Dr. Linda Duska and Dr. Kathleen Moore discuss key studies in the evolving controversy over radical upfront surgery versus neoadjuvant chemotherapy in advanced ovarian cancer.

TRANSCRIPT

Dr. Linda Duska: Hello, and welcome to the ASCO Daily News Podcast. I am your guest host, Dr. Linda Duska. I am a professor of obstetrics and gynecology at the University of Virginia School of Medicine.

On today's episode, we will explore the management of advanced ovarian cancer, specifically with respect to a question that has really stirred some controversy over time, going all the way back more than 20 years: Should we be doing radical upfront surgery in advanced ovarian cancer, or should we be doing neoadjuvant chemotherapy?

So, there was a lot of hype about the TRUST study, also called ENGOT ov33/AGO-OVAR OP7, a Phase 3 randomized study that compares upfront surgery with neoadjuvant chemotherapy followed by interval surgery. So, I want to talk about that study today. And joining me for the discussion is Dr. Kathleen Moore, a professor also of obstetrics and gynecology at the University of Oklahoma and the deputy director of the Stephenson Cancer Center, also at the University of Oklahoma Health Sciences.

Dr. Moore, it is so great to be speaking with you today. Thanks for doing this.

Dr. Kathleen Moore: Yeah, it's fun to be here. This is going to be fun.

Dr. Linda Duska: FYI for our listeners, both of our full disclosures are available in the transcript of this episode.

So let's just jump right in. We already alluded to the fact that the TRUST study addresses a question we have been grappling with in our field. Here's the thing, we have four prior randomized trials on this exact same topic. So, share with me why we needed another one and what maybe was different about this one?

Dr. Kathleen Moore: That is, I think, the key question. So we have to level-set kind of our history. Let's start with, why is this even a question? Like, why are we even talking about this today? When we are taking care of a patient with newly diagnosed ovarian cancer, the aim of surgery in advanced ovarian cancer ideally is to prolong a patient's likelihood of disease-free survival, or if you want to use the term "remission," you can use the term "remission." And I think we can all agree that our objective is to improve overall survival in a way that also does not compromise her quality of life through surgical complications, which can have a big effect.

The standard for many decades, certainly my entire career, which is now over 20 years, has been to pursue what we call primary cytoreductive surgery, meaning you get a diagnosis and we go right to the operating room with a goal of achieving what we call "no gross residual." That is very different – in the olden days, you would say "optimal" and get down to some predefined small amount of tumor. Now, the goal is you remove everything you can see.

The alternative strategy to that is neoadjuvant chemotherapy followed by interval cytoreductive surgery, and that has been the, quote-unquote, "safer" route because you chemically cytoreduce the cancer, and so, the resulting surgery, I will tell you, is not necessarily easy at all. It can still be very radical surgeries, but they tend to be less radical, less need for bowel resections, splenectomy, radical procedures, and in a short-term look, would be considered safer from a postoperative consideration.

Dr. Linda Duska: Well, and also maybe more likely to be successful, right? Because there's less disease, maybe, theoretically.

Dr. Kathleen Moore: More likely to be successful in getting to no gross residual.

Dr. Linda Duska: Right. Yeah, exactly.

Dr. Kathleen Moore: I agree with that. And so, so if the end game, regardless of timing, is you get to no gross residual and you help a patient and there's no difference in overall survival, then it's a no-brainer. We would not be having this conversation. But there remains a question around, while it may be more likely to get to no gross residual, it may be, and I think we can all agree, a less radical, safer surgery, do you lose survival in the long term by this approach? This has become an increasing concern because of the increase in rates of use of neoadjuvant, not only in this country, but abroad. And so, you mentioned the four prior studies. We will not be able to go through them completely.

Dr. Linda Duska: Let's talk about the two modern ones, the two from 2020 because neither one of them showed a difference in overall survival, which I think we can agree is, at the end of the day, yes, PFS would be great, but OS is what we're looking for.

