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$5 device tests for breast cancer in under 5 seconds: study

studyfinds.org

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Re: $5 device tests for breast cancer in under 5 seconds: study

#51

Post by ImageXav »

bluGill wrote: post #44
ImageXav wrote: post #31

Earlier quoted context omitted.

A device such as this would never replace an MRI scan. The information provided is for screening purposes, at best. Also, diagnosis would typically be done using a mammography. The cost of such a scan is lower - around $100[0]. [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4142190/

It doesn't have to replace it in all cases. If it can give a good indication that we don't have to do a MRI that is already a good thing.

That's right, that's typically what is meant by screening purposes [0], apologies if it wasn't clear.

[0] https://www.nhs.uk/conditions/nhs-screening/

Re: $5 device tests for breast cancer in under 5 seconds: study

#52

Post by dheera »

pvaldes wrote: post #37
e63f67dd-065b wrote: post #12

Press release: https://publishing.aip.org/publications/latest-content/would... Actual publication: https://pubs.aip.org/avs/jvb/article/42/2/023202/3262988/Hig... Experiment size is literally N=21, with 4 healthy participants, 3 in-situ breast cancers, and 14 invasive breast cancers. N=21 might as well be useless in my opinion. You can't draw any meaningful conclusions about statistical power of this test; if your pr…

> We tried it with 21 people The new Theranos is here again

No, not at all. Polar opposites.

Theranos was actual lies. TFA is just being honest about a low sample size.

Re: $5 device tests for breast cancer in under 5 seconds: study

#53

Post by dheera »

e63f67dd-065b wrote: post #12

Press release: https://publishing.aip.org/publications/latest-content/would... Actual publication: https://pubs.aip.org/avs/jvb/article/42/2/023202/3262988/Hig... Experiment size is literally N=21, with 4 healthy participants, 3 in-situ breast cancers, and 14 invasive breast cancers. N=21 might as well be useless in my opinion. You can't draw any meaningful conclusions about statistical power of this test; if your pr…

It's still a nonzero sample size, and if anything, says two things:

(a) We should do more tests to increase N

(b) If a $5 device tests you positive, maybe you should go get checked out for $5000 or whatever the doctors charge you (because insurance often only pays AFTER "shit happens" and often does not pay to test "whether shit might happen"), that you wouldn't have thought of doing otherwise.

Re: $5 device tests for breast cancer in under 5 seconds: study

#54

Post by ImageXav »

dmoy wrote: post #46
ImageXav wrote: post #28

Earlier quoted context omitted.

Not at all. The model is quite accurate. In fact, with the distribution of samples that they have a model that predicts all cases as having cancer would also be very accurate. It would get 17/21 predictions right. The model lacks precision . I suspect that even with a fairly high cut off point the model would still produce a bevvy of false positive predictions due to that. It might still be useful as a screening step…

Sure we can be technically more surgical in our terminology, but GP is addressing the usage of 'accuracy' in the news headline. In that context, 'accuracy' is kinda a catchall term for both accuracy and precision.

It's a bit difficult to say, isn't it? The headline is using the term accuracy correctly, the reader might be ascribing the meaning you are to it, especially if they are non technical. As was the parent comment.

My goal in pointing out the difference was not to be snarky. It was to point out the very real statistical consequences. Any model can be accurate on a sufficiently biased dataset, but what matters once a screening test hits the real world are the precision (positive predictive value) and negative predictive value. These are the hurdles that the test will have to pass to see widespread adoption.

Re: $5 device tests for breast cancer in under 5 seconds: study

#55

Post by lambdaone »

joezydeco wrote: post #23
Ginger-Pickles wrote: post #19

Earlier quoted context omitted.

First standout thing I noticed is the “patern generator” array of DIPs - admittedly without having dived into the paper, any answers from the hive mind what they’re doing?

I was focusing more on the "current to frequency" stage, which looks like an empty IC socket. As is the "pulse width counting" stage just a bunch of header pins? I mean yeah, I get it, it's a prototype and a finished product will be on a $2 ASIC to drive the correct signals and etc. But I'm not up to speed on affinity sensors vs. traditional ELISA tech so .

Nothing jumps out at me as being fishy here. There's what appears to be a small device mounted in the middle of that empty socket. It's also possible some of the rest of the pins on the socket are being used as test points. A circuit diagram would have be good to have here.

Re: $5 device tests for breast cancer in under 5 seconds: study

#56

Post by parhamn »

dmoy wrote: post #46
ImageXav wrote: post #28

Earlier quoted context omitted.

Not at all. The model is quite accurate. In fact, with the distribution of samples that they have a model that predicts all cases as having cancer would also be very accurate. It would get 17/21 predictions right. The model lacks precision . I suspect that even with a fairly high cut off point the model would still produce a bevvy of false positive predictions due to that. It might still be useful as a screening step…

Sure we can be technically more surgical in our terminology, but GP is addressing the usage of 'accuracy' in the news headline. In that context, 'accuracy' is kinda a catchall term for both accuracy and precision.

