When I initially was told to expect to live 5–7 years (about 1½–2½ years before progression to castrate resistance and stronger treatments, which hasn't happened), I figured I wouldn't bother with colonoscopies any more, even though I was only 56 at the time, and both my father and maternal grandfather had died of colon cancer.

As my horizon expanded (there's no longer an official "life expectancy" for me), I approached my family doctor and asked if I should have my regular 5-year colonoscopy. She said 100%, and that I should be planning for the future in other areas (like avoid type-2 diabetes) as well. That was great to hear, when only a year early I'd believed I wouldn't have much of a future to plan for.

The gastroenterologist at the colonoscopy clinic wanted to meet with me first, to assess my health and verify the procedure would be safe for me, because my records just said "stage 4b prostate cancer" and "severe spinal compression and nerve damage" which sound pretty grim. When he saw that I was outwardly energetic and healthy, he had no reservations about going ahead with the procedure. He showed me the radiation proctitis on the monitor, and found and removed one small, non-malignant polyp, but otherwise it was just like my two previous colonoscopies before I had PCa.

At my age (59 now) and given my family history, I think continuing colonoscopies was the right choice. Colon cancer is almost fully preventable with 5-year screenings, and it would be very sad to beat prostate cancer only to succumb to colon cancer like my dad and grandpa did. I'm not sure what choice I'd make in my 80s, but I will say (from watching them) that wearing a colostomy bag all day isn't fun, and avoiding that alone might make the colonoscopy worthwhile as you prepare to enjoy your late 80s, your 90s, and hopefully even beyond.