[EnquiringMind]

Perhaps small tumors develop early on and sit relatively dormant, suppressed by the immune system, until resistance ebbs for one reason or another, at which time they break out.

Yes, that makes a lot of sense. Scary. My father had some sort of head/neck cancer that remained dormant until it metastasized to his brain. The doctor said that sometimes the origin is microscopic and shoots off microscopic cells that take hold elsewhere.

[RummyChick]

This is one of the most apt few words I have seen on it

https://scienceblog.cancerresearchuk.org/2018/04/18/science-surgery-do-we-all-have-potentially-cancerous-cells-in-our-bodies/

“A game of cellular cat and mouse”

It’s why people can say I smoked 80 years and didn’t get cancer. That does NOT mean smoking can’t cause cancer. And why you can get lung cancer but never smoked in your life.

[jersey117]

“sometimes the origin is microscopic and shoots off microscopic cells that take hold elsewhere”

Exactly. This is where the new immunotherapy treatments come in. After chemo and radiation hopefully does it’s job, the immunotherapy drug works with the immune system to target hidden cancer cells without damaging healthy cells.