Theyre not being surgical in the terminology. Accuracy and precision are the two things that matter for a diagnostic test. High accuracy, low precision = screener.

Re: $5 device tests for breast cancer in under 5 seconds: study

#57

Post by jncfhnb »

e63f67dd-065b wrote: post #12

Press release: https://publishing.aip.org/publications/latest-content/would... Actual publication: https://pubs.aip.org/avs/jvb/article/42/2/023202/3262988/Hig... Experiment size is literally N=21, with 4 healthy participants, 3 in-situ breast cancers, and 14 invasive breast cancers. N=21 might as well be useless in my opinion. You can't draw any meaningful conclusions about statistical power of this test; if your pr…

You can absolutely draw conclusions about the statistical power of the test. That’s what statistics is for.

If this sample data is randomly sampled it looks like it will be a fairly high precision test for invasive cancers, with room for false negatives. You would have had to have gotten very unlucky to see such a difference in distributions even on a small sample like this. But sure, let’s get more samples.

Re: $5 device tests for breast cancer in under 5 seconds: study

#58

Post by pvaldes »

dheera wrote: post #52
pvaldes wrote: post #37

Earlier quoted context omitted.

> We tried it with 21 people The new Theranos is here again

No, not at all. Polar opposites. Theranos was actual lies. TFA is just being honest about a low sample size.

If somebody claims: our device "accurately tests", and we discover later that "In fact the tests hadn't been done still" (at a meaningful way), It should be taken as a red flag. Specially when it came in the same package with "to make lots of tests would be really cheap" (but for some reason they didn't tried it).

Maybe be a great, honest work, brilliant step?. Yes.

But please don't claim that your model is reproducible if you didn't ever tried seriously to reproduce it first. What if the results are just a random effect?. What if the test says just positive most of the time? The test negative response has been tested in a control group of 4 people? This is 20 bucks well spent.

--At this moment-- isn't different than other thousand projects that seemed too good to be true, took the money and soon vanished. I hope to be wrong.

Re: $5 device tests for breast cancer in under 5 seconds: study

#59

Post by lofatdairy »

e63f67dd-065b wrote: post #12

Press release: https://publishing.aip.org/publications/latest-content/would... Actual publication: https://pubs.aip.org/avs/jvb/article/42/2/023202/3262988/Hig... Experiment size is literally N=21, with 4 healthy participants, 3 in-situ breast cancers, and 14 invasive breast cancers. N=21 might as well be useless in my opinion. You can't draw any meaningful conclusions about statistical power of this test; if your pr…

I appreciate the links but I think this actually misses the point. The novelty isn't in diagnosis of cancer but in sensitivity/cost-efficacy in detection of known biomarkers for breast cancer (and associated risks of recurrence, etc). I'm not familiar with how common ELISA-based HER2 testing takes place, but it seems like it has some impact on drug decisions[^1].

In terms of applicability, it depends on whether or not ELISA is in fact the current standard of care, but it could be useful in low-resource settings where you don't have lab personnel trained to carry out those assays, and drug choice is also restricted by limited availability.

Additionally, there's a point-of-care argument as well. Since breast cancer does benefit from early detection, I can see a future in which biomarker testing is a more regular thing, and high saliva concentrations are flagged. At the very least as something worth bringing up at one's next appointment or wtv.

[^1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7033231/

Re: $5 device tests for breast cancer in under 5 seconds: study

#60

Post by tetramer »

ImageXav wrote: post #28
iandanforth wrote: post #17

Figures 3 and 5 from the paper ( https://pubs.aip.org/avs/jvb/article/42/2/023202/3262988/Hig... ) have overlap between all the groups. The same measured output could have come from any of the non-cancer, or known-cancer, participants. While the means of these groups look nicely separable, that overlap means there will be significant false positives or false negatives. So I'd label the studyfinds headline of this bei…

Not at all. The model is quite accurate. In fact, with the distribution of samples that they have a model that predicts all cases as having cancer would also be very accurate. It would get 17/21 predictions right. The model lacks precision . I suspect that even with a fairly high cut off point the model would still produce a bevvy of false positive predictions due to that. It might still be useful as a screening step…

It also only looks at HER2 and CA15-3 (aka MUC1) expression - what about breast cancers that don't express either of these?

I realize this is an early technology and I think it should continue to be explored, but I would anticipate that if compared head to head with screening mammograms, it would be inferior.

For patients with relapsed disease, this kind of technology would be neat to non-invasively re-assess biomarker status but as a screening tool, I find it lacking (and certainly a positive screening will require dedicated imaging and biopsy anyway).

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