Dr. Kathleen Moore: OS is definitely what we're looking for. I do think a marked improvement in PFS, like a real prolongation in disease-free survival, for me would be also enough. A modest improvement does not really cut it, but if you are really, really prolonging PFS, you should see that-

Dr. Linda Duska: -manifest in OS.

Dr. Kathleen Moore: Yeah, yeah. Okay. So let's talk about the two modern ones. The older ones are EORTC and CHORUS, which I think we've talked about. The two more modern ones are SCORPION and JCOG0602.

So, SCORPION was interesting. SCORPION was a very small study, though. So one could say it's underpowered. 170 patients. And they looked at only patients that were incredibly high risk. So, they had to have a Fagotti score, I believe, of over 9, but they were not looking at just low volume disease. Like, those patients were not enrolled in SCORPION. It was patients where you really were questioning, "Should I go to the OR or should I do neoadjuvant? Like, what's the better thing?" It is easy when it's low volume. You're like, "We're going." These were the patients who were like, "Hm, you know, what should I do?" High volume. Patients were young, about 55.

The criticism of the older studies, there are many criticisms, but one of them is that, the criticism that is lobbied is that they did not really try. Whatever surgery you got, they did not really try with median operative times of 180 minutes for primary cytoreduction, 120 for neoadjuvant. Like, you and I both know, if you're in a big primary debulking, you're there all day. It's 6 hours.

Dr. Linda Duska: Right, and there was no quality control for those studies, either.

Dr. Kathleen Moore: No quality control. So, SCORPION, they went 451-minute median for surgery. Like, they really went for it versus four hours and then 253 for the interval, 4 hours. They really went for it on both arms. Complete gross resection was achieved in 50% of the primary cytoreduced. So even though they went for it with these very long surgeries, they only got to the goal half the time. It was almost 80% in the interval group. So they were more successful there. And there was absolutely no difference in PFS or OS. They were right about 15 months PFS, right about 40 months OS.

JCOG0602, of course, done in Japan, a big study, 300 patients, a little bit older population. Surprisingly more stage IV disease in this study than were in SCORPION. SCORPION did not have a lot of stage IV, despite being very bulky tumors. So a third of patients were stage IV. They also had relatively shorter operative times, I would say, 240 minutes for primary, 302 for interval. So still kind of short. Complete gross resection was not achieved very often. 30% of primary cytoreduction. That is not acceptable.

Dr. Linda Duska: Well, so let's talk about TRUST. What was different about TRUST? Why was this an important study for us to see?

Dr. Kathleen Moore: So the criticism of all of these, and I am not trying to throw shade at anyone, but the criticism of all of these is if you are putting surgery to the test, you are putting the surgeon to the test. And you are assuming that all surgeons are trained equally and are willing to do what it takes to get someone to no gross residual.

Dr. Linda Duska: And are in a center that can support the post-op care for those patients.

Dr. Kathleen Moore: Which can be ICU care, prolonged time. Absolutely. So when you just open these broadly, you're assuming everyone has the surgical skills and is comfortable doing that and has backup. Everybody has an ICU. Everyone has a blood bank, and you are willing to do that. And that assumption could be wrong. And so what TRUST said is, "Okay, we are only going to open this at centers that have shown they can achieve a certain level of primary cytoreduction to no gross residual disease." And so there was quality criteria. It was based on – it was mostly a European study – so ESGO criteria were used to only allow certified centers to participate. They had to have a surgical volume of over 36 cytoreductive surgeries per year. So you could not be a low volume surgeon. Your complete resection rates that were reported had to be greater than 50% in the upfront setting. I told you on the JCOG, it was 30%.

Dr. Linda Duska: Right. So these were the best of the best. This was the best possible surgical situation you could put these patients in, right?

Dr. Kathleen Moore: Absolutely. And you support all the things so you could mitigate postoperative complications as well.

