aggressive to be a surgical oncologist but at the same time being reasonable or practical. It sounds like that's kind of what you're saying and and I did want to talk to you. Because I have read your cat paper and I have always thought we don't do surgery in cat. So Like with the cat, kind of curious just to hear a little bit more about your experience. So like on the mandible, like a lot of those cats, you said you put feeding tubes in, did most of them, then they did come out eventually, like after things healed, or that was your experience?
Dr. Liptak: Yeah, even with the big resections where you take out a total mandible on one side and part on the other side, which Sarah Boston's paper labeled those as radical mandiblectomies. So if those cats are eating beforehand, then they'll almost always eat afterwards, even with those much larger resections. In my experience, I'd love to do that paper again. In fact, we have a residency, so a surgical resident, and one of the dentists is an oral and facial surgeon as well. So either his resident or my resident, we're contemplating doing that study again with more recent cases that are kind of managed at the fellowship level to see their out, 'cause I think it would be a very different story.
Dr. Venable: Yeah, that would be interesting just with the newer techniques. And cats, their mouths are so tiny. What kind of margins are you getting around those tumors roughly? 'Cause I feel like the tumors, a lot of times they're fairly big when we see them. So how much normal are you trying to get around those?
Dr. Liptak: One to one and a half centimeters. I think that's another thing with surgical oncology. People always ask about margins, but truly we only know margins for low-grade mast cell tumors less than three, four centimeters and intestinal tumors. They're the only objective studies that we specifically know margins for. So I can say two centimeters for oral squamous cell carcinomas in dogs and one centimeters are just a guesstimate in cats, but that's typically what I go for.
Dr. Venable: I've heard just even from pathologists, right, that as far as that margins, just that whole debate of things shrink so you have some distortion when they look at it under the microscope and honestly they're only looking at a small section. What do you think? What's a I don't know maybe a better way to try to improve this in the future so we get a better sense of what's you know margins or complete what what are your thoughts on that.
Dr. Liptak: Yeah, talking about pet peeve… I should have mentioned one so margins are in a way a big pet peeve for me because we have this, or to answer your question specifically, when you look at the studies, the tumor itself does not very minimally shrink with formalin fixation. It's the surrounding normal tissue that will shrink to a much greater degree. And that may affect the assessment of margin width, but not margin, the quality of the margin. So I'm not too worried about that aspect of things.
The pet peeve part of it, as you probably well know, is the comment of narrow or close margins. It's not something that is used in human medicine. Human medicine has what's called the residual tumor classification system, where an R0 margin is a margin that doesn't have tumor cells extending to the surgical or the cut margin. An R1 margin, there are two qualifications on that, but an R1 margin is histologically incomplete margin. So there are the tumor cells on the edge or depending on the tumor type within one millimeter. And it's a system that's been used for over 40 years. It's incorporated into the WHO classification system, the AG/DC classification system. It's widely used and being labeled as highly prognostic. We don't use it in veterinary medicine and it's a simple yes/no thing.
And it's there's more traction for using the residual tumor classification scheme. More recently, for some reason, we overcomplicated it. And in the same vein, by overcomplicating it and treating close or narrow margins, which have no consensus to. There's between 1mm and 5 millimeter histologic tumor free margins are classified as close or in narrow margins, and there's no consensus behind it. There's no science behind it. And yet we treat those patients the same as incomplete league-sized patients. So we're tenaciously overtreating a large number of patients that didn't need those treatments. And now we have exposed that. And the iron is to the extra stress, the extra finances, the extra complication rates.
And one study treating patients that had either incompletely excised or narrowly excised Mast Cell Tumor's complication rate for the additional radiation therapy was 90% and for additional surgery is around 35% I think it was. So that's a high complication rate for patients that never needed those treatments in the vast majority cases. Particularly for Mast Cells, where studies have shown that recurrence rates for completely excised were 3% and for narrowly excised were 5%. So there was no significant difference to expose all of those patients to unnecessary treatments and all the emotional stress that it's associated with that. That is a pet peeve.
Dr. Venable: It makes sense why it would be right.I mean, when you're you're saying, you know, is this necessary? Are we doing things that aren't necessary? What do you think it would take to determine or maybe get that more unified in veterinary? You think it's studies or pathologist training, 'cause I remember now, again, I was trained a few years ago, but like three-millimeter margins, we would call that close or we would do more treatment.
