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

#171

Post by giantg2 » Fri, Jun 25, 2021, 2:20 PM UTC

If it's detecting 50 types of cancer and the patient doesn't have symptoms, do they just do a full body MRI to find the source? If so, why not just do full body scans which can find other issues, like aneurysms or the other almost 50% of positives that it missed?

I get that cost is a big issue, but it seems like the test is missing a lot and you might get more bang for the buck with a periodic MRI from the perspective of the number of potential issues it can find. Either way can result in false results.

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

#172

Post by mpfundstein » Fri, Jun 25, 2021, 2:23 PM UTC

the-dude wrote: post #49

refurb wrote: post #47

Earlier quoted context omitted.

Really? Not even a blood pressure check or a physician listening to your lungs or just examine your skin for weird moles? That’s terrible.

I am leaving my current physician because I had a very strange, black patch on my back, surrounded by a 'bleached', growing circle. Due to COVID, I provided videos to her assistant, which the physician reviewed. Physician claimed she needed better pictures ( obviously I had sent the best material ). The response to that was : the doctor needs to see the patch herself. Then when I arrived at the appointment she basica…

my experience is totally differe t. just sayin

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

#173

Post by [deleted] » Fri, Jun 25, 2021, 2:23 PM UTC

jacquesm wrote: post #103

Guillaume86 wrote: post #97

Earlier quoted context omitted.

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 po…

[deleted]

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

#174

Post by rwmj » Fri, Jun 25, 2021, 2:24 PM UTC

plank_time wrote: post #147

TaupeRanger wrote: post #138

Earlier quoted context omitted.

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…

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…

But this isn't the argument. The argument is about all the false positives you get when you mass-screen everyone. All those people then need to be further examined, overwhelming the medical system and causing distress for the individuals (who are, remember, perfectly well).

I agree if we had a test that was 100% accurate (literally never gave a false result either way), only detected dangerous cancers, and cost $1 then that would be a game-changer, but the screening and tests so far are not that.

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

#175

Post by doctoring » Fri, Jun 25, 2021, 2:24 PM UTC

Highly encourage reading the paper referred to (but not linked!) in the article:

https://www.annalsofoncology.org/article/S0923-7534(21)02046...

Some good breakdown of test performance by stage and cancer types.

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

#176

Post by dukeofdoom » Fri, Jun 25, 2021, 2:25 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…

One issue is that your body may have all types of tissues that might be precancerous or slow growing cancerous growths that the test will identify. To get to them and remove them would do far more damage than leaving them alone. Even with things like prostate cancer, which is fairly easy to get to. Leaving it alone, is often the right choice depending on the age of the patient and speed of growth of the cancer.

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

#177

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

giantg2 wrote: post #171

If it's detecting 50 types of cancer and the patient doesn't have symptoms, do they just do a full body MRI to find the source? If so, why not just do full body scans which can find other issues, like aneurysms or the other almost 50% of positives that it missed? I get that cost is a big issue, but it seems like the test is missing a lot and you might get more bang for the buck with a periodic MRI from the perspectiv…

I mostly agree. I had a CT scan of 1/3 of my body for a specific issue, but as a consequence I got very high confidence that I was cancer-free in that portion of my body. It is such a good feeling that part of me wants to pay out-of-pocket to get the rest checked.

I think though that this test has massive value in earlier detection, cost, and remote lab work.

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

#178

Post by rwmj » Fri, Jun 25, 2021, 2:26 PM UTC

bluGill wrote: post #164

TaupeRanger wrote: post #138

Earlier quoted context omitted.

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 ne…

It's approved to be rolled out to a medical trial. You can read what the journal says here: https://www.annalsofoncology.org/article/S0923-7534(21)02046...

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

#179

Post by Engineering-MD » Fri, Jun 25, 2021, 2:27 PM UTC

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 trial which don’t always translate to screening tools (as mentioned in their own discussion).

The problem with screening is that you are doing something on healthy patients, so particularly for rare cancers even a small risk of a false positive is significant. In this case it’s 99.5%. So if you test 1,000,000 people, 5000 (*correction from 500) people will come up positive. This is great for common diseases, but if it’s rare and only 1 in a million has it then you have got 5000 false positive for every 1 positive.

I think this will likely be a useful test (if it translates well to a wider screening population), but it’s not as good as it first seems.

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

#180

Post by elif » Fri, Jun 25, 2021, 2:29 PM UTC

londons_explore wrote: post #31

More technologies like this are coming... Is it worth taking blood samples now, keeping them in a freezer, and then waiting for the test tech to come so I can get it tested to see disease progression of whatever disease I get when I get older?

I take blood tests regularly. They are very picky about sample collection time.