5 ms·

New blood test could detect more than 20 types of cancer

169 points by spking 7y ago

aszantu 7y ago
no mentioning of false positives
- PhantomGremlin 7y ago
  It does mention this, but doesn't use those exact two words: Crucially, 99.4 per cent cases identified as cancer were correctly spotted - meaning just 0.6 per cent of cases were misdiagnoses of healthy patients.
  - kurthr 7y ago
    By the birthday paradox, that means 11% of healthy people will be misdiagnosed for one form of cancer on the 20 test panel. That's going to require some in person discussion and review... maybe they can handle that with the NHS, but I think the US patient would end up spending an extra $1000+ due to required human contact, beyond any test cost.
    - burke 7y ago
      It seems quite obvious to me that the 0.6% is already accounting for there being multiple tests, and even if not, confounding factors are likely not completely independent per test.
    - sandworm101 7y ago
      It isnt 20 tests. It is one test regime that detects the presence of 20 diseases. It doesnt diagnose any one disease, just red-flags patients for more accurate testing.
    - dannykwells 7y ago
      The 99.4% specificity is presence of cancer, not by organ. Nice try though.
WordMixer 7y ago
I'm seeing a similar headline about once per year...
petilon 7y ago
Original press release that is the basis for the story: https://www.dana-farber.org/newsroom/news-releases/2019/new-blood-test-capable-of-detecting-multiple-types-of-cancer/ https://www.dana-farber.org/newsroom/news-releases/2019/new-...
doctoring 7y ago
In addition to the press release someone posted, if you’re interested in some of the (high level) science behind this, I’d encourage you to read the ESMO presentation slides this news comes from: https://grail.com/wp-content/uploads/ESMO_2019_Oxnard_CCGA2_Training_Final.pdf https://grail.com/wp-content/uploads/ESMO_2019_Oxnard_CCGA2_... I don’t think the article mentions it, but the study is funded by Grail, which is commercializing a variety of related technologies.
ethhics 7y ago
From [0], the types of cancer they can screen make up at least 81.4% of new cancer diagnoses, which means that with their 99.4% true positive rate, this test should be able to correctly identify ~80% of new cancer incidences. If I'm doing my math right, that's really impressive. [0]: https://www.wcrf.org/dietandcancer/cancer-trends/worldwide-cancer-data https://www.wcrf.org/dietandcancer/cancer-trends/worldwide-c...
- sandworm101 7y ago
  It seems to have a great false positive rate, but a not-good false negative rate. It misses the bulk of stage one cancers. So its utility for early diagnosis (the important bit) is marginal at this time.
  - chiefalchemist 7y ago
    How so they determine false negatives? Are there other less broad and more expensive test? That said, isn't it also possible at Stage 1 for the body to cure itself? That is, __in theory__ is it possible Stage 1 defecation is too early? That med intervention could be premature?
    - sandworm101 7y ago
      You test for false negative rate by testing known cancer patients. A patient with cancer, but a clean test, is a false negative.
    - bobwaycott 7y ago
      I think you meant detection—and not defecation—right?
      - deleted 7y ago
        [deleted]
      - chiefalchemist 7y ago
        Yeah. Oops. Autocorrect FTL
deleted 7y ago
[deleted]
ganitarashid 7y ago
Theranos?
_ihaque 7y ago
The results Grail presented as a talk at ESMO are fairly similar to those they presented in somewhat less detail at conferences earlier in the year (AACR and ASCO). For those who are interested in a deeper dive on this technology, its potential limitations, and its potential benefits, I wrote up a three-part series earlier this year breaking down recent advances in liquid-biopsy-based cancer detection: Part I: regarding tumor fraction (this goes into depth about the stage I limitations noted by other commenters) https://ihaque.org/posts/2019/07/02/early-detection-mid-2019-part-1/ https://ihaque.org/posts/2019/07/02/early-detection-mid-2019... Part II: technical advances from Grail (the authors here) and Guardant (one of their main commercial competitors) https://ihaque.org/posts/2019/07/08/early-detection-mid-2019-part-2/ https://ihaque.org/posts/2019/07/08/early-detection-mid-2019... Part III: clinical performance and economics - integrating the sensitivity and specificity numbers with a simple model for important clinical parameters like adherence (how many people prescribed to take the test actually do), and cost: https://ihaque.org/posts/2019/08/18/early-detection-mid-2019-part-3/ https://ihaque.org/posts/2019/08/18/early-detection-mid-2019... Disclaimer: I'm the former CSO of a competing company, but I no longer work in this space.
cheschire 7y ago
One day I hope that I will have a device that can digitize my blood sample at home so that remote cloud processing can warn me of issues. Life can sometimes get in the way of preventative checks. Social anxiety might be a part of that too.
- cwkoss 7y ago
  I was thinking about it in terms of cataloguing the foods you eat for later analysis, but could work for this too. Would it be possible to make portable device that could freeze dry a drop of liquid? Heat pumps and pressure vessels both get much simpler with smaller sizes.
Gatsky 7y ago
This is very promising. The performance will definitely get better, this is like the first smoky pictures coming out of an MRI. The real challenge is going to be dealing with the result... it isn’t simply a matter of continuing to use the same treatments we do now but applied to earlier stage disease.
- deleted 7y ago
  [deleted]
- dannykwells 7y ago
  ...Actually, it is. Survival when using the same treatments is much higher in earlier stage patents is much better than in later stage. Full stop. Of course not everyone will be cured, but this will make a big dent.
kaikai 7y ago
A pathologist friend told me “there’s a good chance you already have the cancer that might eventually kill you.” The danger of early detection of cancer is that we’ll end up treating fat more people than we would otherwise, and cancer treatment is often brutal. I’ll be interested to see what better detection actually does for mortality rates.
nerder92 7y ago
Elizabeth Holmes seals of approval.

