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 r...