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Comment by JohnJamesRambo | Hacker News Reader

I would be fine with a pretty high false positive rate when you are getting such vital and useful information.

It's worth noting that there is some disagreement in recent years whether large scale screening for breast cancer does more harm than good (see lengthy comment I made elsewhere), exactly because this information very often is not so vital and useful (many growths are not lethal, or would be detected soon enough anyway that it doesn't change outcomes), yet can be actively harmful (detection often leads to unnecessary treatments as it may be hard to discern lethal cancers from growths that will never pose a threat, and detection also causes stress and other issues).

You also need to keep in mind that that it is very possible the false positive rate will be per test, in which case with regular screening 1% quickly turns to 10%...

Dr. H. Gilbert Welch has made a career out of studying whether or not early detection is useful and necessary. http://tdi.dartmouth.edu/about/our-people/directory/h-gilber...

Cancer treatment is highly lucrative, though.

What exactly are you going to do with this "vital and useful information" keeping in mind that it might also be wrong?

Get CAT scans.

It should be noted that at the moment, the researchers are still working on determining which of the 8 cancers is present in the case of a positive result.

CAT scans are insufficient to determine if a growth is malignant in many cases. Which would lead you down the road to biopsies, which are also insufficient in many cases. Which would lead to unnecessary radiotherapy, chemo or operations in at least some cases.

Are they insufficient because of the way they work, or because their current resolution is too low ?

CAT scans by themselves are also a pretty major radiation dose which slightly increases your risk for cancer.

If there is no way to determine whether a growth is malignant, we are fucked any way. Certainly, this is not the point of a screening test.

Screening tests are about cheaply directing further testing.

It is often possible, but not always. The problem is that for cancer even a lot of that testing is either inconclusive and/or harmful in itself. So for every false positive, and even positive tests where the tumor will never harm the patient, there is a chance of active harm being done. Including causing death.

Early screening will occasionally save some. The question is whether it will save enough to make up for that harm if we increase the frequency of testing.

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