And I've noticed more papers are coming out that I've kind of changed my thinking, but there's still a lot of people, like you said, we're doing that treatment. What do you think it's gonna take or do we need to maybe other people need to see the numbers so that we're not maybe treating those pets? What do you think?
Dr. Liptak: In a way, it's another frustrating component of it, because the American College of Veterinary Pathologists came out with a consensus statement in 2011 or 2012 that pathologists should not use the term narrow or closely excised in their pathology reports. So here's the leading body for veterinary pathologists telling pathologists they shouldn't use this term, yet it's still widely used without its scientific evidence. So I think, you know, Withrow used to say, "strong opinions, weak data," and what we're really facing is a whole lot of people with strong opinions, but not the data to back it up.
But equally, people that believe in the residual treatment classification scheme are also, we have some data to back us up, but it's not strong data, and there's a lot of strong opinions there as well. So the role for the people like me who believe in this system is to prove it. So I think that's part of it. The review paper that I wrote, there is some more traction with some studies coming out, looking at the residual treatment classification scheme and showing local reoccurrence rates.
We certainly have a paper or a study looking at that as well. It's just in progress. I think there is some onus on people like me that propose this system, that wanna get this system in place to show other people with good robust studies to prove that this is something that's applicable in veterinary medicine and if there are modifications that need to be made for instance, if it's not tumor on ink and it is in fact one millimeter then we can tease that out of the statistics. And that's equally the challenge I make to people that support for instance radiation therapy falling soft tissue sarcoma resections. You know, when you look at the vet and literature, there's no improvement in local tumor control with radiation therapy following incomplete or marginal resections for soft issues or sarcomas. And when I get pushed back, when I say that, it's like, well, you're the ones doing radiation therapy, you should do a study to prove me wrong 'cause you've got the cases to do that. So I think that's where we can overcome some of those highly opinionated, but weak data types of approaches if we have the case numbers and the impetus to do it. And so, I think some of the onus to get the residual treatment classification scheme into more common practice is to prove that it works. So that's where the onus falls back on people like me that believe in the system.
Dr. Venable: I think that sounds good. I guess for me, I kind of get to sit back and see. I think it's all really interesting. Yeah, I hadn't really thought about the radiation, but you do bring up some points. I can think of some surgery papers that talk about recurrence, if I think about some of the radiation papers. I guess it is sort of similar. I hadn't really thought of it that way. I guess I would have to look at it more closely, but that is really interesting.
Dr. Liptak: Yeah, I've got a spreadsheet that I produced a few years ago where there's only two head-to-head papers looking at surgery only and surgery and radiation therapy, and they only had five cases each. So, you know, it's not a valid, but those papers showed higher recurrence rates in the the surgery radiation group. And obviously, there may be selection bias and all those kinds of things.
And then obviously, study desire is different between studies and that kind of thing. So it's not a valid comparison, but there are roughly seven papers or eight papers now on surgery only and seven papers I think on surgery and radiation therapy and the recurrence rates the same or slightly less for surgery only.
So as I said you can't really compare them but numerically, they're either equivalent or less for the surgery-only group. And I look at that and think, why are we doing this treatment when we haven't got the evidence that it's effective, and I know we're doing it because that's what they do in people but the disease is different in people. It's what we call grade one and two soft tissue sarcomas, benign tumors or more or less benign tumors in human medicine. So we're dealing with a lot less aggressive tumors or sarcomas than they see in people, which have a much more aggressive local behavior and also much more aggressive distant behavior. So it's apples to oranges, and it's not fair to say, well, they use it in people with soft tissue sarcomas, hence we should use in dogs or soft issues sarcomas. So it's an invalid comparison, just as invalid as comparing surgery only to surgery in radiation papers are. We just had to have good evidence for it. And that's, again, the onus is on someone to show definitively with a good either perspective paper or a retrospective case match paper, something like that to try and answer that question.
Dr. Venable: That is certainly a good question to answer. I do find often in our vet studies, there's just not enough dogs, and we try to make, I think, too many conclusions, 'cause from a medical oncology standpoint, there's definitely some studies showing that chemo doesn't help, and there's times where I wonder, well, is that just because it's underpowered or selection bias, or 'cause there are cases, I feel like it does.