169 points by spking 7y ago

aszantu 7y ago

no mentioning of false positives

PhantomGremlin 7y ago
It does mention this, but doesn't use those exact two words: Crucially, 99.4 per cent cases identified as cancer were correctly spotted - meaning just 0.6 per cent of cases were misdiagnoses of healthy patients.
- kurthr 7y ago
  By the birthday paradox, that means 11% of healthy people will be misdiagnosed for one form of cancer on the 20 test panel. That's going to require some in person discussion and review... maybe they can handle that with the NHS, but I think the US patient would end up spending an extra $1000+ due to required human contact, beyond any test cost.
  - burke 7y ago
    It seems quite obvious to me that the 0.6% is already accounting for there being multiple tests, and even if not, confounding factors are likely not completely independent per test.
  - sandworm101 7y ago
    It isnt 20 tests. It is one test regime that detects the presence of 20 diseases. It doesnt diagnose any one disease, just red-flags patients for more accurate testing.
  - dannykwells 7y ago
    The 99.4% specificity is presence of cancer, not by organ. Nice try though.

WordMixer 7y ago

I'm seeing a similar headline about once per year...

petilon 7y ago

Original press release that is the basis for the story: https://www.dana-farber.org/newsroom/news-releases/2019/new-blood-test-capable-of-detecting-multiple-types-of-cancer/ https://www.dana-farber.org/newsroom/news-releases/2019/new-...

doctoring 7y ago

In addition to the press release someone posted, if you’re interested in some of the (high level) science behind this, I’d encourage you to read the ESMO presentation slides this news comes from: https://grail.com/wp-content/uploads/ESMO_2019_Oxnard_CCGA2_Training_Final.pdf https://grail.com/wp-content/uploads/ESMO_2019_Oxnard_CCGA2_... I don’t think the article mentions it, but the study is funded by Grail, which is commercializing a variety of related technologies.

