I'm an old guy, it's happened several times. The last time, a surgeon removed a tumor, found that it was malignant ... and then told me that it was no big deal, it was a kind of cancer that would not have caused serious problems. She said if she had to get cancer she'd pick this kind. I wish she had told me that before the surgery. I may have had it anyway, but maybe not. Wouldn't you value being fully informed more after that? Surgeons have as much of a conflict of interest when selling their own services as anyone else.

I'm not sure what your point is. This discussion is about medical researchers making decisions on thousands or millions of patients in aggregate... what you're describing is a common thing (don't know how bad a tumor is until it's removed).

The doctor didn't know that before removing the tumor (almost certainly; the alternative is medical fraud).