I know like anal sac carcinoma, you got a big study that you guys are working on, and I don't think you guys found chemo helped too much in that one either, at least in the preliminary, anal sac is the one that I always find tough. It seems like it has a very high metastatic rate, but a lot of the papers that are out, it's sort of mixed to how much chemotherapy helps. But in my mind, I feel like, well, surely it's helping. So is it somewhat comparing apples to oranges? I don't know if you have an opinion on the chemo side of things.
Dr. Liptak: We have the data for the chemo side of things. And it also goes to what you just pointed out. Do we make too much of the papers that we have. The anal sac study that we have, I presented the preliminary results way back, almost 10 years ago. And that was really exciting. 'Cause when I looked at anal sac carcinoma, we kind of lumped it all together as one disease. But really, and there wasn't a paper that showed chemotherapy was a benefit, but we looked at it as one disease. But dogs with non-metastatic disease seem to have a much different biological course than dogs that presented with metastatic disease. When we got the preliminary results for our study, it was really like, oh, this is playing out like I hoped it would. So dogs with non-metastatic disease, vast majority, did not go on to develop metastatic disease. They did not need chemotherapy. That was kind of a no brainer. And then the dogs with metastatic disease. And so this preliminary study had 750 dogs. And so the dogs with metastatic disease, the survival time significantly improved from anal sacculectomy alone to anal sacculectomy and lymph node excision to combining those two with chemotherapy. And with doing surgery at both sites, median survival time was around 540 days, around 18 months. But with chemotherapy, with a p-value of 0.06, it came out at 1927 days. So almost four times the median survival time of surgery alone.
And I was really excited. And then we got another 600 more dogs and followed them out for longer. And the dogs that presented with metastatic disease didn't matter what you did. Anal sacculectomy alone, anal sacculectomy and surgery, plus or minus radiation therapy plus or minus chemotherapy is all around 350 400 days. So that was like, oh, very disappointing result, but it's 1300 dogs. Again, it shows you longer follow ups and higher power that what you got with 750 dogs, which is still a relatively big study in veterinary medicine terms, it changed the results so much. So it's, you know, that extra power and longer follow-up is had a dramatic effect on those results. So when we're making conclusions on 20 dogs and with a whole range of different treatments, really, what are we doing?
Dr. Venable: Sometimes that's what I'm wondering too. It's like, wait, how much can I truly take from this? Are we making a few too many conclusions? And talking about some of these different cancers and things, what's an area that you think is most promising for research and veterinary surgical oncology. I know we just talked about some stuff. Are there any other areas that you guys are looking into or thinking about?
Dr. Liptak: I think the big push is sentinel lymph node mapping. Like if treating cancer from a cancer perspective, there are minimally invasive techniques that are being developed, which I'm not part of. I don't do minimally invasive surgery, but Dr. 1A, for instance, is now doing total prostatectomies minimally invasively. So that boundary is being pushed from a minimally invasive perspective. But they're all surgeries that we could do with open surgery as quickly or even quicker sometimes.So it's just a different technique to get the same result. I think it was as we learn more about margins, we can kind of tailor those surgeries better. But I think things like sentinel lymph node mapping is the diagnostic side is the exciting part. So learning how to do sentinel lymph node mapping effective. with the mapping procedure.
So I presented a conference about a year ago in Italy and it was amazing 'cause we had 600 people attend the conference that was largely based around sentinel lymph node mapping in veterinary medicine. And I don't think I could get 10 people in Canada to attend that meeting. Just their passion for it was amazing. But where I see us failing right now is what do we effectively do with that information that we get from that?
So we get a positive node, what more do we do now? So there's a reason why we're doing the sentinel lymph node mapping, but we should be setting oral melanoma patients with positive nodes to get radiation therapy, which is where this hopefully is leading to, but we're not quite there yet. That I think, is gonna be an active area of research, and you'll see more studies coming out as to kind of refining that process. I always struggle with mast cell tumors, for instance, do I do sentinel lymph node mapping when that lymph node is likely to be in an abdomen or a chest and I'm not going to be able to get it? Do I do lymph node mapping for a low what presents as a low-grade mast cell tumor, knowing that if it is going to be a positive node, it's going to be an HN2 node that I'm going to ignore anyway. There's those kinds of clinical decisions on a pragmatic side that I still struggle with.
Dr. Venable: So, what scenarios would you say that you're really doing more of the sentinel lymph node? Is it like oral tumors? Or where would you say like you would recommend the specialist or primary practitioner really trying to do sentinel lymph node mapping?