Dr. Linda Duska: So we are asking the question now again in the ideal situation, right?

Dr. Kathleen Moore: Right.

Dr. Linda Duska: Which, we can talk about, may or may not be generalizable to real life, but that's a separate issue because we certainly don't have those conditions everywhere where people get cared for with ovarian cancer. But how would you interpret the results of this study? Did it show us anything different?

Dr. Kathleen Moore: I am going to say how we should interpret it and then what I am thinking about. It is a negative study. It was designed to show improvement in overall survival in these ideal settings in patients with FIGO stage IIIB and C, they excluded A, these low volume tumors that should absolutely be getting surgery. So FIGO stage IIIB and C and IVA and B that were fit enough to undergo radical surgery randomized to primary cytoreduction or neoadjuvant with interval, and were all given the correct chemo.

Dr. Linda Duska: And they were allowed bevacizumab and PARP, also. They could have bevacizumab and PARP.

Dr. Kathleen Moore: They were allowed bevacizumab and PARP. Not many of them got PARP, but it was distributed equally, so that would not be a confounder. And so that was important. Overall survival is the endpoint. It was a big study. You know, it was almost 600 patients. So appropriately powered. So let's look at what they reported. When they looked at the patients who were enrolled, this is a large study, almost 600 patients, 345 in the primary cytoreductive arm and 343 in the neoadjuvant arm. Complete resection in these patients was 70% in the primary cytoreductive arm and 85% in the neoadjuvant arm. So in both arms, it was very high. So your selection of site and surgeon worked. You got people to their optimal outcome. So that is very different than any other study that has been reported to date.

But what we saw when we looked at overall survival was no statistical difference. The median was, and I know we do not like to talk about medians, but the median in the primary cytoreductive arm was 54 months versus 48 months in the neoadjuvant arm with a hazard ratio of 0.89 and, of course, the confidence interval crossed one. So this is not statistically significant. And that was the primary endpoint.

Dr. Linda Duska: I know you are getting to this. They did look at PFS, and that was statistically significant, but to your point about what are we looking for for a reasonable PFS difference? It was about two months difference. When I think about this study, and I know you are coming to this, what I thought was most interesting about this trial, besides the fact that the OS, the primary endpoint was negative, was the subgroup analyses that they did. And, of course, these are hypothesis-generating only. But if you look at, for example, specifically only the stage III group, that group did seem to potentially, again, hypothesis generating, but they did seem to benefit from upfront surgery.

And then one other thing that I want to touch on before we run out of time is, do we think it matters if the patient is BRCA germline positive? Do we think it matters if there is something in particular about that patient from a biomarker standpoint that is different? I am hopeful that more data will be coming out of this study that will help inform this. Of course, unpowered, hypothesis-generating only, but it's just really interesting. What do you think of their subset analysis?

Dr. Kathleen Moore: Yeah, I think the subsets are what we are going to be talking about, but we have to emphasize that this was a negative trial as designed.

Dr. Linda Duska: Absolutely. Yes.

Dr. Kathleen Moore: So we cannot be apologists and be like, "But this or that." It was a negative trial as designed. Now, I am a human and a clinician, and I want what is best for my patients. So I am going to, like, go down the path of subset analyses. So if you look at the stage III tumors that got complete cytoreduction, which was 70% of the cases, your PFS was almost 28 months versus 21.8 months.

Dr. Linda Duska: Yes, it becomes more significant.

Dr. Kathleen Moore: Yeah, that hazard ratio is 0.69. Again, it is a subset. So even though the P value here is statistically significant, it actually should not have a P value because it is an exploratory analysis. So we have to be very careful. But the hazard ratio is 0.69. So the hypothesis is in this setting, if you're stage III and you go for it and you get someone to no gross residual versus an interval cytoreduction, you could potentially have a 31% reduction in the rate of progression for that patient who got primary cytoreduction. And you see a similar trend in the stage III patients, if you look at overall survival, although the post-progression survival is so long, it's a little bit narrow of a margin.

