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

#161

Post by goodpoint » Fri, Jun 25, 2021, 2:09 PM UTC

dmitryminkovsky wrote: post #60

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.

Not just that, but neither GP nor anyone else in this thread seems to be mentioning the mental health implications of constantly screening for life threatening diseases. For me, and many others I am sure, this would be bad . My quality of life would suffer tremendously, to the point of likely substantial loss of mental function. And I am definitely not one of these “we all die someday” types. Far from it. It’s just t…

> mental health implications of constantly screening for life threatening diseases

...to be contrasted with the mental health implication of living with the knowledge that you are *not* being tested and that cancer can grow undetected for years.

That, if anything, is a very good reason for anxiety.

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

#162

Post by pessimizer » Fri, Jun 25, 2021, 2:09 PM UTC

laputan_machine wrote: post #117

jacquesm wrote: post #99

Earlier quoted context omitted.

The fact that you link to that and apparently do not understand it combined with a personal attack is enough to disregard your comment for me. 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 nee…

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.

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

#163

Post by wrcwill » Fri, Jun 25, 2021, 2:10 PM UTC

jacquesm wrote: post #80

iandanforth wrote: post #76

Earlier quoted context omitted.

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 problem is not my mindset, but your understanding of the subject material. Patient outcomes have very little to do with the quality of the tests, even a 100% accurate test would not necessarily lead to improved patient outcomes because these are defined independent of the tests. 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 the…

this just reads to me as "our tests don't test for the right things, since when we act on those tests (even if they were 100% accurate), it doesn't lead to better patient outcomes".

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.

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

#164

Post by bluGill » Fri, Jun 25, 2021, 2:12 PM UTC

TaupeRanger wrote: post #138

plank_time wrote: post #128

Earlier quoted context omitted.

Utterly wrong. You are conflating current technology like MRIs and CT scans that only detect lumps, to blood tests that detect CANCER. Yes, if every lump were treated and excised then it would be problematic. But CANCER is different. The only cancer that you might be able to leave alone is prostate because it grows so slowly. Everything else is a risk. And if we can treat cancer at early stage 1, then maybe people wo…

You say "utterly wrong" and yet you clearly have no idea what you're talking about and have never even approached the field of health policy. Screening has to PROVE that it makes people live longer or better, just like any other intervention. It is not the case that screening is automatically good, otherwise we would be giving 20 year olds colonoscopies. Just because you find something, doesn't mean you've helped the…

That this test is approved implies that it to some extent at least makes people live longer. There are a number of cancers that are easily treatable in stage one - but they have no symptoms then, and so often kill people because by the time it is discovered it is too late.

False positives are a concern, but one that is manageable. People should get regular checkups, if something comes up we just do more testing as needed.

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

#165

Post by bildung » Fri, Jun 25, 2021, 2:13 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.

You assume that the treatment works and has no side effects, I think that is the main source of misunderstanding.

A great example is prostate cancer. It often gets detected now, people are informed they have cancer, but most often the correct answer is "watchful waiting", i.e. no treatment, probably forever. But people now know they have cancer, and are frightened, because cancer, and thus press for treatment. But this comes with a 10-90%(!) chance of incontinence and 50-90% chance of erectile dysfunction - for a cancer that most probably wouldn't have caused them bigger problems for their whole life.

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

#166

Post by goodpoint » Fri, Jun 25, 2021, 2:14 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…

> surgery is not without risk, and if there are no symptoms there is a fair chance that there never will be symptoms

Another incredibly irrational argument.

If the risk from surgery outweighs the risk from cancer it it should not be performed.

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

#167

Post by pessimizer » Fri, Jun 25, 2021, 2:15 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…

You're advocating for a policy that may kill or hurt more people than the alternative, and insisting that doing the math is reprehensible.

The enemy is not cancer, the enemy is ill-health and death. You could cure all deaths from cancer by poisoning everyone with cyanide.

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

#168

Post by doctoring » Fri, Jun 25, 2021, 2:15 PM UTC

victor106 wrote: post #150

> 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. While I think this is a great step forward, How can this be described as highly accurate when it missed identifying cancer in 48.5% of the people?

Cancer radiologist here!

I don't know about "highly accurate", but certainly pretty fucking good. Because for most of those cancers for most populations, the asymptomatic detection rate is much, much lower. Like close to 0%.

There is no general population screening test for, say, pancreatic cancer or ovarian cancer etc.

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

#169

Post by goodpoint » Fri, Jun 25, 2021, 2:16 PM UTC

danuker wrote: post #38

Clampower wrote: post #10

Earlier quoted context omitted.

This is not true in the Netherlands. You don’t get any tests if there is nothing wrong. Healthcare in this country scares me.

In the US, the medical system was (and might still be) the top third cause of death, of which 5/6ths were due to medicine side-effects. https://nutritionfacts.org/video/how-doctors-responded-to-be... I suspect doctors in the Netherlands are taught not to over-diagnose. Are they paid through national insurance?

Yes, the US medical system is a disaster.

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

#170

Post by dangerlibrary » Fri, Jun 25, 2021, 2:16 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 only need one false positive test result that ends up with a colonoscopy to understand how costly and uncomfortable these errors can be.

(I'm using an uncomfortable and illustrative example, but a colonoscopy is honestly pretty safe and boring as invasive clinical diagnostic procedures go)