Before my software career I spent a few years working in a diagnostic medical field. Specifically osteoporosis testing. I worked both in a research capacity at Stanford looking at osteoporosis in older men (not pretending to be the PI here) and in a day to day testing clinic. So I've seen exactly what happens when you test a cross-sectional asymptomatic sample of the populous and what happens during the normal course of referred testing.
Low bone mass at the spine, hip, heel, and forearm as measured by DXA are correlated with increased risk of fracture, but it's only a correlation. Some people have resilient architecture which looks porous on an x-ray but only leads to serious fracture much later in life.
Because the current diagnostic tests are set up with levels like 'osteopenia' and 'osteoporosis' the reaction to clinical referrals was most often treatment. Some of those treatments have serious side effects like necrotizing impacts on the jaw. However the reaction to testing in a large asymptomatic population was much more likely to be an increase in preventative behavior (exercise) or no treatment except in extreme cases. While our study was exploratory and didn't have a treatment cohort (we cared about the impact of sleep quality on bone mass) we got to see a lot of older men who if they were referred to a clinic might have received treatment because that's what clinics do. Instead we had sufficient data to discuss what's normal and what isn't. For a time we were the leading experts in the world on what "normal" meant.
Because I've conducted these tests myself and seen data from hundreds of experimental and clinical patients I feel comfortable contrasting the two. The problem is the clinical medical field reacting to a lack of data with over-prescription of treatments.
FWIW I too have some experience with medical diagnostic systems (specifically: cancer testing), and one of the main reasons why I'm still skeptical about this test is that for many cancer types tested for the base rate is much lower than the false positive rate.
“We’ve never had blood tests that detect pancreatic cancer early, therefore we should never use them because when we used other means to try to detect early, it didn’t lead to better outcomes.”
If you can detect colon, kidney pancreatic or liver cancer early, you might be able to do surgery or develop treatments at the stage 1 stage. Right now we don’t have anything except MRIs and CT scans that are too hard and expensive to do frequently. And if you are diagnose with pancreatic cancer it’s usually so late that you will basically die in weeks.
You’re basically saying “give up. Even if we detect early you all die anyway” which is frankly stupid. You’re discounting the possibility that early detection by means of a blood test adds whole new layers of possibilities to fight those particularly dangerous cancers.
So no, I'm not 'basically giving up', and no you won't die anyway (well, unless you take that in the most abstract way), in particular likely not from cancer.
Even for those cancers where we do screen (such as for instance breast cancer) it is not a given that the increased frequency of detection has led to better patient outcomes.
But once you know someone's genetic disposition increased frequency of testing might be advantageous.
Even breast cancer needs x-rays to detect lumps, not detect cancer. You need a subsequent biopsy to differentiate. That’s our technology right now. If we had a blood test to detect cancer, not lumps, it’s game changing.
Maybe after a generation of early detection, new outcomes will emerge if we can detect the most deadly cancers early. You’re taking old studies and applying them to new technologies and saying “it won’t work.” It’s ridiculous that you are doing this.
Yes, it is a game changer, but it is not the kind of game changer that this is being made out to be here and mass screening using this method is not going to lead to improved outcomes.
As an extra tool in the toolbox of the diagnostician it is very useful.
I’m generally inclined towards the position of more testing....but there are very real tradeoffs to any of the interventions that a blood test could prompt.
It would also give the person the opportunity to change lifestyle to perhaps prolong the time that the illness will become a problem, or perhaps halt its progress altogether.
Additionally, the person who is aware of such illness, can keep an eye out for symptoms related to it, that might otherwise be ignored as something else. At which point normal cancer treatment can progress.
Data about unnecessary procedures is relatively plentiful, which is of course sad, whether that's driven by commercial incentives or the need for 'something to be done' is not something that I have any grip on but it certainly is problematic.
Another incredibly irrational argument.
If the risk from surgery outweighs the risk from cancer it it should not be performed.
I'm more than willing to be convinced otherwise but with relevant data. FWIW I've been following this particular development closely because it has direct implications for a start-up that I have had a lot of contact with that is also in the early detection space and they were adamant that the combination of factors is such - and so complex - that test accuracy is trumped significantly by absence of symptoms in otherwise healthy patients.
Your input on this would be greatly appreciated.
I am not arguing with most of your points, it's just that you're not being epistemically humble. I find it's far better to just act humble even when you aare schooling people who persist on believing in magic.
I sincerely hope that this test will drive down the cost of testing and that they will get the kinks ironed out, I think it is a major development and I'm actually afraid that those that oversell it will cause it to end up being tainted, as has happened with many other cancer related diagnostics and potential treatments. Cancer seems to bring out an emotional response rather than a rational one, typically because almost all of us have direct knowledge of one or more people in our environment that succumbed to it.
A lot of work has been done since this development was first announced and there are still quite a few kinks that will need to be ironed out. The whole idea - such as promoted in this thread by some - that this makes cancer a matter of 'simply looking at the right organ' is so laughably oversimplifying reality that some balance is required, and I think at some point my irritation got the better of me.
So thank you for pointing that out.
And to add to that: It definitely is not my intention to suggest that this test is without value.
The WHO, for example, disagree.
https://www.who.int/activities/promoting-cancer-early-diagno...
But let me stress this in case it wasn't clear to you: screening and early diagnosis are not the same thing.
If you screen a large population for cancer you will turn up a lot of cancers that may never become a problem, or that may even end up being re-absorbed without the need for intervention, as well as a large number of false positives.
Early diagnosis means that there are already symptoms.
Please don't confuse the two.
This comment is simply a personal attack.
I will write in this deeply arrogant fashion and refuse to link to anything I'm talking about, and when questioned I will infer that the people I'm replying to are utterly moronic (without saying quite such, I will instead say things like 'I'm sorry you don't understand / let me make this clear / you shouldn't be posting things you don't understand').
I will continue to write as if my stance is absolutely correct even though I am not an expert in this field, I will write as if I am.
And then when people call me out for my arrogance I will insist I've done nothing wrong and will be confused.
Baffling.
IMO, that is inflammatory and arrogant.
More broadly speaking, much of the arguments in this post seem almost political. They are dressed up in fancy language, but essentially boil down to "We can't give these peons information that they aren't smart enough to deal with"
That is an extremely arrogant position to take, even though I do believe there is some truth that knowledge can be counter-productive.
Who gets to be the gate-keeper?
I feel like a better conclusion is that we need better tests, that detect things that when acted upon improve patient outcome. Of course, we're nowhere near that yet, but do you really think in 1000 years we will still wait for patients to be responsible for correctly noticing symptoms and going to the doctor? Of course not.
It's good that we have studies that show we should move with caution in this territory, but completely ignoring it forever seems absurd.
You are treating this like a software problem, but it isn't, it's a medical problem, and medical problems tend to be complex because they have a ton of confounding variables that make it hard to have a one-size-fits-all method for dealing with medical issues.
What needs to change is that people need to realize that they have a field of expertise and that the medical domain has its own experts who typically dedicate a lifetime to their profession, their general consensus is that improved tests are welcome but in and of themselves are not enough to guarantee improved patient outcomes. Yes, this is unfortunate, but it is also a simple reality, you can either accept that or not, that's up to you but if you want to make a change there than you probably should join the medical profession. Most likely by the time that you have completed the requirements you will have shifted your viewpoint away from the software domain's mindset that all bugs can be found and squashed by the next sprint. Which by the way judging by the general quality of software out there is also something that doesn't work out in practice as we believe it should in theory.