3 ms·

Not to disparage a test of equal veracity, but this test demands a blood sample. The stool test is swipe two sticks through your crap on a flushable paper sheet

by ggm 2y ago

Not to disparage a test of equal veracity, but this test demands a blood sample. The stool test is swipe two sticks through your crap on a flushable paper sheet in a toilet, seal, and post. The stool test is well understood and ships out worldwide. Maybe there are concerns about preservation of the sample, postal thermal chain issues, but this one, it means a bill. It's probably similar back-end cost but to the patient or health fund, this one costs more. Why is a blood test which is at best as accurate as a stool test "better" to use?

shiroiushi 2y ago
A blood test seems like it's much more reliable and simpler, because you don't have to rely on the patient to do it. You already need to get a blood sample for your annual health check anyway, so it's pretty easy to just add yet another test to the battery of tests they're doing with that blood draw. Stool and urine samples are just extra work for the patient to do, and to make sure they're done.
- ggm 2y ago
  Good point. So this test will fold into the standard bloods battery, and it's cost amortizes out against annual tests.
- AlbertCory 2y ago
  Those are concerns for a doctor and his/her set of patients. For you, if you're willing to do the stool test, then there's no difference. Right?
  - shiroiushi 2y ago
    I don't follow: I am the patient. For me, a blood test is simpler, because there's absolutely nothing for me to do. A stool test requires me to find not one, but two times before I go to the clinic when I need to poop, and to then go through the task of collecting samples from those poops. (The annual stool test requires 2 samples from two separate BMs.) A blood test literally means absolutely no work or extra time, because I'm already getting a blood draw done at the clinic anyway. It's going to be the same for every patient. The clinic doesn't have to worry about patients forgetting to bring their stool samples, forgetting to do both of them before their appointment, doing them poorly (getting a bad or insufficient sample), etc. The clinic can control everything much better since the blood draw and the handling of the samples is entirely under their control.
    - Rastonbury 2y ago
      Yeah stool tests are annoying, I done mine in clinic, having to hold it day before, going to the clinic restroom, laying out toilet paper etc
    - AlbertCory 2y ago
      Most of your comments were about patients in general." In fact, your last paragraph is entirely about that. For me (or you) in particular, those concerns are irrelevant. It's just what we prefer. "Everyone" might like Taylor Swift, but if you don't, well... there you go.
      - shiroiushi 2y ago
        You're still not making any sense. You prefer taking a stool sample on your own time to doing literally nothing at all and (as far as we know) getting the same test result? Really?
        AlbertCory 2y ago
        > You're still not making any sense. OK, how about this: IF you take a stool sample, the results are just as informative as a blood test. That's what they said. So it's up to the patient. Obviously not doing anything cannot be better. Your second sentence is the one that makes no sense.
        shiroiushi 2y ago
        Did you not read the exchange before? Yes, not doing anything at all IS better, because they can get a blood sample from the blood they're ALREADY drawing from you. So, you have two choices: 1) do a blood draw AND a stool sample, or 2) do a blood draw only. Which one do you think is less work for the patient and the provider? #2 involves absolutely no extra work for the patient. Is this really that hard for you to understand?
        AlbertCory 2y ago
Dr_Birdbrain 2y ago
I think the main thing that is exciting about this is that it can hopefully be extended to other cancers. Currently, detecting lung cancer involves imaging with radiation that can itself trigger cancer, but imagine a world in which you can get screened for all cancers from a blood test.
- jrpt 2y ago
  It's called a multi-cancer early detection test and they already exist. There's still value in specific tests, though.
- nradov 2y ago
  It already has been extended to other cancers. This general type of assay is known as a liquid biopsy. There are a few commercial tests on the market such as Grail Galleri. Accuracy isn't as good as a regular biopsy but accuracy and clinical use will increase over time. https://my.clevelandclinic.org/health/diagnostics/23992-liquid-biopsy https://my.clevelandclinic.org/health/diagnostics/23992-liqu...
jrpt 2y ago
There are many cases where you're getting blood drawn already and if adding another test onto that is inexpensive, that's a pretty convenient add-on. That's useful for many reasons. I was also wondering how it performed compared to a stool test, so I looked it up, and found "While the blood test caught 83% of the cancers found by colonoscopy, it missed 17%. That’s on par with stool-based tests."
- stubish 2y ago
  And will combining the two tests catch a higher percentage? Could go as high as catching 97%, although I suspect lower due to some correlation between what cancers the two tests will pick up (eg. not advanced enough to leak blood into stool may equate to not advanced enough to leave markers in blood). But it will also increase chances of a false positive.

