Basically: "Yeah, looking back on it that was cancer wasn't it? God damnit..."
One problem is: how often do those signs turn out to be cancer, versus something else?
There are now circulating tumor cancer DNA tests (ctDNA), though they're presently expensive: https://www.natera.com/oncology/signatera-advanced-cancer-de.... If they get cheap enough, they'd be interesting as part of, say, an annual blood panel. Mine were like $5k each, however, so that's not going to happen in the general population in the short term.
I was using the Signatera tests to try to determine whether I should start prophylactic chemotherapy after a total glossectomy. The answer turned out to be "yes," but three days before I began chemo, a CT scan ordered to ascertain whether I could use a jaw-stretcher device showed six to eight new tumors, less than two months after the surgery. So the direction was correct.
I'm glad you're still here with us, but I... don't know what to even say.