Blood test that finds 50 types of cancer is accurate enough to be rolled out • Hacker News Board

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#101

Post by TaupeRanger » Fri, Jun 25, 2021, 1:10 PM UTC

sweetdreamerit wrote: post #78

jacquesm wrote: post #56

Earlier quoted context omitted.

Your belief has no representation in medical science, which is mostly evidence based. A lot of data has been collected on this, studies (many) have been conducted and the general consensus is that more testing absent symptoms does not lead to improved patient outcomes. That you want to have some kind of theoretical argument in the face of this evidence might be interesting to you but it isn't to me.

Your point is interesting. Can you cite some literature that supports it?

Look up the term "iatrogenics" or check out oncologist Vinay Prasad's podcast called Plenary Session where he often talks about the dangers of over screening.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#102

Post by plank_time » Fri, Jun 25, 2021, 1:12 PM UTC

jacquesm wrote: post #46

reacharavindh wrote: post #3

This is one of those medical revolutions that I am waiting dearly for. Facilities that are not hospitals(to avoid the risk of occupying medical devices that sick people need) built to _regulary_ check up otherwise healthy people for preventive care. Heck, I have so many alerts defined on my monitoring setup for servers to watch for signals of failure before they get too big. But, my own body is not observed until som…

Regularly checking people that are otherwise healthy for cancer will turn up a lot of cancer through false positives or slowly growing ones, will lead to a lot of unnecessary intervention and will in fact lead to a reduction in quality of life and lifespan. This is one of the reasons why exhaustive cancer screening (which was more costly in the past but could have been done) was not promoted, it had nothing to do wit…

The utter confidence with how you answer all these comments while being completely wrong is sickening. It really shows a lack of vision but you wield your confidence like an expert but you’re not and only displaying the Dunning-Kruger to a t.

Early detection these days consists of things like CT scans which can’t tell the difference between cancerous tumors and benign tumors. I have a friend with a mass near her liver but they didn’t detect it until quite large. She asked what she should do and their answer was “well if it was liver cancer you would be dead by now, so it must be benign.”

This is the state of detection that you think is such a utopia, that we shouldn’t bother trying to improve, because you are so confident with your answers but you literally have no idea how wrong you are.

Having an accurate blood test that can differentiate a cancerous tumor from benign is ground breaking. Early detection of cancers like pancreatic or liver cancer detection is virtually impossibly today until it’s too late is groundbreaking. It could lead to new treatments that work when the cancer is small vs when it’s too big to operate.

You’re taking studies done using very obtuse, inaccurate and costly detection like MRIs and CT-Scans and conflating them with new technologies. It’s backwards, old thinking and trying to pooh-pooh new ideas and technologies because of poor understanding on your part. It had no place here among people with vision and hope for the future.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#103

Post by jacquesm » Fri, Jun 25, 2021, 1:12 PM UTC

Guillaume86 wrote: post #97

jacquesm wrote: post #66

Earlier quoted context omitted.

Even 100% true positive rate would not guarantee improved patient outcomes with massive testing. This is grounded in a poor understanding of what improved patient outcomes are all about, which is fine with me but to see this so misunderstood is a bit disappointing. Better tests do not automatically lead to better outcomes. They will lead to many more cancers detected, and they will lead to more interventions. Just on…

Your point across this thread is weird because it's not the testing itself which is an issue (if we assume the testing has a negligible cost economically and is comfortable/easy for the subject). We just need to improve the decision making after getting test results (one of these decisions is to decide to not do anything), and more data make improving it easier.

But tests do not have a negligible cost, have other costs besides the pure monetary value (such as occupying valuable lab time that could be spent on symptomatic patients instead), are typically not at all comfortable and easy because you'll be looking at a biopsy at a minimum (which again takes away valuable resources from symptomatic patients) and so on.

My argument is not about particular individuals, but about populations as a whole and wholesale screening of those populations. The consensus is that this does not lead to improved patient outcomes across that population, though in individual cases it may very well be the result.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#104

Post by elbasti » Fri, Jun 25, 2021, 1:12 PM UTC

iandanforth wrote: post #76

jacquesm wrote: post #46

Earlier quoted context omitted.

