Comment by timr

Don't do this. Nearly all cancer tests are overly sensitive, and not great at detecting the cancers you care about (the ones that will progress).

If you run out and get a bunch of random cancer tests, you are basically ensuring that you will get unnecessary and painful treatment for a finding that probably wouldn't have harmed you in the first place.

It's not a satisfying answer, but it's true. The reason most cancers are found late is because there's no effective alternative.