But I do think there are some nuggets here that, one of our colleagues who is really one of the experts in surgical studies, Dr. Mario Leitao, posted this on X, and I think it really resonated after this because we were all saying, "But what about the subsets?" He is like, "It's a negative study." But at the end of the day, you are going to sit with your patient. The patient should be seen by a GYN oncologist or surgical oncologist with specialty in cytoreduction and a medical oncologist, you know, if that person does not give chemo, and the decision should be made about what to do for that individual patient in that setting.

Dr. Linda Duska: Agreed. And along those lines, if you look carefully at their data, the patients who had an upfront cytoreduction had almost twice the risk of having a stoma than the patients who had an interval cytoreduction. And they also had a higher risk of needing to have a bowel resection. The numbers were small, but still, when you look at the surgical complications, as you've already said, they're higher in the upfront group than they are in the interval group. That needs to be taken into account as well when counseling a patient, right? When you have a patient in front of you who says to you, "Dr. Moore, you can take out whatever you want, but whatever you do, don't make me a bag." As long as the patient understands what that means and what they're asking us to do, I think that we need to think about that.

Dr. Kathleen Moore: I think that is a great point. And I have definitely seen in our practice, patients who say, "I absolutely would not want an ostomy. It's a nonstarter for me." And we do make different decisions. And you have to just say, "That's the decision we've made," and you kind of move on, and you can't look back and say, "Well, I wish I would have, could have, should have done something else." That is what the patient wants. Ultimately, that patient, her family, autonomous beings, they need to be fully counseled, and you need to counsel that patient as to the site that you are in, her volume of disease, and what you think you can achieve. In my opinion, a patient with stage III cancer who you have the site and the capabilities to get to no gross residual should go to the OR first. That is what I believe. I do not anymore think that for stage IV. I think that this is pretty convincing to me that that is probably a harmful thing.

However, I want you to react to this. I think I am going to be a little unpopular in saying this, but for me, one of the biggest take-homes from TRUST was that whether or not, and we can talk about the subsets and the stage III looked better, and I think it did, but both groups did really well. Like, really well. And these were patients with large volume disease. This was not cherry-picked small volume stage IIIs that you could have done an optimal just by doing a hysterectomy. You know, these were patients that needed radical surgery. And both did well.

And so what it speaks to me is that anytime you are going to operate on someone with ovary, whether it be frontline, whether it be a primary or interval, you need a high-volume surgeon. That is what I think this means to me. Like, I would want high volume surgeon at a center that could do these surgeries, getting that patient, my family member, me, to no gross residual. That is important. And you and I are both in training centers. I think we ought to take a really strong look at, are we preparing people to do the surgeries that are necessary to get someone to no gross residual 70% and 85% of the time?

Dr. Linda Duska: We are going to run out of time, but I want to address that and ask you a provocative question. So, I completely agree with what you said, that surgery is important. But I also think one of the reasons these patients in this study did so well is because all of the incredible new therapies that we have for patients. Because OS is not just about surgery. It is about surgery, but it is also about all of the amazing new therapies we have that you and others have helped us to get through clinical research. And so, how much of that do you think, like, for example, if you look at the PFS and OS rates from CHORUS and EORTC, I get it that they're, that they're not the same. It's different patients, different populations, can't do cross-trial comparisons. But the OS, as you said, in this study was 54 months and 48 months, which is, compared to 2010, we're doing much, much better. It is not just the surgery, it is also all the amazing treatment options we have for these patients, including PARP, including MIRV, including lots of other new therapies. How do you fit that into thinking about all of this?

Dr. Kathleen Moore: I do think we are seeing, and we know this just from epidemiologic data that the prevalence of ovarian cancer in many of the countries where the study was done is increasing, despite a decrease in incidence. And why is that? Because people are living longer.

Dr. Linda Duska: People are living longer, yeah.