Regularly checking people that are otherwise healthy for cancer will turn up a lot of cancer through false positives or slowly growing ones, will lead to a lot of unnecessary intervention and will in fact lead to a reduction in quality of life and lifespan. This is one of the reasons why exhaustive cancer screening (which was more costly in the past but could have been done) was not promoted, it had nothing to do wit…

I detest this mindset. It is incredibly counter productive. "Our tests are bad, so lets not test" is not a thought worthy of respect. This states that you know about a problem but want to continue to ignore that problem. Reprehensible. No, we should take the exact opposite approach. Test everyone constantly until such methods become both cheap and powerful. So yeah we all have some cancer load but if the diagnostic o…

This is not a question of mindset, it's a question of statistics when you're trying to identify anything that is rare.

Take prostate cancer as an example. It's a relatively common cancer, with an incidence of .1% [0].

If you have an _incredible_ screening test with a 99% specificity (ie, 1% false positive rate), then:

If you test 100,000 people, you will correctly identify 100 people with cancer, and misdiagnose one thousand people as false positives.

There are consequences to having a false positive: unnecessary interventions, surgery "just to be safe", stress, etc.

This is why you limit testing to populations that have a higher probability of being ill (namely, show some sort of symptom).

Now imagine being tested for 100 things: the odds of coming up with a false positive for something start to approach 1!

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#105

Post by TaupeRanger » Fri, Jun 25, 2021, 1:13 PM UTC

iandanforth wrote: post #76

jacquesm wrote: post #46

Earlier quoted context omitted.

Regularly checking people that are otherwise healthy for cancer will turn up a lot of cancer through false positives or slowly growing ones, will lead to a lot of unnecessary intervention and will in fact lead to a reduction in quality of life and lifespan. This is one of the reasons why exhaustive cancer screening (which was more costly in the past but could have been done) was not promoted, it had nothing to do wit…

I detest this mindset. It is incredibly counter productive. "Our tests are bad, so lets not test" is not a thought worthy of respect. This states that you know about a problem but want to continue to ignore that problem. Reprehensible. No, we should take the exact opposite approach. Test everyone constantly until such methods become both cheap and powerful. So yeah we all have some cancer load but if the diagnostic o…

The only problematic mindset is yours, and you clearly have not engaged with the subject of iatrogenics in any meaningful way. The policy you advocate for would cause real harm to real people, likely to no benefit. Please understand how wrong you are.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#106

Post by BallyBrain » Fri, Jun 25, 2021, 1:13 PM UTC

jacquesm wrote: post #89

plank_time wrote: post #87

Earlier quoted context omitted.

This is an absolutely absurd thing to say. “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 M…

But: that surgery is not without risk, and if there are no symptoms there is a fair chance that there never will be symptoms. Depending on your age and your genetic make-up you might be more or less at risk. There is such a thing as spontaneous remission and so on. 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 can…

I don't see why early detection means early treatment. What if after detected, the illness is monitored instead. If it then gets to a point where the treatment is no longer considered risky for the stage of the illness, then the treatment can proceed.

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.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#107

Post by jacquesm » Fri, Jun 25, 2021, 1:14 PM UTC

mrtnmcc wrote: post #90

jacquesm wrote: post #62

Earlier quoted context omitted.

Yes, that's a very important point. Even regular checks for cervical cancer or breast cancer can be a huge stress factor, especially in the period just prior to the test and in the waiting period until the results are in, and even more so if the test yields a false positive.

Is the problem not so much the testing, but that most current treatments for cancers are so crude? If you have a relatively asymptomatic cancer, the treatments (chemo, surgery, proton beams) and psychological stress of discovery could be worse (statistically) than letting the body naturally take care of it. This probably depends very much on the cancer ( e.g., some Thyroid cancers might be better left alone). If our…

Fair point: if we had a completely non-invasive cancer treatment then that would be a game changer (I made that some point in an earlier comment far down in the thread). And in that case it would lead to improved patient outcomes. But the current regime of tests+treatment options does not in the general case - and there are quite a few exceptions that mostly have to do with genetics - lead to improved outcomes.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#108

Post by asdfasgasdgasdg » Fri, Jun 25, 2021, 1:15 PM UTC

dmitryminkovsky wrote: post #93

hans1729 wrote: post #69

Earlier quoted context omitted.

