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

#211

Post by plank_time » Fri, Jun 25, 2021, 3:23 PM UTC

rackjack wrote: post #184

plank_time wrote: post #147

Earlier quoted context omitted.

We don’t give colonoscopies to 20 years olds because it’s an expensive, invasive test with a low rate of cancer. We don’t give mammograms to under 40 year olds these days because the same and it’s notoriously inaccurate. We give blood glucose level tests and cholesterol tests to everyone every year at the physical because they are cheap and easy to administer. Even though the effects of both may take decades to have…

> It correctly identified when cancer was present in 51.5% of cases, across all stages of the disease, and wrongly detected cancer in only 0.5% of cases. If all 300 million Americans get blood tested each year, that is 1 and a half MILLION people who are falsely told they have CANCER. One and a half MILLION people whose life gets turned upside down, WRONGLY, due to a blood test -- at least, until they take a second o…

Do you think that technology doesn’t improve over time? You are suffering from a fixed mindset, where you think people or technology is as good as it gets now and never improve.

You should read up more on growth mindsets. People and technology aren’t fixed. They change and improve over time.

If people had your attitude about AIDS we would have let all AIDS patients die because “oh well nothing we can do.”

Luckily those with growth mindsets and optimism didn’t listen to people like you and now AIDS patients take a single pill a day.

The same could happen with cancer to, but not if people like you are in charge.

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

#212

Post by dekhn » Fri, Jun 25, 2021, 3:26 PM UTC

jacquesm wrote: post #195

dekhn wrote: post #185

Earlier quoted context omitted.

I think you should stop trying to derate people who you think know less than you. It's very unattractive. Be aware there are folks with extensive public health experience (that would be me) watching you insist you're right. While I totally appreciate what you're trying to do (help software engineers understand why medicine is complex), please do understand that GRAIL is tightly integrated with the PH community, did t…

That's perfectly accurate: the problem is that people tend to run with things like this as though they are the miracle that everybody has been waiting for and that is not the case, it is a very important development but in the right hands and not as a tool that will lead to - yet another - round of disappointment in the 'war on cancer'. The whole thread has devolved into people arguing from hope rather than from fact…

my input is that I've been involved with GRAIL since the beginning and I think they've actually done something. We don't have the data to say one way or the other.

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.

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

#213

Post by a_conservative » Fri, Jun 25, 2021, 3:26 PM UTC

pessimizer wrote: post #162

laputan_machine wrote: post #117

Earlier quoted context omitted.

You come in and flame other users, but then take deep offense when you get it back. Treat others with respect and in turn you'll receive it.

Disagreement is not "flaming." Jacquesm has been generally respectful and factual. The closest they have come to rudeness is when people refer to "facts" not in evidence or link to things that they haven't read or understood well, and even that impatience was explanatory. This comment is simply a personal attack.

> The problem is not my mindset, but your understanding of the subject material.

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?

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

#214

Post by robocat » Fri, Jun 25, 2021, 3:29 PM UTC

Engineering-MD wrote: post #179

For those interested in reading the actual paper, this appears to be it (open access too): https://www.annalsofoncology.org/article/S0923-7534(21)02046... I’ve only skimmed it, but seen quite a few limitations, notably those with “non-malignant conditions at enrolment” (it would be nice to know more what that means), previous cancer or recent corticosteroids use were excluded. Additionally, it’s a case controlled tri…

> 500 people

5000 people

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

#215

Post by rackjack » Fri, Jun 25, 2021, 3:29 PM UTC

plank_time wrote: post #211

rackjack wrote: post #184

Earlier quoted context omitted.

> It correctly identified when cancer was present in 51.5% of cases, across all stages of the disease, and wrongly detected cancer in only 0.5% of cases. If all 300 million Americans get blood tested each year, that is 1 and a half MILLION people who are falsely told they have CANCER. One and a half MILLION people whose life gets turned upside down, WRONGLY, due to a blood test -- at least, until they take a second o…

Do you think that technology doesn’t improve over time? You are suffering from a fixed mindset, where you think people or technology is as good as it gets now and never improve. You should read up more on growth mindsets. People and technology aren’t fixed. They change and improve over time. If people had your attitude about AIDS we would have let all AIDS patients die because “oh well nothing we can do.” Luckily tho…

> If people had your attitude about AIDS we would have let all AIDS patients die because “oh well nothing we can do.”

