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

#221

Post by JumpCrisscross » Fri, Jun 25, 2021, 3:38 PM UTC

dabbledash wrote: post #29

radu_floricica wrote: post #16

Earlier quoted context omitted.

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.

The idea is that treatment also has risks and false positives are an issue. If you gave a mammogram to every 20 year old woman, you would end up doing a large number of unnecessary biopsies and you’d find almost no real cancer. In the end, you’d lose more people than you would save. Or that’s the idea. I’m no expert in this but it makes sense to me conceptually.

> If you gave a mammogram to every 20 year old woman, you would end up doing a large number of unnecessary biopsies and you’d find almost no real cancer

If you gave a mammogram to every 20-year old, you wouldn't do a biopsy when you got a positive. You'd increase monitoring and maybe suggest lifestyle changes. The same way we don't immediately catherize everyone who comes back with high cholesterol.

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

#222

Post by [deleted] » Fri, Jun 25, 2021, 3:41 PM UTC

fabian2k wrote: post #127

ggrrhh_ta wrote: post #53

Earlier quoted context omitted.

Have heard your argument on the false positives and unnecessary interventions many times. It is not a good argument. In fact, it makes no sense. If you get a positive with an uncertainty in its accuracy, at the very least, the test is repeated. But even more, you can use the information from the investigation of the reason for the false positive to improve the tests in the first place. If we weren't humans and the un…

This is a very well known problem for many kinds of screenings, and the solution is not as simple as you claim. You can't just repeat the test, that is generally not where the problem lies. You'll get a second positive result and still don't know if it's a false positive or not. And in many cases there aren't other non-invasive test you can perform. If you can't actually determine reliably if some anomaly will cause…

[deleted]

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

#223

Post by rackjack » Fri, Jun 25, 2021, 3:44 PM UTC

JumpCrisscross wrote: post #208

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…

> 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 big deal? The deal is that these cures are often brutal chemotherapy or radiotherapy or whatever treatments that destroy your body, your sleep, your appetite, your ability to go to the bathroom yourself, your ability to do chores by yourself, your ability to do anything a normal human being can do. They DESTROY you.

THAT'S the "huge deal". NOT the frequency. Cancer RUINS YOUR LIFE for the period you get treated, IF you survive the treatment at all, let ALONE the cancer. And you are proposing we tell sub-1.5 million people EACH YEAR that they might have to go through that, while STILL ignoring the proportion of the population that will never learn they have a false positive because they got unlucky (which, AGAIN, we need to consider, since even miniscule probabilities matter at this scale.)

So until the day we figure out a way to make getting rid of cancer as easy as popping a pill (we're getting closer thanks to gene therapy, but patients may still receive the destructive treatments in the meantime), culture will not "adapt", it will remain a "huge deal", and we will keep "this type of thinking".

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

#224

Post by daemonk » Fri, Jun 25, 2021, 3:47 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…

I understand this argument. But if we separate out the mass screening/data-collection approach from its practical constraints (undue stress, overwhelm medical system), I think we can both at least agree that it is a correct direction to head towards? Or is the status-quo already as well optimized as it could be?

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

#225

Post by JumpCrisscross » Fri, Jun 25, 2021, 3:48 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…

> these cures are often brutal

Heart disease is a huge deal. It ruins your life. (Maybe not in all caps.) Nevertheless, we regularly test for it, including with techniques with high rates of false positives. Few panic because almost everyone knows someone who got a false positive and didn't promptly keel over and die.

If healthy adults are screened for cancer, there will be cultural memory of people who got a false positive. The response to a positive test result won't be chemo. It will be further testing, if non-invasive, or suggestions of lifestyle changes and increased monitoring of the suspected system.

People aren't too stupid to understand an early test with a high false positive rate. People with family histories of cancer don't wake up every morning screaming. Some may. But barring everyone because some people will overreact is why orthodox health policy is losing public trust.

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

#226

Post by msrenee » Fri, Jun 25, 2021, 3:48 PM UTC

pieno wrote: post #63

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…

It seems like you and GP are agreeing on the fact that right now we don’t do too many preventive checks because the cost of testing is higher than the benefits (mainly because false positives could lead to risky and invasive follow-up testing to confirm that it’s indeed a /false/ positive; and knowing that you have something sooner rather than later may not meaningfully affect the outcome of the disease; and costs of…

I'd need to know more about the specific types of cancer this screening covers to say anything for sure. However, the errors that cause cancerous growth are more common than most think and many are not life-threatening. I think that's what the other commenter is talking about. The intervention for these types of cancer may be more damaging than the cancer itself. If these are detected by this test, the patient may not understand that intervention is not necessarily in their best interest and may have increased anxiety or demand treatment when it is not needed.

This is just the first article I ran into.

https://www.sciencealert.com/new-evidence-finds-numerous-can...

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

#227

Post by Silhouette » Fri, Jun 25, 2021, 3:50 PM UTC

jacquesm wrote: post #204

Silhouette wrote: post #198

Earlier quoted context omitted.

So you do agree that evidence-based screening programmes can be effective then? In that case, I'm sorry but I don't quite understand the point you're trying to make here.

Yes, they can, but not in a blanket fashion where a test with a relatively high false positive rate and a relatively low sensitivity (between 18 and 50% for this particular test) is released without patient outcomes as the main driver of whether or not to apply the test absent further symptoms. Whether this test is one that can serve in that particular role is definitely not something that has already been determined…

Well, yes, it's only worth running a screening programme if you have a usefully accurate test and if you can then make some useful intervention after a positive result. Is anyone here disagreeing with that, though?

Maybe we interpreted OP's comment that you quoted differently? I read it as being in favour of preventative medicine as a whole, not necessarily endorsing this specific test at this specific point in time.

Maybe I'm also interpreting some of the other comments in this discussion, including yours, differently to how their authors intended them. My concern is that as written they appear to be criticising all use of screening, regardless of its efficacy, which is extremely dangerous.

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

#228

Post by msrenee » Fri, Jun 25, 2021, 3:50 PM UTC

Clampower wrote: post #10

zrail wrote: post #5

Earlier quoted context omitted.

That's already a thing, at least everywhere I've ever lived. You have a primary care doctor, you see them at least once a year, they do a physical exam, maybe some blood work. This test maybe becomes standard of care for everyone annually.

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

No mammograms? No pap smears? No prostrate screening? That's shocking.

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

#229

Post by andai » Fri, Jun 25, 2021, 3:54 PM UTC

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…

I expect this won't catch on until it becomes a wearable technology, and then it will catch on overnight.

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

#230

Post by m3kw9 » Fri, Jun 25, 2021, 3:56 PM UTC

throwawaynotmd wrote: post #109

TaupeRanger wrote: post #96

Earlier quoted context omitted.

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…

“ 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.”

This is easy to say but hard to do, just need to imagine