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Re:Blood test that finds 50 types of cancer is accurate enou... by moralestapia on Friday June 25, 2021 @01:51PM (#27634090)
I feel it's a net win anyway, if the procedure is not invasive and cheap, you could take one every so often (yearly?) and if something shows up you just double check with a better method or w/e. Better than nothing, which is the current alternative.
Re:Blood test that finds 50 types of cancer is accurate enou... by colinmhayes on Friday June 25, 2021 @03:37PM (#27635302)
The problem is people are idiots. They get a false positive and their doctors tells them "well there are a lot of false positives with this test" but all people hear is "you have cancer." Then they get an invasive biopsy because the healthcare system is glad to take your money.
Re:Blood test that finds 50 types of cancer is accurate enou... by theptip on Friday June 25, 2021 @05:50PM (#27636698)
I appreciate you stating it frankly, I think a lot of people in this thread are arguing a variation of this point without saying it aloud.

A couple thoughts -

1) If this is the only/main objection, then the test is good news for those that are analytically capable, even if it's potentially bad for Joe Median.

2) While what you describe is how it probably happens in general in the USA, but I wonder if it plays out differently in, say, the UK / Canada under NHS/Medicare. In those systems you don't get to pick your treatments; your doctor will only prescribe a follow-up if it meets ROI standards. (Then the health system picks up the bill). Of course you can go private but there's a pretty big barrier there, and perhaps having your GP push back more strongly (as they would if you were not actually at high risk) that might prevent many people from inferring too much from a potentially-false positive result.

Re:Blood test that finds 50 types of cancer is accurate enou... by Robotbeat on Friday June 25, 2021 @02:59PM (#27634895)
Right. If the objection is that it has a high false positive rate and doctors don’t understand Bayesian statistics enough to take that into account, then the solution isn’t to ban the test but instead require clinicians who interpret the test to learn Bayesian statistics better.
Re:Blood test that finds 50 types of cancer is accurate enou... by scarecrowboat on Friday June 25, 2021 @04:07PM (#27635612)
What if the followup procedure is invasive and expensive? It's possible that this procedure could be net negative in aggregate depending on the % of false positives and # of resulting needless followup procedures. Not to mention the emotional stress.
Re:Blood test that finds 50 types of cancer is accurate enou... by timy2shoes on Friday June 25, 2021 @05:04PM (#27636264)
Exactly! This reminds of the recent case of the AMA increasing the suggested age of regular mammograms. More testing means earlier detection of breast cancer. But a false positive means an invasive biopsy. These are the two sides that need to be balanced. The AMA decided that since the base rate of cancer is so low in women under 50, the posterior probability that you have cancer given a positive mammogram for the under 50 age group is considerably low. Therefore they decided that the increased costs (monetary and emotional) do not outweigh the benefits.

From https://www.ama-assn.org/sites/ama-assn.org/files/corp/media...

"Screening mammography reduces mortality from breast cancer, including in women younger than age 50 years. However, screening mammography carries harms such as false positive results that can lead to additional imaging and invasive biopsy procedures, and overdiagnosis that could lead to treatment in patients who may not benefit from it. The USPSTF considered the balance of benefits and harms using a commissioned targeted systematic evidence review of randomized clinical trials and a decision analysis that compared the expected health outcomes of starting and ending mammography at different ages and using annual and biennial screening strategies; it concluded (in part) that routine screening should begin at age 50 years and continue biennially until age 74 years."

Re:Blood test that finds 50 types of cancer is accurate enou... by moralestapia on Friday June 25, 2021 @06:17PM (#27636952)
>But a false positive means an invasive biopsy.

Nah, there's plenty of other things you'd try before the biopsy.

Re:Blood test that finds 50 types of cancer is accurate enou... by moralestapia on Friday June 25, 2021 @06:19PM (#27636960)
Don't do it, then. Try homeopathy or whatever thing feels good for you.