“ One study in 2020 found that 95% of asymptomatic patients had some type of "abnormal" finding, but just 1.8% of these findings were indeed cancer.”
This has been my experience. And I’ve had oncologists echo exactly this. In the words of one: MRIs find too much.
The CT and the PET/CT are the gold standards for finding cancer, finding recurrences, and staging cancer. The trouble is the radiation dose.
MRI provides very inconclusive results. You’ll see something but it’ll be unclear what it is. And often what you see is not even visible on a CT. Or it’s visible on a PET/CT and is showing metabolic activity indicating its cancer.
MRIs are great for certain things like herniated disks in your back. They suck at cancer.
mcbain 4 minutes ago [-]
Spot on. And dealing with false positives sucks.
One caveat is that regular PET isn't so good in the brain - there is so much metabolic activity that everything glows. So I get an MRI Brain to go with my regular full body PET/CT (cancer 5 years ago with recurrence 18 months later, currently NED).
rembal 27 minutes ago [-]
Anecdotal evidence to confirm: I had two false alarms from an unrelated MRI scan, and beside wasting a lot of time on diagnosing them - it was also extremely stressful.
My father is a part of "full body PET scan every 3 years" program as part of post - cancer treatment, and it worked twice: early detected lung and prostate tumors, both removed.
p0pularopinion 18 minutes ago [-]
> My father is a part of "full body PET scan every 3 years" program as part of post - cancer treatment,
These treatments are wonderful and it is great that they exist. But many people fail to understand the difference in terms of pretest probability, etc.
I can absolutely see the heavy psychological impact pending biopsy results may have. People are quick to discount these issues when you raise them as a concern, but only if they never went through this stress themselves
mcbain 3 minutes ago [-]
I have multiple scans a year. "Scanxiety" is real.
mgraczyk 2 minutes ago [-]
And yes getting frequent full body MRIs is still overwhelming the right thing for the patient.
lucb1e 1 hours ago [-]
Answering the question in the title...
> One study in 2020 found that 95% of asymptomatic patients had some type of "abnormal" finding, but just 1.8% of these findings were indeed cancer.
So a bit less than 1.8% of the time in this study
> Prenuvo's recent Polaris Study followed 1,011 patients for at least one year following a whole-body MRI scan. Of these patients, 41 had biopsies. More than half of the 41 were diagnosed with cancer.
That's 2.0%
Note that this doesn't mean that 1.7~2.0% of people have cancer without knowing it. It could be more:
> A negative scan doesn’t mean you’re disease-free. Some cancers and conditions simply aren’t visible yet or aren’t reliably detected on a one-time full-body MRI."
But also perhaps less, in a way:
> "You're finding something that never would have caused you any problem in your life, and in cancer, we call that overdiagnosis," Vickers says.
jml78 54 minutes ago [-]
Yep, I have experience with both. It found cancer for my wife and she was able to treat it immediately. Fully recovered.
It found a weird spot on me that turned out to a pancreatic rest.
The only reason we did the scans were because we were making a significant life decision that we didn’t want to have to backtrack if either got diagnosed with cancer within a year . We knew nothing was guaranteed but we wanted to do some tests.
majorchord 47 minutes ago [-]
> You're finding something that never would have caused you any problem in your life
Is it though? Isn't it possible you could be early-detecting something serious that is much easier to treat now vs when symptoms appear?
sxg 14 minutes ago [-]
Yes, you could early-detect something, but the likelihood of this thing being life-threatening are extremely low. If you choose to manage this thing aggressively anyway, you have to undergo more invasive testing (e.g., biopsies, surgery, anesthesia, etc.) that all have small risks of catastrophic events. In most cases, the risks of more invasive testing outweigh the risks of just not pursuing any further workup.
Nothing in medicine comes for free—everything is a tradeoff.
p0pularopinion 23 minutes ago [-]
> Isn't it possible you could be early-detecting something serious that is much easier to treat now vs when symptoms appear?
It could be. It could also be the cade that you undergo invasive surgery for something that would have never caused you problems within your life. The problem is that cancer isn‘t cancer. Even if it originates from the same tissue, some tumors behave very different from others.
giantg2 15 minutes ago [-]
Just to point out, cancer isn't the only reason to get these. Aneurisms, hemachromatosis, etc can all be serious. I know someone who got scanned for $500 and they caught hemachromatosis via iron deposits in the liver. Much better than eventual chirrosis and liver failure.
jmward01 47 minutes ago [-]
Maybe the right answer isn't to do a biopsy, but to monitor the area with follow-up scans? It seems like that addresses much of the harm that a false positive can cause (invasive biopsy leading to complications) while maintaining most of the gains (still very early detection).
p0pularopinion 17 minutes ago [-]
The problem is that just because you‘re detecting something, it does not mean it is worth watching. Bodies are not standardized and most people habe something off. But you can‘t really reschedule everybody constantly, as that would entirely break the concept.
cyberax 7 minutes ago [-]
"Worth watching" implies that watching is expensive. It's really not. A full-body MRI scan is about $1k, and it can be even cheaper.
So if you have abnormal findings in 10% of patients that merit follow-up scans, you can trivially do a series of 3-4 scans without affecting the overall cost too much.
Doctors simply need to get out of the headspace where MRIs are extremely scarce tools of last resort and treat them like we treat blood tests.
joezydeco 1 hours ago [-]
I pay an extra $60 a year to have my ophthalmologist take a digital image of my retina. It comes back as normal every year, but if something does change we can diff the image against the baseline.
