I believe that I was also stage 4 rectal/anal cancer. 12 chemo sessions (every 2 weeks including 2 days on a chemo pump) and 6 weeks of daily radiation and the surgeon has told me that he can find no sign of cancer.

I am elated and it seems to show that chemo and radiation is very effective. Wishing you the very best on your journey, it's very doable but quite a tough road.