Shouldn’t we have a non-negligible prior on possible cancer risks at all timescales? That doesn’t mean we don’t approve drugs without 80-year clinical trials, but I think it’s a non-negligible risk that has to be accepted.

For instance, my impression is that lung cancer rates only really become strongly pronounced — in the sense of being statistically detectable in the small population sizes you find in clinical studies, rather than the entire US population — after like 15 years of smoking. (Correct me if I’m wrong.)