No, if people had my attitude about AIDS they would say "Jesus Christ, don't tell 1 and half million people each year who don't have AIDS that they might have AIDS." I am talking about diagnosis, not treatment.

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

#216

Post by function_seven » Fri, Jun 25, 2021, 3:32 PM UTC

rackjack wrote: post #190

fallingknife wrote: post #186

Earlier quoted context omitted.

> but doctors can't always predict this and aren't perfect decision making machines So mass screen healthy people, collect the data, run models, and get better at it. People like you would rather not try, and this is the same reaction I get from doctors. Applying the same tech that we use to improve ad targeting to disease prediction is a no brainer to anyone whose cushy job doesn't depend on the current medieval sta…

Same vibe as "I would just simply..." What do you think the entire medical, pharmaceutical, bioinformatic, etc. industries have been doing for decades? Are you really so arrogant to think that other people are too lazy and stupid to think of your brilliant idea and that you are simply more intelligent than everybody else? Do you really think people haven't been trying?

If they aren't mass collecting this data in the first place (for the reasons outlined above), then how can they be doing this?

Or, if they are doing this from quality samples of the population, then we have data to show that, for example, "Yes, Mr. Function Seven, your scan shows elevated levels of Widget-5a enzymes. This is often a precursor to Gadget Cancer, but 30% of the population shows this elevation, while only 1% develop the cancer. It's best to do nothing at this time unless we see further elevation. Have a good day, see you next year"

So either we have this data and we can give accurate advice, or we don't have this data because we're afraid of over-diagnosing non-problems.

I understand the fear, but it's still burying one's head in the sand to not even look.

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

#217

Post by a_conservative » Fri, Jun 25, 2021, 3:34 PM UTC

jacquesm wrote: post #77

mrfusion wrote: post #73

Earlier quoted context omitted.

My car’s check engine light came on and a costly mechanic visit didn’t find any problems so we decided to remove the check engine light.

That's not an appropriate analogy for more reasons than I care to relate here. Suffice to say that if you believe that the engine check light is the equivalent to a positive cancer test that you probably should stay out of medicine ;) And maybe out of your garage as well...

Why are you responding to random commenters on HN as if they are the ones getting ready to go out and start writing the official policy of a country?

Discussion is good. It's ok for people to be wrong and disagree. I'm not even saying they are wrong, but if they were- do you really need to go around telling everyone that some opinion that crossed their mind over a cup of morning coffee would be a disaster if implemented as national policy?

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

#218

Post by TaupeRanger » Fri, Jun 25, 2021, 3:34 PM UTC

fallingknife wrote: post #186

TaupeRanger wrote: post #133

Earlier quoted context omitted.

Lots of problematic assumptions in your reply. >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. Absolutely and demonstratively false. There is an entire field of health policy that destroys this harmful…

> but doctors can't always predict this and aren't perfect decision making machines So mass screen healthy people, collect the data, run models, and get better at it. People like you would rather not try, and this is the same reaction I get from doctors. Applying the same tech that we use to improve ad targeting to disease prediction is a no brainer to anyone whose cushy job doesn't depend on the current medieval sta…

You are assigning beliefs to me that I do not hold. As I said, we would need a solid randomized controlled clinical trial to determine whether any particular intervention actually helps patients live longer and/or better. That's the only way we know. So go ahead and collect data, do an RCT, and let us know how it goes.

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

#219

Post by bcrosby95 » Fri, Jun 25, 2021, 3:35 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.

> somewhat reliable marker

For the USA...

Something around 1.8 million people are diagnosed with cancer per year. At a 50% false negative rate, all else being equal it would detect 900k of those.

And all else being equal, at a 0.5% false positive rate, if it were used as suggested it would incorrectly diagnose cancer in around 1.6 million of the population.

So around 60% of the people it says has cancer wouldn't have cancer. I guess it depends upon what you mean by "somewhat reliable".

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

#220

Post by jacquesm » Fri, Jun 25, 2021, 3:35 PM UTC

dekhn wrote: post #212

jacquesm wrote: post #195

Earlier quoted context omitted.

That's perfectly accurate: the problem is that people tend to run with things like this as though they are the miracle that everybody has been waiting for and that is not the case, it is a very important development but in the right hands and not as a tool that will lead to - yet another - round of disappointment in the 'war on cancer'. The whole thread has devolved into people arguing from hope rather than from fact…

my input is that I've been involved with GRAIL since the beginning and I think they've actually done something. We don't have the data to say one way or the other. 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.

Fair enough.

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.