Dr. Kathleen Moore: Which is phenomenal. That is what we want. And we do have, I think, better supportive care now. PARP inhibitors in the frontline, which not many of these patients had. Now some of them, this is mainly in Europe, will have gotten them in the first maintenance setting, and I do think that impacts outcome. We do not have that data yet, you know, to kind of see what, I would be really interested to see. We do not do this well because in ovarian cancer, post-progression survival can be so long, we do not do well of tracking what people get when they come off a clinical trial to see how that could impact – you know, how many of them got another surgery? How many of them got a PARP? I think this group probably missed the ADC wave for the most part, because this, mirvetuximab is just very recently available in Europe.

Dr. Linda Duska: Unless they were on trial.

Dr. Kathleen Moore: Unless they were on trial. But I mean, I think we will have to see. 600 patients, I would bet a lot of them missed the ADC wave. So, I do not know that we can say we know what drove these phenomenal – these are some of the best curves we've seen outside of BRCA. And then coming back to your point about the BRCA population here, that is a really critical question that I do not know that we're ever going to answer. There have been hypotheses around a tumor that is driven by BRCA, if you surgically cytoreduced it, and then chemically cytoreduced it with chemo, and so you're starting PARP with nothing visible and likely still homogeneous clones. Is that the group we cured? And then if you give chemo first before surgery, it allows more rapid development of heterogeneity and more clonal evolution that those are patients who are less likely to be cured, even if they do get cytoreduced to nothing at interval with use of PARP inhibitor in the front line. That is a question that many have brought up as something we would like to understand better. Like, if you are BRCA, should you always just go for it or not? I do not know that we're ever going to really get to that. We are trying to look at some of the other studies and just see if you got neoadjuvant and you had BRCA, was anyone cured? I think that is a question on SOLO1 I would like to know the answer to, and I don't yet, that may help us get to that. But that's sort of something we do think about. You should have a fair number of them in TRUST. It wasn't a stratification factor, as I remember.

Dr. Linda Duska: No, it wasn't. They stratified by center, age, and ECOG status

Dr. Kathleen Moore: So you would hope with randomization that you would have an equal number in each arm. And they may be able to pull that out and do a very exploratory look. But I would be interested to see just completely hypothesis-generating what this looks like for the patients with BRCA, and I hope that they will present that. I know they're busy at work. They have translational work. They have a lot pending with TRUST. It's an incredibly rich resource that I think is going to teach us a lot, and I am excited to see what they do next.

Dr. Linda Duska: So, outside of TRUST, we are out of time. I just want to give you a moment if there were any other messages that you want to share with our listeners before we wrap up.

Dr. Kathleen Moore: It's an exciting time to be in GYN oncology. For so long, it was just chemo, and then the PARP inhibitors nudged us along quite a bit. We did move more patients, I believe, to the cure fraction. When we ultimately see OS, I think we'll be able to say that definitively, and that is exciting. But, you know, that is the minority of our patients. And while HRD positive benefits tremendously from PARP, I am not as sure we've moved as many to the cure fraction. Time will tell. But 50% of our patients have these tumors that are less HRD. They have a worse prognosis. I think we can say that and recur more quickly.

And so the advent of these antibody-drug conjugates, and we could name 20 of them in development in GYN right now, targeting tumor-associated antigens because we're not really driven by mutations other than BRCA. We do not have a lot of things to come after. We're not lung cancer. We are not breast cancer. But we do have a lot of proteins on the surface of our cancers, and we are finally able to leverage that with some very active regimens. And we're in the early phases, I would say, of really understanding how best to use those, how best to position them, and which one to select for whom in a setting where there is going to be obvious overlap of the targets. So we're going to be really working this problem. It is a good problem. A lot of drugs that work pretty well. How do you individualize for a patient, the patient in front of you with three different markers? How do you optimize it? Where do you put them to really prolong survival?

