>,What if cancer rates sharply decline?
They already are = well the rate of death is declining.
https://www.google.com/search?q=cancer+rates+chart+decline&rlz=1C1UEAD_enUS954US954&sxsrf=AOaemvLO1ZzlTsXJLPBZ3G9QM2sclItedw:1633004794609&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjgwcv12KbzAhWUuJ4KHSQICVIQ_AUoAXoECAEQAw&biw=1459&bih=864&dpr=1.25#imgrc=e1XE3yMGZ_H6fM