The parents premise is wrong. You can't just "establish a better baseline" and "if the test says you might have cancer don't worry about it maybe?" The former i

The parents premise is wrong. You can't just "establish a better baseline" and "if the test says you might have cancer don't worry about it maybe?" The former is hampered by base rate fallacy [1] (specifically the part about disease in a low-incidence population) and the in the latter, if you're going to disregard the outcome why are you testing? A concrete example is the NHS recommends against the PSA prostate cancer antigen screening test completely for everyone of any age because this test does more harm than good. They have a good write-up on why. [2] Generally I agree this data should be collected, but aggregated and not used for individual treatments. [1] https://en.wikipedia.org/wiki/Base_rate_fallacy https://en.wikipedia.org/wiki/Base_rate_fallacy [2] https://www.nhs.uk/conditions/prostate-cancer/psa-testing/ https://www.nhs.uk/conditions/prostate-cancer/psa-testing/