Dr. Liptak: Definitely for a known oral melanoma. The main reason for that obviously is that they can cross to the other side. There are three major sets of regional lymph nodes. So the parodied the heart mandibular and the medial retropharyngeal, but they can also go to the lateral retropharyngeal, they can go to the superficial cycle, and they can cross, so you've got 10 major lymph nodes that it could go to and just over 50 % go to the mandibular, so if you're just taking the ipsilateral mandibular node you've got a high chance that you're actually missing the representative node and in at least one cat I saw the central node was the buccal lymph node underneath the zygomatic arch, they can really go anywhere. So I think the central lymph node mapping for oral tumors is important, melanomas in particular, because of their predilection to metastasized nodes. I don't often do it for oral osteosarcomas or fibro sarcomas, but sometimes I question why because you know the metastatic rates in some papers are up close to 20%, and obviously in appendicular osteosarcoma if they've made it to the lymph nodes, the prognosis is so much worse, so that's probably one that I should be doing more often. And then, for mast cells that are greater than three centimeters or obviously acting like a high-grade mast cell tumor, definitely recommend it for those.
Sometimes I just do it intraoperatively, like for mammary tumors, where I know I can see the intraoperative where it's going to either the inguinal or the auxiliary, and Sometimes I dive down into the medial iliac, but I'm there, I can open up the belly and just grab that. So sometimes I just do it in drop and we got that.
Dr. Venable: Very cool. And just to clarify, I think most of our listeners are more oncology-related, you know, veterinary oncologist, but just to confirm like the sentinel lymph node mapping. So that's just telling you the draining lymph node. It's not giving you any suggestions of that there's likely spread or not. It's just telling you where you should go next. Is that correct?
Dr. Liptak: That's correct. So it's obviously started in human surgical oncology and one of the classic examples is women with breast cancer. They used to do these axillary lymph node dissections which is about 30 lymph nodes in the auxillary region, and that resulted in a lot of complications particularly lymph edema and nerve problems and things like that. So the idea behind central lymph node mapping is to identify the first draining lymph node and just take that lymph node. And with a fairly high degree of certainty, that lymph node was representative of all the lymph nodes. So if you were clear on that lymph node, then there was highly unlikely to be a metastasis in any of the other lymph nodes. And so that spared those big dissections in the higher complication rates. But for those women that did have metastasis in that lymph node, then they took out the entire lymph node bed and followed up with radiation. So, you select for the more aggressive patients with the more aggressive treatment approaches.
But going back to your question or your point is exactly, we know that's the first draining lymph node. In veterinary medicine, we don't know whether that first draining lymph node is actually representative of the entire lymph node bed like it is in people, but that's the assumption. And then you have to sample that lymph node either by cytology or preferably histopathology by taking out that entire node to see where there's metastasis in there.
Dr. Venable: And do you think that should be more routine? Because I feel like even when I see tumor resections from different specialists, they don't always take the regional lymph node, like let's just say melanoma, an oral tumor. I don't always see them dissect out the lymph nodes, especially if they otherwise seem normal and things. Is it something where do you think we need to get to the point of taking out those lymph nodes? Or What are your thoughts on some of those tumors with a higher metastatic rate?
Dr. Liptak: Yeah, I think the onus has been asked to remove those. You know, I don't know how long ago that paper was published, but in melanomas, in mast cell tumors, we know that a high number of normal nodes as regards the size and palpation characteristics can be metastatic. So a normal node does not rule out the possibility of metastasis. And metastasis may change the approach. For melanomas, we want to get down to microscopic disease. They have the melanoma vaccine work more effectively. So if you're leaving a tumor burden there, then we're going to have a less effective tumor control afterward. So I think it is for those ones that have a high metastatic rate and a known poorer prognosis. And this is where I struggle a bit with marshal tumors, where we make a difference is where they're HN3 nodes, but not the ones with HN2 nodes. So that's where I struggle a bit with just, you know, carte blanche lymph node removal, but definitely for melanomas and, you know, probably for most other malignant oral tumors as well.
Dr. Venable: Yeah. I think that's really interesting. And I agree with you with mast cell tumor, especially with more of the studies that have been coming out recently where it's like, well, we remove the node and it is technically metastasis, but the survival time I get it's, you know, even in, the Weishaar paper where they classify that metastases, a lot of those dogs, unless it was that agent three did really well.
So I even struggle on the medical oncology side, like, well, if we know it's starting to spread, should we do something? You know, it's like, do we pull the trigger or is this a case where.. not really. You know, I think we're still learning, but I struggle with some of those mast cell tumors as well.