Maybe I don't want to look for cancer right now but if I spend $1,000 every 5 years to take an image for later use... isn't that useful?
dgacmu 39 minutes ago [-]
Might be, but in the context it's also worth asking what better options you have for your health with that $1000.
(for some people that question may not apply, of course, but at a population level it does, and we have population-level questions about effective use of MRI time.). And if there's something better, you should spend it on that and then ask the question _again_. So it could be that getting a whole-body MRI is something like $30k down the list of best ways to spend money for improved health.
I'm not sure what the best use of $1k is from a health standpoint is, just noting that it's good to have a comparator.
butvacuum 48 minutes ago [-]
Yes, and it seems like its purposefully ignored in the "body scan" debate. full CT scans would be more problematic, and MRI's (especially no contrast ones) don't pick up a lot of things... but having annual comparisons over a few years would likely fill in some of those gaps. literally and figuratively.
johndhi 1 hours ago [-]
Er wait is retinal cancer a thing?
lbreakjai 51 minutes ago [-]
Yes. Like OP, I do a picture every year. Three years ago there was a scare, that turned out to be nothing.
p0pularopinion 15 minutes ago [-]
Yes. You can also have melanoma on your uvea
butvacuum 48 minutes ago [-]
theres a ton of degeneative stuff too that's not strongly age corrilated.
monero-xmr 42 minutes ago [-]
There’s a major difference between having insurance cover something (socialized cost, immediately drives up provider fees for bizarre reasons) and letting the market allow people to buy it themselves (individual cost, the market drives the cost down fast and hard). Notice the pattern with LASIK and GLP1 where lack of insurance coverage has counterintuitively made it cheaper and more accessible.
Let everyone who wants to pay get their scans! But don’t make me pay for you
dmitrygr 53 minutes ago [-]
1. collecting baseline info for later comparison is good
2. i can afford the money for the chance of early detection. Many cancers are symptomatic only in the latter stages. It does not hurt to check.
Rendered at 22:18:10 GMT+0000 (Coordinated Universal Time) with Vercel.
This has been my experience. And I’ve had oncologists echo exactly this. In the words of one: MRIs find too much.
The CT and the PET/CT are the gold standards for finding cancer, finding recurrences, and staging cancer. The trouble is the radiation dose.
MRI provides very inconclusive results. You’ll see something but it’ll be unclear what it is. And often what you see is not even visible on a CT. Or it’s visible on a PET/CT and is showing metabolic activity indicating its cancer.
MRIs are great for certain things like herniated disks in your back. They suck at cancer.
One caveat is that regular PET isn't so good in the brain - there is so much metabolic activity that everything glows. So I get an MRI Brain to go with my regular full body PET/CT (cancer 5 years ago with recurrence 18 months later, currently NED).
My father is a part of "full body PET scan every 3 years" program as part of post - cancer treatment, and it worked twice: early detected lung and prostate tumors, both removed.
These treatments are wonderful and it is great that they exist. But many people fail to understand the difference in terms of pretest probability, etc.
I can absolutely see the heavy psychological impact pending biopsy results may have. People are quick to discount these issues when you raise them as a concern, but only if they never went through this stress themselves
> One study in 2020 found that 95% of asymptomatic patients had some type of "abnormal" finding, but just 1.8% of these findings were indeed cancer.
So a bit less than 1.8% of the time in this study
> Prenuvo's recent Polaris Study followed 1,011 patients for at least one year following a whole-body MRI scan. Of these patients, 41 had biopsies. More than half of the 41 were diagnosed with cancer.
That's 2.0%
Note that this doesn't mean that 1.7~2.0% of people have cancer without knowing it. It could be more:
> A negative scan doesn’t mean you’re disease-free. Some cancers and conditions simply aren’t visible yet or aren’t reliably detected on a one-time full-body MRI."
But also perhaps less, in a way:
> "You're finding something that never would have caused you any problem in your life, and in cancer, we call that overdiagnosis," Vickers says.
It found a weird spot on me that turned out to a pancreatic rest.
The only reason we did the scans were because we were making a significant life decision that we didn’t want to have to backtrack if either got diagnosed with cancer within a year . We knew nothing was guaranteed but we wanted to do some tests.
Is it though? Isn't it possible you could be early-detecting something serious that is much easier to treat now vs when symptoms appear?
Nothing in medicine comes for free—everything is a tradeoff.
It could be. It could also be the cade that you undergo invasive surgery for something that would have never caused you problems within your life. The problem is that cancer isn‘t cancer. Even if it originates from the same tissue, some tumors behave very different from others.
So if you have abnormal findings in 10% of patients that merit follow-up scans, you can trivially do a series of 3-4 scans without affecting the overall cost too much.
Doctors simply need to get out of the headspace where MRIs are extremely scarce tools of last resort and treat them like we treat blood tests.
Maybe I don't want to look for cancer right now but if I spend $1,000 every 5 years to take an image for later use... isn't that useful?
(for some people that question may not apply, of course, but at a population level it does, and we have population-level questions about effective use of MRI time.). And if there's something better, you should spend it on that and then ask the question _again_. So it could be that getting a whole-body MRI is something like $30k down the list of best ways to spend money for improved health.
I'm not sure what the best use of $1k is from a health standpoint is, just noting that it's good to have a comparator.
Let everyone who wants to pay get their scans! But don’t make me pay for you
2. i can afford the money for the chance of early detection. Many cancers are symptomatic only in the latter stages. It does not hurt to check.