One of your greatest fears in life is to be regularly checked for diseases that would end your life unless thy are detected in time? ...What? e: you mean the emotional distress caused by the process? But that's just in your head, and it's beyond irrational. Getting checked is inherently a good thing . Even if you are extremely anxious, the people who love you want you to live - this is a psychological problem that yo…

Yes that is right. I make no claims to being a rational being. I am at best pseudo rational. As much as I love computers, I make no claim to being one. I am a human. And yes, I do also greatly appreciate evidence based medicine. There are many terminal illnesses where there is no evidence that constant screening improves outcomes. My impression is that people successfully market products like this to give people a fa…

> My impression is that people successfully market products like this to give people a sense of control where given the state of the art, control is lacking.

There can be no such evidence for a screening method like this, because it is brand new. We may find that even detection as early as Grail provides is still insufficient, but we don't and can't know yet. Certainly with many cancers earlier detection does lead to better outcomes. You also seem to be focusing on cases where screening has not improved outcomes while ignoring cases where it has.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#109

Post by throwawaynotmd » Fri, Jun 25, 2021, 1:15 PM UTC

TaupeRanger wrote: post #96

reacharavindh wrote: post #3

This is one of those medical revolutions that I am waiting dearly for. Facilities that are not hospitals(to avoid the risk of occupying medical devices that sick people need) built to _regulary_ check up otherwise healthy people for preventive care. Heck, I have so many alerts defined on my monitoring setup for servers to watch for signals of failure before they get too big. But, my own body is not observed until som…

Actually you don't want this, and you are describing a nightmare scenario that everyone who studies health policy understands all too well. Mass screening of healthy people will result in extreme iatrogenics and unnecessary psychological damage and stress (which leads to physical effects as well), not to mention overwhelming the medical system. The fact is that many things that could be detected will never result in…

The argument you’re making has always bothered me because it’s hiding the ball.

If finding something that otherwise carries no symptoms is best left untreated, then the fact that you found it should make no difference to the decision. The doctor should say that the best course of action is to do nothing. More information can never be harmful. If you know information is best not acted on in the abstract, then you also know you should not act on it in particular.

So what you really mean but have left unspoken is one of two things.

First, that doctors are untrustworthy people who make recommendations and decisions based on concerns other than their patient’s wellbeing, such as covering their asses from lawsuits or making more money.

But rather than fix that, you would rather keep patients more ignorant and away from the doctor in the first place. Which actively harms people who do have honest doctors. That is, your approach of not testing hurts people with honest doctors to protect people with dishonest doctors.

Or second, if you take dumb patients as the problem, you are willing to hurt people with good decision making ability (who would heed their good doctor’s advice to leave the possible ailment untreated) so you can protect people with bad decision making.

Because many times, these tests will uncover things that obviously need treatment. They will save many lives. But because more stupid people will hurt themselves, then no one should have access to them.

The political and moral assumptions built into these positions are immense and yet the medical field tucks those away and pretends that this is just a purely scientific truth, that someone running more harmless tests is actually inherently harmful.

That is a lie! And a very nasty one at that.

Re: Blood test that finds 50 types of cancer is accurate enough to be rolled out

#110

Post by hans1729 » Fri, Jun 25, 2021, 1:16 PM UTC

dmitryminkovsky wrote: post #93

hans1729 wrote: post #69

Earlier quoted context omitted.

One of your greatest fears in life is to be regularly checked for diseases that would end your life unless thy are detected in time? ...What? e: you mean the emotional distress caused by the process? But that's just in your head, and it's beyond irrational. Getting checked is inherently a good thing . Even if you are extremely anxious, the people who love you want you to live - this is a psychological problem that yo…

Yes that is right. I make no claims to being a rational being. I am at best pseudo rational. As much as I love computers, I make no claim to being one. I am a human. And yes, I do also greatly appreciate evidence based medicine. There are many terminal illnesses where there is no evidence that constant screening improves outcomes. My impression is that people successfully market products like this to give people a fa…

That still escapes the main argument: your problem isn't the medicine, your problem is your anxiety.

If "this sort of thing would just wreck your day to day existence and destroy your quality of life" (let your own wording sink in), you should work through that exact problem, probably rather sooner than later.

Detecting diseases before they actually destroy your life isn't bad, it's good - and so you should perceive it as good. Not because you're a rational acteur, but because it's literally, by definition, in your personal best interest. Take a step back from the panic, just purely observe, and try to see it for what it is: it prevents real suffering - your own very real suffering - and the price to pay is working through imaginary suffering.

Getting your blood checked isn't linearly related with fears of death, the exact opposite is the case. Try to see it for what it actually is, instead of intuitively letting panic-mode take over. If your intuition doesn't serve your well-being, proactively go ahead and fix your intuition - you can.