Friend of mine’s life was saved by a colonoscopy, found the polyps in the final pre-cancer stage.
Fact is, the oncology cartel (including family practice in this respect) acts as though it is inevitable that pre-cancers progress to cancers. No suggestion to the contrary is allowed. It is not inevitable and the probability is exaggerated. In fact, with respect to colorectal cancer, the incidence is only about 25 out of 100,000. So you know that a whole bunch of those precancerous polyps did not progress to malignancy.
I probably have 50 small "pre-cancerous" skin lesions, many microscopic. They'd rip them all out if I gave them the chance. But my mother has the same stuff and she's made it to 96 with no malignancies (had one colonoscopy years ago; said she wouldn't do it again).
Also, your anecdote presupposes that one wants to be "saved" from a malignancy or other disastrous condition. I don't.