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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

#61

Post by oliwarner »

fuhrtf wrote: post #49
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…

That’s a bit harsh. It’s an exploratory study testing a new paradigm.

It's only as harsh as the the headline is rose-tinted.

"Exploratory study shows promise" is better. When n=21, flipping a coin as about as accurate.

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

#62

Post by jncfhnb »

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…

Backwards. The distributions here imply it will be a high precision model with not great recall.

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

#63

Post by Dylan16807 »

ImageXav wrote: post #51
bluGill wrote: post #44

Earlier quoted context omitted.

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/

The unclear part was more the phrase "would never replace an MRI scan". But it's clear now.

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

#64

Post by hn_throwaway_99 »

jncfhnb wrote: post #57
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.

Thank you for this! I get frustrated with the "N of only 21? Might as well flip a coin!" responses. Like you say, the whole purpose of statistical testing is to give an accurate, numeric value that says how likely the results are due to chance.

One thing I'd note, though, is that the paper's title is "High sensitivity saliva-based biosensor in detection of breast cancer biomarkers: HER2 and CA15-3". My understanding is that sensitivity was never really the problem with breast cancer detection - it's specificity that is the real challenge with all types of broadly-deployed medical screening tools.

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

#65

Post by asdefghyk »

The PCB picture above the words "...The printed circuit board used in the saliva-based biosensor,..." makes me think the article is a scam. As a electronics engineer the word labels seem to be not especially relevant to the invention. Who makes boards with lots DIP chips?

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

#66

Post by s1artibartfast »

shermantanktop wrote: post #30
m3kw9 wrote: post #21

If it’s any good it will filter thru to a doctor near you otherwise, it all sounds nice

Really? Will the $5 Arduino people woo the doctor near you with golf trips? Will they strong arm HMOs to cover the cost? Will they carpetbomb the airwaves telling consumers to “ask their doctor?” Will they defeat the army of marketers and salespeople with entrenched competing tech? This device may be total crap, I don’t know, but “trust the system” isn’t a great way to navigate the American medical system. Other coun…

Doctors do gravitate towards effective tests and medicines, and insurance plans are interest in cheaper alternatives.

There is a lot that could be improved about the US medical system, but Nobody has to bribe doctors and insurance to sell tongue depressors.

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

#68

Post by tetramer »

bluGill wrote: post #43
iamthepieman wrote: post #26

Earlier quoted context omitted.

"but even a few percent more early detections due to frequent testing would be a win" This is not the current medical thought on early screenings for various cancers. It used to be and I was confused about it until very recently. Indeed the medical community is still wrestling with the issue of screening harms. The consensus is shifting that screening should only be done if there is an existing condition or symptom o…

That depends on how harmful the screening is, how harmful treatment is, how harmful the disease is, how well the test works, and how common the disease is. (probably more that I'm not aware of) Most cancer treatments are really nasty. Thus false positives are really bad: you destroy someone's quality of life. The earlier cancer is discovered the better chance that we can use a less harmful treatment (if only because…

You're right that benefits of screening vary widely depending on type of cancer, type of test, and even a patients own co-morbidities. However, there are a lot of inaccuracies in this comment.

False positives on a screening test are bad because you follow a screening test up with a confirmatory test (a biopsy for cancer) - sometimes the procedure for the biopsy results in additional complications and even death in rare cases (and if it's a false positive, a patient goes through all of that for a benign finding).

I want to be very clear that oncologists are not going to start cancer treatment on the results of a screening test, you need confirmation.

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

#69

Post by matthewmacleod »

oliwarner wrote: post #61
fuhrtf wrote: post #49

Earlier quoted context omitted.

That’s a bit harsh. It’s an exploratory study testing a new paradigm.

It's only as harsh as the the headline is rose-tinted. "Exploratory study shows promise" is better. When n=21, flipping a coin as about as accurate.

This statement belies a fundamental misunderstanding of statistics on your part.

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

#70

Post by biomcgary »

Using the performance in the paper, the false positive rate means the current test in clinically useless (due to harm from screening and follow-up). Refining the test requires improving the selection of biomarkers and antibodies, not the hardware (which looks great).
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