ethhics 7y ago

From [0], the types of cancer they can screen make up at least 81.4% of new cancer diagnoses, which means that with their 99.4% true positive rate, this test should be able to correctly identify ~80% of new cancer incidences. If I'm doing my math right, that's really impressive. [0]: https://www.wcrf.org/dietandcancer/cancer-trends/worldwide-cancer-data https://www.wcrf.org/dietandcancer/cancer-trends/worldwide-c...

sandworm101 7y ago
It seems to have a great false positive rate, but a not-good false negative rate. It misses the bulk of stage one cancers. So its utility for early diagnosis (the important bit) is marginal at this time.
- chiefalchemist 7y ago
  How so they determine false negatives? Are there other less broad and more expensive test? That said, isn't it also possible at Stage 1 for the body to cure itself? That is, __in theory__ is it possible Stage 1 defecation is too early? That med intervention could be premature?
  - sandworm101 7y ago
    You test for false negative rate by testing known cancer patients. A patient with cancer, but a clean test, is a false negative.
  - bobwaycott 7y ago
    I think you meant detection—and not defecation—right?
    - deleted 7y ago
      [deleted]
    - chiefalchemist 7y ago
      Yeah. Oops. Autocorrect FTL

deleted 7y ago

[deleted]

ganitarashid 7y ago

Theranos?

_ihaque 7y ago

The results Grail presented as a talk at ESMO are fairly similar to those they presented in somewhat less detail at conferences earlier in the year (AACR and ASCO). For those who are interested in a deeper dive on this technology, its potential limitations, and its potential benefits, I wrote up a three-part series earlier this year breaking down recent advances in liquid-biopsy-based cancer detection: Part I: regarding tumor fraction (this goes into depth about the stage I limitations noted by other commenters) https://ihaque.org/posts/2019/07/02/early-detection-mid-2019-part-1/ https://ihaque.org/posts/2019/07/02/early-detection-mid-2019... Part II: technical advances from Grail (the authors here) and Guardant (one of their main commercial competitors) https://ihaque.org/posts/2019/07/08/early-detection-mid-2019-part-2/ https://ihaque.org/posts/2019/07/08/early-detection-mid-2019... Part III: clinical performance and economics - integrating the sensitivity and specificity numbers with a simple model for important clinical parameters like adherence (how many people prescribed to take the test actually do), and cost: https://ihaque.org/posts/2019/08/18/early-detection-mid-2019-part-3/ https://ihaque.org/posts/2019/08/18/early-detection-mid-2019... Disclaimer: I'm the former CSO of a competing company, but I no longer work in this space.

cheschire 7y ago

One day I hope that I will have a device that can digitize my blood sample at home so that remote cloud processing can warn me of issues. Life can sometimes get in the way of preventative checks. Social anxiety might be a part of that too.

cwkoss 7y ago
I was thinking about it in terms of cataloguing the foods you eat for later analysis, but could work for this too. Would it be possible to make portable device that could freeze dry a drop of liquid? Heat pumps and pressure vessels both get much simpler with smaller sizes.

Gatsky 7y ago

This is very promising. The performance will definitely get better, this is like the first smoky pictures coming out of an MRI. The real challenge is going to be dealing with the result... it isn’t simply a matter of continuing to use the same treatments we do now but applied to earlier stage disease.

deleted 7y ago
[deleted]
dannykwells 7y ago
...Actually, it is. Survival when using the same treatments is much higher in earlier stage patents is much better than in later stage. Full stop. Of course not everyone will be cured, but this will make a big dent.

kaikai 7y ago

A pathologist friend told me “there’s a good chance you already have the cancer that might eventually kill you.” The danger of early detection of cancer is that we’ll end up treating fat more people than we would otherwise, and cancer treatment is often brutal. I’ll be interested to see what better detection actually does for mortality rates.

nerder92 7y ago

Elizabeth Holmes seals of approval.