You have to remember that the rectal cuff is retained colonic tissue. All of the colon isn't removed; what remains is the cuff. So to extent that any cancer starts in the cuff and migrates to the J pouch proper which is comprised of Ileal tissue, the cancer is migratory colon cancer as opposed to originating in the J Pouch. In much rarer cases it starts in the ileum or ileal tissue. Ileal cancers as opposed to colonic cancers are very rare, but they are not nonexistent.
If there is any kind of ongoing inflammation with the cuff or cuffitis that becomes chronic, this would likely be as much or more of a warning sign than chronic pouchitis. Most important is that the inflammation needs to be getting treated. I have been fortunate that my pattern of inflammation all appears to be at the other end of the J Pouch and the neoterminal ileum. Notwithstanding the stricture I have in this area that is being dilated, my pouchitis has mostly been under control for 25 plus years.