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

#311

Post by mahkeiro » Fri, Jun 25, 2021, 7:06 PM UTC

rackjack wrote: post #223

JumpCrisscross wrote: post #208

Earlier quoted context omitted.

> One and a half MILLION people whose life gets turned upside down, WRONGLY, due to a blood test Culture adapts. Getting a cancer diagnosis today is a huge deal because testing is infrequent, usually in response to a problem, and the diagnosis tends to be late and accurate. If 1.5mm healthy people get a false positive every year, the general response will be stress until a second test confirms a false positive. The l…

> Getting a cancer diagnosis today is a huge deal because testing is infrequent, usually in response to a problem, and the diagnosis tends to be late and accurate. Getting a cancer diagnosis is a "huge deal" because getting cancer is one of the worst experiences a human can go through. Getting cancer carries the weight of imminent death, obviously. But some cancers can be cured with high survival rate, so what's the…

Most stage 1 can be treated successfully with surgery alone, it's getting a late diagnosis that force you to go through a brutal treatment. If all cancer were detected in phase 1 it would not be seen as a "huge deal" anymore.

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

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Post by invisible » Fri, Jun 25, 2021, 7:07 PM UTC

There is a big discussion in this post about iatrogenics being introduced by these tests. It sounds like the fear here is that it'll tax an already burdened system with more patients (some of which just got a false positive).

I'm failing to understand how that's any different from other blood tests: they signal a problem, then more has to be established to validate the signal. Nobody is saying "this test proves someone has cancer" and I'm pretty sure doctors already have to discuss how tests can be inaccurate with patients. I believe it's the case that symptoms of cancer (just like other illnesses) may be ignored exactly because there aren't any other signals to indicate cancer. Plus zebras and horses and all of that too. Perhaps someone does have symptoms but nobody connects the dots, and these tests might connect those dots. Is there some reason that this argument is invalid in medical science?

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

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Post by cma » Fri, Jun 25, 2021, 7:13 PM UTC

invisible wrote: post #312

There is a big discussion in this post about iatrogenics being introduced by these tests. It sounds like the fear here is that it'll tax an already burdened system with more patients (some of which just got a false positive). I'm failing to understand how that's any different from other blood tests: they signal a problem, then more has to be established to validate the signal. Nobody is saying "this test proves someo…

Chalk it up to the techno-rationalist community saying doctors can't handle bayesian statistics, on the basis of results of brain teaser surveys, and then extending that to anything related to testing or medicine.

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

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Post by colinmhayes » Fri, Jun 25, 2021, 7:18 PM UTC

melling wrote: post #126

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.

Less information is better? That would be a bit of a paradox in science. I suppose we might take 2 steps forward and 1 step backward in the short term. As medical science advances, hopefully we can address any shortcomings from the additional early knowledge. I noticed that pancreatic is on the list. This cancer is almost always fatal because we can't detect it early.

People are idiots that don't understand statistics. Telling them they tested positive is all they hear, and it leads to them making subpar decisions that often involve invasive surgery. Yes, it's paternalistic, but the fact is most people aren't informed enough to make medical decisions for themselves.

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

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Post by throwawaynotmd » Fri, Jun 25, 2021, 7:19 PM UTC

Fomite wrote: post #304

throwawaynotmd wrote: post #109

Earlier quoted context omitted.

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…

"More information can never be harmful." In my particular field of biomedical research, there has recently been a push for "Diagnostic Stewardship" because more information has demonstrably been harmful to patient well-being.

It’s not enough to say it’s harmful. How is it harmful? A blood test, for example, cannot be inherently harmful. (Okay, no more harmful than drawing blood). So it must be about what people then decide to do based on that test. That’s what my post is about.

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

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Post by jghn » Fri, Jun 25, 2021, 7:22 PM UTC

Robotbeat wrote: post #309

jghn wrote: post #274

Earlier quoted context omitted.

To go further, a large issue/distraction in biomedical research has been Big Tech types coming in assuming that the roadblock all along has been lack of smart computational people in the process. I will not name names, but have seen so many instances of personal tech heroes coming in & claiming the underlying problem was that some of the brightest computational I've ever encountered simply didn't know how to computer…

While it’s absolutely true that naive non-experts can end up adding a lot more heat than light, I’ve also seen non-expert people come into stagnant domains and absolutely completely transform and improve upon the state of the art. I am skeptical of the “more data is bad” meme of screening hesitancy. It cannot be scientifically true in the strictest sense, and to the degree it’s an accurate assertion, it really seems…

In a perfect world you're right. What it's getting at is that screening itself isn't very good in the grand scheme of things, and thus the negatives of extra screening can be argued to be worse than the extra screening. Whether or not that's true, well that's another matter.

The issue in this subthread was the notion that the only thing between the current state of affairs and high quality screening is a bit of disruption. The problem is hard, smart people are working on it, more smart people are always welcome, it'll still take a while.

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

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Post by colinmhayes » Fri, Jun 25, 2021, 7:23 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 public health literature has been over this again and again. Over zealous non-symptomatic testing consistently leads to worse outcomes. You can get as philosophical as you want, the fact remains that it lowers total utility.

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

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Post by colinmhayes » Fri, Jun 25, 2021, 7:29 PM UTC

axxto wrote: post #154

hannob wrote: post #146

Earlier quoted context omitted.

The reason this is not happening isn't a technical one. It's that people with a medical background will tell you this isn't a healthy utopia, it's a nightmare. Medical tests are complicated. They often have significant false positive and false negative rates. Testing people at scale increases the number of people with wrong test results and can cause harm if you start treating people based on wrong test results. The…

The point of this is not that you get a definitive diagnosis; it's just a somewhat reliable marker on whether you may need to be concerned and get more accurate (but more harmful) imaging or invasive tests to rule out something.

You don't see how causing many people to worry and get invasive screening per person you have a true positive for is a worse outcome?

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

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Post by colinmhayes » Fri, Jun 25, 2021, 7:33 PM UTC

radu_floricica wrote: post #16

sbelskie wrote: post #11

Earlier quoted context omitted.

A big part of this is the fact that learning information (about a disease or condition) early is often NOT the same thing as learning information that will change a patient’s clinical outcome.

I never understood this. I mean I totally get the concept, but I don't get how it came to influence policy. Put it like this: how many people are you willing to kill to make sure people don't find out they're sick? Because that's what it boils down to. And it sounds... sociopathic.

How many people are you willing to give chemo to even thought they don't have cancer to save a life? Over zealous testing makes outcomes worse.

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

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Post by Buttons840 » Fri, Jun 25, 2021, 7:34 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…

> so by detecting it early you are just reducing the amount of life they have left without worrying about their disease

I wonder if people would rather continue to live care free, spending most of their waking hours commuting and at work, or if they'd rather learn the truth and face the harsh reality that their time is about up and adjust their priorities accordingly?