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. 2022 Apr 6;27(5):e393–e401. doi: 10.1093/oncolo/oyac039

Table 2.

Key themes and illustrative quotes.

Theme Optimistic Pessimistic
Clinical utility When it comes to like screening for pancreatic cancer, I think everyone would jump on board because we have no prevention and we have no screening. —ctDNA06 So, not all cancers have a detectable, per-clinical phase, which is the thing you’re always trying to find with that. At least with the tests that we have. So, the question is ‘would ctDNA, you know, for pancreas cancer would there be a detectable, pre-clinical phase where you could actually intervene and cure the cancer?’ —ctDNA12
Where catching them early is quite hard, ovarian cancer, 
pancreatic cancer. I think those are the priority 
ones. —ctDNA02 But, when we look at ovarian cancer risk...I mean we have a fairly successful intervention model. It’s not ideal. It’s not what anybody wants to do. But, people really believe ‘if I do this, this is going to save my life.’ So, if I’m looking at doing this blood test in order to afford that, am I putting myself at risk? —ctDNA20
Ovarian and I’m thinking pancreatic and I think there would 
be huge buy-in in that population. —ctDNA30 I think it’s probably potentially useful for certain cancers that we know we have reasonable treatment for. I would be very worried about ovarian and pancreas and those sort of, you know, those bad ones. Well, you know, I mean you’d be picking at a stage, I mean I assume you’d be picking it up at a little bit earlier stage than the patient presents with this, and then they’ll undergo all those treatments, but they’re still going to die fairly soon. —ctDNA03
Role in screening pathway I think it’s going to take a lot of time to get there which 
means I think that will probably be an interim period of 
probably many years where maybe it does serve as a supplement to you getting your mammogram, your MRI and your 
circulating tumor DNA... Or, if it’s just, you know, showing 
that there’s something on the circulating tumor DNA maybe that’s the point where someone would say “ready to [go] 
for preventative surgery”.—ctDNA06 Is there ever a point where you would feel comfortable not using confirmatory tests like mammography? I think I would always because that’s just like a hint of where or what’s happening. You don’t actually know what’s going on. You would still need to image them—ctDNA04
And so, I think at the very least if we had cell-free tumor DNA monitoring that for a period of time it would have to be done in conjunction with screening in order for us to satisfy ourselves that it was at least as effective, if not more effective than the screening. So, I would envision them being done together for enough time, with a large enough cohort of patients that we could be satisfied that there was efficacy there. –ctDNA08 I don’t see a world yet where it would be stand-alone and people not avail of all the other recommended screening preventions. –ctDNA25
The golden ticket and we can scrap all course of screening and now just do this blood test. Of course it’s not going to work like that. But then, maybe with further time, if it is that adjuvant test and it is running parallel and then you’ve got good results with it, then maybe you’ll be able to make those alterations. —ctDNA10 I think that you know, one day there may be a utility for certain cancers. But, I can’t see it necessarily being superior or used in isolation of the current screening which we know is really good. –ctDNA15
Invasiveness Because it would be a simple blood test that could be done a little more often. It could be done quarterly or semi-annually.—ctDNA02 Well, I imagine that it would be very stressful for the patient because they would be worried that they have cancer we can’t find; and just waiting for the other shoe to drop type of thing. I would imagine that for, as a clinician, that it would potentially force us to go on a big, you know, hunt. And, maybe require fairly extensive and who knows maybe unnecessary investigations. —ctDNA16
I think it would be really welcomed and really exciting to 
be able to offer them something that’s less invasive and 
hopefully better or earlier detection. —ctDNA06 It would, obviously add to the burden for the system because you might be doing additional investigations and finding nothing. —ctDNA08
And so that gives the patient, you know, an opportunity to 
make some choices. If they were diagnosed at later stages then, you know, you still have a choice but you still…most people 
end up doing this chemotherapy. And, the chemotherapy is not easy; it’s not. You know? If we can avoid that at any, you know at any way, shape or form that would be great. —ctDNA20 And then…like from the blood draw. And then, you’re also going to want to make sure that you’re not delaying the diagnosis beyond what your other strategies would, if you’re looking for it as a replacement. —ctDNA04
Enthusiasm And so, if you can skip your imaging and blood work for a single blood test that would clearly be superior for patients.—ctDNA01
I mean I think circulating DNA has the potential to be a game-changer. You know, obviously detecting cancers early would be amazing.—ctDNA32
I think most patients would be all over it. You know, if you’re told you have a higher than average risk of getting a cancer and that there might be a blood test that helped detect that cancer early and there are really no…I mean, aside from minor inconvenience and bruising there’s no down side to having a blood test… I think you’d want anything and everything that might find a cancer earlier.—ctDNA08
Universal concerns Often it’s sort of a screening fatigue that happens after a few years of normal screening. —ctDNA01
Unless you do your blood test first and then, you know, I don’t know. I don’t know. I mean if you have nothing that you can do beyond what you’re already doing you’re just going to have an anxious patient. —ctDNA03
I’m generally not like a fishing expedition kind…you know what I mean? I’m like, if you have a question; target the question to get a target, you know to get your answer. But, I mean, all of that and then they consent to well, okay, well this is a general screening test for everybody and then what is [the] positive rate and then what is the subsequent work? And again, if it is very broad, then does that mean that, you know, whole body MRI’s for basically everybody? —ctDNA10
I mean, I think you’re probably going to want to make sure that it’s you know something you can get back within a few weeks, at most, like a month probably or so; ideally a few weeks. And then…like from the blood draw. And then, you’re also going to want to make sure that you’re not delaying the diagnosis beyond what your other strategies would, if you’re looking for it as a replacement—ctDNA02
A false-negative is a problem because somebody that might have had prophylactic surgery, is going to delay. And then, she’s going to sit on that cancer.—ctDNA11
You know, you can have p53 mutated and the cell dies and, you know. Right? And, there isn’t a cancer anywhere. So, you could be chasing all sorts of stuff or left feeling like, you know, having the person feel like they’re sitting on a time bomb when not really. So, you know, that’s going to be a huge thing. And then, as you say false-negatives. So, you...it would have to be a pretty good test to say ‘well, we’re not going to do colonoscopies anymore. We’re just going to do a blood test.’ Isn’t that great? It would do it but, yeah. So, I think there’s potential for big false-negative and false-positive issues with this. So, we’ll have to see how the science is for sure. —ctDNA12