Wait a sec: mammograms, postate exams, colonoscopies? You don't have these regular screenings when you hit a certain age? AFAIK, the data is very good on the early detection power of these exams.
What is the right time? Here in Ontario, Canada a letter gets sent at around 50 (I think) asking you to do a FIT test. Call your Dr, get the kit, do the self-test and mail it in.
