How many months/ years does it take for mets to be visible with colon cancer ? my dad had all clear scans until after surgery.

6 mo to one year: Many feel that if a lesion is localized, Dukes A that mets wont occur. If a C2 lesion with 4 or more nodes present and preop scans are neg while there is a high incidence of recurrent or metastatic tumor it will take somewhere around one year for cells that have broken free prior to surgery to implant and grow to present with scan visibility. That's why in such cases adjuvanct chemo employed .