Colonoscopy prognosis

Hi

I'm struggling to know what to think. My partner has been having trouble with his bowel movements for ages. 3 weeks ago I convinced him to phone the doctor and today he finally had a colonoscopy and a large 10cm growth was found in the very bottom part of the bowel (presumably anal canal and rectum) it is protruding on the outside. The doctor has not given any indication of prognosis but has taken biopsy samples to check for cancer and referred for CAT and MRI scans. Does anybody know if a growth/tumor like this can be non-cancerous? I just want to prepare myself for the likely outcome.

Any information or advice would be very gratefully received.