by ggm 2y ago

shiroiushi 2y ago

A blood test seems like it's much more reliable and simpler, because you don't have to rely on the patient to do it. You already need to get a blood sample for your annual health check anyway, so it's pretty easy to just add yet another test to the battery of tests they're doing with that blood draw. Stool and urine samples are just extra work for the patient to do, and to make sure they're done.

ggm 2y ago
Good point. So this test will fold into the standard bloods battery, and it's cost amortizes out against annual tests.
AlbertCory 2y ago
Those are concerns for a doctor and his/her set of patients. For you, if you're willing to do the stool test, then there's no difference. Right?
- shiroiushi 2y ago
  I don't follow: I am the patient. For me, a blood test is simpler, because there's absolutely nothing for me to do. A stool test requires me to find not one, but two times before I go to the clinic when I need to poop, and to then go through the task of collecting samples from those poops. (The annual stool test requires 2 samples from two separate BMs.) A blood test literally means absolutely no work or extra time, because I'm already getting a blood draw done at the clinic anyway. It's going to be the same for every patient. The clinic doesn't have to worry about patients forgetting to bring their stool samples, forgetting to do both of them before their appointment, doing them poorly (getting a bad or insufficient sample), etc. The clinic can control everything much better since the blood draw and the handling of the samples is entirely under their control.
  - Rastonbury 2y ago
    Yeah stool tests are annoying, I done mine in clinic, having to hold it day before, going to the clinic restroom, laying out toilet paper etc
  - AlbertCory 2y ago
    Most of your comments were about patients in general." In fact, your last paragraph is entirely about that. For me (or you) in particular, those concerns are irrelevant. It's just what we prefer. "Everyone" might like Taylor Swift, but if you don't, well... there you go.
    - shiroiushi 2y ago
      You're still not making any sense. You prefer taking a stool sample on your own time to doing literally nothing at all and (as far as we know) getting the same test result? Really?
      - AlbertCory 2y ago
        > You're still not making any sense. OK, how about this: IF you take a stool sample, the results are just as informative as a blood test. That's what they said. So it's up to the patient. Obviously not doing anything cannot be better. Your second sentence is the one that makes no sense.
        shiroiushi 2y ago
        Did you not read the exchange before? Yes, not doing anything at all IS better, because they can get a blood sample from the blood they're ALREADY drawing from you. So, you have two choices: 1) do a blood draw AND a stool sample, or 2) do a blood draw only. Which one do you think is less work for the patient and the provider? #2 involves absolutely no extra work for the patient. Is this really that hard for you to understand?
        AlbertCory 2y ago

Dr_Birdbrain 2y ago

I think the main thing that is exciting about this is that it can hopefully be extended to other cancers. Currently, detecting lung cancer involves imaging with radiation that can itself trigger cancer, but imagine a world in which you can get screened for all cancers from a blood test.

jrpt 2y ago
It's called a multi-cancer early detection test and they already exist. There's still value in specific tests, though.
nradov 2y ago
It already has been extended to other cancers. This general type of assay is known as a liquid biopsy. There are a few commercial tests on the market such as Grail Galleri. Accuracy isn't as good as a regular biopsy but accuracy and clinical use will increase over time. https://my.clevelandclinic.org/health/diagnostics/23992-liquid-biopsy https://my.clevelandclinic.org/health/diagnostics/23992-liqu...

jrpt 2y ago

There are many cases where you're getting blood drawn already and if adding another test onto that is inexpensive, that's a pretty convenient add-on. That's useful for many reasons. I was also wondering how it performed compared to a stool test, so I looked it up, and found "While the blood test caught 83% of the cancers found by colonoscopy, it missed 17%. That’s on par with stool-based tests."

stubish 2y ago
And will combining the two tests catch a higher percentage? Could go as high as catching 97%, although I suspect lower due to some correlation between what cancers the two tests will pick up (eg. not advanced enough to leak blood into stool may equate to not advanced enough to leave markers in blood). But it will also increase chances of a false positive.