Dr. Liptak: Yeah. I think for the probably the most studied tumor that we have, we're still more in the dark about what we should effectively do than not. But it's good to see those studies come out and, you know, push those boundaries and hopefully further define how we move forward with a treatment regimen for, you know, those different trees of the presentation.
Dr. Venable: Yeah, I totally agree. I think often some even anal sac tumors, I feel like there's just some aspects of this cancer that we just haven't figured out yet. You know, like you were saying, some of them, it just doesn't behave the same. So like mast cell tumors, you know, figuring out the different trees. Like if we could just find these different things that would help clue us in like, okay, you know, this one we need to go after and this one you don't. Maybe genetics will help us more without overtime. Who knows? I'm sure, I'm hopeful we will continue to figure that stuff out over time. And talking about overtime, where do you see just surgical oncology in the next decade or so? Where are some things that you envision it? Do you envision more surgical oncologists or what do you think?
Dr. Liptak: Oh yeah, surgical oncology is one of the three biggest fields in surgery, as in, obviously there's orthopedics. Now there's been an invasive surgery that's making a big push, and that's not mutually exclusive from surgical oncology and obviously surgical oncology. So we're having more fellowship training programs, there's more surgical oncologists coming out, there are more schools developing surgical oncology programs, and with that is, you know, teaching students about surgical oncology and oncology in general. And as obviously our pet population is getting older, there are more, you know, pets getting cancer as well, and as you know, owners become more demanding of subspecialization because they see that in the human world, that's where we come in that we do these kinds of procedures more regularly, more advanced surgical oncology procedures more regularly, and hence there's more of a need or demand for us as well.
Having that as my main interest and the largest proportion of my practice is fairly typical for most surgical oncologists. So we're not just purely doing that. But I think, yeah, as subspecialization becomes more accepted and the fellowship programs expand and then more people being trained, we'll see a lot more out there.
Dr. Venable: Yeah, I agree. I think it is something like you said, the pet population, we're taking better care of our pets. So they're living longer. And I do think pet owners are demanding some of the more specialty care, like what they see in themselves. So I'm excited. I think we'll be able to do more. It'll be interesting and exciting to see sort of where the profession is, and I think about the early days when Withrow was one of the only people really pushing for some of these surgeries, that it's come a long way. So it'll be exciting to see where we continue to go.
Dr. Liptak: Yep, very definitely.
Dr. Venable: Well, and I really appreciate you being on this podcast. I've learned so much. I love the discussion and just kind of rethinking what we already know. I think it's so important in a lot of aspects of life to question why we believe what we believe, and do we have the data, I'm a big data head. So I like seeing the numbers, does it make sense? And so I just really thank you for this great conversation. And as we start to just wrap up, who are some other people that you would recommend to be on this podcast?
Dr. Liptak: I just learned you already had Sarah Boston, so I would have recommended her. But Will Ewerd is an amazing person. Dr. Eward started off as a veterinarian. He completed his DVM. And I forget the exact line, but somewhere along that line, he was involved in sarcoma research and just fascinated by sarcomas, and based on that, he became an MD and then did his surgery residency and then did his surgical oncology training just to work in sarcomas and so now he's working as a surgical oncologist and a researcher at Duke University. He regularly speaks at veterinary meetings, he's involved with the Veterinary Society of Surgical Oncology and when he contributes to the Listserv, we're always amazed. His insight, and his pragmatism is just wonderful, and he's such a great guy too. He is someone that we all throughout the Veterinary Surgical Oncology, well he's highly valued and important, and we really appreciate his contributions. So it would be a very good person to interview.
Dr. Venable: Well, that's awesome. Thank you so much. We'll definitely have to reach out to him. And again, I just really appreciate you being on the podcast today. This was a great learning opportunity for me and I'm sure for many of our listeners as well. So again, thank you. And I hope you have a great rest of your day.
Dr. Liptak: Thanks, Rachel.
Dr. Venable: Well, that's it for this episode of the Veterinary Cancer Pioneers podcast. If you enjoyed this episode and gained valuable insight, we would be so grateful if you could share our podcast with your friends and colleagues. And it would be even more wonderful if you want to give us a five-star rating, positive review, or any kind of feedback on Apple Podcasts or wherever you listen. The Veterinary Cancer Pioneers Podcast is presented to you by ImpriMed.
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