And then we finally have cell surface. We saw at ASCO, CDK2 come into play here for the first time, we've got a cell cycle inhibitor. We've been working on WEE1 and ATR for a long time. CDK2s may hit. Response rates were respectable in a resistant population that was cyclin E overexpressing. We've been working on that biomarker for a long time with a toxicity profile that was surprisingly clean, which I like to see for our patients. So that is a different platform. I think we have got bispecifics on the rise. So there is a pipeline of things behind the ADCs, which is important because we need more than one thing, that makes me feel like in the future, I am probably not going to be using doxil ever for platinum-resistant disease. So, I am going to be excited to retire some of those things. We will say, "Remember when we used to use doxil for platinum-resistant disease?"

Dr. Linda Duska: I will be retired by then, but thanks for that thought.

Dr. Kathleen Moore: I will remind you.

Dr. Linda Duska: You are right. It is such an incredibly exciting time to be taking care of ovarian cancer patients with all the opportunities.

And I want to thank you for sharing your valuable insights with us on this podcast today and for your great work to advance care for patients with GYN cancers.

Dr. Kathleen Moore: Likewise. Thanks for having me.

Dr. Linda Duska: And thank you to our listeners for your time today. You will find links to the TRUST study and other studies discussed today in the transcript of this episode. Finally, if you value the insights that you hear on the ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts.

Disclaimer:

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

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Disclosures of Potential Conflicts of Interest:

Dr. Linda Duska:

Consulting or Advisory Role: Regeneron, Inovio Pharmaceuticals, Merck, Ellipses Pharma

Research Funding (Inst.): GlaxoSmithKline, Millenium, Bristol-Myers Squibb, Aeterna Zentaris, Novartis, Abbvie, Tesaro, Cerulean Pharma, Aduro Biotech, Advaxis, Ludwig Institute for Cancer Research, Leap Therapeutics

Patents, Royalties, Other Intellectual Property: UptToDate, Editor, British Journal of Ob/Gyn

Dr. Kathleen Moore:

Leadership: GOG Partners, NRG Ovarian Committee Chair

Honoraria: Astellas Medivation, Clearity Foundation, IDEOlogy Health, Medscape, Great Debates and Updates, OncLive/MJH Life Sciences, MD Outlook, Curio Science, Plexus, University of Florida, University of Arkansas for Medical Sciences, Congress Chanel, BIOPHARM, CEA/CCO, Physician Education Resource (PER), Research to Practice, Med Learning Group, Peerview, Peerview, PeerVoice, CME Outfitters, Virtual Incision

Consulting/Advisory Role: Genentech/Roche, Immunogen, AstraZeneca, Merck, Eisai, Verastem/Pharmacyclics, AADi, Caris Life Sciences, Iovance Biotherapeutics, Janssen Oncology, Regeneron, zentalis, Daiichi Sankyo Europe GmbH, BioNTech SE, Immunocore, Seagen, Takeda Science Foundation, Zymeworks, Profound Bio, ADC Therapeutics, Third Arc, Loxo/Lilly, Bristol Myers Squibb Foundation, Tango Therapeutics, Abbvie, T Knife, F Hoffman La Roche, Tubulis GmbH, Clovis Oncology, Kivu, Genmab/Seagen, Kivu, Genmab/Seagen, Whitehawk, OnCusp Therapeutics, Natera, BeiGene, Karyopharm Therapeutics, Day One Biopharmaceuticals, Debiopharm Group, Foundation Medicine, Novocure

Research Funding (Inst.): Mersana, GSK/Tesaro, Duality Biologics, Mersana, GSK/Tesaro, Duality Biologics, Merck, Regeneron, Verasatem, AstraZeneca, Immunogen, Daiichi Sankyo/Lilly, Immunocore, Torl Biotherapeutics, Allarity Therapeutics, IDEAYA Biosciences, Zymeworks, Schrodinger

Other Relationship (Inst.): GOG Partners