The peak period of recurrence and metastasis is 1-2 years after colon cancer surgery. If it is relatively early stage colon cancer, more than 90% of patients can survive beyond five years. Patients with stage II, III or IV need chemotherapy, which includes injections or drugs, and after chemotherapy is completed, they must be reviewed regularly in the outpatient clinic and have their blood tested for tumor markers. Once the markers are found to be elevated, it is considered that the tumor may have recurred. At this time, colonoscopy or abdominal CT must be repeated to rule out distant metastasis or local recurrence of tumor.